NSC LM556J-MIL, LM556CN, LM556CM, LM556CMX Datasheet

LM556
Dual Timer

General Description

The LM556 Dual timing circuit is a highly stable controller ca­pable of producing accurate time delays or oscillation. The
556 is a dual 555. Timing is provided by an external resistor
and capacitor for each timing function. The two timers oper­ate independently of each other sharing only V

CC

and
ground. The circuits may be triggered and reset on falling
waveforms. The output structures may sink or source
200mA.

Features

n Direct replacement for SE556/NE556
n Timing from microseconds through hours
n Operates in both astable and monostable modes
n Replaces two 555 timers
n Adjustable duty cycle
n Output can source or sink 200mA
n Output and supply TTL compatible
n Temperature stability better than 0.005% per ˚C
n Normally on and normally off output

Applications

n Precision timing
n Pulse generation
n Sequential timing
n Time delay generation
n Pulse width modulation
n Pulse position modulation
n Linear ramp generator

Connection Diagram

Ordering Information

Package Part Number Package Marking Media Transport NSC Drawing

14-Pin SOIC LM556CM LM556CM Rails

M14A

LM556CMX LM556CM 2.5k Units Tape and Reel

14-Pin MDIP LM556CN LM556CN Rails N14a

Dual-In-Line, Small Outline Packages

DS007852-1

Top View

March 2000

LM556 Dual Timer

© 2000 National Semiconductor Corporation DS007852 www.national.com

Schematic Diagram

DS007852-2

LM556

www.national.com 2

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage +18V

Power Dissipation (Note 2)

LM556CM 410 mW
LM556CN 1620 mW

Operating Temperature Ranges

LM556C 0˚C to +70˚C

Storage Temperature Range −65˚C to +150˚C

Soldering Information

Dual-In-Line Package

Soldering (10 Seconds) 260˚C

Small Outline Packages

Vapor Phase (60 Seconds) 215˚C
Infrared (15 Seconds) 220˚C

See AN-450 “Surface Mounting Methods and Their Effect
on Product Reliability” for other methods of soldering
surface mount devices.

Electrical Characteristics

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

Parameter Conditions Limits Units

LM556C

Min Typ Max

Supply Voltage 4.5 16 V
Supply Current

(Each Timer Section)

V

CC

= 5V, RL=

∞

VCC= 15V, RL=

∞

(Low State) (Note 3)

3

10

6

14 mA

Timing Error, Monostable

Initial Accuracy 0.75 %
Drift with Temperature R

A

= 1k to 100kΩ, 50 ppm/˚C

C = 0.1µF, (Note 4)
Accuracy over Temperature 1.5 %
Drift with Supply 0.1 %/V

Timing Error, Astable

Initial Accuracy 2.25 %
Drift with Temperature R

A,RB

= 1k to 100kΩ, 150 ppm/˚C
Accuracy over Temperature C = 0.1µF, (Note 4) 3.0 %
Drift with Supply 0.30 %/V

Trigger Voltage V

CC

= 15V 4.5 5 5.5 V

V

CC

= 5V 1.25 1.67 2.0 V
Trigger Current 0.2 1.0 µA
Reset Voltage 0.4 0.5 1 V
Reset Current 0.1 0.6 mA
Threshold Current V

TH

= V-Control (Note 6)

V

TH

= 11.2V

0.03 0.1
250

µA
nA

Control Voltage Level and
Threshold Voltage

V

CC

= 15V

V

CC

=5V

9

2.6

10

3.33

11

4

V

Pin 1, 13
Leakage Output High

1 100 nA

Pin 1, 13 Sat (Note 7)

Output Low V

CC

= 15V, I = 15mA 180 300 mV

Output Low V

CC

= 4.5V, I = 4.5mA 80 200 mV

Output Voltage Drop (Low) V

CC

= 15V

I

SINK

= 10mA 0.1 0.25 V

I

SINK

= 50mA 0.4 0.75 V

I

SINK

= 100mA 2 2.75 V

I

SINK

= 200mA 2.5 V

V

CC

=5V

I

SINK

= 8mA V

I

SINK

= 5mA 0.25 0.35 V

LM556

www.national.com3