For more information visit www.microchip.com

Microchip Announces Two New Entry-Level Development ToolsPAGE 1 Microchip Announces Two New Entry-Level Development Tools

PAGE 2 MCP7386X Battery Chargers Maximize Battery Capacity, Life Cycle and Safety

PAGE 3 MCP1630 Power-Supply, Pulse-Width Modulation (PWM) Controller - Fastest in the Market

PAGE 4 Microchip Introduces Eight Flash PIC® Microcontrollers in 28-, 40- and 44-pin Packages

PAGE 5 New Field Reprogrammable Battery Manager Accurately Reports Battery Capacity

PAGE 6 Microchip Delivers Two dsPIC® 16-bit Digital Signal Controllers

PAGE 7-8 Tips n’ Tricks: – PICmicro® Microcontroller Comparators

PAGE 9 – dsPIC® DSC Introductory Seminars are Coming to a City Near You!

– Archived WebSeminars

PAGE 10-11 What’s New in Microchip Literature?

PAGE 12 Web Site Highlights

IN THIS ISSUE

For more product information visit:

www.microchip.com

Microchip’s new, cost-effective development

tools, the PICtail™ Analysis Daughter Board,

(part number AC164120) and the Baseline

Flash Microcontroller Programmer (BFMP),

(part number PG164101), allow user-

friendly evaluation of analog processing

and simple programming with low pin-count

PIC® microcontrollers.

The Signal Analysis PICtail Daughter

Board and accompanying PC software,

when plugged into the PICkit™ 1

Flash Starter Kit, enables engineers to

analyze analog signals as processed

by Microchip’s low pin-count 8-bit

PIC® microcontrollers. This new daughter board, with its Graphical User

Interface (GUI), provides designers with a toolbox for learning and evaluating

the capabilities of low pin-count PIC microcontrollers without expensive test

equipment or tools.

The Baseline Flash Microcontroller Programmer is a simple, In-Circuit Serial

Programming™ (ICSP™) programmer intended to be used with any of

Microchip’s new baseline 8-bit PIC Flash microcontrollers. When paired with

the PIC10F2XX Programmer Adapter, (part number AC163020), the BFMP

provides the least expensive programming method and includes standard

ICSP technology support and stand-alone programming for the 6-pin PIC10F

family. Utilizing USB and the included GUI, the BFMP enables users to easily

read, write and verify Microchip’s Flash-based, Baseline PIC microcontrollers.

“With the introduction of these two development tools, Microchip continues to

make it easy for designers to try our PIC microcontrollers,” said Steve Drehobl,

Vice President of Microchip’s Security, Microcontroller and Technology

Division. “The Signal Analysis PICtail Daughter Board and BFMP allow users

to get up-and-running with minimal time and fi nancial investment.”

The Signal Analysis PICtail Daughter Board is an add-on board to the popular

low-cost PICkit 1 Flash Starter Kit that contains the 14-pin PIC16F684

8-bit Flash microcontroller and 16 Kbytes of serial EEPROM memory. When

the Signal Analysis Board is plugged into the PICkit 1 Flash Starter Kit and

used with the accompanying Signal Analysis PC software, the designer can

perform real-time measurements and display them on a strip chart.

Engineers can also acquire data, which can then be processed and analyzed

in an oscilloscope plot, FFT or histogram. By including an easy-to-use PC

software program, this daughter board can be used both to explore new

concepts and to process and display data in traditional formats that are

familiar to design engineers.

The BFMP is compatible with all of Microchip’s new Baseline 8-bit PIC Flash

microcontrollers, including the following devices:

PIC10F200/202/204/206

PIC12F508/509

PIC16F505

PIC16F54/57/59

The BFMP also provides a 6-pin linear ICSP header for standard ICSP

support. Its powered USB connection eliminates the need for an external

power supply.

Tools and Product Availability

The Signal Analysis PICtail Daughter Board and the Baseline Flash

Microcontroller Programmer are available now.

For additional information, please contact any Microchip sales

representative, authorized worldwide distributor or visit

http://buy.microchip.com.

Figure 1. Baseline Flash Microcontroller

Programmer (BFMP)

Figure 2. BFMP and PIC10F2XX

Programmer Adapter

Figure 3. BFMP and PICtail™ Analysis

Daughter Board

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 2

Microchip’s MCP7386X single-cell and

dual-cell, fully integrated, charge-management

controllers each feature a charge-safety timer and

a temperature monitor. With an overall system

accuracy of ±0.5 percent, these devices maximize

system runtime between charges and ensure that

the battery-cell capacity is fully utilized without

cycle-life degradation. Meanwhile, the on-board

thermal regulation optimizes charge-cycle time,

while maintaining the devices’ reliability and

simplifying the board design.

The MCP7386X devices extract information regarding charge and temperature status, giving the

user elaborate control and sophisticated protection. On-board safety timers and thermal monitor

provide time- and temperature-based charge termination, protecting applications from defective

batteries and increasing the battery safety. The MCP7386X controllers also feature reverse-

blocking protection, which allows current from a correctly installed battery to fl ow to the load and

block current fl ow to a backward-installed battery.

MCP7386X Features

• Built-in pass transistor – minimizes the number of external components and the overall

footprint

• Reverse leakage current of less than 0.4 microamps (typical) extends battery life

• Programmable fast-charge current up to 1.2 amps

• MCP73861 device is specifi ed from 4.5V to 12V

• MCP73862 device is specifi ed from 8.7V to 12V

• Temperature Range –40°C to +85°C (MCP73861/2)

• Available in 4.1V/4.2V and 8.2V/8.4V:

Accommodates a variety of portable products that are powered by one- or two-cell Lithium

Ion/ Lithium Polymer batteries (with coke or graphite anodes)

• Devices are synergistic with Microchip’s power management product portfolio, including the

company’s DC/DC converters, linear regulators in power management applications and its

PowerSmart® battery managers and monitors

• Pb-free, leadless, 4x4 QFN package:

Allows for higher power dissipation and therefore, shorter charging times

Fully Integrated Linear Battery Chargers Maximize Battery Capacity, Life Cycle and Safety

The new MCP7386X devices are available today for sampling and volume production

in the following package.

• MCP73861 - leadless, 4 x 4 QFN

• MCP73862 - leadless, 4 x 4 QFN

For more information, contact your authorized worldwide distributor or visit Microchip’s

Web site at www.microchip.com

For more product information visit:

www.microchip.com/mcp7386X

ENSTAT1 STAT2

VSET

VDD1

VDD2

VSS2

TIMERPROG THERMTHREF

VBAT3

VBAT2

VBAT1

VSS3

CTIMER

Regulated orUnregulatedWall Cube

User-set Current

Charge CurentUp to 1.2A

Safety Timer

Fault and Status Indicators

RPROG RT1

RT2

+

–

SingleLithium-IonCell

VSS1

1

2

3

4

141516

5 6 7 8

9

10

11

12

13

MCP73861

Figure 1. MCP73861 Typical Application Circuit

For more information visit www.microchip.com 3

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

Microchip’s power supply pulse-width modulation (PWM) controller with a current sense-to-output delay of 12 nanoseconds makes it the fastest PWM on the market*. This device enables power-system designers to add precision control, digital communication and programmability for initial settings or an “on-the-fl y” adjustment or calibration.

Microchip’s MCP1630 is comprised of a high-speed comparator with a high-performance error amplifi er and a PWM latch to perform the analog power-supply PWM function. This device, when used in conjunction with a microcontroller, can support the development of high-speed, intelligent, power-system controllers. The

microcontroller adjusts the output voltage (or current), switching frequency, maximum duty cycle and other features, making the power system more intelligent and adaptable. This enables the power system to adapt to many external signals and variables in order to optimize performance and facilitate calibration.

The MCP1630 can yield a power supply with advanced features, communications and programmability and it supports all Switch Mode Power Supply (SMPS) topologies. It is best suited for applications requiring medium-to-high levels of intelligence and operating at frequencies exceeding 200 kHz.

MCP1630 Typical Applications• Battery chargers for Lithium-Ion and Nickel Metal Hydride chemistries • Intelligent power systems • Brick DC/DC converters • AC power-factor correction • Multiple output-power supplies and multiple-phase power supplies

MCP1630 Features• Under-voltage lockout (UVLO)• Output short circuit and over-temperature protection• Low operating current of 2.8 milliamps (typical) • Fast output rise and fall times of 5.9 nanoseconds and 6.2 nanoseconds, respectively • Precise peak-current limit of ±5 percent and a peak-current mode operation to 1 MHz

To aid in the development with this device, Microchip is offering a battery-charger demonstration board. On this board is a SEPIC (Single-End Primary Inductor Circuit) converter that provides a constant charge current to the battery. The MCP1630 regulates this charge current by monitoring it through a battery-sense resistor and by providing the proper pulse-width.

Microchip Offers Digital Control for the Analog Power Supply Function With the World’s Fastest Pulse-Width Modulator

For more product information visit:

www.microchip.com/mcp1630

MCP1630

PIC16LF818

+8V to +15V Input Voltage

5.7V

+5V Bias

+5V Bias

1/2 MCP6042

1/2 MCP6042

SEPIC Converter

MCP1630 NiMH Battery Charger and Fuel Gauge Application Diagram

4 NiMH Cells

N-channelMOSFET

1:1

A/D

PWM OUT

A/D

+VBATT

IBATT

VDD

VDD

I2C™ To System

VDD

+VBATT

CC

ISW

CIN

VEXT

VIN

VREF

COUT

3V

0V

MCP17003.0V

SOT-23

GNDCS

COMPFBOSC IN

–+

–+

–+

FIgure 1. MCP1630 Typical Application Circuit

Additional features, including trickle charge, fast charge and over-voltage protection, can be added to the system using the programmability of the microcontroller and the fl exibility of the MCP1630.

The MCP1630 is available for sampling and volume production in the following

package.

• MCP1630 – 8-pin MSOP

For more information, contact your authorized worldwide distributor or visit Microchip’s

Web site at www.microchip.com

*Based on a study of similar devices with similar features.

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 4

Microchip has expanded its 28-, 40-

and 44-pin Flash PIC® microcontroller

portfolio with eight PIC18FXXXX

devices targeting mid-range

applications requiring up to 32 Kbytes

of program memory in low pin counts.

These cost-effective microcontrollers

feature nanoWatt Technology for

optimum power management and

improved C compiler efficiency for

applications written with re-entrant

code, which is common in real-time

operating systems.

Designers of embedded control applications have a growing need for 8-bit microcontrollers

with the most popular, mid-size memories in small form factors, balanced with a requirement

to consume less power over a broad range of applications. These new 28-, 40- and 44-pin

PIC18FXXXX microcontrollers help solve these design concerns with 16 or 32 Kbytes of Flash

program memory, up to 1.5 Kbytes of RAM and nanoWatt Technology low-power modes.

“Microchip continues to see growing design activity in the already popular 28-, 40- and 44-pin

8-bit microcontroller market,” said Ganesh Moorthy, vice president of Microchip’s Advanced

Microcontroller and Memory Division. “The new Flash PIC microcontrollers expand the options

available to designers in these pin counts by adding the most popular, mid-size program

memories.”

This PIC microcontroller family offers Standard Flash and Enhanced Flash memory technologies.

The Enhanced Flash family has self-programming capability, allowing the microcontroller to be

programmed after being placed in a circuit board, providing tremendous flexibility, reducing

development time, increasing manufacturing efficiency and faster time to market. The Enhanced

Flash devices also contain 256 bytes of high-endurance EEPROM data memory.

Ideal Applications for these new devices include:

• Appliance (controller for air handlers)

• Automotive (LIN-to-LIN gateways, remote-keyless-entry receivers)

• Computing (encrypted security systems)

• Consumer (radio-frequency remote water/gas meter reading)

• Industrial (differential air pressure sensors)

Microchip Introduces Eight Flash PIC® Microcontrollers with Most Popular Memory Sizes and Power Management

For more product information visit:

www.microchip.com/pic18FXXXX

With the unique nanoWatt Technology, these microcontrollers offer power-managed

modes that make them ideal for battery and low-power applications. The devices also

feature Microchip’s advanced PMOS Electrically Erasable Cell (PEEC) Flash process

technology, which enables up to 1,000,000 data memory ERASE/WRITE cycles and

up to 100,000 program memory ERASE/WRITE cycles, with 40 years of data retention.

Additional features include:

• Internal core performance of up to 40 MHz (10 MIPS)

• 32 kHz to 32 MHz internal oscillator, software-configurable in real time

• Fail-safe clock monitor

• Wide voltage range of 2.0 – 5.5 volts and a -40°C to +125°C temperature range

• In-Circuit Serial Programming™ (ICSP™) capability

• 10-bit Analog-to-Digital Converter (ADC) with up to 13 signal channels and 100k samples-per-second

• Two analog comparators with programmable brown-out reset and programmable low-voltage detect

• SPI™, I2C™ and AUSART (supports LIN, RS485 and RS232)

• Two Capture/Compare PWM Modules

Development Tools

All eight microcontrollers are supported by Microchip’s high-performance development

systems, including:

• MPLAB® Integrated Development Environment (IDE)

• MPLAB® C18 C Compiler

• MPLAB® ICD 2 In-Circuit Debugger

• MPLAB® ICE 2000 In-Circuit Emulator

Product Availability

The eight microcontrollers are available today for general sampling and volume

production, in the package options listed below.

• PIC18F2520: 28-pin SDIP, SOIC, QFN

• PIC18F2410, PIC18F2420, PIC18F2510: 28-pin SDIP, SOIC

• PIC18F4510, PIC18F4520, PIC18F4420, PIC18F4410: 40-pin PDIP; 44-pin TQFP, QFN

For more information visit www.microchip.com 5

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

Microchip has expanded its battery-management product line with the introduction of an integrated,

fi eld-reprogrammable, fuel-gauge for two-, three-and four-cell Lithium Ion (Li-Ion) and Lithium

Polymer (Li-Poly), or six to 12-cell Nickel Metal Hydride (NiMH) & Nickel Cadmium (NiCD).

This Smart Battery System (SBS) compliant device provides precise predictions of battery capacity.

It offers cell monitoring for safety conditions along with End of Discharge (EOD) control, thereby

maximizing battery life and runtime.

The PS501 battery-manager IC combines Microchip’s high-performance, low-power PIC18

microcontroller core with its Accuron® proprietary algorithm stored in 16-Kbytes of on-chip Flash

memory. This battery-manager offers a low-operating current of 150 microamps. When the

application is not in use, the device enters a low-power sleep mode using less than 1 microamp,

which optimizes the capacity and minimizes over discharge of the battery.

Also included is a 16-bit programmable, sigma-delta integrating A/D converter and application-

optimized mixed-signal circuitry. This enables precision measurement of battery current,

temperature and voltage as well as direct connection of up to four-series cell Li-Ion or Li-Poly

packs. On-chip EEPROM provides storage of user-customizable and “learned” battery parameters.

The PS501 battery-manager integrates an accurate silicon oscillator, eliminating the need for an

external crystal. To further optimize the PS501 battery-manager for Li-Poly applications, hardware

and advanced algorithms are integrated for cell balancing. Twelve general purpose pins support

charge and safety control or user programmable digital I/O. Eight of them can be used as LED

drivers and two are open-drain for direct FET drive. Communication with the host is compliant with

the industry-standard SMbus protocol and all Sbdata parameters are supported.

New Field Reprogrammable Battery Manager Accurately Reports Battery Capacity Lithium- and Nickel-Based Battery Packs

For more product information visit:

www.microchip.com/PS501

Development system availability for the PS501 battery-manager includes:

• PS5164EV - for the four-series cell

• PS5163EV - for the three-series cell

• PS5162EV - for the two-series cell battery pack for Li-Ion or Li-Poly

For NiMH and NiCD, the PS5200EV is available, which can be confi gured for six-12

cells in series. This development system includes:

• An application board

• PowerInfo™ 2 interface board (PS051)

• Accompanying cables and documents

• Microsoft Windows® software-based PowerTool™ 2 (PS050) software with

embedded wizard allows optimization of application-and-battery specifi c parameters

during evaluation and development as well as production support such as custom

programming and calibration of a PS501 application board

The PS501 battery-manager is available in a Pb-free, 28-pin SSOP package.

Product Availability

Samples and volume production are now available.

For more information, contact your authorized worldwide distributor or visit Microchip’s

Web site at www.microchip.com

The PS501 Maximizes Battery Runtime

and Safety in Mobile Devices

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 6

Microchip has begun volume production of the dsPIC30F5011 and dsPIC30F5013 dsPIC®

Digital Signal Controllers (DSCs). Both devices offer designers performance speeds of up to 30

Million Instructions Per Second (MIPS) and 66 Kbytes of selfprogramming Flash memory with

industrial and extended temperature ranges. These DSCs are ideal for a variety of embedded

applications that require higher performance than is obtainable on current 16-bit microcontroller

offerings.

“When we coined the term ‘Digital Signal Control’ we saw a rapidly emerging market that

needed a high-performance, 16-bit microcontroller and Digital Signal Processor on a single-

chip solution,” said Sumit Mitra, vice president of Microchip’s Digital Signal Controller Division.

“Our customers were looking for attributes not common to DSPs in this performance range.

Microchip was able to offer them an inexpensive Flash program memory, small form factor,

effi cient C code generation, wide-operating voltage range, integrated mixed-signal elements

and low-cost tools. The dsPIC DSC is a skillful blend of a MCU and a DSP in one device that

provides our customers the best of both worlds.”

Microchip’s Enhanced Flash self-programming capability features a remote upgrade to the

Flash program memory, allowing code and data revisions at the end of the production process

or in end-users’ applications. This combination of features provides:

• Flexibility

• Reduced development time

• Increased manufacturing effi ciency

• Faster time-to-market

Both dsPIC DSC devices integrate an array of on-chip functions, such as:

• 16- and 32-bit timers

• Input capture/output compare

• Communication modules (such as UART, SPI™ interface, I2C™ interface, CAN and

Codec interface) and a 12-bit Analog-to-Digital Converter (ADC)

• 4 Kbytes of data RAM and 1 Kbyte of high-endurance EEPROM data memory. Both are

specifi ed in industrial, extended temperatures ranges and are applicable to a variety of

applications, including industrial, automotive, consumer and offi ce-automation equipment

Microchip Technology Delivers Two dsPIC® 16-bit Digital Signal Controllers for High-Peformance,

General-Purpose Applications

Development Tools, Application Libraries and Reference Designs

All dsPIC DSCs are supported by Microchip’s high-performance development systems,

including:

• MPLAB® Integrated Development Environment (IDE),

• MPLAB® C30 C Compiler,

• MPLAB® SIM tool

• MPLAB® ICD 2 In-Circuit Debugger,

• MPLAB® Visual Device Initializer and

• MPLAB® ICE 4000 In-Circuit Emulator (ICE).

Availability

The dsPIC30F5011 and dsPIC30F5013 are available today for volume production

shipment.

The dsPIC30F5011 is offered in 64-pin TQFP packages

The dsPIC30F5013 is offered in 80-pin TQFP packages

About dsPIC Digital Signal Controllers

The dsPIC DSC is a 16-bit (data) modifi ed Harvard RISC machine that combines the control

advantages of a high-performance 16-bit microcontroller with the high computation speed of

a fully implemented digital signal processor (DSP) to produce a tightly coupled single-chip

single-instruction stream solution for embedded systems design. All dsPIC DSCs integrate

Flash program memory and most have EEPROM data storage.

For more information, contact your authorized worldwide distributor or visit Microchip’s Web

site at www.microchip.com

For more product information visit:

www.microchip.com

For more information visit www.microchip.com 5

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

Tips n’ Tricks - PICmicro® Microcontroller Comparators

TIP 1. Window Comparison

When monitoring an external sensor, it is often convenient to be able to determine when

the signal has moved outside a pre-established safe operating range of values or window of

operation. This windowing provides the circuit with an alarm when the signal moves above or

below safety limits, ignoring minor fl uctuations inside the safe operating range. To implement a

window comparator, two voltage comparators and 3 resistors are required (see Figure 1-1).

TIP 1. Window Comparison (continued)

R2

R3R1

Output

Input

VDD

+

–

Figure 1-1. Window Comparator

TIP 2. Hysteresis

When the voltages on a comparator’s input are nearly equal, external noise and switching

noise from inside the microcontroller can cause the comparator output to oscillate or

“chatter”. To prevent chatter, some of the comparator output voltage is fed back to the

non-inverting input of the comparator to form hysteresis (see Figure 2-1). Hysteresis moves

the comparator threshold up when the input is below the threshold and down when the input

is above the threshold. The result is that the input must overshoot the threshold to cause a

change in the comparator output. If the overshoot is greater than the noise present on the

input, the comparator output will not chatter.

Figure 2-1 Comparator with Hysteresis

Resistors R1, R2 and R3 form a voltage divider

which generates the high and low threshold

voltages. The outputs HIGH LIMIT and LOW

LIMIT are both active high, generating a logic

one on the HIGH LIMIT output when the input

voltage rises above the high threshold, and a

logic one on the LOW LIMIT output when the

input voltage falls below the low threshold. To

calculate values for R1, R2 and R3, fi nd values

that satisfy Equation 1-1 and Equation 1-2.

Note: A continuous current will fl ow

through R1, R2 and R3. To limit the

power dissipation in the resistors, the total

resistance of R1, R2 and R3 should be at

least 1k. The total resistance of R1, R2 and

R3 should also be kept less than 1 megohm

to prevent offset voltages due to the input

bias currents of the comparator.

VTH-HI =

VDD * (R3 + R2)

Equation 1-1:

R1 + R2 + R3

VTH-LO =

VDD * R3

Equation 1-2:

R1 + R2 + R3

Example:

• VDD = 5.0V, VTH = 2.5V, VTL = 2.0V

• R1 = 12k, R2 = 2.7k, R3 = 10k

• VTH (actual) = 2.57V, VTL (actual) = 2.02V

Adding Hysteresis:

To add hysteresis to the HIGH LIMIT comparator, follow the procedure outlined in Tip #2.

Use the series combination of R2 and R3 as the resistor R2 in Tip #2. To add hysteresis to

the LOW LIMIT comparator, choose a suitable value for Req, 1k to 10 kOhm, and place it

between the circuit input and the noninverting input of the LOW LIMIT comparator. Then

calculate the needed feedback resistor using Equation 2-1 and Equation 2-2.

DR = (VTH + VTL)

Equation 2-1:

VDD

Finally, calculate the feedback resistor R3

using Equation 2-2.

Equation 2-2:

Example:

• A VDD = 5.0V, VH = 3.0V and VL = 2.5V

• VAVG = 2.77V

• R = 8.2k and R2 = 10k, gives a VAVG = 2.75V

• REQ = 4.5k

• DR = .1

• R3 = 39k (40.5 calculated)

• VHACT = 2.98V

• VLACT = 2.46V

R3 =

REQ [ (

1 ) – 1]

DR

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 6

For more information visit:

www.microchip.com/solutions/tipstricks/sep04

Tips n’ Tricks - PICmicro® Microcontroller Comparators

VDD

R1Input

Output

Comparator

C1

R2

R3

In both wired and wireless data transmission, the data signal may be subject to DC offset

shifts due to temperature shifts, ground currents or other factors in the system. When this

happens, using a simple level comparison to recover the data is not possible because the

DC offset may exceed the peak-to-peak amplitude of the signal. The circuit typically used

to recover the signal in this situation is a data slicer.

The data slicer shown in Figure 3-1 operates by comparing the incoming signal with

a sliding reference derived from the average DC value of the incoming signal. The

DC average value is found using a simple RC low-pass fi lter (R1 and C1). The corner

frequency of the RC fi lter should be high enough to ignore the shifts in the DC level while

low enough to pass the data being transferred. Resistors R2 and R3 are optional. They

provide a slight bias to the reference, either high or low, to give a preference to the state of

the output when no data is being received. R2 will bias the output low and R3 will bias the

output high. Only one resistor should be used at a time and its value should be at least 50

to 100 times larger than R1.

TIP 3. Pulse Width Measurement

Figure 3-1. Data Slicer

When dealing with short duration signals or glitches, it is often convenient to stretch out

the event using a mono-stable, multi-vibrator or one-shot. Whenever the input pulses, the

one-shot fi res holding its output for a preset period of time. This stretches the short trigger

input into a long output which the microcontroller can capture.

The circuit is designed with two feedback paths around a comparator. The fi rst is a

positive hysteresis feedback which sets a two level threshold, VHI and VLO, based on the

state of the comparator output. The second feedback path is an RC time circuit. The one-

shot circuit presented in Figure 4-1 is triggered by a low-high transition on its input and

generates a high output pulse. Using the component values from the example, the circuit’s

operation is as follows.

TIP 4. One-Shot Circuit (continued)

VDD

R1

Input

Output

Comparator

C1 R2

C2

V1

V2VDD

D1

R3

R5R4

Figure 4-1. One-Shot Circuit

TPULSE = R2 * C1 In(VTH + VTL)

Equation 4-1:

4

Example:

Data rate of 10 kbits/second. A low pass

fi lter frequency of 500 Hz:

R1 = 10k, C1 = 33 µF. R2 or R3 should

be 500k to 1 MB.

TIP 4. One-Shot Circuit

Prior to triggering, C1 will have charged to a voltage slightly above 0.7V due to resistor divider

R1 and R2 and the voltage drop across D1. The comparator output will be low, holding the non-

inverting input slightly below 0.7V due to the hysteresis feedback through R3, R4 and R5 (the

hysteresis lower limit is designed to be less than 0.7V). With the non-inverting input held low,

C2 will charge up to the difference between the circuit input and the voltage present at the non-

inverting input.

When the circuit input is pulsed high, the voltage present at the non-inverting input is pulled

above 0.7V due to the charge in C2. This causes the output of the comparator to go high, the

hysteresis voltage at the non-inverting input goes to the high threshold voltage and C1 begins

charging through R2. When the voltage across C1 exceeds the high threshold voltage, the output

of the comparator goes low, C1 is discharged to just above the 0.7V limit, the non-inverting input

is pulled below 0.7V and the circuit is reset for the next pulse input, waiting for the next trigger

input.

To design the one-shot, fi rst create the hysteresis feedback using the techniques from

Tip #2. Remember to set the low threshold below 0.7V. Next, choose values for R2 and C1 using

Equation 4-1.

Example:

• VDD = 5V, VTH = 3.0V, VTL = 2.5V

• From Tip 2: R4 = 1k, R5 = 1.5k and R3 = 12k

• TPULSE = IMS, C1 = .1 ∝F and R2 = 15k

• D1 is a 1N4148, R1 = 220. and C2 = 150 pF

D1 can be any low voltage switching diode. R1

should be 1% to 2% of R2 and C2 should be

between 100 and 220 pF.

For more information visit www.microchip.com 9

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

Stop holding your breath.........A new world of Digital

Signal Control is here.

The time has come to unleash your imagination with the dsPIC® Digital Signal

Controller (DSC) from Microchip. Seamlessly blending a powerful 16-bit Microcontroller

(MCU) with outstanding Digital Signal Processing (DSP) capabilities, the dsPIC DSC brings

the best of both worlds to your fi ngertips.

The dsPIC DSC breezes through demanding real-time control and fast, complex algorithm

processing with equal ease, all in a package size as small as a pencil eraser. With an easy-

to-use MCU look and feel, best in class C effi ciency, cost-effective Flash, low-cost real-time

development tools and a substantial portfolio of libraries – the dsPIC DSC is the solution for

you!

Atlanta, GA:

10/12

Austin, TX:

11/4

Baltimore, MD:

11/9

Bedford, NH:

11/10

Chicago, IL:

10/21

Cleveland,

OH:10/7

Denver, CO:

11/3

Detroit, MI:

10/5

El Paso, TX:

11/9

Houston, TX:

11/2

Las Vegas, NV:

10/12

Mashantucket,

CT: 11/11

Milwaukee, WI:

10/20

Minneapolis, MN:

10/19

Montreal,

Quebec: 12/1

Nashville, TN:

11/4

Newton, MA:

11/9

Orlando, FL:

11/2

Ottawa, ONT:

12/2

Phoenix, AZ:

10/5

Portland, OR:

10/26

Princeton, NJ:

10/26

Raleigh, NC:

11/11

Rochester,

NY:10/28

Sacramento,

CA:10/21

San Jose, CA:

10/19

San Diego, CA:

10/7

Seattle, WA:

10/28

St. Louis, MO:

9/22

Toronto, ONT:

11/30

Tucson, AZ:

10/13

Tulsa, OK:

11/11

dsPIC DSC Introductory Seminars are coming to a city near you. Join us for a six-hour

seminar and learn how to apply this exciting new family into your designs. Don’t waste

time – register today!

Digital Signal Controller

Introductory seminars are

coming to a city near you!

For more information visit: www.microchip.com

Archived WebSeminars That May Interest You

Archived versions of the WebSeminars shown in the table below are available for

you to download and view whenever you wish.

Title Category Date Duration

Introduction to the MPLAB® Visual Device Initializer (VDI) Dev Tools Aug 2004 30 min

Selecting the Ideal Temperature Sensor Analog Aug 2004 30 min

PIC10F Development Tools: Small Tools for Small Parts Dev Tools Aug 2004 30 min

An Introduction to the Controller Area Network (CAN) Interface Jun 2004 30 min

Control the World with the World’s Smallest

Microcontroller (PIC10F)

Products Jun 2004 30 min

Predict the Repeatability of Your ADC to the BIT Analog May 2004 20 min

What Does “Rail-to-Rail” Operation Really Mean? Analog Apr 2004 20 min

Introduction to MPLAB® IDE Dev. Tools Mar 2004 25 min

Lithium-Ion Battery Charging: Techniques and Trade-offs Analog Mar 2004 20 min

Techniques that Reduce System Noise in ADC Circuits Analog Feb 2004 20 min

Introduction to Microchip’s Development Tools Dev. Tools Feb 2004 25 min

Wireless Communication Using the IrDA® Standard

Protocol

Applications Jan 2004 20 min

Driving Lumileds LEDs with Microchip Microcontrollers Applications Jan 2004 60 min

AC Induction Motor (ACIM) Control Using the

PIC18FXX31

Motor

Control

Jan 2004 20 min

Peripheral-Rich, Low Pin-Count, PIC® MCUs with

nano-Watt Technology

Products Jan 2004 30 min

Brushless DC Motor (BLDC) Motor Control Using

PIC18FXX31

Motor

Control

Dec 2003 20 min

Smaller Packages = Bigger Thermal Challenges Analog Dec 2003 20 min

Design Considerations When Adding CANbus to Your

System

Applications Nov 2003 20 min

Select the Right Operational Amplifi er for Your Filtering

Circuits

Analog Oct 2003 20 min

Amplify Sensor Signals Using the PGA Analog Sep 2003 20 min

Microchip’s nanoWatt Technology Products Apr 2003 45 min

For more information visit: www.microchip.com

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 10

What’s New in Microchip Literature?

Click on a Document Title to view the document.

(Continued)

Type of Document Title of Document DS# Print/Web

Analog Design Note Flexible Integrated Temperature Sensors Lower System Costs (ADN11) 21901A Web

Application Notes Practical PICmicro® Oscillator Analysis and Design App. Note (AN943) 00943A Web

Matching MOSFET Drivers to MOSFETs (AN799) 00799B Web

Effi ciently Powering Nine White LEDs with the MCP1650 (AN948) 00948A Web

Data Sheets 24LCS61/62 1K/2K Software Addressable I2C™ Serial EEPROM Data Sheet 21226E Web

25AA320/LC/C320 32K SPI™ Bus Serial EEPROM Data Sheet 21227E Web

TC7129 - 4-1/2 Digit Analog-to-Digital Converter with On-Chip LCD Drivers 21459C Web

MCP6231 - 20 µA, 300 kHz Rail-to-Rail Op Amp 21881B Web

MCP6241 - 50 µA, 650 kHz Rail-to-Rail Op Amp 21882B Web

MCP111/112 - Micropower Voltage Detector 21889B Web

TC54 - Voltage Detector 21434G Web

TC4420/9 - 6A High-Speed MOSFET Drivers 21419C Web

TC650/TC651 - Tiny Integrated Temperature Sensor and Brushless DC Fan Controller with Overtemperature 21450C Web

PIC18F6390/6490/8390/8490 39629B Web

PS700 Data Sheet 21760F Web

dsPIC30F3014, dsPIC30F4013 Data Sheet 70138A Web

dsPIC30F DS Motor Control and Power Conversion Families 70082G Web

dsPIC30F4011/4012 Data Sheet 70135B Web

dsPIC30F DS General Purpose and Sensor Families 70083G Web

PIC16F785 20-Pin, Flash-based, 8-bit CMOS MCU w/Two-Phase Asynchronous Feedback PWM, Dual High

Speed Comparators and Dual Operational Amplifi ers

41249A Web

Design Guides Temperature Sensor Design Guide 21895A Printed/Web

For more information visit www.microchip.com 9

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

Click on a Document Title to view the document.

Type of Document Title of Document DS# Print/Web

Erratas PIC16F688 Rev. A Silicon Errata 80181B Web

PIC12F683 Data Sheet Errata 80196B Web

PIC16F684 Rev. A Silicon Data Sheet 80197B Web

PIC16F818/819 Rev. A4 Silicon/Data Sheet Errata 80159C Web

PIC18F6310/6410/8310/8410 Rev. B3 Silicon Errata 80206A Web

PIC18F6390/6490/8390/8490 Rev. B3 Silicon Errata 80207A Web

dsPIC30F5011/5013 Rev. A1 Silicon Errata 80201A Web

dsPIC30F4011/4012 Rev. A1 Silicon Errata 80205A Web

Product Briefs PIC12F510/16F506 Product Brief 41248A Web

MCP2122 - IrDA® Standard Encoder/Decoder Product Brief 21840B Web

PIC18F6627/6722/8627/8722 Product Brief 39627B Web

Programming Spec. PIC16F91X Memory Programming 41244A Web

Technical Briefs Soft-Start Controller for Switching Power Supplies Tech. Brief (TB81) 91081A Web

Selecting an MCP21XXX Device for IrDA® Applications (TB73) 91073B Web

User Guides MCP1630 NiMH Demo Board User’s Guide 51505A Web

MPLAB® ICE 2000 In-Circuit Emulator User’s Guide 51488A Printed/Web

MPLAB® ICE 4000 In-Circuit Emulator User’s Guide 51490A Printed/Web

dsPIC30F Speech Recognition Word Library Builder User’s Guide 70137A Printed

What’s New in Microchip Literature?

The Microchip name and logo, the Microchip logo, dsPIC, KEELOQ, MPLAB, PIC, PICmicro, and PowerSmart are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.

In-Circuit Serial Programming, ICSP, PICkit and PICtail are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. All other trademarks mentioned herein are property of their respective companies.

MICROCHIP TECHNOLOGY’S MICROSOLUTIONS eNEWSLETTER - September 2004

For more information visit www.microchip.com 12

DID YOU KNOW.....

� buy.Microchip has grown again? Customers in the following regions can now

purchase products online at http://buy.microchip.com.

– Poland, the Czech Republic, Slovakia, Slovenia, Hungary, Estonia and Vietnam.

– Coming soon: Thailand, Switzerland, Israel, South Africa and China .

web siteHIGHLIGHTS

DID YOU KNOW.....

Microchip design centers for KEELOQ® Authentication and Home Appliance

Solutions have been updated with more links to:

• Technical documentation

• Product recommendations

• Application notes

• Available development tools

• Frequently asked questions

Visit all the design centers to learn more about:

Automotive Solutions

Designing for Mechatronics

Connectivity

Motor Control

Infrared Solutions

Check back often because NEW design centers are coming soon on battery

management and metering!

For more information visit: www.microchip.com

Visit Microchip Technology’s user-friendly

e-commerce site:

� Special offers on silicon and

development systems

� Powerful parametric search tool

� Live inventory status

� Hassle-free buying

Figure 1. Home Page

DID YOU KNOW.....

� Many popular tape and reel as well as tray products are now available at

reduced minimum order quantities. Over 400 products have had their minimum

order quantity reduced, particularly our analog and memory products.