ASM1834 Datasheet, PDF (1/11 Pages) Alliance Semiconductor Corporation – Dual 5V and 3.3V uP Power Supply Supervisor with Manual Reset

ASM1834, ASM1834A,
ASM1834D
Dual 5 V and 3.3 V mP
Power Supply Supervisor
with Manual Reset
Description
The ASM1834 supervisors simultaneously monitor both 3.3 V and
5 V power sources and generate reset signals when either supply is out
of tolerance. When an out−of−tolerance condition is detected, the
output−reset signal of the affected supply becomes active and resets
the system microprocessor/microcontroller. On power−up and after
the supply voltage returns to an in−tolerance condition, the reset signal
remains active for approximately 350 ms. This allows the power
supply and system microprocessor to stabilize.
Tolerance levels are independently selectable for both supplies.
Tolerance options are 5% and 10% for the 5 V supply and 10% and
20% for the 3.3 V supply.
The ASM1834 and ASM1834D have push−pull reset output stages.
The ASM1834A reset outputs are open drain devices that can both be
connected to either 5 V or 3.3 V supply. The ASM1834 and
ASM1834A have active LOW reset outputs. The ASM1834D has
active HIGH reset outputs.
All devices can generate reset signals through an internally
debounced pushbutton reset input that affects both reset outputs.
All devices operate over the extended industrial temperature range.
Devices are available in 8−pin DIP, surface mount 8−pin SO and 8−Pin
MicroSO packages. Die are also available.
http://onsemi.com
PDIP−8
NO SUFFIX
CASE 646AA
MICRO−8
U SUFFIX
CASE 846AA
SOIC−8
S SUFFIX
CASE 751BD
PIN CONFIGURATION
5V_IN
5V RESET*
5V TOL
GND
1
ASM1834
ASM1834A
ASM1834D
3.3V_IN
3.3V RESET*
3.3V TOL
PBRST
(Top View)
*AS1834D reset outputs are active HIGH
(5V RESET and 3.3V RESET) Outputs are
open−drain for AS1834A.
Features
• Monitors 5 V and 3.3 V Supplies Simultaneously
• 5 V and 3.3 V Power−on Reset
• 350 ms Reset Time
• Debounced Pushbutton Reset Input
• Push−pull CMOS Output
ASM1834, ASM1834D
Eliminates External Pull−up Resistors
Active LOW (ASM1834), HIGH (ASM1834D)
• Open Drain Output
ASM1834A
Active LOW
• Selectable 5 V and 3.3 V Trip Point Tolerance
• Internal Power Drawn from Highest Input Voltage,
5 V or 3.3 V
• Precision Temperature−compensated Voltage Reference
and Comparator
• Low Cost Surface Mount SO, Compact MicroSO and
DIP Packages
• Wide Operating Temperature: −40°C to +85°C
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
Applications
• Microprocessors
• PDAs, Hand−held PCs
• Embedded Controllers
• Telecommunication Systems
• Power Supplies
• Wireless / Cellular Systems
• Networking Hardware
© Semiconductor Components Industries, LLC, 2011
1
August, 2011 − Rev. 3
Publication Order Number:
ASM1834/D