Test Procedure for the NCV887720BSTGEVB Evaluation Board Operational Guidelines The demo board is rated to operate full load (2.5 A) for an input voltage as low as 3.75 V at the input terminal under full power. The DISB pin is rated 6 V maximum and is TTL compatible. - A ‘0’ state disables the power supply. A ‘1’ state enables the power supply. Notes: 1- Limit time spent with the power supply operating at minimum input voltage (PCB VIN = 3.75 V) to avoid overheating the power semiconductors. Test Procedure: 1. 2. 3. 4. 5. 6. 7. Connect a DC source voltage (15 A capable) set to a voltage of 13-14 V as shown in Fig. 1. Connect the DISB TTL control signal as shown in Fig. 1. The initial DISB state should be set to logic-‘0’. Connect a 2.5 A constant current load on the output. Decrease the DC input voltage until the PCB VIN voltage is 5.5V + 0.5V. Set the DISB control signal to a TTL high state (i.e. 5 V). Verify that the unit is regulating at VOUT = 10.0 V. Reduce the DC input voltage until the PCB VIN = 3.75 V. Verify that the unit is regulating at VOUT = 10.0 V. DISB Command (TTL) DISB VOUT GND VIN 2.5 A Constant Current Load NCV887720 10 V / 2.5 A Demo Board DC Source (15 A capable) GND GND Figure 1. Demo Board Connections 6/17/2014 1 www.onsemi.com