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Take control of your power supply sequencing

Whether your system has two voltage rails or dozens, Texas Instruments has a power sequencer to fit your requirements.

Power sequencing is an essential part of any design, especially in complex systems that utilize multiple power rails. Today's high-performance processing devices, such as FPGAs, ASICs, PLDs, DSPs, ADCs, and microcontrollers, require multiple voltage rails just to power their own internal circuitry, such as the core, memory, and I/O. These types of applications demand very specific voltage rail power-up and power-down sequencing in order to guarantee reliable operation, better efficiency, and overall system health.

Analog power supply sequencers

Simple power supply sequencing to power up and power down with ease.

Digital power supply sequencers

Flexible sequencing to configure, control, and monitor. TI's digital power supply sequencers offer the benefits of PMBus and digital power without changing your power tree.

Analog

TI offers the easiest method to control the power up and power down sequence of multiple power supplies. Discrete solutions with a combination of resistors and capacitors can provide power-up sequencing, but by themselves cannot provide a reverse sequence during power down. The LM3880 and LM3881 simple power supply sequencers offer:

  • Power-up and power-down sequence control
  • Simple implementation
  • Tiny footprint (LM3880 - 2.9x1.6 mm; LM3881 - 3.0x3.0 mm)
  • Cascade two sequencers to achieve up to 6 sequenced rails
  • Adjustable sequence timing with external capacitor (LM3881)

Power sequencing with reset ICs

TI also offers a simple option to consider for power-up sequencing using reset ICs with adjustable timing. The family of TPS3860xx supervisors offers:

  • Ability to monitor and sequence up to four individual rails
  • Allow timing to be adjusted with four individual external capacitors
  • Small 4x4 mm footprint
  • Consume minimal power (11 μA)
Analog power supply sequencers diagram

Digital

The UCD90xxx family of digital power supply sequencers, also known as system health monitors, provides a comprehensive digital solution for complex power systems:

  • Configurable power-up and power-down sequence control for up to 24 power rails based on timing and/or dependencies (rail and/or pin)
  • PMBus/I2C interfaces, voltage, current and temperature monitoring
  • Multiple levels of Fault Detection and Recovery (shutdown/re-start/re-sequence)
  • Easy-to-use Fusion Digital Power™ GUI allows easy configuration creation and full customization without firmware development
  • Additional features such as open and close loop voltage margining, NV memory fault logging, fully customizable sequencing dependencies, customized Boolean logic driven GPIOs, fan control, system watchdog timer, and system reset
  • Larger systems can cascade multiple devices

TI's digital power supply sequencers offer the benefits of PMBus and digital power without changing your power tree.

UCD90240 Block Diagram

Digital sequencer selection guide

  UCD90240 UCD90320 UCD90160A UCD90120A UCD90124A UCD9090A UCD90910 UCD9081
# Rails Sequenced 24 32 16 12 12 10 10 8
# of Monitor Inputs 24 32 16 13 13 11 13 8
ADC Ref Accuracy External External 0.5% Internal 0.5% Internal 0.5% Internal 0.5% Int ot Ext 0.5% Internal External
Voltage Margining* 24 24 10 10 10 10 10 N/A
Fan Control* N/A N/A N/A N/A 4 N/A 10 N/A
Multi-phase PWM 24 24 8 8 8 8 8 N/A
clock outputs* N/A
ACPI Sleep State Control Yes Yes Yes Yes No Yes No No
Current and Temp Yes Yes No Yes Yes Yes Yes No
Monitor Scaling N/A
NV Fault Logs 100 100 18 16 10 15 20 8
Other NV Logging Blackbox, Peaks, Resets, RTC Blackbox, Peaks, Resets, RTC Peaks, Resets, Run-time clock Peaks, Resets, Run-time clock Peaks, Resets, Run-time clock Peaks, Resets, Run-time clock Peaks, Resets, Run-time clock N/A
Max GPI/GPO* 24/12 32/16 8/16 8/12 8/12 8/10 8/10 0/4
Internal Temp Sensor Yes Yes Yes Yes Yes Yes Yes No
Communication and Programming I/F ** PMBus/I2C, JTAG PMBus/I2C, JTAG PMBus/I2C, JTAG PMBus/I2C, JTAG PMBus/I2C, JTAG PMBus/I2C, JTAG PMBus/I2C, JTAG I2C
Watchdog Timer Yes Yes Yes Yes Yes Yes Yes No
Package Type (size, mm) 157-ball BGA (9x9) 169NFBGA (12x12) 64-pin QFN(9x9) 64-pin QFN(9x9) 64-pin QFN (9x9) 48-pin QFN (7x7) 64-pin QFN (9x9) 32-pin QFN
(5x5)
Availability Production Production Production Production Production Production Production Production