MC34845DEPLow cost6 channelsLEDBacklightdriveWithIntegrated power supply
The MC34844/A is a high efficiency, LED-backlit LCD display using drivers from 10" to 27".Operating from 7V to 28V supply, the MC34844/A is capable of traveling more than 150 LEDs in series and parallel.The 10 strings in are current matched within ±2% and can be programmed via the I2C/SM-bus interface.
The MC34844/A also includes an LED dimming pulse width modulation (PWM) generator.The LED lamp can be dimmed to 256 levels and programmed through the I2C/SM-bus interface.Therefore, dimming ratios up to 65,000:1 (PWM 256:1, 256:1 current output DAC) can be supported.An external PWM input can also be used.Multiple devices can synchronize PWM frequencies to reduce image noise.NOISE IS ALSO REDUCED BY SUPPORTING FREQUENCIES UP TO 27KHZ (34844 FROM 100Hz TO 25kHz AND 110HZ TO 27KHZ 34844A).
The MC34844/A also supports temperature and light
peculiarity
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Input voltage from 7V to 28V
Output voltage up to 60V, headroom control
2.5A integrated boost
Up to 50 mA LED current per channel (34844)
Up to 80 mA LED current per channel (34844A)
90% efficiency (DC:DC)
The 10-channel current mirror is ±2% current matched
I2C/SMBus interface
8-bit programmable current DAC
User-Programmable Overvoltage Protection (OVP)
LED fault detection and OTP/OCP/UVLO locking
Programmable or synchronizable PWM frequency from 100 to 25,000 Hz 34844
Programmable or synchronizable PWM frequency from 110 to 27000 Hz 34844A
32-LD 5x5x0.8mm TQFN lead-free package
The product is included in Freescale's Product Longevity Program, which guarantees availability for at least 10 years
Microchip century-old electronic technology---
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