Welcome to the TPS37/38 design calculator!

This tool guides the user through the design process for the adjustable variants of the TPS37 and TPS38 dual channel over and under voltage supervisors.

The default voltage threshold and hysteresis level are set to 800 mV and 2% respectively and can be adjusted through the addition of key resistors.

User interaction is required in order to get the best possible results. Enter the desired specification where prompted, and solutions will appear in a red box. Calculations for the design are based on the inputs.

Where applicable, a recommended value is given that will be the best choice to meet the given specification. It is in the best interest of the user to use a value as close as possible to the suggested recommended value. For accurate results, the user must enter the actual value used in the appropriate cell.

  • This calculator only functions for open drain, active low devices.
  • To keep the default hysteresis level of a channel, input a 0 in the hysteresis resistor cell and select a desired R2 or R4.
  • See the TPS37/38 datasheets for more information about over and undervoltage channel definitions.
  • Vdd must be greater than UVLO for the device to operate properly.
  • Reset and sense capacitors should not exceed 10 uF in order to prevent unexpected device behavior.
Variable Definitions:
  • Monitored Rail Voltage: The nominal voltage of the monitored input rail (Vmon)
  • Desired Hysteresis Level: The desired hysteresis level. Default value = 2%
  • Reset Trigger Voltage: The desired voltage tripping point. See device datasheet for over/under voltage channel behavior
  • Pullup Resistance: The pullup resistance (RP). Recommended = 10 KOhm
  • Hysteresis Resistance: The hysteresis resistance (RH). Recommended = 1 MOhm

This product is designed as an aid for customers of Texas Instruments. No warranties, either expressed or implied, with respect to this software or its fitness for any particular purpose are claimed by Texas Instruments or the Author. The software is licensed solely on an "as is" basis. The entire risk as to its quality and performance is with the customer.

Designed by Andrew Li in Santa Clara