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Voltage Sequencer | Cypress Semiconductor

Voltage Sequencer

Last Updated: 
Jan 29, 2018

Supported Devices: CY8C21x23, CY8C21x34, CY8C2xx45, CY8C23x33, CY8C24x33, CY8C24x23A, CY8C27x43, CY8C24x94, CY8C29x66, CY8C28xxx

General Description:

The Voltage Sequencer User Module is a flexible and easy way to implement voltage sequencing function using a PSoC 1 device. Voltage sequencing is required to ensure reliable power up and power down of power rails in a system and flag a fault condition in case of a failure. The User Module Wizard allows you to control ramp timing as well as time delays between power rails. Voltage sequencing is popularly used in computing (servers, storage arrays) as well as communication (basestation, routers, VOIP equipments) systems in addition to general industrial and consumer systems.

The User Module enables PSoC 1 to read PGOOD (power good) signals from power regulators and generate EN (enable) signals for power regulators based on user-defined ramp timing. If PSoC 1 does not receive the PGOOD signal in the user-defined 'RAMP' time, then it asserts a power-up failure interrupt and continues with the user-defined power-down sequence, if the auto power-down mode is enabled. This User Module uses an on-chip 16-bit timer (implemented using programmable digital blocks) to generate user-defined time delays.

Voltage Sequencer User Module Diagram

Voltage Sequencer User Module


  • Drag-n-drop ‘virtual IC’ in PSoC Designer 5.3 or later
  • Implements voltage sequencing in a PSoC 1 device
  • Provides a graphical Wizard for configuration
  • Reads PGOOD signals and generates EN signals
  • Enables user-defined time delays and power-up as well as power-down sequences
  • Detects a fault in case of a failure
Voltage Sequencer User Module Wizard Screen Shot
Voltage Sequencer User Module Wizard

Related Pages: Application Notes, Technical Reference Manuals, Design Guides