Automotive Boost-Buck Lamp Driver IC

    The AT9932 is an advanced fixed frequency PWM controller IC designed to control an LED lamp driver using a boost-buck topology that can step the input voltage up or down automatically. The IC provides fast output current transient response and very low susceptibility to input voltage transients, which allows the lamp driver to pass the rigorous ectrical transient requirements of SAE J1455 or ISO 7637-2, making the AT9932 an ultimate solution for automobile lighting. Capacitive isolation protects the LED Lamp from failure of the switching MOSFET.

    The AT9932 features a unique feed-forward current control scheme, differential output current sensing, soft start, protection from short or open LED load. Switching frequency can be programmed with a single external resistor. The AT9932 includes a temperature fold-back of the output current using an external NTC resistor. This feature allows maximizing the light output of the LED load over the entire operating temperature range.

AT9932主要特性：

    Constant output current

    Steps output voltage up or down

    Very low susceptibility to Input voltage transients

    Frequency jitter

    Externally programmable fixed switching frequency

    Temperature foldback with external NTC resistor

    Internal 40V voltage regulator

    +/-1A MOSFET gate driver

    Short LED protection

    Open LED protection

    Input undervoltage protection

    Enable & PWM dimming

    Trimmed reference ( 3% accurate)

    AEC-Q100 compliant

AT9932应用：

    Automobile lighting

    Battery powered LED lamps

    Other low voltage AC/DC or DC/DC LED drivers

图1。AT9932功能方框图

图2。AT9932典型应用电路图

详情请见：

http://www.supertex.com/pdf/datasheets/AT9932.pdf