BP5319 / BP5319X Power Module DC/DC converter for LCDs BP5319 / BP5319X The BP5319, BP5319X is a DC/DC converter designed for driving liquid crystal displays(LCDs). If this module is used, a negative power supply for LCD can be made of the power supply easily 5V. !Applications A power supply for the LCD panels in copiers, facsimile, personal computers, word processors, musical instrument, and units. !Features 1) High accurate output voltage (-24V±0.75V). 2) High conversion efficiency (75%Typ). 3) An output voltage can be changed by the external resistor. 4) Built-in protect 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=25°C) Parameter Symbol Input voltage VIN Output current Io ON/OFF control voltage VCTL Operating temperature Topr Storage temperature Tstg Limits 7 30 7 -10∼+60 -30∼+85 Unit V mA V °C °C BP5319 / BP5319X Power Module !Electrical characteristics (Unless otherwise noted, Ta=25°C) Symbol Parameter Min. Typ. Input voltage VIN 4.5 Output current IOUT Out put voltage VOUT -24.75 -24.00 Line regulation ∆V1 Load regulation ∆V2 Output voltage temperature -10 ∆Vt Coefficient Ripple noise voltage ν1 Conversion efficiency 70 75 η ON/OFF CTL voltage when OFF VCTL 2.0 ON/OFF CTL voltage when ON VCTL - Max. 5.5 30 -23.25 0.24 0.24 - Unit V mA V V V mV/°C Conditions VIN=5V, IOUT=25mA VIN=4.5∼5.5V, IOUT=25mA VIN=5V, IOUT=0∼25mA VIN=5V, IOUT=25mA*2 150 0.5 mVP-P % V V VIN=5V, IOUT=25mA*1 VIN=5V, IOUT=25mA VIN=5V VIN=5V (Alternatively, when Open) ON/OFF CTL input current Current consumption when OFF ICTL IOFF - 100 - 150 0.5 µA mA VIN=4.5∼5.5V, VCTL=5V*2 VIN=4.5∼5.5V, VCTL=5V*2 R1 resistance R2 resistance R1 R2 50 50 - ∞ ∞ kΩ kΩ VIN=4.5∼5.5V, VCTL=5V*2 VIN=4.5∼5.5V, VCTL=5V*2 *1 Measured with a bandwidth of 20MHz. *2 Ta = -10~60°C !Pin descriptions Pin No, Pin name 1 Co 2 3 VOUT Vref 4.7 8 GND VCTL 9 VIN Function Output smoothing capacitor connection pin; connect a low-impedance capacitor with a recommended capacitance of 47µF between this pin and GND. Output pin Output voltage adjustment pin for contrast; output voltage is adjusted by connecting a resistor between pins 2 and 3 or pins 3 and 4. Ground pin. pins 4 and 7 is internal connection. Output ON/OFF control pin; output starts when the pin is LOW level or OPEN, and stops when the pin HIGH level. Input pin; connect a low-impedance capacitor with a recommended capacitance of 100µF between this pin and GND. BP5319 / BP5319X Power Module !Measurement circuit !Operation notes (1) Place I/O external capacitors as near as possible to the connection pins. In particular, make sure to minimize the impedance between the input-side capacitor(C1)and pin 9 (Reference value: A length less than 50mm for a copper foil of 1.0mm wide and 35µm thickness). (2) Avoid frequent switching using the ON/OFF CTL pin (four times per second at the maximum). !Application example (1) When increasing the output voltage (A minus side). (2) When reducing the output voltage (It is drawn to the zero electric potential wear). BP5319 / BP5319X Power Module !Electrical characteristic curves Fig.2 Use possibility range !External dimensions (Units: mm) Fig.3 Output voltage vs. Feedback resistance (R1, R2) Fig.4 Output voltage vs. Feedback resistance (R2<100kΩ)