Datasheet

Ultralow Power, 3-Lead, SOT-23
Microprocessor Reset Circuits
ADM6326/ADM6328/ADM6346/ADM6348
Rev. 0
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FEATURES
Ultralow supply current of 1 μA maximum (ADM6326/ADM6328)
Accurate monitoring of 2.5 V, 3 V, 3.3 V, and 5 V rails
Reset thresholds available in increments from 2.2 V to 4.63 V
Glitch immunity from negative-going V
CC
transients
2 reset output options
Push-pull
RESET
(ADM6326/ADM6346)
Open-drain
RESET
(ADM6328/ADM6348)
Minimum reset timeout of 100 ms
Operating temperature range of −40°C to +85°C
3-lead SOT-23 package
APPLICATIONS
Telecommunications
Microprocessor systems
Desktop and notebook computers
Portable equipment
FUNCTIONAL BLOCK DIAGRAMS
RESET
GENERATOR
(100ms)
ADM6326/ADM6346
V
REF
V
CC
GND
RESET
08052-001
Figure 1.
RESET
GENERATOR
(100ms)
ADM6328/ADM6348
V
REF
V
CC
GND
RESET
08052-002
Figure 2.
GENERAL DESCRIPTION
The ADM6326/ADM6328/ADM6346/ADM6348 devices provide
low cost solutions for protecting sensitive circuitry, such as micro-
processor and telecommunications circuitry.
With built-in glitch immunity, ultralow supply currents, and
24 reset threshold voltage options, the ADM6326/ADM6328/
ADM6346/ADM6348 not only ensure that systems are immune
to fast transients on V
CC
, but also that the devices are suitable
for monitoring a variety of supply voltages in low power,
portable equipment.
These devices provide a reset output during power-up, power-
down, and brownout conditions. On power-up, an internal
timer holds
RESET
asserted for at least 100 ms. This holds the
microprocessor in a reset state until conditions have stabilized.
The reset output remains operational with V
CC
as low as 1 V.
The ADM6326 and ADM6346 have an active low push-pull reset
output. The ADM6328 and ADM6348 have an active low open-
drain reset output, which requires an external pull-up resistor.
The ADM6326 and ADM6328 offer a choice of ten reset thresholds
in increments between 2.2 V and 3.08 V, whereas the ADM6346
and ADM6348 offer a choice of 14 reset thresholds between 3.3 V
and 4.63 V.
These devices are available in a 3-lead SOT-23 package and
operate over the extended temperature range of −40°C to +85°C.