ST NE556, SA556, SE556 User Manual

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.

N

DIP14

(Plastic package)

D

SO14

(Plastic micropackage)

Pin connections

(top view)

January 2009

Rev 2

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Schematic diagrams	NE556 - SA556 - SE556

1 Schematic diagrams

Figure 1. Block diagram

Figure 2. Schematic diagram

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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
VCC		Supply voltage	18	V
IOUT		Output current (sink and source)	±225	mA
		Thermal resistance junction to ambient(1)
Rthja		DIP14	80	°C/W
		SO-14	105
		Thermal resistance junction to case (1)
Rthjc		DIP14	33	°C/W
		SO-14	31
		Human body model (HBM)(2)	1000
ESD		Machine model (MM)(3)	150	V
		Charged device model (CDM)(4)	1500
		Latch-up immunity	200	mA
TLEAD		Lead temperature (soldering 10 seconds)	260	°C
Tj		Junction temperature	150	°C
Tstg		Storage temperature range	-65 to 150	°C

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
	Symbol		Parameter	Value	Unit
			Supply voltage
	VCC		NE556	4.5 to 16	V
			SA556	4.5 to 16
			SE556	4.5 to 18
	Vth, Vtrig,		Maximum input voltage	VCC	V
	Vcl, Vreset
	IOUT		Output current (sink and source)	±200	mA
			Operating free air temperature range
	Toper		NE556	0 to 70	°C
			SA556	-40 to 105
			SE556	-55 to 125

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Electrical characteristics						NE556 - SA556 - SE556
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.
	Supply current (RL ) (2 timers)
ICC	Low state	VCC = +5V		6	10		6	12	mA
		VCC = +15V		20	24		20	30
	High State	VCC = +5V		4			4
	Timing error (monostable)
	(RA = 2kΩ to 100kΩ, C = 0.1μF)
	Initial accuracy (1)			0.5	2		1	3	%
	Drift with temperature			30	100		50		ppm/°C
	Drift with supply voltage			0.05	0.2		0.1	0.5	%/V
	Timing error (astable)
	(RA, RB = 1kΩ to 100kΩ, C = 0.1μF, VCC= +15V)
	Initial accuracy (1)			1.5			2.25		%
	Drift with temperature			90			150		ppm/°C
	Drift with supply voltage			0.15			0.3		%/V
	Control voltage level
VCL	VCC = +15V		9.6	10	10.4	9	10	11	V
	VCC = +5V		2.9	3.33	3.8	2.6	3.33	4
	Threshold voltage
Vth	VCC = +15V		9.4	10	10.6	8.8	10	11.2	V
	VCC = +5V		2.7	3.33	4	2.4	3.33	4.2
Ith	Threshold current (2)			0.1	0.25		0.1	0.25	µA
	Trigger voltage
Vtrig	VCC = +15V		4.8	5	5.2	4.5	5	5.6	V
	VCC = +5V		1.45	1.67	1.9	1.1	1.67	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
	Reset current
Ireset	Vreset = +0.4V			0.1	0.4		0.1	0.4	mA
	Vreset = 0V			0.4	1		0.4	1.5
	Low level output voltage
	VCC = +15V	IO(sink) = 10mA		0.1	0.15		0.1	0.25
VOL		IO(sink) = 50mA		0.4	0.5		0.4	0.75	V
		IO(sink) = 100mA		2	2.2		2	2.5
		IO(sink) = 200mA		2.5			2.5
	VCC = +5V	IO(sink) = 8mA		0.1	0.25		0.3	0.4
		IO(sink) = 5mA		0.05	0.2		0.25	0.35
	High level output voltage
VOH	VCC = +15V	IO(sink) = 200mA		12.5			12.5		V
		IO(sink) = 100mA	13	13.3		12.75	13.3
	VCC = +5V	IO(sink) = 100mA	3	3.3		2.75	3.3

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NE556 - SA556 - SE556

Electrical characteristics

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.

Idis(off)

Discharge pin leakage current (output high)

20

100

20

100

nA

(Vdis = 10V)

Discharge pin saturation voltage (output low) (4)

Vdis(sat)

VCC = +15V, Idis = 15mA

180

480

180

480

mV

VCC = +5V, Idis = 4.5mA

80

200

80

200

tr

Output rise time

100

200

100

300

ns

Output fall time

100

200

100

300

tf

toff

Turn-off time (5) (V

reset

= V

)

0.5

0.5

µs

CC

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.

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