Texas Instruments TPS563211, User Manual

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3.2 Output Voltage Setpoint
The output voltage is set with a resistor divider from the output node to the FB pin. TI recommends using 1%
tolerance or better divider resistors. Referring to the application schematic of
Figure 6-1 , start with a 10 kΩ or 20
kΩ for R9 and use Equation 1 to calculate R8. To improve efficiency at light loads, consider using larger value
resistors. If the values are too high, the regulator is more susceptible to noise and voltage errors from the FB
input current are noticeable.
8 9
OUT REF
REF
V V
R R
V
˜
(1)
Table 3-2 lists the R8 and R9 values for some common output voltages. Note that the values given in Table 3-2
are standard values and not the exact value calculated using above equation.
Table 3-2. Recommended Component Values
OUTPUT VOLTAGE
(1)
(V) R8
(2)
(kΩ) R9 (kΩ) L1
(3)
(µH) C
OUT
(4)
(µF)
RANGE of L1·C
OUT_E
(5)
(μH × μF)
0.76 5.36 20.0 1 3 × 22 60 to 160
1.05 15.0 20.0 1.5 2 × 22 60 to 160
1.8 40.0 20.0 2.2 2 × 22 50 to 200
2.5 31.6 10.0 3.3 2 × 22 50 to 200
3.3 45.3 10.0 3.3 2 × 22 50 to 200
5 73.2 10.0 4.7 2 × 22 50 to 200
(1) Please use the recommended L1 and C
OUT
combination of the higher and closest output rail for the unlisted output rails.
(2) R8 = 10 kΩ and R9 = Float for V
OUT
= 0.6 V.
(3) Inductance values are calculated based on V
IN
=18 V, but they can also be used for other input voltages. Users can calculate their
preferred inductance value per TPS563211 datasheet.
(4) The C
OUT
is the sum of nominal output capacitance. 22-uF, 0805, 10-V or higher specficications capacitors are are recommended .
(5) The C
OUT_E
is the effective value after derating, the value of L1·C
OUT_E
should be within in the range.
4 Test Setup
This section describes how to properly connect, set up, and use the TPS563211EVM.
4.1 Input/Output Connections
The TPS563211EVM is provided with input/output connectors and test points as shown in Table 4-1 . Figure 4-1
shows connectors and jumpers placement on TPS563211EVM board.
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 J2 through a pair of 20-AWG wires. The maximum load current capability is 3 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. TP3 is used to monitor the output voltage with TP4
as the ground reference.
www.ti.com Modifications
SLUUCC6 – SEPTEMBER 2020
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TPS563211 18-V Input, 3-A Output, 600-kHz, Synchronous Buck Converter
SOT583 Evaluation Module
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