DC / DC converter for LCDs BP5319 / BP5319X The BP5319 and BP5319X are DC / DC converters for supplying power to liquid crystal displays (LCDs) panels. These modules supply a negative voltage from power supply of 5V. They are available in a single in-line package as an upright (BP5319) or L-shaped lead (BP5319X) type. Applications LCD panels in copiers, facsimiles, personal computers, word processors, instruments, and other displays Features 1) Accurate output voltage. (24V0.75V) 2) High conversion efficiency. (typically 75%) 3) The external resistor can change an output voltage. 4) Built-in protection circuit. 5) Built-in ON/OFF switch. 6) Compact and light. 7) Available as an upright or L-shaped lead type. Absolute maximum ratings (Ta=25C) Parameter Symbol Limits Unit Input voltage VIN 7 V Output current Io 30 mA ON / OFF CTL voltage VCTL 7 V Operating temperature range Topr 10~+60 C Storage temperature range Tstg 30~+85 C 1/5 BP5319 / BP5319X Pin descriptions Pin No. Pin name Function Output smoothing capacitor connection pin connect a 1CO low-impedance capacitor with a recommended capa- citance of 47 F between this pin and GND. 2VOUT Output pin Output voltage adjustment pin for contrast output voltages is adjusted by connecting a resistor between pins 2 and 3 3 Vref or pins 3 and 4. 4, 7 GND Ground pin pins 4 and 7 are internal connection. Output ON / OFF control pin output starts when the pin is 8 VCTL LOW level or OPEN, and stops when the pin HIGH level. Input pin connect a low-impedance capacitor with a recom- 9VIN mended capacitance of 100mF between this pin and GND. Electrical characteristics (Unless otherwise noted, Ta=25C) Parameter Symbol Min. Typ. Max. Unit Conditions Input voltage VIN 4.5 5.5 V Output current IOUT 30 mA Output voltage VOUT 24.75 24.00 23.25 V VIN=5V, IOUT=25mA Line regulation V1 0.24 V VIN=4.5~5.5V, IOUT=25mA Load regulation V2 0.24 V VIN=5V, IOUT=0~25mA Output voltage temperature coefficient Vt 10 mV / C VIN=5V, IOUT=25mA 2 Ripple noise voltage 1 150 mVPP VIN=5V, IOUT=25mA 1 Conversion efficiency 70 75 % VIN=5V, IOUT=25mA ON / OFF CTL voltage when OFF VCTL 2.0 V VIN=5V ON / OFF CTL voltage when ON VCTL 0.5 V VIN=5V (Alternatively, when Open) ON / OFF CTL input current ICTL 100 150 A VIN=4.5~5.5V, VCTL=5V 2 Current consumption when OFF IOFF 0.5 mA VIN=4.5~5.5V, VCTL=5V 2 R1 resistance R1 50 k VIN=4.5~5.5V, VCTL=5V 2 R2 resistance R2 50 k VIN=4.5~5.5V, VCTL=5V 2 1 Measured with a bandwidth of 20MHz. 2 Ta=10~60C 2/5