FEATURES AND BENEFITS
• Automotive AEC-Q100 qualified
• Supply voltage 4.5 to 36 V, maximum 40 V
• Complete 1.5 A output compact LED driver
• Integrated inductor, VIN and boot capacitors
• Ultra-low EMI architecture, fSW > 2 MHz
• Spread spectrum for improved EMC
• Integrated high-side and low-side MOSFETs:
80 mΩ / 60 mΩTYP, 90% efficiency at 1 A
• 5 V, 14 mA LDO regulator for peripheral circuits
• Dimming via external PWM or EN pin
• Programmable internal PWM dimming
• Analog dimming for brightness calibration and thermal
foldback
• Low power shutdown (1 μA typical)
• High side current sense, ±3% accuracy
• Fault flag output
• LED open fault mask setting for low VIN operation
• Undervoltage lockout (UVLO) and thermal shutdown
protection
• Robust protection against:
□ Adjacent pin-to-pin short
□ Pin-to-ground short
□ Component open/short faults
DESCRIPTION
The APM80904 is a complete synchronous buck switching
regulator module that provides constant current output to drive
high-power LEDs. It integrates both high-side and low-side
N-channel switches, inductor, high frequency VIN and boot
capacitors. A true average current is output using a cycle-bycycle, controlled on-time method.
Output current is user-selectable by an external current sense
resistor. Output voltage automatically adjusts to the LED
string voltage to ensure optimal system efficiency.
LED dimming is accomplished by a direct logic input pulsewidth modulation (PWM) signal at the PWM pin while EN
is enabled. Alternatively, applying a PWM signal at the EN
pin while the PWM pin is high provides “chopped battery”
PWM dimming for legacy control modules. Additionally, the
APM80904 includes programmable internal dimming.
The analog dimming input (ADIM pin) can be used to
calibrate the LED current or implement thermal foldback in
conjunction with an external NTC thermistor.
The APM80904 is provided in a compact, thermally enhanced
4 mm × 6 mm × 2.1 mm QFN-32 package with wettable flanks.
APPLICATIONS:
• Daytime running lights
• Front and rear fog lights
• Turn/stop lights
• Map light
• Dimmable interior lights
• Puddle lights