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

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 UCD90120A 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 UCD90120A offers

support for margining, and general-purpose 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.