Quad Voltage Up and Down Sequencer
and Monitor with Programmable Timing
Data Sheet
Rev. B Document Feedback
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FEATURES
Powered from 2.7 V to 5.5 V on the VCC pin
Monitors four supplies via 0.8% accurate comparators
Digital core supports up and down supply sequencing
Multiple devices can be cascaded (ADM1186-1)
Four inputs can be programmed to monitor different voltage
levels with resistor dividers
Capacitor programmable supply sequence time delays
and a timeout delay to 5% accuracy at 25°C
Four open-drain enable outputs
Open-drain power-good output
Open-drain sequence complete pin and bidirectional
open-drain fault pin (ADM1186-1 only)
APPLICATIONS
Monitor and alarm functions
Up and down power supply sequencing
Telecommunication and data communication equipment
PCs, servers, and notebook PCs
GENERAL DESCRIPTION
The ADM1186-1 and ADM1186-2 are integrated, four-channel
voltage monitoring and sequencing devices. A 2.7 V to 5.5 V
power supply is required on the VCC pin for power.
Four precision comparators, VIN1 to VIN4, monitor four
voltage rails. All four comparators share a 0.6 V reference and
have a worst-case accuracy of 0.8%. Resistor networks that are
external to the VIN1, VIN2, VIN3, and VIN4 pins set the
undervoltage (UV) trip points for the monitored supply rails.
The ADM1186-1 and ADM1186-2 have four open-drain enable
outputs, OUT1 to OUT4, that are used to enable power supplies.
An open-drain power-good output, PWRGD, indicates whether
the four VINx inputs are above their UV thresholds.
A state machine monitors the state of the UP and
DOWN
pins
on the ADM1186-1 or the UP/
DOWN
pin on the ADM1186-2
to control the supply sequencing direction (see
Figure 2). In the
WAIT START state, a rising edge transition on the UP or
UP/
DOWN
pin triggers a power-up sequence. A falling edge
transition on the
DOWN
or UP/
DOWN
pin in the POWER-UP
DONE state triggers a power-down sequence.
APPLICATION DIAGRAM
07153-003
5V
IN
EN
OUT
ADP1706
5V
IN
EN OUT
ADP2107
5V
3.3V
AUX
IN
EN
OUT
ADP1821
5V
IN
EN OUT
ADP1706
FAULT
U
P
DOWN
DLY_EN_OUT1
DLY_EN_OUT2
DLY_EN_OUT3
DLY_EN_OUT4
BLANK_DLY
PWRGD
SEQ_DONE
VIN1
VIN2
VIN3
VIN4
VCC OUT1 OUT2
GND
OUT3 OUT4
ADM
1186-1
3.3V AUX
2.5V AUX
2.5V
1.8V
1.2V
3.3V
SEQUENCE CONTROL
3.3V AUX
1µF
100nF
3.3V AUX
5V
3.3V
AUX
5V
Figure 1.
