Introduction
1
Introduction
The Texas Instruments TPS3847085EVM-577 EVM helps design engineers to evaluate the operation and
performance of the TPS3847xxx family of supervisors for possible use in their own circuit applications.
This particular EVM configuration contains the TPS3847085 supervisor with an internal push-pull RESET
output, in a 5-pin, DBV (SOT-23) package. The TPS3847xxx is an ultralow quiescent current, supervisory
circuit with a fixed threshold voltage. The threshold voltage is indicated by the last three digits of the part
number. In this case, 085 indicates the 8.5-V, fixed-threshold version; other values indicate various fixed
thresholds. This document describes the configuration and setup of the TPS3847085EVM-577 EVM
board.
2
Hardware
This section describes the connectors on the EVM, as well as how to properly connect, set up, and use
the TPS3847085EVM-577.
2.1
Input and Output Connectors
2.1.1
J1—VDD
The power-supply connection and the signal that is being monitored by the TPS3847085. RESET
transitions low when the power-supply voltage drops below the threshold. Two pins are provided to allow
space for multiple connections. Note that the device data sheet uses VCC to denote the power supply. In
this case, VCC and VDD are functionally equivalent.
2.1.2
J2—GND
Return connector for the input power supply. Two pins are provided to allow space for multiple
connections.
2.1.3
J3—RESET
This connector is the RESET output. Connect this output to a multimeter, oscilloscope, or external circuit
to verify that RESET goes low when VDD goes below the threshold. Two pins are provided to allow space
for multiple connections.
2.1.4
J4—VPU
VPU is the test point connection to the MR pin. If manual reset is required, then an external source is
required. Connect this external source to the VPU terminal. If manual reset is not required, place a
shorting jumper on J4 connecting VPU (and thus MR) to VDD.
2.1.5
J5—RPU
This connector is used for the pull-up version of the TPS3847, and is not connected for the push-pull
version. Connect the RPU terminal to a power supply; the voltage on this power supply is the logic-high
value for RESET. Two pins are provided to allow space for multiple connections.
2.2
Components
2.2.1
S1
This switch is normally open and connected to MR and GND. Use this switch to trigger a manual reset
event instead of using an external supply.
2.2.2
C1
This 100-nF input capacitor is connected to VDD and GND. Although not required for proper device
operation, this capacitor helps reduce the impedance of the input supply line. Use this capacitor in order to
reduce the effects of the periodic increased quiescent current when the reference voltage is refreshed.
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2
TPS3847085EVM-577 Evaluation Module
SBVU023 – August 2014
Copyright © 2014, Texas Instruments Incorporated