1 Features

1• Monitor and sequence 12 voltage rails

– All rails sampled every 400 μs

– 12-bit ADC with 2.5-V, 0.5% internal VREF

– Sequence based on time, rail and pin

dependencies

– Four programmable undervoltage and

overvoltage thresholds per monitor

• Nonvolatile error and peak-value logging per

monitor (up to 12 fault detail entries)

• Closed-loop margining for 10 Rails

– Margin output adjusts rail voltage to match

user-defined margin thresholds

• Programmable watchdog timer and system reset

• Flexible digital I/O configuration

• Pin-selected rail states

• Multiphase PWM clock generator

– Clock frequencies from 15.259 kHz to

125 MHz

– Capability to configure independent clock

outputs for synchronizing switch-mode power

supplies

• JTAG and I2C/SMBus/PMBus™ interfaces

• Fan control and monitoring system functions.

– Supports four fans with five user-defined

speed-vs-temperature setpoints

– Supports two-, three-, and four-wire fans

2 Applications

• Industrial ATE

• Telecommunications and networking equipment

• Servers and storage systems

• Any system requiring sequencing and monitoring

of multiple power rails

3 Description

The UCD90124A is a 12-rail PMBus/I2C addressable

power-supply sequencer and monitor. The device

integrates a 12-bit ADC for monitoring up to 12

power-supply voltage inputs. Twenty-six GPIO pins

can be used for power supply enables, power-on

reset signals, external interrupts, cascading, or other

system functions. Twelve of these pins offer PWM

functionality. Using these pins, the UCD90124A offers

support for fan control, margining, and generalpurpose

PWM functions.

Specific power states can be achieved using the Pin-

Selected Rail States feature. This feature allows with

the use of up to 3 GPIs to enable and disable any

rail. This is useful for implementing system low-power

modes and the Advanced Configuration and Power

Interface (ACPI) specification that is used for

hardware devices.

The TI Fusion Digital Power™ designer software is

provided for device configuration. This PC-based

graphical user interface (GUI) offers an intuitive

interface for configuring, storing, and monitoring all

system operating parameters.