ST NE556, SA556, SE556 User Manual

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

NE556

SA556 - SE556

General-purpose dual bipolar timers

N

DIP14

(Plastic package)

D

SO14

(Plastic micropackage)

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.

Discharge

Threshold

Control Voltage

Reset

Output

Trigger

GND

Pin connections

(top view)

1

2

3

4

5

6

7

14

V

Discharge

13

Threshold

12

Control Voltage

11

Reset

10

Output

9

Trigger

8

CC

January 2009 Rev 2 1/16

www.st.com

16

Schematic diagrams NE556 - SA556 - SE556

6

T

1 Schematic diagrams

Figure 1. Block diagram

+

V

CC

W

5k

THRESHOLD

CONTROL VOLTAGE

TRIGGER

COMP

W

5k

COMP

W

5k

R

FLIP-FLOP

S

INHIBIT/ RESET

Q

DISCHARGE

OUT

1/2 NE55

RESET

Figure 2. Schematic diagram

THRESHOLD

COMPARATOR

V

HRESHOLD

TRIGGER

RESET

DISCHARGE

G N D

CC

R1

4.7k

Q5 Q6 Q7 Q8 Q9

Q1

Q2

2

4

Q15

7

Q14

1

R2

830

W

Q3

R5

10k

4.7k

Q4

Q10

W

S

CONTROL VOLTAGE

5

R3

100k

W

R6

Q11 Q12

W

R4

R8

1k

5k

W

Q19

R11 5k

W

Q13

100k

R9

5k

W

R7

W

D2

Q16 Q18

Q17

R10 5k

W

4.7k

R17

R12

6.8k

W

Q20

W

Q23

R16

100

Q21

OUTPUT

Q22

R13

3.9k

W

D1

R14

220

R15

4.7k

W

3

W

Q24

W

TRIGGER COMPARATOR FLIP FLOP

2/16

NE556 - SA556 - SE556 Absolute maximum ratings and operating conditions

2 Absolute maximum ratings and operating conditions

Table 1. Absolute maximum ratings

Symbol Parameter Value Unit

V

CC

I

OUT

R

thja

R

thjc

ESD

Supply voltage 18 V

Output current (sink and source) ±225 mA

(1)

80

105

33 31

1000

150

1500

°C/W

VMachine model (MM)

Thermal resistance junction to ambient

DIP14 SO-14

Thermal resistance junction to case

DIP14 SO-14

Human body model (HBM)

Charged device model (CDM)

(2)

(3)

(4)

Latch-up immunity 200 mA

T

LEAD

T

j

T

stg

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

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.

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.

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.

Table 2. Operating conditions

Lead temperature (soldering 10 seconds) 260 °C

Junction temperature 150 °C

Storage temperature range -65 to 150 °C

Symbol Parameter Value Unit

Supply voltage

V

CC

NE556 SA556 SE556

, V

cl

th

, V

I

OUT

trig

reset

,

Maximum input voltage V

Output current (sink and source) ±200 mA

V

4.5 to 16

4.5 to 18

CC

Operating free air temperature range

T

oper

NE556 SA556 SE556

0 to 70

-40 to 105

-55 to 125

°C

3/16

V

Electrical characteristics NE556 - SA556 - SE556

3 Electrical characteristics

Table 3. T

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

amb

Symbol Parameter

Supply current (RL ∝) (2 timers)

I

Low state V

CC

High State V

= +5V

CC

VCC = +15V

= +5V

CC

Timing error (monostable) (R

= 2kΩ to 100kΩ, C = 0.1μF)

A

Initial accuracy

(1)

Drift with temperature Drift with supply voltage

Timing error (astable)

, RB = 1kΩ to 100kΩ, C = 0.1μF, VCC= +15V)

(R

A

Initial accuracy

(1)

Drift with temperature Drift with supply voltage

Control voltage level

V

CL

V

CC

= +15V

VCC = +5V

Threshold voltage

V

th

I

th

VCC = +15V

= +5V

V

CC

Threshold current

(2)

Trigger voltage

V

trig

I

trig

V

reset

= +15V

V

CC

= +5V

V

CC

Trigger current (V

Reset voltage

(3)

= 0V) 0.5 0.9 0.5 2.0 µA

trig

Reset current

I

reset

V V

reset

= +0.4V

= 0V

Low level output voltage VCC = +15V I

V

OL

= +5V I

V

CC

O(sink)

I

O(sink)

I

O(sink)

I

O(sink)

I

O(sink)

= 10mA = 50mA = 100mA = 200mA = 8mA = 5mA

High level output voltage

= +15V I

V

OH

CC

= +5V I

V

CC

O(sink)

I

O(sink)

= 200mA = 100mA = 100mA

SE556 NE556 - SA556

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

6

20

4

0.5 30

0.05

1.5 90

0.15

9.6

2.9103.33

9.4

2.7103.33

10 24

2

100

0.2

10.4

3.892.6103.33114

10.648.8

2.4103.33

6

20

4

1

50

0.130.5

2.25 150

0.3

11.2

12 30

ppm/°C

4.2

0.1 0.25 0.1 0.25 µA

4.8

1.4551.67

5.2

1.9

4.5

1.151.67

5.6

2.2

0.4 0.7 1 0.4 0.7 1 V

13

3

0.1

0.4

0.1

0.4

2.5

0.1

0.05

12.5

13.3

3.3

0.4 1

0.15

0.5

2

2.2

0.1

0.4

0.1

0.4 2

0.4

1.5

0.25

0.75

2.5

0.25

0.2

0.3

0.25

0.4

0.35

12.5

12.75

2.75

13.3

3.3

Unit

mA

%

%/V

%

%/V

V

mA

V

4/16

NE556 - SA556 - SE556 Electrical characteristics

Table 3. T

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

amb

SE556 NE556 - SA556

Symbol Parameter

Unit

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

I

dis(off)

V

dis(sat)

1. Tested at V

2. This will determine the maximum value of R 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 V output trigger is tied to threshold.

Discharge pin leakage current (output high)

= 10V)

(V

dis

Discharge pin saturation voltage (output low)

VCC = +15V, I VCC = +5V, I

Output rise time

t

r

t

Output fall time

f

toff Turn-off time

= +5 V and VCC = +15 V

CC

(5)

dis

(V

= 15mA

= 4.5mA

= VCC)0.50.5µs

reset

20 100 20 100 nA

(4)

18080480

200

100 100

+ RB for +15V operation the max total is R = 20 MΩ and for +5 V operation

A

into the threshold to the drop from high to low of the

CC

200 200

18080480

200

100

300

100

300

mV

ns

5/16