Preliminary Datasheet
3-PIN MICROPROCESSOR RESET CIRCUIT
General Description
The AZ809A is a precision system supervisor and reset
circuit designed to monitor the power supplies in
microprocessor and digital system. It provides a reset
signal to the host processor during power-up, power-
down, and brownout conditions.
The AZ809A has an active-low RESET output, three
standard reset options are offered to support 5V, 3.3V,
and 3.0V system.Whenever the system supply voltage
declines below the internal fixed reset threshold, the
AZ809A asserts a reset signal and the reset signal
remains asserted for 240mS after V
CC
rises above the
threshold.
The AZ809A has a push-pull output, no external com-
ponents are required. The output is guaranteed to be in
the correct state at V
CC
level as low as 1V. The
AZ809A is optimized to reject fast transient glitches
on the VCC line. When the V
CC
is 3.3V, the supply
current consumption is about 6µA typically.
The IC is available in SOT-23 package.
AZ809A
Features
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Precise Monitoring of 3.0V, 3.3V, and 5.0V Sup-
ply Voltages
140ms Minimum Reset Pulse Width
Active-low RESET Output
Push-Pull RESET Output
No External Components
Reset Valid Down to V
CC
=1.0V
Power Supply Fast Transient Immunity
Specified Over Full Temperature Range: -40 to
105
o
C
Applications
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Microprocessor Systems
Portable/Battery-Powered Systems
Embedded Controllers
Automotive
Intelligent Instruments
Wireless Communication Systems
PDAs and Handheld Equipment
Set-Top Boxes
ADSL Modems
SOT-23
Figure 1. Package Type of AZ809A
Jan. 2008 Rev. 1. 0
1
BCD Semiconductor Manufacturing Limited