NE556D - STMicroelectronics

January 2009 Rev 2 1/16

NE556

SA556 - SE556

General-purpose dual bipolar timers

Features

■Low turn-off time

■Maximum operating frequency greater than

500 kHz

■Timing from microseconds to hours

■Operates in both astable and monostable

modes

■Output can source or sink up to 200 mA

■Adjustable duty cycle

■TTL compatible

■Temperature stability of 0.005% per °C

Description

The NE556, SA556 and SE556 dual monolithic

timing circuits are highly stable controllers

capable of producing accurate time delays or

oscillation. In the time delay mode of operation,

the time is precisely controlled by one external

resistor and capacitor. For a stable operation as

an oscillator, the free running frequency and the

duty cycle are both accurately controlled with two

external resistors and one capacitor.

The circuits may be triggered and reset on falling

waveforms, and the output structure can source

or sink up to 200 mA.

DIP14

(Plastic package)

SO14

(Plastic micropackage)

Pin connections

(top view)

Trigger

Output

Control Voltage

Trigger

Threshold

Discharge

Reset

Output

Discharge

GND

Threshold

Control Voltage

Reset

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Schematic diagrams NE556 - SA556 - SE556

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1 Schematic diagrams

Figure 1. Block diagram

Figure 2. Schematic diagram

THRESHOLD

COMP

TRIGGER

FLIP-FLOP

DISCHARGE

OUT

INHIBIT/

RESET

COMP

CONTROL VOLTAGE

VCC

1/2 NE55

OUTPUT

CONTROL

VOLTAGE

THRESHOLD

COMPARATOR

VCC

4.7k

830

Q5 Q6 Q7 Q8 Q9

4.7k

1kW

5kW

Q2 Q3

Q10

Q11 Q12

Q13

HRESHOLD

TRIGGER

RESET

DISCHARGE

G N D

Q14

Q15

10k

100k

R10

5kW

Q17

Q16 Q18

5kW

R16

100W

R15

4.7k

R14

220W

Q24

Q23

R17

4.7k

Q22

R13

Q19

Q20

Q21

R12

6.8k

TRIGGER COMPARATOR FLIP FLOP

R11

3.9k

NE556 - SA556 - SE556 Absolute maximum ratings and operating conditions

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2 Absolute maximum ratings and operating conditions

Table 1. Absolute maximum ratings

Symbol Parameter Value Unit

VCC Supply voltage 18 V

IOUT Output current (sink and source) ±225 mA

Rthja

Thermal resistance junction to ambient(1)

DIP14

SO-14

1. Short-circuits can cause excessive heating. These values are typical and valid only for a single layer PCB.

105

°C/W

Rthjc

Thermal resistance junction to case (1)

DIP14

SO-14

°C/W

ESD

Human body model (HBM)(2)

2. Human body model: a 100 pF capacitor is charged to the specified voltage, then discharged through a

1.5kΩ resistor between two pins of the device. This is done for all couples of connected pin combinations

while the other pins are floating.

1000

VMachine model (MM)(3)

3. Machine model: a 200 pF capacitor is charged to the specified voltage, then discharged directly between

two pins of the device with no external series resistor (internal resistor < 5 Ω). This is done for all couples of

connected pin combinations while the other pins are floating.

150

Charged device model (CDM)(4)

4. Charged device model: all pins and the package are charged together to the specified voltage and then

discharged directly to the ground through only one pin. This is done for all pins.

1500

Latch-up immunity 200 mA

TLEAD Lead temperature (soldering 10 seconds) 260 °C

TjJunction temperature 150 °C

Tstg Storage temperature range -65 to 150 °C

Table 2. Operating conditions

Symbol Parameter Value Unit

VCC

Supply voltage

NE556

SA556

SE556

4.5 to 16

4.5 to 18

Vth, Vtrig,

Vcl, Vreset

Maximum input voltage VCC V

IOUT Output current (sink and source) ±200 mA

Toper

Operating free air temperature range

NE556

SA556

SE556

0 to 70

-40 to 105

-55 to 125

°C

Electrical characteristics NE556 - SA556 - SE556

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3 Electrical characteristics

Table 3. Tamb = +25° C, VCC = +5 V to +15 V (unless otherwise specified)

Symbol Parameter

SE556 NE556 - SA556

Unit

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

ICC

Supply current (RL ∝) (2 timers)

Low state VCC = +5V

VCC = +15V

High State VCC = +5V

30 mA

Timing error (monostable)

(RA = 2kΩ to 100kΩ, C = 0.1μF)

Initial accuracy (1)

Drift with temperature

Drift with supply voltage

0.5

0.05

100

0.2

0.1

0.5

ppm/°C

%/V

Timing error (astable)

(RA, RB = 1kΩ to 100kΩ, C = 0.1μF, V CC= +15V)

Initial accuracy (1)

Drift with temperature

Drift with supply voltage

1.5

0.15

2.25

150

0.3

ppm/°C

%/V

VCL

Control voltage level

VCC = +15V

VCC = +5V

9.6

2.9

3.33

10.4

3.8

2.6

3.33

Vth

Threshold voltage

VCC = +15V

VCC = +5V

9.4

2.7

3.33

10.6

8.8

2.4

3.33

11.2

4.2

Ith Threshold current (2) 0.1 0.25 0.1 0.25 µA

Vtrig

Trigger voltage

VCC = +15V

VCC = +5V

4.8

1.45

1.67

5.2

1.9

4.5

1.1

1.67

5.6

2.2

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

Vreset Reset voltage (3) 0.4 0.7 1 0.4 0.7 1 V

Ireset

Reset current

Vreset = +0.4V

Vreset = 0V

0.1

0.4

0.1

0.4

1.5

VOL

Low level output voltage

VCC = +15V IO(sink) = 10mA

IO(sink) = 50mA

IO(sink) = 100mA

IO(sink) = 200mA

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

IO(sink) = 5mA

0.1

0.4

2.5

0.1

0.05

0.15

0.5

2.2

0.25

0.2

0.1

0.4

2.5

0.3

0.25

0.75

2.5

0.4

0.35

VOH

High level output voltage

VCC = +15V IO(sink) = 200mA

IO(sink) = 100mA

VCC = +5V IO(sink) = 100mA

12.5

13.3

3.3

12.75

2.75

12.5

13.3

3.3

NE556 - SA556 - SE556 Electrical characteristics

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Idis(off)

Discharge pin leakage current (output high)

(Vdis = 10V) 20 100 20 100 nA

Vdis(sat)

Discharge pin saturation voltage (output low) (4)

VCC = +15V, Idis = 15mA

VCC = +5V, Idis = 4.5mA

180

480

200

180

480

200

Output rise time

Output fall time

100

200

100

300

300 ns

toff Turn-off time (5) (Vreset = VCC)0.50.5µs

1. Tested at VCC = +5 V and VCC = +15 V

2. This will determine the maximum value of RA + RB for +15V operation the max total is R = 20 MΩ and for +5 V operation

the max total R = 3.5 MΩ

3. Specified with trigger input high

4. No protection against excessive pin 7 current is necessary, providing the package dissipation rating will not be exceeded

5. Time measured from a positive going input pulse from 0 to 0.8 x VCC into the threshold to the drop from high to low of the

output trigger is tied to threshold.

Table 3. Tamb = +25° C, VCC = +5 V to +15 V (unless otherwise specified) (continued)

Symbol Parameter

SE556 NE556 - SA556

Unit

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

Electrical characteristics NE556 - SA556 - SE556

6/16

Figure 3. Minimum pulse width required for

triggering

Figure 4. Supply current versus supply

voltage

Figure 5. Delay time versus temperature Figure 6. Low output voltage versus output

sink current

Figure 7. Low output voltage versus output

sink current

Figure 8. Low output voltage versus output

sink current

NE556 - SA556 - SE556 Electrical characteristics

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Figure 9. High output voltage drop versus

output

Figure 10. Delay time versus supply voltage

Figure 11. Propagation delay versus voltage

level of trigger value

Application information NE556 - SA556 - SE556

8/16

4 Application information

4.1 Typical application

Figure 12. 50% duty cycle oscillator

t1 = 0.693 RA.C

Figure 13. Pulse width modulator

Output

1/2

NE556

SE556

(8)

(10)

(9) (11)

(12)

51k

(13)

22k

0.01nF

t2 = [(RARB)/(RA+RB)]CLn RB 2RA–

2RB RA–

---------------------------

f = t1

t1 t2+

----------------- RB < 1

--- RA ti

Output

1/2

NE556

SE556

(8)

(10)

(9) (11)

(12)

(13)

Trigger

MODULATION

INPUT

NE556 - SA556 - SE556 Application information

9/16

Figure 14. Tone burst generator

For a tone burst generator the first timer is used as a monostable and determines the tone

duration when triggered by a positive pulse at pin 6. The second timer is enabled by the high

output or the monostable. It is connected as an astable and determines the frequency of the

tone.

Figure 15. Monostable operation

OutputReset

Output

Control

f =

1.44

R + 2R ) C

Ground

0.01

FC2

Control

Trigger

Threshold

1/2

NE556

SE556

+15V

Discharge

0.01

Ground

1/2

NE556

SE556

Trigger

Threshold

Discharge

Trigger

ResetVcc

414

T = 1.1 R .C1

Output

1/2

NE556

SE556

(10)

(8)

(11)

(12)

(13)

414

10nF

(9)

Trigger

T = 1.1 R .C

Application information NE556 - SA556 - SE556

10/16

Figure 16. Astable operation

t1 = 0.693 (RA + RB) C output high

t2 = 0.693 RBC output low

Output

1/2

NE556

SE556

(10)

(9)

(11)

(12)

(13)

414

(8)

Operating frequency

0.01nF

f =

1.44

R + 2R ) C

NE556 - SA556 - SE556 Package information

11/16

5 Package information

In order to meet environmental requirements, ST offers these devices in different grades of

ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®

specifications, grade definitions and product status are available at: www.st.com.

ECOPACK® is an ST trademark.

Package information NE556 - SA556 - SE556

12/16

5.1 DIP14 package information

Figure 17. DIP14 package mechanical drawing

Note: D and E1 dimensions do not include mold flash or protrusions. Mold flash or protrusions

shall not exceed 0.25 mm.

Table 4. DIP14 package mechanical data

Dimensions

Ref.

Millimeters Inches

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

A5.330.21

A1 0.38 0.015

A2 2.92 3.30 4.95 0.11 0.13 0.19

b 0.36 0.46 0.56 0.014 0.018 0.022

b2 1.14 1.52 1.78 0.04 0.06 0.07

c 0.20 0.25 0.36 0.007 0.009 0.01

D 18.67 19.05 19.69 0.73 0.75 0.77

E 7.62 7.87 8.26 0.30 0.31 0.32

E1 6.10 6.35 7.11 0.24 0.25 0.28

e2.54 0.10

e1 15.24 0.60

eA 7.62 0.30

eB 10.92 0.43

L 2.92 3.30 3.81 0.11 0.13 0.15

NE556 - SA556 - SE556 Package information

13/16

5.2 SO-14 package information

Figure 18. SO-14 package mechanical drawing

Note: D and F dimensions do not include mold flash or protrusions. Mold flash or protrusions must

not exceed 0.15 mm.

Table 5. SO-14 package mechanical data

Dimensions

Ref.

Millimeters Inches

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

A 1.35 1.75 0.05 0.068

A1 0.10 0.25 0.004 0.009

A2 1.10 1.65 0.04 0.06

B 0.33 0.51 0.01 0.02

C 0.19 0.25 0.007 0.009

D 8.55 8.75 0.33 0.34

E 3.80 4.0 0.15 0.15

e1.27 0.05

H 5.80 6.20 0.22 0.24

h 0.25 0.50 0.009 0.02

L 0.40 1.27 0.015 0.05

k 8° (max.)

ddd 0.10 0.004

Ordering information NE556 - SA556 - SE556

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6 Ordering information

Table 6. Order codes

Part number Temperature range Package Packing Marking

NE556N 0°C, +70°C DIP14 Tube NE556N

NE556D/DT SO-14 Tube or tape & reel NE556

SA556N -40°C, +105°C DIP14 Tube SA556N

SA556D/DT SO-14 Tube or tape & reel SA556

SE556N -55°C, + 125°C DIP14 Tube SE556N

SE556D/DT SO-14 Tube or tape & reel SE556

NE556 - SA556 - SE556 Revision history

15/16

7 Revision history

Table 7. Document revision history

Date Revision Changes

01-Jun-2003 1 Initial release.

27-Jan-2009 2

Document reformatted.

Added IOUT value in Table 1: Absolute maximum ratings and

Table 2: Operating conditions.

Added ESD tolerance, latch-up tolerance, Rthja and Rthjcin

Table 1: Absolute maximum ratings.

Updated Section 5.1: DIP14 package information and

Section 5.2: SO-14 package information.

NE556 - SA556 - SE556

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