Texas Instruments TPS54202EVM-716, Руководство пользователя

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ENFALLING
STOP ENFALLING p h
R4 V
R5
V V R4 (I I )
´
=
- + +
ENFALLING
START STOP
ENRISING
ENFALLING
p h
ENRISING
V
V V
V
R4
V
I 1 I
V
æ ö
-
ç ÷
è ø
=
æ ö
- +
ç ÷
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Test Setup and Results
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4 SLVUAP3 – April 2016
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Copyright © 2016, Texas Instruments Incorporated
TPS54202EVM-716 2-A Regulator Evaluation Module
1.3.3 Adjustable UVLO
The under voltage lock out (UVLO) can be adjusted externally using R4 and R5. The EVM is set for a start
voltage of 6.74 V and a stop voltage of 5.83 V using R4 = 510 k
Ω and R5 = 105 k Ω . Use Equation 4 and
Equation 5 to calculate required resistor values for different start and stop voltages. For higher light-load
efficiency, consider choosing a larger R4 and R5. Make adjustments to V
START
or V
STOP
for a proper R4.
(4)
(5)
I
p
= 0.7 µA, I
h
= 1.55 µA, V
ENFALLING
= 1.19 V and V
ENRISING
= 1.22 V
2 Test Setup and Results
This section describes how to properly connect, set up, and use the TPS54202EVM-716 evaluation
module. The section also includes test results typical for the evaluation module and covers efficiency,
output voltage regulation, load transients, loop response, output ripple, input ripple, and start-up.
2.1 Input/Output Connections
The TPS54202EVM-716 is provided with input/output connectors and test points as shown in Table 4 . A
power supply capable of supplying 2 A must be connected to J1 through a pair of 20-AWG wires. The load
must be connected to J2 through a pair of 20-AWG wires. The maximum load current capability must be
at least 3 A to use the full capability of this EVM. Wire lengths must be minimized to reduce losses in the
wires. Test-point TP1 provides a place to monitor the V
IN
input voltages with TP2 providing a convenient
ground reference. TP6 is used to monitor the output voltage with TP7 as the ground reference.
Table 4. EVM Connectors and Test Points
Reference Designator Function
J1 VIN (see Table 1 for V
IN
range)
J2 VOUT, 5 V at 2 A maximum
JP1 2-pin header for enable. Connect EN to ground to disable, open to enable.
TP1 V
IN
test point at VIN connector
TP2 GND test point at VIN
TP3 GND test point
TP4 SW test point
TP5 Test point between voltage divider network and output. Used for loop response measurements.
TP6 Output voltage test point at OUT connector
TP7 GND test point at VOUT connector