BP5311XA

DC / DC converter for LCDs BP5311A / BP5311XA The BP5311A and BP5311XA are DC / DC converters for supplying power to liquid crystal display (LCD) panels. The modules supply a positive voltage for LCDs from a logic circuit power supply (+5). They are available in a single in-line package as an upright (BP5311A) or L-shaped lead (BP5311XA) type. Applications LCD panels in personal computers and word processors. Features 1) High conversion efficiency 2) Built-in protection circuit 3) Built-in ON/OFF switch. 4) Compact and light. 5) Surface mounting is possible because parts are concentrated on one side. 6) Available as an upright or L-shaped lead type. Absolute maximum ratings (Ta=25°C) Parameter Power supply voltage Symbol Limits Unit VIN 7 V Operating temperature range Topr 0~60 °C Storage temperature range Tstg −30~+85 °C Block diagram CURRENT SENSOR TRANSFORMER SW CTRL CONTROL CIRCUIT 9 8 7 4 3 2 1 VIN VCTL GND GND Vref VOUT Co ON / OFF 1/4 BP5311A / BP5311XA Pin descriptions Pin No. Pin name Function 1 Co Output smoothing capacitor connection pin ; connect a low-impedance capacitor with a recommended capacitance of 47µF between this and GND. 2 VOUT Output pin. 3 Vref Output voltage adjustment pin for contrast ; output voltage is adjusted by connecting a resistor between pins 2 and 3 or pins 3 and 4. 4, 7 GND Ground pin. 8 VCTL Output ON/OFF control pin ; output starts when the pin is HIGH level, and stops when the pin is LOW or OPEN. 9 VIN Input pin ; connect a low-impedance capacitor with a recommended capacitance of 100µF between this pin and GND. Electrical characteristics (unless otherwise noted, Ta=25°C, VCTL=5V, R1~R2 resistors are disconnected) Parameter Symbol Min. Typ. Max. Unit Conditions VIN 4.5 5.0 5.5 V − mA Input voltage Output current IOUT − − 25 Output voltage VOUT1 28.0 29.5 31.0 Output voltage when OFF − V VIN=4.5~5.5V, IOUT=0~25mA VIN=4.5~5.5V, VCTL=0V VIN=5V, IOUT=20mA ∗ VOUT2 − − 0.3 V Ripple noise voltage ν1 − 100 200 mVP-P Efficiency η 67 77 − % VIN=5V, IOUT=20mA ON / OFF CTL voltage when ON VCTL 1.5 − − V VIN=5V, Vo>28V ON / OFF CTL voltage when OFF VCTL − − 0.5 V VIN=5V, Vo