
TP14TP11
Metal Ground Barrel
Probe Tip
Test Setup
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4 Test Setup
4.1 Test Equipment
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 3.
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 J2 as shown in Figure 3.
Multimeters:
V1: V5IN at TP2 (V5IN) and TP3 (GND).
V2: VIN at TP5 (VIN) and TP8 (GND).
V3: VDDQ at TP11 (VDDQ) and TP14 (GND).
V4: VTT at TP12 (VTT) and TP13 (GND).
V5: VTTREF at TP17 (VTTREF) and TP18 (GND).
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
20 Adc at 1.5 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, 2-µs/division horizontal resolution,
20-mV/division vertical resolution. Test points TP11 and TP14 can be used to measure the output ripple
voltage by placing the oscilloscope probe tip through TP11 and holding the ground barrel on TP14 as
shown in Figure 2. Using a leaded ground connection may induce additional noise due to the large ground
loop.
Figure 2. Tip and Barrel Measurement for VDDQ Output Ripple
Fan: Some of the components in this EVM may approach temperatures of 60ºC 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 if the fan is not running.
Recommended Wire Gauge:
1. 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).
2. VIN to J2(12-V input):
The recommended wire size is 1x AWG 16 per input connection, with the total length of wire less than
4 feet (2-foot input, 2-foot return).
3. J5 to LOAD:
The minimum recommended wire size is 2x AWG 16, with the total length of wire less than 4 feet
(2-foot input, 2-foot return)
6
Using the TPS51916EVM-746 Complete DDR2, DDR3, DDR3L, and DDR4 SLUU526– August 2011
Memory Power Solution Synchronous Buck Controller, 2-A LDO, Buffered
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