Datasheet AL8861Q (Diodes) - 2
| Manufacturer | Diodes |
| Description | High Efficiency 40V 1.5A Automotive Grade Buck LED Driver |
| Pages / Page | 15 / 2 — AL8861Q. Typical Applications Circuit. T C U D O R P. W E. Pin … |
| File Format / Size | PDF / 666 Kb |
| Document Language | English |
AL8861Q. Typical Applications Circuit. T C U D O R P. W E. Pin Descriptions. Pin Number. Pin Name. Function. Functional Block Diagram
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Text Version of Document
AL8861Q Typical Applications Circuit
VIN (4.5V to 40V)
T C U D O R P W E Pin Descriptions N Pin Number Pin Name Function
Connect resistor RS from this pin to VIN to define nominal average output current. 1 ISENSE IOUTNOM = 0.1/RS 2,3 GND Ground (0V) Multi-function On/Off and Brightness Control Pin: Leave floating for normal operation Drive voltage below 0.2V to turn off output current Drive with DC voltage (0.3V < VSET < 2.5V) to adjust output current from 0 to 100% of IOUTNOM. 4 VSET Linear adjustment range from 5% to 100% of IOUTNOM Drive with PWM signal from open-collector or open-drain transistor to adjust output current. Linear adjustment range from 1% to 100% of IOUTNOM for f < 500Hz Connect a capacitor from this pin to Ground to increase soft-start time. (Default soft-start time = 0.1ms. Additional soft-start time is approximately 1.5ms/1nF) 5, 6 LX Drain of NDMOS switch. 7 N/C No Connection Input voltage (4.5V to 40V). Decouple to Ground with 10μF or higher X7R ceramic capacitor close to 8 VIN device. Exposed Pad. Connect to GND and thermal mass for enhanced thermal impedance. Should not be used EP EP as electrical ground conduction path.
Functional Block Diagram
ISENSE LX 1 5, 6 8 VIN 4.5V VDD Current Current 4.5V Drv Generator Monitor Limiter Comp BG & Ref Hysteresis Logic & Reference Control PWM Driver PWM/DC PWM OTP VSET OTP 4 Dimming 2, 3 GND AL8861Q 2 of 15 May 2019 Document number: DS41798 Rev. 2 - 2
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© Diodes Incorporated
VIN (4.5V to 40V)
T C U D O R P W E Pin Descriptions N Pin Number Pin Name Function
Connect resistor RS from this pin to VIN to define nominal average output current. 1 ISENSE IOUTNOM = 0.1/RS 2,3 GND Ground (0V) Multi-function On/Off and Brightness Control Pin: Leave floating for normal operation Drive voltage below 0.2V to turn off output current Drive with DC voltage (0.3V < VSET < 2.5V) to adjust output current from 0 to 100% of IOUTNOM. 4 VSET Linear adjustment range from 5% to 100% of IOUTNOM Drive with PWM signal from open-collector or open-drain transistor to adjust output current. Linear adjustment range from 1% to 100% of IOUTNOM for f < 500Hz Connect a capacitor from this pin to Ground to increase soft-start time. (Default soft-start time = 0.1ms. Additional soft-start time is approximately 1.5ms/1nF) 5, 6 LX Drain of NDMOS switch. 7 N/C No Connection Input voltage (4.5V to 40V). Decouple to Ground with 10μF or higher X7R ceramic capacitor close to 8 VIN device. Exposed Pad. Connect to GND and thermal mass for enhanced thermal impedance. Should not be used EP EP as electrical ground conduction path.
Functional Block Diagram
ISENSE LX 1 5, 6 8 VIN 4.5V VDD Current Current 4.5V Drv Generator Monitor Limiter Comp BG & Ref Hysteresis Logic & Reference Control PWM Driver PWM/DC PWM OTP VSET OTP 4 Dimming 2, 3 GND AL8861Q 2 of 15 May 2019 Document number: DS41798 Rev. 2 - 2
www.diodes.com
© Diodes Incorporated
