The MAX8647/MAX8648 drive up to six white LEDs or
two sets of RGB LEDs with regulated constant current
for display backlight and fun light applications. By utilizing
an inverting charge pump and extremely low-dropout
adaptive current regulators, these ICs achieve
very high efficiency over the full 1-cell Li+ battery voltage
range and even with large LED forward voltage
mismatch. The 1MHz fixed-frequency switching allows
for tiny external components. The regulation scheme is
optimized to ensure low EMI and low input ripple. The
MAX8647/MAX8648 include thermal shutdown, open- and
short-circuit protection.
The MAX8647 features an I²C serial port, while the
MAX8648 features a three-wire serial-pulse logic interface.
Both devices support independent on/off and
dimming for main and subbacklights. The dimming
ranges are pseudo-logarithmic from 24mA to 0.1mA
and off in 32 steps. Both devices include a temperature
derating function to safely allow bright 24mA full-scale
output current setting while automatically reducing current
to protect LEDs at high ambient temperatures
above +60°C.
The MAX8647/MAX8648 are available in a 16-pin, 3mm x 3mm thin QFN package (0.8mm max height).
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