ASM690A/692A,
ASM802L/802M, ASM805L
mP Power Supply Supervisor
with Battery Backup Switch
Description
The ASM690A / ASM692A / ASM802L / ASM802M / ASM805L
offers complete single chip solutions for power supply monitoring and
control battery functions in microprocessor systems. Each device
implements four functions: Reset control, watchdog monitoring,
battery−backup switching and power failure monitoring. In addition to
microprocessor reset under power−up and power−down conditions,
these devices provide battery−backup switching to maintain control in
power loss and brown−out situations. Additional monitoring
capabilities can provide an early warning of unregulated power supply
loss before the voltage regulator drops out. The important features of
these four functions are:
http://onsemi.com
PDIP−8
P SUFFIX
SOIC−8
S SUFFIX
CASE 646AA
CASE 751BD
• 1.6 second watchdog timer to keep microprocessor responsive
PIN CONFIGURATIONS
• 4.40 V or 4.65 V VCC threshold for microprocessor reset at
1
V
V
power−up and power−down
OUT
BATT
ASM690A,
ASM692A,
ASM802L,
ASM802M
• SPDT (Single−pole, Double−throw) PMOS switch connects backup
power to RAM if VCC fails
V
RESET
WDI
CC
GND
PFI
• 1.25 V threshold detector for power loss or general purpose voltage
PFO
monitoring
These features are pin−compatible with the industry standard
power−supply supervisors. Short−circuit and thermal protection have
also been added. The ASM690A / ASM802L / ASM805L generate a
reset pulse when the supply voltage drops below 4.65 V and the
ASM692A / ASM802M generate a reset below 4.40 V. The ASM802L
/ ASM802M have power−fail accuracy to 2%. The ASM805L is the
same as the ASM690A except that RESET is provided instead of
RESET.
1
V
V
OUT
BATT
V
RESET
WDI
CC
ASM805L
GND
PFI
PFO
(Top Views)
Features
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
• Two Precision Supply−voltage Monitor Options
4.65 V (ASM690A / ASM802L / ASM805L)
4.40 V (ASM692A / ASM802M)
• Battery−backup Power Switch On−chip
• Watchdog Timer: 1.6 Second Timeout
• Power Failure / Low Battery Detection
• Short Circuit Protection and Thermal Limiting
• Small 8−pin SO and 8−pin PDIP Packages
• No External Components
• Specified Over Full Temperature Range
Applications
• Embedded Control Systems
• Portable/Battery Operated Systems
• Intelligent Instruments
• Wireless Communication Systems
• PDAs and Hand−held Equipments
• mP / mC Power Supply Monitoring
• Safety System
• Wireless Instruments
© Semiconductor Components Industries, LLC, 2011
1
Publication Order Number:
ASM690A/D
August, 2011 − Rev. 3