SLUS557G March 2003 – December 2016 UC28023 , UC28025
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
The UC28023 and UC28025 operate from an external bias supply. TI recommends powering the device from a regulated auxiliary supply. (This device is not intended to be used from a bootstrap bias supply. A bootstrap bias supply is fed from the input high voltage through a resistor with sufficient capacitance on VCC to hold up the voltage on VCC until current can be supplied from a bias winding on the boost inductor. For that reason, the minimal hysteresis on VCC would require an unreasonable value of hold-up capacitance.)