HPL5331

The HPL5331 linear regulator is designed to provide a regulated voltage with bi-directional output current for DDR-SDRAM termination. It integrates two power transistors to source or sink current up to 3A. It also incorporate current-limit, thermal shutdown and shutdown control functions into a single chip. Current- limit circuit limits the short-circuit current.

On-chip thermal shutdown provides protection against any combination of overload that would create excessive junction temperature. The output voltage of HPL5331 track the voltage at VREF pin. A resistor divider connected to VIN, GND and VREF pins is used to provide a half voltage of VIN to VREF pin. In addition, an external ceramic capacitor and an opendrain transistor connected to VREF pin provides softstart and shutdown control respectively. Pulling and holding the VREF to GND shuts off the output. The output of HPL5331 will be high impedance after being shut down by VREF or thermal shutdown function.