LM556 Dual Timer
March 2000
LM556
Dual Timer
General Description
The LM556 Dual timing circuit is a highly stable controller ca-
pable 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 oper-
ate 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
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Direct replacement for SE556/NE556
Timing from microseconds through hours
Operates in both astable and monostable modes
Replaces two 555 timers
Adjustable duty cycle
Output can source or sink 200mA
Output and supply TTL compatible
Temperature stability better than 0.005% per ˚C
Normally on and normally off output
Applications
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Precision timing
Pulse generation
Sequential timing
Time delay generation
Pulse width modulation
Pulse position modulation
Linear ramp generator
Connection Diagram
Dual-In-Line, Small Outline Packages
DS007852-1
Top View
Ordering Information
Package
14-Pin SOIC
14-Pin MDIP
Part Number
LM556CM
LM556CMX
LM556CN
Package Marking
LM556CM
LM556CM
LM556CN
Media Transport
Rails
2.5k Units Tape and Reel
Rails
NSC Drawing
M14A
N14a
© 2000 National Semiconductor Corporation
DS007852
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
