July 1998

®

.LOW TURN OFF TIME.MAXIMUM OPERATING FREQUENCYGREATER THAN 500kHz.TIMING FROM MICROSECONDS TO HOURS.OPERATES IN BOTH ASTABLE ANDMONOSTABLE MODES.HIGH OUTPUT CURRENT CAN SOURCE ORSINK 200mA.ADJUSTABLE DUTY CYCLE.TTL COMPATIBLE.TEMPERATURE STABILITY OF 0.005%PER oC

ORDER CODES

Part Number

TemperatureRange

Pakcage

N D

NE556 0oC, 70oC • •SA556 –40oC, 105oC • •SE556 –55oC, 125oC • •

DESCRIPTION

The NE556 dual monolithic timing circuit is a highlystable controller capable of producing accurate timedelays or oscillation. In the time delay mode of op-eration, the time is precisely controlled by one exter-nal resistor and capacitor. For a stable operation asan oscillator, the free running frequency and the dutycycle are both accurately controlled with two exter-nal resistors and one capacitor. The circuit may betriggered and reset on falling waveforms, and theoutput structure can source or sink up to 200mA.

GENERAL PURPOSE DUAL BIPOLAR TIMERS

NDIP14

(Plastic Package)

DSO14

(Plastic Micropackage)

Trigger

Output

Control Voltage4

8

5

6

7

9

10

11

12

13

14

Trigger

Threshold

Discharge

Reset

Output

Discharge

GND

1

2

3

Threshold

Control Voltage

Reset

CCV

PIN CONNECTIONS (top view)

NE556SA556 - SE556

1/9

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

Vcc Supply Voltage 18 V

Toper Operating Free Air Temperature Range for NE556for SA556for SE556

0 to 70–40 to 105–55 to 125

°C

Tj Junction Temperature 150 °CTstg Storage Temperature Range – 65 to 150 °C

THRESHOLDCOMP

5kW

5kW

5kW

TRIGGER

R

FLIP-FLOP

S

Q

DISCHARGE

OUT

INHIBIT/

RESET

RESET

COMP

S

+

CONTROL VOLTAGE

VCC

1/2 NE556

BLOCK DIAGRAM

OUTPUT

CONTROLVOLTAGE

THRESHOLDCOMPARATOR

VCC

R14.7kW

R2830W

Q5 Q6 Q7 Q8 Q9

R34.7kW

R41kW

R85kW

Q1

Q2 Q3

Q4

Q10

Q11 Q12

Q13

THRESHOLD

TRIGGER

RESET

DISCHARGE

G N D

2

4

7

1

Q14

Q15

R510kW

R6100kW

R7100kW

R105kW

Q17

Q16 Q18

R95kW D2

R16100W

R154.7kW

R14220W

Q24

Q23

R174.7kW

3

Q22

R13

D1

Q19Q20

Q21

R126.8kW

5

TRIGGER COMPARATOR FLIP FLOP

R115kW

3.9kW

SCHEMATIC DIAGRAM

NE556/SA556/SE556

2/9

Notes : 1. Supply current when output is high is typically 1mA less.2. Tested at VCC = +5V and VCC = +15V.3. This will determine the maximum value of RA + RB for +15V operation the max total is R = 20MΩ and for 5V operation

the max total R = 3.5MΩ.4. Specified with trigger input high.

ELECTRICAL CHARACTERISTICSTamb = +25oC, VCC = +5V to +15V (unless otherwise specified)

Symbol ParameterSE556 NE556 - SA556

UnitMin. Typ. Max. Min. Typ. Max.

ICC Supply Current (RL ∞) (- note 1) - (2 timers)Low State VCC = +5V

VCC = +15VHigh State VCC = 5V

6204

1024

6204

1230

mA

Timing Error (monostable)(RA = 2k to 100kΩ, C = 0.1µF)Initial Accuracy - (note 2)Drift with TemperatureDrift with Supply Voltage

0.530

0.05

21000.2

1500.1

3

0.5

%ppm/°C

%/V

Timing Error (astable)(RA, RB = 1kΩ to 100kΩ, C = 0.1µF,VCC = +15V) Initial Accuracy - (note 2)Drift with TemperatureDrift with Supply Voltage

1.590

0.15

2.251500.3

%ppm/°C

%/V

VCL Control Voltage levelVCC = +15VVCC = +5V

9.62.9

103.33

10.43.8

92.6

103.33

114

V

Vth Threshold VoltageVCC = +15VVCC = +5V

9.42.7

103.33

10.64

8.82.4

103.33

11.24.2

V

Ith Threshold Current - (note 3) 0.1 0.25 0.1 0.25 µA

Vtrig Trigger VoltageVCC = +15VVCC = +5V

4.81.45

51.67

5.21.9

4.51.1

51.67

5.62.2

V

Itrig Trigger Current (Vtrig = 0V) 0.5 0.9 0.5 2.0 µA

Vreset Reset Voltage - (note 4) 0.4 0.7 1 0.4 0.7 1 V

Ireset Reset CurrentVreset = +0.4VVreset = 0V

0.10.4

0.41

0.10.4

0.41.5

mA

VOL Low Level Output VoltageVCC = +15V, IO(sink) = 10mA

IO(sink) = 50mAIO(sink) = 100mAIO(sink) = 200mA

VCC = +5V, IO(sink) = 8mAIO(sink) = 5mA

0.10.42

2.50.1

0.05

0.150.52.2

0.250.2

0.10.42

2.50.3

0.25

0.250.752.5

0.40.35

V

VOH High Level Output VoltageVCC = +15V, IO(source) = 200mA

IO(source) = 100mAVCC = +5V, IO(source) = 100mA

133

12.513.33.3

12.752.75

12.513.33.3

V

OPERATING CONDITIONS

Symbol Parameter SE556 NE556 - SA556 Unit

VCC Supply Voltage 4.5 to 18 4.5 to 18 V

Vth, Vtrig, Vcl, Vreset Maximum Input Voltage VCC VCC V

NE556/SA556/SE556

3/9

Notes : 5. No protection against excessive Pin 7 current is necessary, providing the package dissipation rating will not be exceeded.6. Time mesaured from a positive going input pulse from 0 to 0.8x VCC into the threshold to the drop from high to low of the

output trigger is tied to treshold.

ELECTRICAL CHARACTERISTICS (continued)

Symbol ParameterSE556 NE556 - SA556

UnitMin. Typ. Max. Min. Typ. Max.

Idis(off) Discharge Pin Leakage Current(output high) (Vdis = 10V)

20 100 20 100 nA

Vdis(sat) Discharge pin Saturation Voltage(output low) - (note 5)VCC = +15V, Idis = 15mAVCC = +5V, Idis = 4.5mA

18080

480200

18080

480200

mV

trtf

Output Rise TimeOutput Fall Time

100100

200200

100100

300300

ns

toff Turn off Time - (note 6) (Vreset = VCC) 0.5 0.5 µs

Figure 1 : Minimum Pulse Width Required forTrigering

Figure 2 : Supply Current versus Supply Voltage

Figure 3 : Delay Time versus Temperature Figure 4 : Low Output Voltage versus OutputSink Current

NE556/SA556/SE556

4/9

Figure 5 : Low Output Voltage versus OutputSink Current

Figure 6 : Low Output Voltage versus OutputSink Current

Figure 7 : High Output Voltage Drop versusOutput

Figure 8 : Delay Time versus Supply Voltage

Figure 9 : Propagation Delay versus VoltageLevel of Trigger Value

NE556/SA556/SE556

5/9

t1= 0.693 RA.C

t2 = [(RARB) ⁄ (RA + RB)] CLn

RB − 2RA

2RB − RA

f = 1

t1+ t2 RB <

12

RA ti

t2

t1

Output

R

C

1/2NE556SE556

6

4

5

7

3

2

1

14

A

(8)(10)

(9) (11)

(12)

VCC

51kW

(13)

22kW

Rs

0.01nF

50% DUTY CYCLE OSCILLATOR

Output

R

C

1/2NE556SE556

6

4

5

7

3

2

1

14

A

(8)(10)

(9) (11)

(12)

VCC

(13)Trigger

MODULATIONINPUT

PULSE WIDTH MODULATOR

TYPICAL APPLICATION

NE556/SA556/SE556

6/9

t2

t1

RA

RB

Output Reset

OutputControl

f =1.44

R + 2R ) CBA

Ground

Ground

0.01m F C2

Control

Trigger

Threshold

1/2NE556SE556

+15V

Discharge

11

12

8

13

14

9

5

3

10

0.01m FGround

1/2NE556SE556

Trigger

Threshold

C1

Discharge

Trigger

Reset Vcc4 14

6

1

2

R t

T = 1.1 R .C1t

TONE BURST GENERATOR

For a tone burst generator the first timer is used as a monostable and determines the tone duration whentriggered by a positive pulse at pin 6. The second timer is enabled by the high output os the monostable. Itis connected as an astable and determines the frequency of the tone.

Output

R

1/2NE556SE556

A

(10)

(9)

(11)

(12)

VCC

(13)

RL

RL

7

5

2

1

4 14

3 6

(8)

RB

C

Operating frequency

0.01nF

f =1.44

R + 2R ) CBA

ASTABLE OPERATION

Output

R

1/2NE556SE556

A

(10)(8)

(11)

(12)

VCC

(13)

RL

RL

7

6

2

1

4 14

3C

10nF

(9)5

Trigger

T = 1.1 R .CA

MONOSTABLE OPERATION

t1 = 0.693 (RA + RB) C Output Hight2 = 0.693 RBC Output Low

NE556/SA556/SE556

7/9

DimensionsMillimeters Inches

Min. Typ. Max. Min. Typ. Max.a1 0.51 0.020B 1.39 1.65 0.055 0.065b 0.5 0.020

b1 0.25 0.010D 20 0.787E 8.5 0.335e 2.54 0.100

e3 15.24 0.600F 7.1 0.280i 5.1 0.201L 3.3 0.130Z 1.27 2.54 0.050 0.100

PACKAGE MECHANICAL DATA14 PINS - PLASTIC DIP

NE556/SA556/SE556

8/9

DimensionsMillimeters Inches

Min. Typ. Max. Min. Typ. Max.A 1.75 0.069a1 0.1 0.2 0.004 0.008a2 1.6 0.063b 0.35 0.46 0.014 0.018

b1 0.19 0.25 0.007 0.010C 0.5 0.020c1 45o (typ.)D 8.55 8.75 0.336 0.334E 5.8 6.2 0.228 0.244e 1.27 0.050

e3 7.62 0.300F 3.8 4.0 0.150 0.157G 4.6 5.3 0.181 0.208L 0.5 1.27 0.020 0.050M 0.68 0.027S 8o (max.)

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for theconsequences of use of such information nor for any infringement of patents or other rights of third parties which may resultfrom its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specif i-cations mentioned in this publication are subject to change without notice. This publication supersedes and replaces all infor-mation previously supplied. STMicroelectronics products are not authorized for use as critical components in life supportdevices or systems without express written approval of STMicroelectronics.

© The ST logo is a trademark of STMicroelectronics

© 1998 STMicroelectronics – Printed in Italy – All Rights ReservedSTMicroelectronics GROUP OF COMPANIES

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PACKAGE MECHANICAL DATA14 PINS - PLASTIC MICROPACKAGE (SO)

NE556/SA556/SE556

9/9

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