Data Sheet
FEATURES Quad Voltage Up and Down Sequencer and Monitor with Programmable Timing ADM1186
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. 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 APPLICATION DIAGRAM
5V 5V IN ADP1706
EN 5V IN OUT 5V 2.5V ADP2107
EN 3.3V AUX 3.3V AUX 1µF 5V IN OUT 3.3V AUX IN 1.8V ADP1821
EN OUT 5V 1.2V ADP1706
100nF 3.3V AUX VCC FAULT SEQUENCE CONTROL UP DOWN OUT1 OUT2 OUT3 OUT4 VIN1 VIN2 VIN3 VIN4 2.5V AUX EN OUT 3.3V ADM1186-1 DLY_EN_OUT1 DLY_EN_OUT2 DLY_EN_OUT3 DLY_EN_OUT4 BLANK_DLY GND PWRGD SEQ_DONE 3.3V AUX Figure 1.
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