JAJSJZ4B October 2020 – June 2024 TPS54J061
PRODUCTION DATA
The TPS54J061 has an internal 3-V LDO feature using input from VIN and output to VCC. When the VIN voltage rises above VINUVLO rising threshold (typically 2.4 V), and the EN voltage rises above the enable threshold (typically 1.22 V), the internal LDO is enabled and outputs voltage to the VCC pin. The VCC voltage provides the bias voltage for the internal analog circuitry. The VCC voltage also provides the supply voltage for the gate drives.
When the EN pin voltage rises above the enable threshold voltage, and VCC rises above the VCCUVLO rising threshold (typically 2.85 V), the device enters the start-up sequence. The device then uses the first 400-μs to calibrate the MODE setting resistance attached to the MODE pin and sets the switching frequency internally. During this period, the MODE pin resistance determines the operation mode too. The device remains in the disabled state when the EN pin floats due to an internal pulldown resistance with a nominal value of 6.5 MΩ.
There is an internal 2-µs filter to filter noise on the EN pin. If the pin is held low longer than the filter, then the IC shuts down. If the EN pin is taken high again after shutdown, then the sequence begins as if EN is taken high for the first time.