Texas Instruments TPS548A28, User Manual

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Introduction
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4 SLVUBO0A – March 2020 – Revised May 2020
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Using the TPS54JA20EVM-023 12-A, Buck Converter Evaluation Module
1.3.2 Frequency and Operation Mode Setting
To change the frequency and operation mode of the part, the MODE pin is used. J6 and the surrounding
circuitry allows for an easy change to the frequency and operation mode setting. All 6 options offered by
J6 are shown in
Table 3
Table 3. TPS54JA20EVM Mode Pin Selection
Switching Frequency (F
SW
)
Operation Mode Under
Light Load
Mode Pin Connections
Connection Jumper Setting
600 kHz Skip Mode Short to VCC Short Pins 1 and 2
800 kHz Skip Mode 243k Ω +/- 10% to AGND Short Pins 3 and 4
1000 kHz Skip Mode 121k
Ω
+/- 10% to AGND Short Pins 5 and 6
1000 kHz Forced CCM 60.4k Ω +/- 10% to AGND Short Pins 7 and 8
800 kHz Forced CCM 30.1k Ω +/- 10% to AGND Short Pins 9 and 10
600 kHz Forced CCM Short to AGND Short Pins 11 and 12
1.3.3 Enable Pin Selection
The converter can be enabled and disabled by J5.
Default setting: EN pin connected to VIN.
Table 4. Enable Pin Selection
Set On Connection Enable Selection
Pins 2-3 Shorted EN pin connected to VIN pins through resistor divider
J3 Open EN pin is left floating
Pins 1-2 Shorted EN pin connected to PGND
1.3.4 Remote Sensing
The EVM is not set-up for remote sensing by default. To set up remote sensing follow these steps:
1. Replace R8 and R11 with 100 Ω resistors
2. Connect your sense points to the Vsns+ and Vsns- test points
1.3.5 Adjustable UVLO
The undervoltage lockout (UVLO) can be adjusted externally using R2 and R9. See the TPS54JA20 Data
Sheet to get detailed instructions for setting the external UVLO.