DC1988A - Schematic6/26/2014
Demonstration circuit 1988A is a 2kV AC (3kVDC) isolated flyback μModule® DC/DC converter with LDO post regulator featuring the LTM8058. The demo circuit is designed for a 6V flyback output and a 5V post regulator output from a 4.5V to 30V input. The current capability of the 6V flyback output varies with input voltage from about 100mA at 4.5VIN to about 320mA at 30VIN. Figure 1 shows the typical maximum output current on VOUT1 when VOUT2 is not loaded. VOUT2 is the LDO post regulator from VOUT1. The current capability of VOUT2 is limited by either the current capability of VOUT1 minus VOUT1 loading or the 300mA current limit on the LDO post regulator itself. R1 provides the necessary minimum load current to keep the VOUT1 in regulation throughout the entire input voltage range. Please see the typical performance characteristic curves in the LTM8058 data sheet to determine the minimum load current for other input/output configurations.