Test Point Descriptions

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Test Point Descriptions

Wire-loop test points have been provided as convenient connection points for digital voltmeters (DVM) or

oscilloscope probes to aid in the evaluation of this device. A description of each test point follows.

VIN

Input voltage monitoring point. Connect a DVM to this point for measuring efficiency.

VOUT

Output voltage monitoring point. Connect a DVM to this point for measuring efficiency,

line regulation, and load regulation.

TB3 VIN

Connect an oscilloscope probe with a short grounding tip to this pair of holes to

measure input ripple voltage.

TB4 VOUT

Connect an oscilloscope probe with a short grounding tip to this pair of holes to

measure output ripple voltage and transient response.

SS/TR

Monitor the voltage on the soft-start capacitor here. Also use it as an input for the

Tracking function.

INH/UVLO

Ground this terminal to inhibit power conversion. When open, the voltage on this pin is

the voltage of the UVLO resistor divider network.

RT/CLK

Monitors the RT pin (timing resistor) of the device. Adding resistance to ground to this

pin raises the switching frequency. The pin also can be driven by a 3.3-V, logic-level

clock signal to set the switching frequency. A frequency range of 400 kHz to 1 MHz is

supported.

PWRGD

Monitors the Power Good pin. A weak pullup to 5.1 V is provided on the EVM. PWRGD

is high when the output voltage is within ±8% of its nominal value.

GND

Ground points for meters of oscilloscope probes.

PH

Via test point for monitoring the Phase pin (switching node) of the device with an

oscilloscope. This test point can be used to measure the switching frequency of the

regulator. Use only a x10 oscilloscope probe to monitor this point. The operation of the

device can be affected by the stray capacitance of conventional cables or x1 probes.

VS+

This signal monitors the point where the feedback-loop monitors the output voltage.

This point can be used to remote sense the output voltage at an external load. It also

can be used as an injection point for a frequency-response loop analyzer. The injection

signal can be applied across the SENSE+ and VOUT test points.

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TPS84250EVM-001 2.5-A, Integrated Power Solution Evaluation Module

SLVU460A – November 2011 – Revised July 2012

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