AT9932 Automotive Boost-Buck LED Lamp Driver IC Features General Description Constant Output Current The AT9932 is an advanced fixed-frequency PWM controller IC designed to control an LED lamp driver Steps Output Voltage Up or Down using a boost-buck topology that can step the input Very Low Susceptibility to Input Voltage voltage up or down automatically. The IC provides fast Transients output current transient response and very low Frequency Jitter susceptibility to input voltage transients. This allows the Externally Programmable Fixed Switching lamp driver to pass the rigorous electrical transient Frequency requirements of SAE J1455 or ISO 7637-2, making the Temperature Foldback with External NTC AT9932 an ultimate solution for automobile lighting. Resistor Capacitive isolation protects the LED Lamp from failure of the switching MOSFET. Internal 40V Voltage Regulator +/1A MOSFET Gate Driver The AT9932 features a unique feed-forward current control scheme, differential output current sensing, soft Short LED Protection start and protection from short or open LED load. Open LED Protection Switching frequency can be programmed with a single Input Undervoltage Lockout Protection external resistor. Enable and PWM Dimming The AT9932 includes a temperature foldback of the 3% Accurate Trimmed Reference output current using an external NTC resistor. This AEC-Q100 Compliant feature allows optimization of the light output of the LED load for safe operation over the entire operating Applications temperature range. Automobile Lighting Battery-Powered LED Lamps Other Low-Voltage AC/DC or DC/DC LED Drivers Package Type 24-lead TSSOP (Top view) 1 24 VIN REF AVDD UVLO PVDD NC GATE NC PGND DRP GND FB JTR COMP RT SS FFN PWMD FFP FLT T2 DIV T1 NTC See Table 2-1 for pin information. 2018 Microchip Technology Inc. DS20005789A-page 1AT9932 Functional Block Diagram VIN 4.25V/ Regulator Current Mirror 2 - S/D: I > 3I + 6I 4.50V REF NTC T1 T2 Recovery: I < 3I T1 NTC T1 AVDD + I T1 + I FLT T2 NTC I T2 - Reset DIV + + UVLO 1.05V/ - - 1.25V POR NTC 4 (I - 3I ) NTC T1 OSC RT 30 0.7V - + DRP JTR Jitter g 0.7V PVDD m - S - GATE + FB RQ + PGND COMP PWMD I N 15 A I - I N P FFN Current SS Mirror 1 Reset Reset FFP GND I P DS20005789A-page 2 2018 Microchip Technology Inc.