Schematic for the NCP690, 1A, Adjustable Output Voltage LDO Demonstration Board *R1, R2 – Please choose proper values for required output voltage option To Calculate the values of R1, R2 for chosen Vout please use the following equation: Vout=1.25(1+R1/R2) NCP690, 1A, Adjustable Output Voltage LDO Schematic View 06-MAY-09 Page 1 of 2 www.onsemi.com Schematic for the NCP690, 1A, Adjustable Output Voltage LDO Demonstration Board The table below shows the example values of R1, R2 resistors for some typical Output Voltages: Desired Output Voltage [V] 1.50 1.80 2.50 2.70 3.30 3.60 5.00 Feedback Resistors Set Output Output Voltage Resistor Divider R1 [kΩ] R2 [kΩ] Voltage [V] Error [mV] Current IDIV [µA] 2 10 1.5000 125 0 1.6 3.6 1.8055 347 + 5.5 9.1 9.1 2.5000 137 0 3.9 3.3 2.7300 378 + 27.3 15 9.1 3.3104 137 + 10.4 6.8 3.6 3.6111 347 + 11.1 30 10 5.0000 125 0 Please also note that the feedback resistors should be chosen to satisfy the minimum output current requirement, which is 100µA. 06-MAY-09 Page 2 of 2 www.onsemi.com