Datasheet

Test Setup and Results www.ti.com
Table 3 lists the R1 values for some common output voltages. For higher output voltages of 1.8 V or
above, a feedforward capacitor (C4) may be required to improve phase margin. Pads for this component
(C4) are provided on the printed-circuit board. Note that the resistor values given in Table 3 are standard
values and not the exact value calculated using Equation 1.
Table 3. Output Voltages
Output Voltage R1 R2 C4 L1 C9, C10,
(V) (kΩ) (kΩ) (pF) (µH) C11Total
Capacitance
(µF)
1.0 6.81 22.1 2.2 20 - 68
1.05 8.25 22.1 2.2 20 - 68
1.2 12.7 22.1 2.2 20 - 68
1.5 21.5 22.1 2.2 20 - 68
1.8 30.1 22.1 5 - 22 3.3 20 - 68
2.5 49.9 22.1 5 - 22 3.3 20 - 68
3.3 73.2 22.1 5 - 22 3.3 20 - 68
5.0 124 22.1 5 - 22 4.7 20 - 68
6.5 165 22.1 5 - 22 4.7 20 - 68
3.2 Output Filter and Closed-Loop Response
The TPS54229 relies on the output filter characteristics to ensure stability of the control loop. The
recommended output filter components for common output voltages are given in Table 3. It may be
possible for other output filter component values to provide acceptable closed-loop characteristics. R3 and
TP4 are provided for convenience in breaking the control loop and measuring the closed-loop response.
4 Test Setup and Results
This section describes how to properly connect, set up, and use the TPS54229EVM-056. The section also
includes test results typical for the evaluation modules and efficiency, output load regulation, output line
regulation, load transient response, output voltage ripple, input voltage ripple, start-up, and switching
frequency.
4.1 Input/Output Connections
The TPS54229EVM-056 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 is 2 A.
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. TP8 is used to monitor the output
voltage with TP9 as the ground reference.
Table 4. Connection and Test Points
Reference Designator Function
J1 V
IN
(see Table 1 for V
IN
range)
J2 V
OUT
, 1.05 V at 2 A maximum.
JP1 EN control. Connect EN to OFF to disable, connect EN to ON to enable.
TP1 V
IN
test point at V
IN
connector.
TP2 GND test point at V
IN
connector.
TP3 EN test point.
TP4 Loop response measurement test point.
TP5 VREG5 test point.
TP6 Switch node test point.
TP7 Analog ground test point.
4
TPS54229EVM-056, 2-A, SWIFT™ Regulator— Evaluation Module SLVU493–October 2011
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