LT8391A 60V 2MHz Synchronous 4-Switch Buck-Boost LED Driver Controller FEATURES DESCRIPTION n 4-Switch Single Inductor Architecture Allows V The LT 8391A is a synchronous 4-switch buck-boost LED IN Above, Below or Equal to V controller that regulates LED current from input voltage OUT n Up to 95% Efficiency at 2MHz above, below, or equal to the output voltage. The propri- n Proprietary Peak-Buck Peak-Boost Current Mode etary peak-buck peak-boost current mode control scheme n Wide V Range: 4V to 60V allows adjustable and synchronizable 600kHz to 2MHz IN n Wide V Range: 0V to 60V (51V LED) fixed frequency operation, or internal 25% triangle spread OUT n 3% LED Current Accuracy spectrum operation for low EMI. With 4V to 60V input, n 2000:1 External and 128:1 Internal PWM Dimming 0V to 60V output, and seamless low noise transitions n High Side PMOS PWM Switch Driver between operation regions, the LT8391A is ideal for LED n No Top MOSFET Refresh Noise in Buck or Boost driver and battery charger applications in automotive, n Adjustable and Synchronizable: 600kHz to 2MHz industrial, and battery-powered systems. n Flicker-Free Spread Spectrum for Low EMI The LT8391A provides both internal (up to 128:1) and n Open and Short LED Protection with Fault Reporting external (up to 2000:1) LED current PWM dimming with n Available in 28-Lead TSSOP with Exposed Pad and a high-side PMOS switch. Two CTRL pins provide flexible 28-Lead QFN (4mm 5mm) 20:1 analog dimming with 3% LED current accuracy at n AEC-Q100 Qualified for Automotive Applications 100mV full scale. Fault protection is provided to detect an open or short LED condition, during which the LT8391A APPLICATIONS retries, latches off, or keeps running. n All registered trademarks and trademarks are the property of their respective owners. Automotive Head Lamps/Running Lamps n High Frequency LED Lighting TYPICAL APPLICATION 94% Efficient 24W (16V, 1.5A) 2MHz Buck-Boost LED Driver 2.2H V 6m IN 6V TO 32V CONTINUOUS 4V TO 56V TRANSIENT 10F 4.7F 0.1F 0.1F 22F SW1 LSP LSN SW2 100V 25V 63V 2 BST1 BST2 2 Efficiency vs V IN 100 INTV INTV CC CC BG1 BG2 95 GND 90 TG1 TG2 V LT8391A V IN OUT 85 1F 1F 383k 1M 48.7k 80 EN/UVLO FB SSFM OFF 165k 75 ISP SYNC/SPRD SSFM ON INTV CC 56m 70 INTV CC ISN 4.7F 100k 65 PWMTG FAULT FAULT 60 ANALOG DIM CTRL1 PWM PWM DIM 0 5 10 15 20 25 30 35 40 45 100k INPUT VOLTAGE (V) V REF 8391a TA01b 0.47F 90.9k 16V PWM SETTING CTRL2 RP 1.5A LEDs 113k SS V RT C EXT INT 59.0k 4.7k 22nF 2MHz 300k 3.3nF 488Hz 8391a TA01a Rev. A 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8391A ABSOLUTE MAXIMUM RATINGS (Note 1) V , EN/UVLO, V , ISP, ISN ...................................60V Operating Junction Temperature Range (Notes 2, 3) IN OUT (ISP-ISN) .........................................................1V to 1V LT8391AE .......................................... 40C to 125C BST1, BST2 ...............................................................66V LT8391AI ........................................... 40C to 125C SW1, SW2, LSP, LSN .................................... 6V to 60V LT8391AH .......................................... 40C to 150C INTV , (BST1-SW1), (BST2-SW2) .............................6V LT8391AJ ........................................... 40C to 150C CC (BST1-LSP), (BST1-LSN) ............................................6V Storage Temperature Range .................. 65C to 150C FB, PWM, SYNC/SPRD, CTRL1, CTRL2, FAULT ...........6V PIN CONFIGURATION TOP VIEW TOP VIEW 1 28 BG2 BG1 2 27 BST2 BST1 3 26 SW2 SW1 28 27 26 25 24 23 4 25 TG2 TG1 TG1 1 22 TG2 5 24 V LSP OUT LSP 2 21 V OUT 6 23 PWMTG LSN LSN 3 20 PWMTG 7 22 SYNC/SPRD V IN 29 V 4 29 19 SYNC/SPRD IN GND GND 8 21 RT INTV INTV 5 18 RT CC CC 9 20 V EN/UVLO 6 17 EN/UVLO V C C 10 19 FB RP 7 16 FB RP PWM 8 15 SS 11 18 SS PWM 9 10 11 12 13 14 12 17 FAULT V REF 13 16 CTRL2 CTRL1 14 15 ISN ISP UFD PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN FE PACKAGE 28-LEAD PLASTIC TSSOP = 43C/W, = 3.4C/W JA JC EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB = 30C/W, = 5C/W JA JC EXPOSED PAD (PIN 29) IS GND, MUST BE SOLDERED TO PCB Rev. A 2 For more information www.analog.com V SW1 REF CTRL1 BST1 ISP BG1 ISN BG2 CTRL2 BST2 FAULT SW2