FEATURES
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LTC2934
Ultra-Low Power
Adjustable Supervisor with
Power-Fail Output
DESCRIPTION
The LTC
®
2934 ultra-low power voltage monitor provides
system initialization, power-fail warning and reset gen-
eration functions. Low quiescent current (500nA typical)
makes the LTC2934 an ideal choice for battery-operated
applications.
Precision power-fail and reset voltages can be configured
independently. Early warning of an impending low volt-
age condition is provided at the power-fail output (PFO)
when the PFI input falls below 0.4V. Supervisory circuits
monitor the ADJ input and pull
RST
low when ADJ falls
below 0.4V. When ADJ is rising from an under-threshold
condition, an internal reset timer is started after exceeding
the ADJ threshold by 5%. The reset timeout delays the
return of the
RST
output to a high state. A pushbutton
switch connected to the
MR
input is typically used to
force a manual reset. Outputs
RST
and
PFO
are available
with open-drain (LTC2934-1) or active pull-up circuits
(LTC2934-2). Operating temperature range is from –40ºC
to 85ºC.
500nA Quiescent Current
±1.5% (Max) Accuracy over Temperature
Operates Down to 1.6V Supply
Adjustable Reset Threshold
Adjustable Power-Fail Threshold
Early Warning Power-Fail Output
Selectable 15ms or 200ms Reset Timeout
Manual Reset Input
Compact 8-Lead, 2mm
×
2mm DFN and TSOT-23
(ThinSOT™) Packages
APPLICATIONS
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Portable Equipment
Battery-Powered Equipment
Security Systems
Point-of-Sale Devices
Wireless Systems
, LT, LTC, LTM are registered trademarks of Linear Technology Corporation. ThinSOT is
a trademark of Linear Technology Corporation. All other trademarks are the property of
their respective owners.
TYPICAL APPLICATION
Configurable Low Power Voltage Supervisor
Selectable Reset Timeout Period
V
IN
750k
0.1μF
11.8k
PFI
237k
MR
RT
GND
2934 TA01a
V
CC
ADJ
LTC2934-2
PFO
BATTERY
POWERED
SYSTEM
LOGIC
RST
V
CC
15ms
RST, RT = GND
200ms
2934 TA01b
RST, RT = V
CC
POWER FAIL FALLING THRESHOLD = 1.686V
RESET FALLING THRESHOLD = 1.606V
2934f
1
LINER [ LINEAR TECHNOLOGY ]
