a
Power Supply Monitor
with Reset
ADM709
FEATURES
Precision Supply Voltage Monitor
+5 V, +3.3 V, +3 V Power Supply Monitor
35 A Quiescent Current
140 ms (min) Power-On Reset Pulse
Low Cost
8-Pin DIP/SO Packages
Upgrade for MAX709
FUNCTIONAL BLOCK DIAGRAM
ADM709
VCC
RESET
GENERATOR
VTH
RESET
GND
APPLICATIONS
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Critical P Monitoring
Automotive Systems
Critical P Power Monitoring
VCC
VCC
ADM709
RESET
µP
RESET
GND
GENERAL DESCRIPTION
The ADM709 contains a power supply monitor which generates
a system reset during power-up, power-down and brownout
conditions. When VCC falls below the reset threshold, RESET
goes low and holds the µP in reset. On power-up the RESET
output is held low for 140 ms after VCC rises above the threshold. The RESET output remains operational with VCC as low
as 1 V.
Three supply-voltage threshold levels are available suitable for
+5 V, +3.3 V and for +3 V supply monitoring. The actual reset
voltage threshold is given below.
The ADM709 is available in 8-pin DIP and SOIC packages.
Table I. Reset Threshold
Suffix
Voltage (V)
L
M
T
S
R
4.65
4.40
3.08
2.93
2.63
GND
Typical Operating Circuit
ORDERING GUIDE
Model
Reset
Threshold
Temperature
Range
Package
Option*
ADM709LAN
ADM709LAR
ADM709MAN
ADM709MAR
ADM709TAN
ADM709TAR
ADM709SAN
ADM709SAR
ADM709RAN
ADM709RAR
4.65 V
4.65 V
4.40 V
4.40 V
3.08 V
3.08 V
2.93 V
2.93 V
2.63 V
2.63 V
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
N-8
SO-8
N-8
SO-8
N-8
SO-8
N-8
SO-8
N-8
SO-8
*N = Plastic DIP; SO = SOIC.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1995
One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703
