Setup and Test
2.2.3
R1
This 47-k
Ω
resistor is used only for the pull-up version of the TPS3847, and is not installed on this EVM.
2.2.4
R2
This 1-M
Ω
resistor connects the VPU jumper (J4) to the MR pin and S1. This resistor allows MR to be
shorted to GND without drawing excessive amounts of current from the power supply connected to VPU.
3
Setup and Test
•
Set the input power supply voltage to 0 V. Connect the positive voltage lead from the power supply to
J1 (VDD). Connect the ground lead from the power supply to J2 (GND).
•
Short VPU to VDD using a jumper, or connect it to a separate power supply.
•
Connect a voltmeter across J3 (RESET) and J2 (GND).
•
Vary the input power-supply voltage as necessary for test purposes.
•
Vary the power supply connected to VPU as necessary, or use S1 to short MR to GND in order to test
the manual reset functionality.
4
Operation
The TPS3847085EVM-577 is a fixed, single-rail monitor, and triggers a reset when its own supply rail
VDD falls below the set threshold of 8.5 V. An internal push-pull RESET circuit eliminates the need for a
pull-up resistor.
3
SBVU023 – August 2014
TPS3847085EVM-577 Evaluation Module
Copyright © 2014, Texas Instruments Incorporated