Datasheet

TP7

Probe Tip

Metal Ground Barrel

TP8

Test Setup

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4 Test Setup

4.1 Test Equipment

Voltage Source VIN: The input voltage source VIN must be a 0-V to 20-V variable DC source capable of

supplying 10 Adc. Connect VIN to J4 as shown in Figure 4.

Voltage Source V5IN: The input voltage source V5IN must be a 0-V to 5-V variable DC source capable of

supplying 1 Adc. Connect V5IN to J1 as shown in Figure 4.

Multimeters:

V1: VIN at TP11 (VIN) and TP12 (VIN_GND)

V2: V5IN at TP10 (V5IN) and TP9 (V5IN_GND)

V3: VSNS at J6-2 and GSNS at J6-1

A1: VIN input current

A2: V5IN input current

Output Load: The output load must be an electronic constant-resistance mode load capable of 0-Adc to

30-Adc at 1.05 V.

Oscilloscope: A digital or analog oscilloscope can be used to measure the output ripple. The oscilloscope

must be set for 1-MΩ impedance, 20-MHz bandwidth, ac coupling, 1-µs/division horizontal resolution, 20-

mV/division vertical resolution. Test point J6 can be used to measure the differential output ripple voltage,

using a passive probe with the shortest leaded ground clip. For switch node voltage measurement, TP7

and TP8 can be used by placing the passive probe tip through TP7 and holding the ground barrel TP8 as

shown in Figure 3. In this case, using a leaded ground connection may induce additional noise due to the

large ground loop.

Figure 3. Tip and Barrel Measurement for Switch Node Voltage

Fan: Some of the components in this EVM may get hot, approaching temperatures of 60°C during

operation. A small fan capable of 200-400 LFM is recommended to reduce component temperatures while

the EVM is operating. The EVM must not be probed when the fan is not running.

Recommended Wire Gauge:

1. VIN to J4 (8-V to 20-V input)

The recommended wire size is 1x AWG 14 per input connection, with the total length of wire less than

4 feet (2-foot input, 2-foot return).

2. V5IN to J1 (5-V input)

The recommended wire size is 1x AWG 18 per input connection, with the total length of wire less than

4 feet (2-foot input, 2-foot return).

3. J12 to LOAD

The minimum recommended wire size is 2x AWG 14, with the total length of wire less than 4 feet (2-

foot input, 2-foot return).

Using the TPS51219EVM-630 High-Performance, Single, Synchronous, SLUU818–April 2012

Step-Down Controller for Notebook Power Supply

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