Test Procedure for the NCP1256B60WGEVB Evaluation Board Equipment Required: 1. An ac source, delivering 80 V ac to 265 V ac, needed power is below 100 W. An electronic source or a simple variac can do. 2. An input ac watt-meter, up to 100 W 3. A dc load absorbing up to 100 W, Vin,max < 30 V, Iout,max < 5 A 4. Either the above load can display dc V and dc A or separated V and A-meters are necessary If the load does not use local Kelvin sensors, then the output voltage must be measured at the board level, not at the cable ends. Vcc OVP Enabled LED can be Turned Off Test Procedure: Test n°1: - Apply 90 V rms - No output current - Read output voltage: 18.5 V < Vout < 20 V -Apply 230 V rms -Repeat the above -Let the board warm up for 15 mn -Read input power, LED on 50 mW < Pin < 70 mW 3/10/2014 1 www.onsemi.com Test n°2: - Apply 90 V rms - Load with 3.2 A - Read output voltage and Pin: 18.5 V < Vout < 20 V 65 W < Pin < 75 W -Apply 265 V rms -Load with 3.2A -Repeat the above Test n°3: - Apply 90 V rms - Increase Iout while reading output voltage - At a certain point, Iout,max, Vout collapses, the converter hiccups (typical is 4.2 A) 3.9 A < Iout,max < 5 A -Apply 265 V rms -Repeat the above steps -The Iout,max points slightly increases Test n°4: - Apply 90 V rms - Apply a short-circuit at the output, usually via the dc load - Vout must collapse, the converter tries to re-start (hiccup mode). Read the input power (wattmeter in average mode) 5 W < Pin < 15 W -Apply 265 V rms -Repeat the above steps End Of Test 3/10/2014 2 www.onsemi.com