1 Features
• AEC-Q100 qualified for automotive applications
– Grade 1: –40°C to 125°C ambient operating
temperature
– Device HBM classification level H1C
– Device CDM classification level C5
• Input voltage range: 5.5 V to 36 V
– Operation down to 5.15 V after start-up
• Up to 3-A continuous with 4% accuracy
• Adaptive on-time current control
– Low offset high-side current sense amplifier
– Stable with any combination of ceramic, and
aluminum capacitors
• Programmable switching frequency from 100 kHz
to 2.2 MHz
• Advanced dimming operation
– 1000:1 precision PWM dimming
– 15:1 precision analog dimming
– 1.4-kHz internal analog input to PWM duty
cycle translation
• Cycle-by-cycle switch overcurrent protection
• Open-drain fault indicator output
– LED short circuit, open circuit and cable
harness fault indication
• Thermal shutdown protection

2 Applications
• Headlight
• Front fog light LED driver module

3 Description
The TPS92643-Q1 is a monolithic, synchronous Buck
LED driver with a wide 5.5-V to 36-V operating
input voltage range and 40-V tolerance that supports
load dump for duration of 400 ms. The TPS92643-
Q1 implements an adaptive on-time average current
mode control based on inductor valley current
detection. The adaptive on-time control provides
near constant switching frequency that can be set
between 100 kHz and 2.2 MHz. Inductor current
sensing and closed-loop feedback enables better than
±4% accuracy over wide input, output and ambient
temperature.
The high-performance LED driver can independently
modulate LED current using both analog or PWM
dimming techniques. Linear analog dimming range
with over 15:1 range is obtained by setting the IADJ
voltage. PWM dimming of LED current is achieved by
directly modulating the UDIM input pin with desired
duty cycle or setting the analog voltage at APWM
to enable internal analog-to-PWM conversion. The
internal PWM generator translates the external analog
voltage by comparing it to an internal 1.4-kHz ramp
signal.
The TPS92643-Q1 incorporates advanced diagnostic
and fault protection featuring: cycle-by-cycle switch
current limit, bootstrap undervoltage, LED open, LED
short and thermal shutdown.
The TPS92643-Q1 is available in a 6.6-mm × 5.1-mm
thermally-enhanced 16-pin HTSSOP package with
0.65-mm lead pitch.