Texas Instruments LM21212-1EVM Evaluation Board LM21212-1EVM/NOPB LM21212-1EVM/NOPB 数据表
产品代码
LM21212-1EVM/NOPB
Powering and Loading Considerations
3
Powering and Loading Considerations
Read this entire page prior to attempting to power the evaluation board.
3.1
Quick Setup Procedure
1. Set the input source current limit to 10A. Turn off the input source. Connect the positive output of the
input source to V
IN
and the negative output to the corresponding GND.
2. Connect the load (with 12A capability) to V
OUT
for the positive connection and GND for the negative
connection.
3. Leave the ENABLE pin open for normal operation.
4. Set the input source voltage to 5V. The load voltage should be in regulation with a nominal 1.2V
output.
5. Slowly increase the load while monitoring the load voltage at V
OUT
. It should remain in regulation with a
nominal 1.2V output as the load is increased up to 12A.
6. Slowly sweep the input source voltage from 2.95V to 5.5V. The load voltage should remain in
regulation with a nominal 1.2V output. If desired, the output of the device can be disabled by
connecting the ENABLE pin to GND.
connecting the ENABLE pin to GND.
7. Connect a 2.0V square-wave positive signal between SYNC and GND to vary the frequency of
operation as desired.
3.2
Powering Up
It is suggested that the load power be kept low during the first power up. Once the device is powered up,
immediately check for 1.2V at the output.
immediately check for 1.2V at the output.
A quick efficiency check is the best way to confirm that everything is operating properly. If something is
amiss you can be reasonably sure that it will affect the efficiency adversely. Few parameters can be
incorrect in a switching power supply without creating losses and potentially damaging heat.
amiss you can be reasonably sure that it will affect the efficiency adversely. Few parameters can be
incorrect in a switching power supply without creating losses and potentially damaging heat.
Some voltage supplies can exhibit severe voltage overshoot during high current transients. If a supply
overshoots above 6.0V, damage to the LM21212-1 can occur. For these supplies, a large capacitor across
the terminals of the supply (1000µF) can alleviate this problem.
overshoots above 6.0V, damage to the LM21212-1 can occur. For these supplies, a large capacitor across
the terminals of the supply (1000µF) can alleviate this problem.
3.3
Over Current Protection
The evaluation board is configured with over-current protection. This function is completely contained in
the LM21212-1. The peak current is limited to approximately 17A.
the LM21212-1. The peak current is limited to approximately 17A.
2
AN-2107 LM21212-1 Evaluation Board
SNVA467B – February 2011 – Revised May 2013
Copyright © 2011–2013, Texas Instruments Incorporated