TPS53353 Step-Down Converter Evaluation Module User's Guide
Trademarks
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All trademarks are the property of their respective owners.
1 Description
The TPS53353EVM-744 is designed to use a regulated 12-V bus to produce a regulated 1.5-V output at up to 20 A of load current. The TPS53353EVM-744 is designed to demonstrate the TPS53353 in a typical low-voltage application while providing a number of test points to evaluate the performance of the TPS53353.
1.1 Typical Application
- Server/storage
- Workstations and desktops
- Telecommunication infrastructure
1.2 Features
The TPS53353EVM-744 features:
- 20-Adc, steady-state output current
- Support prebias output voltage start-up
- J5 for selectable switching frequency setting
- J4 for selectable soft-start time
- J2 for enable function
- J6 for auto-skip and forced CCM selection
- Convenient test points for probing critical waveforms
2 Electrical Performance Specifications
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNITS |
|---|---|---|---|---|---|
| Input Characteristics | |||||
| Voltage range | VIN | 8 | 12 | 14 | V |
| Maximum input current | VIN = 8 V, IO = 20 A | 4.1 | A | ||
| No-load input current | VIN = 14 V, IO = 0 A with auto-skip mode | 1 | mA | ||
| Output Characteristics | |||||
| Output voltage VOUT | 1.5 | V | |||
| Output voltage regulation | Line regulation (VIN = 8 V – 14 V) | 0.1 | % | ||
| Load regulation (VIN = 12 V, IO = 0 A – 20 A) | 1 | ||||
| Output voltage ripple | VIN = 12 V, IO = 20 A | 20 | mVpp | ||
| Output load current | 0 | 20 | A | ||
| Output overcurrent | 26 | A | |||
| Systems Characteristics | |||||
| Switching frequency | 500 | kHz | |||
| Peak efficiency | VIN = 12 V, 1.5 V/10 A | 91.87 | % | ||
| Full-load efficiency | VIN = 12 V, 1.5 V/20 A | 91.38 | % | ||
| Operating temperature | 25 | °C | |||
Jumpers are set at the factory to default locations; for details, see Section 5 of this user’s guide.
3 Schematic
Figure 3-1 TPS53353EVM-744 Schematic4 Test Setup
4.1 Test Equipment
Voltage Source: The input voltage source VIN must be a 0-V to 14-V variable DC source capable of supplying 10 ADC. Connect VIN to J1 as shown in Figure 4-2.
Multimeters:
- V1: VIN at TP1 (VIN) and TP2 (GND)
- V2: VOUT at TP5 (VOUT) and TP7 (GND)
- A1: VIN input current
Output Load: The output load should be an electronic constant resistance mode load capable of 0 ADC–30 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 the following:
- 1-MΩ impedance
- 20-MHz bandwidth
- AC coupling
- 2-µs/division horizontal resolution
- 50-mV/division vertical resolution
Test points TP5 and TP7 can be used to measure the output ripple voltage by placing the oscilloscope probe tip through TP5 and holding the ground barrel on TP7 as shown in Figure 4-1. Using a leaded ground connection may induce additional noise due to the large ground loop.
Figure 4-1 Tip and Barrel
Measurement for VOUT RippleFan: Some of the components in this EVM can approach 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 while the fan is not running.
Recommended Wire Gauge:
- VIN to J1 (12-V input):
The recommended wire size is 1× AWG 14 per input connection, with the total length of wire less than four feet (2-foot input, 2-foot return).
- J3 to LOAD:
The minimum recommended wire size is 2× AWG 14, with the total length of wire less than four feet (2-foot input, 2-foot return).
