Product details


Supply voltage (Min) (V) 3 Number of supplies monitored 13 Supply voltage (Max) (V) 3.6 Iq (Typ) (uA) 50000 Time delay (ms) Programmable Number of sequenced outputs 12 Rating Catalog open-in-new Find other Sequencers

Package | Pins | Size

VQFN (RGC) 64 81 mm² 9 x 9 VQFN (RGC) 64 81 mm² 9.0 x 9.0 open-in-new Find other Sequencers


  • Monitor and Sequence 12 Voltage Rails
    • All Rails Sampled Every 200µs
    • 12-bit ADC With 2.5V, 0.5% Internal VREF
    • Sequence Based on Time, Rail and Pin Dependencies
    • Six Hardware Comparators for Power Supply Fault Response in < 80µs
    • Four Programmable Under-Voltage and Over-Voltage Thresholds per Monitor
    • Programmable Fault Response Including Retries, Shutdown Slaves and Resequence
  • Non-Volatile Error Logging
    • Stores Up To 18 Faults
    • Log Peak Values For All Monitor Inputs
  • Closed Loop Margining for 10 Rails
    • Margin Output Adjusts Rail Voltage to Match User-Defined Margin Thresholds
    • Unused Margin Outputs can be Used as GPIOs or General-Purpose PWM Outputs
  • Watchdog Timer and System Reset
    • Programmable WDT Reset and Start Times
    • Configurable System Reset Pulse Widths
  • Flexible Digital I/O Configuration
    • Boolean Logic Builder for GPO Config
    • GPIOs can be Used as Enables, Resets, Power Good and Other On-Board Functions
  • Wide Range Single Supply (3.3V to 12V)
    • Internal Temperature Sensor
    • 64-Pin QFN Package
  • JTAG and I2C/SMBus/PMBus Interfaces
  • Fusion Digital Power GUI for Configuring and Monitoring Device Operation
    • Industrial / ATE
    • Telecommunications and Networking Equipment
    • Servers and Storage Systems
    • Any System Requiring Sequencing and Monitoring of Multiple Power Rails

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The UCD90120 Power Supply Sequencer and System Health Monitor monitors and sequences up to 12 independent voltage rails. The device integrates a 12-bit ADC with a 2.5V internal reference for monitoring up to 13 power supply voltage, current, or temperature inputs.

26 GPIO pins can be used for power supply enables, power-on reset signals, external interrupts, cascading multiple UCD90120 devices, or other system functions. 12 of these pins can be used as PWM outputs for power supply margining or general-purpose PWM functions including clock generation for switch-mode power supplies.

The TI Fusion Digital Power Designer 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.

The UCD90120 has an I2C/PMBus/SMBus communication interface for pre-production and in-system configuring and monitoring and a JTAG Port for production programming.

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The most current UCD90xxx PMBus™ Command Reference is available at

Technical documentation

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Type Title Date
* Data sheet UCD90120 12-Channel Sequencer and System Health Controller datasheet Sep. 08, 2009
* Errata Errata Report for the UCD90120 and UCD90124 Devices Apr. 26, 2010
Selection guide Voltage Supervisors (Reset ICs) Quick Reference Guide (Rev. H) Feb. 28, 2020
Application note How to Decode UCD90xxx Fault Log With PMBus (Rev. A) Nov. 07, 2019
Application note Design Voltage Margining Circuit for UCD90xxx Power Sequencer and System Manager (Rev. A) May 21, 2019
Application note UCD90xxx Family Frequently Asked Questions and Answers (Rev. B) Apr. 12, 2019
User guide UCD90xxx Sequencer and System Health Controller PMBus™ Command Reference (Rev. G) Apr. 03, 2019
Technical article Sequencing and managing multiple power rails in a system: common questions answered Feb. 01, 2017
Application note Monitoring Voltage, Current and Temperature Using the UCD9012x Mar. 23, 2012
User guide UCD90SEQ64EVM-650: 64-Pin Sequencer Development Board Dec. 27, 2010
User guide UCD90120/4 EVM User's Guide Oct. 06, 2009

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide

The UCD90SEQ64EVM-650 is a fully assembled and tested circuit for evaluating the 64-pin Sequencer and System Health Controller, including the UCD90120, UCD90124, UCD90120A, UCD90124A, UCD90910 and UCD90160.

  • Monitor and Sequence 12 Voltage Rails
  • Non-Volatile Error Logging
  • Closed Loop Margining for 10 Rails
  • Watchdog Timer and System Reset
  • Flexible Digital I/O Configuration
  • Wide Range Single Supply (3.3V to 12V)

This EVM serves as an interface adapter or a bridge between a host PC (IBM™ compatible) and one or multiple slave devices via a standard type-A to mini-B USB cable. The communication between the USB interface adapter and the host PC is via USB, while the communication between the USB interface (...)

  • Supports master mode I²C, SMBus or PMBus as well as GPIO.
  • Supports USB1.1 full speed at 12 Mbit/s. The USB interface adapter is recognized by the host as a generic human interface device (HID), so no proprietary USB or HID driver is needed. Therefore, the USB interface adapter can be treated as a (...)

Software development

Digital Power Software
FUSION_DIGITAL_POWER_DESIGNER Fusion Digital Power™  is the Graphical User Interface (GUI) used to configure and monitor select Texas Instruments digital power controllers and sequencer/health monitors. The application uses the PMBus protocol to communicate with the device over serial bus by way of a TI USB adapter.

Some of the tasks you can perform with the GUI include:

  • Turn on or off the power supply output, either through the hardware control line or the PMBus OPERATION command
  • Monitor real-time data. Items such as input voltage, output voltage, output current, temperature, and warnings/faults are continuously (...)
Fusion Digital Power Manufacturing Tool
FUSION_MFR_GUI The Fusion Digital Power Manufacturing Tool (aka MFR GUI) is a Graphical User Interface used to download firmware, upgrade firmware, configure, calibrate and test .

The MFR GUI supports the same devices as Fusion Digital Power Designer software.  This tool is typically used in manufacturing (...)


Some of the tasks the tool can perform include:

  • Download/Upgrade firmware
  • Program a device configuration
  • Calibrate a device (manually or instrumented via GPIB):
    • Input voltage (Vin)
    • Output voltage (Vout)
    • Output current (Iout)
    • Temperature
  • Test the device (validate power conversion falls within acceptable Vout (...)

Design tools & simulation

SLVC321.ZIP (2 KB) - BSDL Model
PSpice® for TI design and simulation tool
PSPICE-FOR-TI — PSpice® for TI is a design and simulation environment that helps evaluate functionality of analog circuits. This full-featured, design and simulation suite uses an analog analysis engine from Cadence®. Available at no cost, PSpice for TI includes one of the largest model libraries in the (...)
  • Leverages Cadence PSpice Technology
  • Preinstalled library with a suite of digital models to enable worst-case timing analysis
  • Dynamic updates ensure you have access to most current device models
  • Optimized for simulation speed without loss of accuracy
  • Supports simultaneous analysis of multiple products
  • (...)
SLVC676.ZIP (88 KB)

CAD/CAE symbols

Package Pins Download
VQFN (RGC) 64 View options

Ordering & quality

Information included:
  • RoHS
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Support & training

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