Figure 5-1. (CH1) Cut Trace Underneath R6
Figure 5-2. (CH2) Cut Trace Underneath R20
5.4 Overcurrent Limit and Discharge Selection
The overcurrent limit threshold and discharge function can be set by the TRIP pin using JP1 on the EVM.
Default setting is 60 mV and discharge enabled.
Table 5-5. TRIP/ Discharge Mode Selection
Jumper (JP2) set to
TRIP
VOCL
Discharge
Top (1-2 pin shorted)
GND
31 mV
Enabled
Second (3-4 pin shorted)
VREF2
31 mV
Disabled
Third (5-6 pin shorted)
VREG3
60 mV
Disabled
Bottom (7-8 pin shorted)
VREG5
60 mV
Enabled
5.5 Control Mode and Protection Selection
The control mode and protection function can be set by the FUNC pin using JP2 on the EVM.
Default setting is current mode and UVP/OVP-enabled.
Table 5-6. Control Mode/OVP Selection
Jumper (JP2) set to
FUNC
Mode
OVP
Top (1-2 pin shorted)
GND
Current
Enabled
Second (3-4 pin shorted)
VREF2
D-CAP
Disabled
Third (5-6 pin shorted)
VREG3
D-CAP
Enabled
Bottom (7-8 pin shorted)
VREG5
Current
Disabled
5.6 Soft-Start Setting Selection
Output voltage soft-start time can be set by the ENx pin using some capacitors on the EVM.
Default setting is integrated soft start.
Table 5-7. Soft-Start Setting Selection
CH1 (C20)
CH2 (C7)
Integrated soft start
Open
(adding small bypass-capacitor; 100 pF)
Open (adding small bypass-capacitor; 100 pF)
External soft start
Put on
Put on
(1)
When external soft start is selected, add appropriate capacitor on C20 and/or C7.)
5.7 Output Voltage Adjustment
Output voltage is programmable by changing R2, R3, and R5 for CH1 and R21, R23, and R24 for CH2.
Default setting is 5 V for CH1 and 3.3 V for CH2.
Configuration
6
TPS51220 Buck Controller Evaluation Module User's Guide
SLVU251B – JUNE 2008 – REVISED FEBRUARY 2022
Copyright © 2022 Texas Instruments Incorporated