Texas Instruments TPS5430, User Manual

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Table 1-2. TPS5430EVM-173 and TPS5431EVM-173 Performance Specification Summary (continued)
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
Loop bandwidth
TPS5430EVM-173 VIN = 25 V, I
O
= 1 A 25.0
kHz
TPS5431EVM-173 VIN = 15 V, I
O
= 1 A 23.9
Phase margin
TPS5430EVM-173 VIN = 25 V , I
O
= 1 A 50°
TPS5431EVM-173 VIN = 15 V, I
O
= 1 A 51°
Input ripple voltage
TPS5430EVM-173
I
O
= 3 A
255 300
mVpp
TPS5431EVM-173 295 350
Output ripple voltage
TPS5430EVM-173
I
O
= 3 A
20
mVpp
TPS5431EVM-173 20
Output rise time 8 ms
Operating frequency 500 kHz
Max efficiency
TPS5430EVM-173 VIN = 10 V, V
O
= 5 V, I
O
= 0.75 A 93.6%
TPS5431EVM-173 VIN = 9 V, V
O
= 5 V, I
O
= 0.75 A 94.0%
1.3 Modifications
These evaluation modules are designed to demonstrate the small size that can be attained when designing with
the TPS5430 and TPS5431. A few changes can be made to this module.
1.3.1 Output Voltage Set Point
To change the output voltage of the EVMs, it is necessary to change the value of resistor R2. Changing the
value of R2 can change the output voltage above 1.25 V. The value of R2 for a specific output voltage can be
calculated using
Equation 1 .
R2
+
10 k
W
1.221 V
V
O
*
1.221 V
(1)
Table 1-3 lists the R2 values for some common output voltages. Note that VIN must be in a range so that the
minimum on-time is greater than 200 ns, and the maximum duty cycle is less than 87%. The values given in
Table 1-3 are standard values, not the exact value calculated using Equation 1 .
Table 1-3. Output Voltages Available
Output Voltage (V) R
2
Value (kΩ)
1.8 21.5
2.5 9.53
3.3 5.90
5 3.24
2 Test Setup and Results
This section describes how to properly connect, set up, and use the TPS5430EVM-173 and TPS5431EVM-173
evaluation modules. The section also includes test results typical for the evaluation modules and covers
efficiency, output voltage regulation, load transients, loop response, output ripple, input ripple, and startup.
2.1 Input/Output Connections
The TPS5430EVM-173 and TPS5431EVM-173 are provided with input/output connectors and test points as
shown in
Table 2-1 . A power supply capable of supplying 3 A must be connected to J1 through a pair of 20 AWG
wires. The load must be connected to J3 through a pair of 20 AWG wires. The maximum load current capability
should be 3 A. Wire lengths must be minimized to reduce losses in the wires. Test-point TP1 provides a place
to monitor the VIN input voltages with TP2 providing a convenient ground reference. TP3 is used to monitor the
output voltage with TP4 as the ground reference.
www.ti.com Introduction
SLVU157A – MARCH 2006 – REVISED OCTOBER 2021
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