Step-Up IC For EL Backlights MM1365 MITSUMI Step-Up IC For EL Backlights Monolithic IC MM1365 Outline This is a step-up IC developed for use in EL backlights. Because of their ability to light the entire panel uniformly, EL backlights are gradually becoming more widespread compared with LEDs. In particular, recently there has been a strong tendency toward smaller sizes and lighter weights, and more manufacturers are adopting ICs in place of transformers to step up voltages. This IC was designed to meet these market needs. Features 1. Low-voltage driving possible 2. Brightness can be adjusted 3. Can be driven using a small coil 4. On/off control possible VIN=0.95V min. The brightness can be adjusted by changing the oscillation frequency through the externally mounted capacitance Coil inductance of about 820µH required Current consumption while off=10µA or less Package VSOP-8 Applications 1. 2. 3. 4. Pagers Portable phones, PHS Wristwatches Display components of remote-controlled minidiscs, CD players, headphone stereos, other equipment Pin Assignment 8 1 7 2 6 3 5 4 1 GND 2 N.C 3 CT1 For setting discharge frequency 4 CT2 For setting charging frequency 5 Power supply switch 6 VCC 7 O2 8 O1 VSOP-8 GND H to turn on, L to turn off Power supply pin Charging frequency setting; drives external transistor Discharge frequency setting; drives external transistor Step-Up IC For EL Backlights MM1365 MITSUMI Absolute Maximum Ratings Item Symbol Ratings Units Storage temperature TSTG -40~+125 °C Operating temperature TOPR -20~+75 °C Power supply voltage VCC max. -0.3~+6 V Operating power supply voltage VCCOP 0.95~+6 V Voltage applied to O1, O2 output pins VO max. -0.3~VCC V Allowable loss Pd 300 mW Electrical Characteristics Item Consumption current for complete circuit 1 (under recommended circuit operating conditions for EL) Consumption current for 2 IC only (under recommended circuit operating conditions for EL) Current consumption 3 (entire circuit off) O1 pin output current (charge signal) O1 pin sync current (charge signal) O2 pin output current (discharge signal) CT1 charge current (Discharge setting pin) CT2 charge current (charge setting pin) CT1 pin "H" threshold CT2 pin "H" threshold CT1 pin "L" threshold CT2 pin "L" threshold Charge signal oscillation frequency (CT2 measurement) (Except where noted otherwise, Ta=25°C, VCC=1.5V, VCONT=1.5V) Symbol Measurement circuit Measurement conditions ICC1 1 C1=39nF, C2=1.5nF SW1 OFF, SW2 ON 15 25 35 ICC2 1 C1=39nF, C2=1.5nF SW1 ON, SW2 OFF 1.3 2.5 4.5 mA ICC3 1 VCONT=0V, SW1 ON, SW2 OFF ISOU1 2 ISIN 2 ISOU2 2 ICT1 2 ICT2 2 VTHH1 VTHH2 VTHL1 VTHL2 1 1 1 1 fct2 1 Min. Typ. Max. Units 1.0 VO1=0V, VCT1=0.8V 25 50 75 O1 output current measurement VCT1=0V, VO1=0.3V 1.00 2.50 VCT2=0V VCT1=0V, VCT2=0V VCT1=0.3V, CT2=OPEN CT1 output current VCT1=0V, VCT2=0.3V CT2 output current SW1 OFF, SW2 ON SW1 OFF, SW2 ON SW1 OFF, SW2 ON SW1 OFF, SW2 ON C1=39nF, C2=1.5nF SW1 OFF, SW2 ON mA µA µA mA 1.00 1.80 3.00 mA 1.2 2.0 2.7 µA 10 18 25 µA 0.65 0.65 0.15 0.18 V V V V 20 kHz Step-Up IC For EL Backlights MM1365 MITSUMI Block Diagram/Application Circuits Note 1: C3 is a capacitance used to suppress abnormal voltages at the O1 pin due to the coil. Note 2: The O2 frequency and O1 frequency are set to 20 kHz and 100 Hz respectively. Measuring Circuit Measuring Circuit 1 Step-Up IC For EL Backlights MM1365 MITSUMI Measuring Circuit 2 Timing Chart 1.5V VCC 1.5V CONT 0V 0V fCT2 Unsettled VTHH2 CT2 VTHL2 02 fCT1 VTHH1 CT1 VTHL1 01 VELOUT Characteristics O1, O2 capacitances vs. frequency O1 pin frequency O2 pin frequency 1000 O2 pin Oscillation frequency (charging) 10000 1000 Frequency (Hz) Frequency (Hz) 1000000 100 10 0.1 1 Capacitance (nF) 10 O1 pin Oscillation frequency (charging) 1 10 100 Capacitance (nF) 1000