LED driver AT8001 features and applications

The AT8001 is a high efficiency driver chip for backlighting applications that allows for a wide supply voltage range of 2.7V to 5.5V, making it ideal for lithium battery powered devices. The AT8001 sets the LED current through an external resistor. When the power supply voltage is above 3V, the AT8001 can drive up to 30mA per channel, and the total current drive capability can reach 120mA. The AT8001 can be adaptively switched between 1x operation mode or 1.5x operation mode depending on the power supply voltage and load. This reduces internal power consumption and ensures high efficiency. AT8001 can ensure better current matching when the voltage difference between parallel white LEDs is relatively large. The AT8001 uses a non-inductive charge pump boosting principle. The peripheral components require only two 1μF input-output capacitors and two 0.47μF charge-pump capacitors. The superior circuit control features ensure low power supply surge current and EMI. The AT8001 is available in a lead-free QFN 3×3 package and is RoHS compliant. The operating frequency is 1 MHz in 1.5x mode of operation. The AT8001 has a shutdown mode. In shutdown mode, the quiescent current of the AT8001 is less than 0.1μA.

Block diagram of AT8001:

Device characteristics

● Drive up to 4 LEDs, maximum current per LED: 30mA

● Current matching accuracy: 0.4% (typical)

●High efficiency 1x/1.5x mode, adaptive switching according to input voltage and load, the efficiency can be up to 90%

●Support PWM (frequency range: 0Hz ~ 50KHz) brightness adjustment mode

●Low input current ripple and low EMI

● No external inductance required

●Switching frequency: 1MHz

●Overcurrent protection and overheat protection

● Operating voltage range: 2.7V~5.5V

●Small 3mm*3mm QFN 16L package

●Shutdown current ICC<0.1μA

●RoHS compliant, 100% lead-free package

Pin arrangement and description of AT8001:

Application field

●Mobile phone

●Digital camera f

●MP3, PMP, PDA

Typical application circuit: