SNVU753A November 2019 – May 2021 TPS542A52
The operation of the TPS542A52 can be enabled or disabled using J3_2. The EN pin of the TPS542A52 is connected to J3_2-2 (pin 2 of J3_2) and TP14_2. The EN pin threshold is 1.2 V. By leaving J3_2-2 floating, a pullup current source internal to the TPS542A52 enables the device, and the device is operational across all valid input voltages (4 V - 18 V).
Undervoltage lockout (UVLO) can be implemented by connecting a jumper between J3_2-2 and J3_2-3. In this configuration, R12_2 and R15_2 should be populated according to the TPS542A52 device data sheet based on the desired UVLO requirements. By default, R12_2 and R15_2 are not populated.
The TPS542A52 can be disabled by pulling J3_2-2 (the EN pin) below 1.2 V. When J3_2-2 is brought below 1.2 V, the regulator stop switching and enters into a low power shutdown mode.
To externally control the EN pin of the TPS542A52, a control signal referenced to AGND (TP15_2, TP16_2, or TP17_2, recommended between 0 V and 5.5 V) can be connected directly to the EN_2 test point (TP14_2). Using this method, a jumper on J3_2 is not necessary.
The converter can be put into shutdown mode manually by connecting a jumper between J3_2-2 and J3_2-1, which grounds the EN pin.
Default setting: J3_2 open, EN floating for always-on operation.
J3_2 CONNECTION | ENABLE SELECTION |
---|---|
J3_2-2 floating | Device is enabled |
J3_2-2 and J3_2-3 shorted | UVLO implemented if R12_2 and R15_2 are populated - see data sheet for details |
J3_2-1 and J3_2-2 shorted | Converter is disabled |