SLUUAY7B May 2014 – August 2021 TPS544B20 , TPS544C20
Voltage Source: The input voltage source VIN must be a 0-V to 14-V variable dc source capable of supplying at least 5 Adc. Connect VIN to J2 Figure 4-1.
Multimeters: It is recommended to use two separate multimeters Figure 4-1. One meter is used to measure Vin and one to measure Vout.
Output Load: A variable electronic load is recommended for testing Figure 4-1. It must be capable of 30 A at voltages as low as 0.9 V.
Oscilloscope: An oscilloscope is recommended for measuring output noise and ripple. Output ripple must be measured using a Tip-and-Barrel method or better as shown in Figure 4-3.The scope must be adjusted to 20-MHz bandwidth, ac coupling at 50 mV/division, and must be set to 1-µs/division.
Fan: During prolonged operation at high loads, it may be necessary to provide forced air cooling with a small fan aimed at the EVM. Temperature of the devices on the EVM must be maintained below 105°C.
USB-to-GPIO Interface Adapter: A communications adapter is required between the EVM and the host computer. This EVM was designed to use the Texas Instruments USB-to-GPIO Adapter (see Figure 4-2). This adapter can be purchased at http://www.ti.com/tool/usb-to-gpio.
Recommended Wire Gauge: The voltage drop in the load wires must be kept as low as possible in order to keep the working voltage at the load within its operating range. See the following table for recommended wire gauge and length to achieve a voltage drop of no more than 0.2 V at the maximum 30-A load.
AWG GAUGE | Ω PER FOOT (Ω) | LOAD WIRES COMBINED LENGTH (Ft) | EACH WIRE LENGTH (Ft) |
---|---|---|---|
12 | 1.59E-3 | 6.30 | 3.15 |
14 | 2.53E-3 | 3.96 | 1.98 |
16 | 4.02E-3 | 2.49 | 1.25 |
18 | 6.39E-3 | 1.57 | 0.78 |
As an example, if AWG 12 wire is used, no more than 3.15 feet of wire must be used between the EVM and the load.