White LED Driver MM3097
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Monolithic IC MM3097 Outline This IC is a white LED driver IC. It is a step-up DC-DC converter IC designed to drive up to 7 LEDs and suitable for backlight drivers. Feedback voltage is as low as 95mV, which can reduce power consumption in a current set resistor. A small 0.22µF capacitor can be used, so that not only space but costs can be reduced. Features 1. Enables to drive up to 7 white LEDs in a series connection 2. Input voltage range 2.5 to 6V 3. Shutdown current 0.1µA typ. 4. High efficiency 85% typ. 5. Luminance control PWM system 6. Feedback voltage 95mV Applications 1. Cell phones 2. Digital video cameras 3. Digital still cameras 4. Portable game devices 5. PDA • Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification. • The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

SHUTDOWN RAMP GENERATOR • Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification. • The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

Functions Switch pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI. GND pin. Feedback pin. Reference voltage is 95mV. Connect cathode of lowest LED and resistor. Shutdown pin. Tie to 1.5V or higher to enable device; 0.4V or less to disable device. Input supply pin. Must be locally bypassed. Absolute Maximum Ratings Item Symbol Ratings Units Storage temperature TSTG -65~+150 °C Operating temperature TOPR -40~+85 °C Input voltage VINMAX 8 V SW voltage VSWMAX 36 V FB voltage VFBMAX 8 V SHDN voltage VSHDNMAX 8 V Allowable loss PD 150 mW Note: Absolute Maximum...

(Except where noted otherwise Ta=+25°C, VIN=3V, VSHDN=3V) Item Feedback voltage FB pin bias current Supply current Switching frequency Maximum duty cycle Switch current limit Switch VCESAT Switch leakage current SHDN voltage high SHDN voltage low SHDN pin bias current fSW MaxDuty ISWLMT VCESAT ISWLEAK VSHDNH VSHDNL ISHDN Note: The MM3097 is guaranteed to meet specifications from 0°C to 70°C. Specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. (Except where noted otherwise Ta=+25°C,...

Measuring Circuit The following is recommended application for MM3097. Recommend application L: MITSUMI ELECTRIC C3-Y1.5R (22µH) SBD: PHILIPS PMEG4005AEA ZD: ROHM UDZS B (zener voltage > VOUT) LED: NICHIA NSCW215 No internal soft-start circuit is included in MM3097. The capacitor in left figure is recommended for MM3097 if necessity. Dimming control is possible with the PWM signal applied to the SHDN pin. The magnitude of the PWM signal should be higher than the SHDN voltage high. • Any products mentioned in this catalog are subject to any modification in their appearance and others for...

Characteristics Quiescent current Quiescent current Feedback bias current (nA) SHDN voltage SHDN hysteresis voltage Feedback bias current Switching frequency Switching frequency (MHz) Switching frequency SHDN hysteresis voltage (V) • Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification. • The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

SHDN pin bias current (µA) SHDN pin bias current • Any products mentioned in this catalog are subject to any modification in their appearance and others for improvements without prior notification. • The details listed here are not a guarantee of the individual products at the time of ordering. When using the products, you will be asked to check their specifications.

LED Current Control The LED current is controlled by the feedback resistor (R in Measuring Circuit). The feedback reference is 95mV, so the LED current is 95mV/R. ILED=95mV/R The relation between LED current and resistance R is shown in Table.1. Table.1 Selection of Resistance R ILED (mA) 5 10 12 15 20 Applications Information Inductor Selection A 22µH inductor is recommended for MM3097 applications. Small size and high efficiency are the major concerns for most applications. Inductors with low core losses and small DCR (copper wire resistance) at 1.2MHz are good choices for applications....