BP5319X

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. (−24V±0.75V) 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=25°C) Parameter Input voltage Output current ON / OFF CTL voltage Operating temperature range Storage temperature range Symbol VIN Io VCTL Topr Tstg Limits 7 30 7 −10~+60 −30~+85 Unit V mA V °C °C 1/5 BP5319 / BP5319X Pin descriptions Pin No. 1 2 3 4, 7 8 9 Pin name CO VOUT Vref GND VCTL VIN Function Output smoothing capacitor connection pin; connect a low-impedance capacitor with a recommended capacitance of 47 µ F between this pin and GND. Output pin Output voltage adjustment pin for contrast; output voltages is adjusted by connecting a resistor between pins 2 and 3 or pins 3 and 4. Ground pin; pins 4 and 7 are 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 100mF between this pin and GND. Electrical characteristics Parameter (Unless otherwise noted, Ta=25°C) Symbol Min. Typ. Max. Unit V Conditions Input voltage Output current Output voltage Line regulation Load regulation Output voltage temperature coefficient Ripple noise voltage Conversion efficiency ON / OFF CTL voltage when OFF ON / OFF CTL voltage when ON VIN IOUT VOUT ∆V1 ∆V2 ∆Vt ν1 η VCTL VCTL 4.5 − −24.75 − − − − 70 2.0 − − − 50 50 − − −24.00 − − −10 − 75 − − 5.5 30 −23.25 0.24 0.24 − 150 − − 0.5 mA V V V VIN=5V, IOUT=25mA VIN=4.5~5.5V, IOUT=25mA VIN=5V, IOUT=0~25mA ∗2 ∗1 mV / °C VIN=5V, IOUT=25mA mVPP % V V µA mA kΩ kΩ VIN=5V, IOUT=25mA VIN=5V, IOUT=25mA VIN=5V VIN=5V (Alternatively, when Open) ON / OFF CTL input current Current consumption when OFF R1 resistance R2 resistance ∗1 Measured with a bandwidth of 20MHz. ∗2 Ta=−10~60°C ICTL IOFF R1 R2 100 − − − 150 0.5 VIN=4.5~5.5V, VCTL=5V ∗2 VIN=4.5~5.5V, VCTL=5V ∗2 VIN=4.5~5.5V, VCTL=5V ∗2 VIN=4.5~5.5V, VCTL=5V ∗2 ∞ ∞ 2/5 BP5319 / BP5319X Measurement circuit BP5319 / BP5319X 1 2 3 4 7 8 9 VIN VOUT ON / OFF SW C2 C3 + C1 VCTL + GND GND Fig.1 C1 : 100µF / 16V (Low-impedance capacitor) C2 : 47µF / 35V (Low-impedance capacitor) C3 : 0.022µF / 50V (Ceramic capacitor) Application example (1) When increasing the output voltage (to negative voltage side) (2) When reducing the output voltage (near to zero voltage) BP5319 / BP5319X BP5319 / BP5319X 1 2 R1 3 4 7 8 9 Be sure to use fuse for safety 1 2 3 R2 4 7 8 9 Be sure to use fuse for safety VOUT C2 GND ON / OFF + C1 VIN VOUT C2 ON / OFF + C1 VIN + GND GND + GND Note) Set up the change of the output voltage in the range of the territory(Fig.2) which can be used. 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 is recommended for a copper foil of 1.0mm wide and 35µm thick.) (2) Avoid frequent switching using the ON / OFF CTL pin (5 times per second at the maximum). 3/5 BP5319 / BP5319X Electrical characteristic curves −30 OUTPUT VOLTAGE : VO (V) −25 −20 −15 −10 −5 Unusable range Ta=60°C VIN OUTPUT VOLTAGE : VO (V) OUTPUT VOLTAGE : VO (V) =5 V ∗1. R1>50kΩ R1 2pin − 3pin R2