ZHCSM35F January 2007 – May 2021 LM5002
PRODUCTION DATA
The 12-V automotive SEPIC converter shown in Figure 8-9 uses the internal bandgap voltage reference for the regulation setpoint. The output is 12 V at 25 mA while the input voltage can vary from 3.1 V to 60 V. The output current rating can be increased if the minimum VIN voltage requirement is increased. The switching frequency is set to 750 kHz. The internal VCC regulator provides 6.9-V bias power for the LM5002. The output voltage can be used as an auxiliary voltage if the nominal VIN voltage is greater than 12 V by adding a diode from the output into the VCC pin. In this configuration, the minimum input voltage must be greater than 12 V to prevent the internal VCC to VIN diode from conducting. If the applied VCC voltage exceeds the minimum VIN voltage, then an external blocking diode is required between the VIN pin and the power source to block current flow from VCC to the input supply.