Alliance Semiconductor
2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com
Notice: The information in this document is subject to change without notice
September 2005
rev 1.5
ASM6381 - ASM6390
Single/Dual Low Voltage, Low Power Microcontroller Power Supply Supervisor
General Description
The ASM6381 - ASM6390 are cost effective +1.8V to +5V
power supply supervisor circuits optimized for low-power
microprocessor (P), microcontroller (C) and digital systems.
They provide a reset output during power-up, power-down and
brown-out conditions. They provide excellent reliability by
eliminating external components and adjustments.
A reset signal is issued if the power supply voltage drops below
a preset reset threshold and is asserted for a minimum reset
timeout period after the supply has risen above the reset
threshold. The reset timeout periods are available from 1ms to
1200ms. The ASM6381, ASM6384 and ASM6387 have a push-
pull active-low reset output. The ASM6382, ASM6385 and
ASM6388 have a push-pull active-high reset output, and the
ASM6383, ASM6386, ASM6389 and ASM6390 have an open-
drain active-low reset output. The ASM6384, ASM6385 and
ASM6386 also feature a manual reset input.
The ASM6387, ASM6388, ASM6389 have an auxiliary input
RESET IN for monitoring a second voltage. The ASM6390
offers a manual reset input with a longer VCC reset timeout
period and a shorter manual reset timeout.
The reset output state is guaranteed to be in the correct logic
state for VCC down to 1V. The reset comparator is designed to
ignore fast transients on VCC.
Low supply current makes the ASM6381 - ASM6390 ideal for
use in portable and battery operated equipments. The
ASM6381 - ASM6383 are available in a compact, industry
standard 3-pin SC70 package and the ASM6384 - ASM6390
are available in a compact, industry standard 4-pin SC70
package. The ASM63811, ASM63812,
ASM63832 are
available in 3-pin SOT23 package. ASM63813 is available in
3-pin and 5-pin SOT23 package.
Reset thresholds are available from +1.58V to 4.63V in
approximately 100mV increments to support +1.8V to +5V
systems.
Features:
Factory-set Reset Threshold Voltages ranging from +1.58V
to 4.63V.
Monitor 1.8V to 5V supplies.
Push-Pull Active-low reset valid with 1.0V supply.
Small 3-pin SC-70, 4-pin SC-70, 3-pin and 5-pin SOT23
packages.
No external components.
Specified over full temperature range: -40°C to 125°C
Seven Reset Timeout periods: 1ms, 20ms, 140ms, 280ms,
560ms, 1120ms, 1200ms (min).
Low power consumption: 3A at +1.8V.
Auxiliary RESET IN
Manual Reset input.
Applications
Embedded controllers
Portable/Battery operated systems
Intelligent instruments
Wireless communication systems
PDAs and handheld equipment
Computers
Typical Operating Circuit
VCC
P
RESET
Input
RESET
(RESET)
GND
(RESET)
MR
RESET IN
R1
R2