SNVU769A September 2021 – October 2022
In its default configuration, connecting +12 V and GND to the VBAT terminal block (J33) will power up the EVM. While loading the regulators, ensure that input power supply has sufficient current source capabilities to avoid supply voltage collapse due to current limiting.
EVM can also be powered through external 3.3 V input supply or through USB power by modifying jumper settings on the EVM. Table 4-1 describes the jumper settings for different supply options.
| Power Source | Input Voltage Range | Jumpers |
|---|---|---|
| VBAT | 5 V - 20 V | Both 3V3_PREREG jumpers in J4 (Default option). Leave J5 open. |
| Vin 3.3V | 3.1 V - 3.5 V | Remove 3V3_PREREG jumpers on J4 and place them on 3V3_PS position on J4. With this configuration, do not apply power to VBAT terminal. Leave J5 open. |
| USB | 5 V USB cable | J5, 3V3_USB. With this option, jumpers on J4 must be removed. |
The LP877451Q1EVM does not require any specific power-down sequence. The EVM can be powered down by turning off the power supply or by toggling the EN Pin off in the GUI, if the GUI control signal is used to enable/disable the device. Refer to Table 3-2 and GUI section for more information about configuring jumpers and using GUI.