RT9378 RICHTEK [Richtek Technology Corporation], RT9378 Datasheet
RT9378
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RT9378 Summary of contents
Page 1
... The RT9378 WLED driver with auto mode selection of x1, x1.5 and x2 mode with low dropout voltage in current sources. The RT9378 can power white LEDs with regulated constant current for uniform intensity. Each channel (LED1 to LED4) can support up to 25mA. ...
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... RT9378 Functional Pin Description Pin No. Pin Name 1 C1N 2 GND 13 (Exposed Pad) 3 C1P 4 C2P 5 VIN LED1 8 LED2 9 LED3 10 LED4 11 VOUT 12 C2N Function Block Diagram VIN EN GND www.richtek.com 2 Fly Capacitor 1 Negative Connection. Ground Pin. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation ...
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... UVLO I x1 Mode 4.5V SHDN 25mA LEDx I = 25mA LEDx f OSC Minimum Turn On > 20μ 100mA, I OUT LEDx I = 100mA, I OUT LEDx V – OUT RT9378 = 15mA 25°C, unless otherwise specified) A Min Typ 2 100 -- 1 -- 0.4 −5 0 − 25mA -- 3.6 = 25mA -- 200 -- ...
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... RT9378 Parameter Enable EN Low Time for Shutdown Logic-Low EN Threshold Voltage Logic-High EN Pull Low Current Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied ...
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... LED Current vs. Input Voltage 30 28.5 27 25.5 24 22.5 21 19.5 18 16.5 15 2.8 3 3.2 3.4 3.6 3.8 4 Input Voltage (V) x2 Mode Quiescent Current vs. Input Voltage 4 3.75 3.5 3.25 3 2.75 2.5 2.25 2 1.75 1.5 1.25 1 2.8 3 3.2 3.4 3.6 3.8 4 Input Voltage (V) x1 Mode Inrush Current Response V = 3.7V IN OUT Time (100μs/Div) RT9378 LED1 LED2 LED3 LED4 LED V = 3.42V F 4.2 4.4 4.6 4.8 5 4.2 4.4 4.6 4.8 5 www.richtek.com 5 ...
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... RT9378 x1.5 Mode Inrush Current Response (5V/Div) V OUT (2V/Div) C2P (2V/Div (200mA/Div) Time (100μs/Div) x1 Mode Dimming Operation EN (2V/Div) I LED (10mA/Div) Time (1ms/Div) www.richtek.com 6 x2 Mode Inrush Current Response (5V/Div) V OUT (2V/Div) C2P (2V/Div (200mA/Div (50mV/Div) ...
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... LED connection The RT9378 supports white LEDs. The 4 LEDs are connected from VIN to pin7 and 10 respectively. If the LED is not used, the LED pin should be connected to VIN directly ...
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... P D(MAX) WQFN-12L 2x2 packages The maximum power dissipation depends on operating ambient temperature for fixed T resistance θ . For RT9378 packages, the Figure derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. 0.8 0.7 ...
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... V IN and connected to ground plane. The trace of VIN in the PCB should be placed far away the sensitive devices or shielded by the ground. Figure 2. PCB Layout for RT9378 RT9378 All the traces of LED pins running from chip to LEDs should be wide and ...
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... RT9378 Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time ...