Features
| • | Adaptive charge pump with 1x and 1.5x gain provides up to 95% LED drive efficiency |
| • | Charge pump with soft start and overcurrent/short circuit protection |
| • | Low input ripple and EMI |
| • | Very small solution size, no inductor or resistors required |
| • | 200 nA typical shutdown current |
| • | Automatic power save mode |
| • | I
2C compatible interface
|
| • | Independently programmable constant current outputs with 8-bit current setting and 8-bit PWM control |
| • | Typical LED output saturation voltage 50 mV and current matching 1% |
| • | Three program execution engines with flexible instruction set |
| • | Autonomous operation without external control |
| • | Large SRAM program memory |
| • | Two general purpose digital outputs |
| • | microSMD-20 package, 0.4 mm pitch |
| • | Bumped LLP-24 package, 0.5 mm pitch |
Description The LP5521 is a three channel LED driver designed to produce variety of lighting effects for mobile devices. High efficiency
charge pump enables LED driving over full Li-Ion battery voltage range. The device has a program memory for creating variety
of lighting sequences. When program memory has been loaded, LP5521 can operate independently without processor control.
LP5521 maintains excellent efficiency over a wide operating range by automatically selecting proper charge pump gain based
on LED forward voltage requirements. LP5521 is able to automatically enter power-save mode, when LED outputs are not active
and thus lowering current consumption.
Three independent LED channels have accurate programmable current sources and PWM control. Each channel has program memory
for creating desired lighting sequences with PWM control.
LP5521 has a flexible digital interface. Trigger I/O and 32 kHz clock input allow synchronization between multiple devices.
Interrupt output can be used to notify processor, when LED sequence has ended. LP5521 has four pin selectable I
2C addresses. This allows connecting up to four parallel devices in one I
2C bus. GPO and INT pins can be used as a digital control pin for other devices.
LP5521 requires only four small and low cost ceramic capacitors.
LP5521 is available in tiny 2.1x1.7x0.6 mm microSMD-20 package and in 4.0x5.0x0.8 mm bumped LLP-24 package.
Comprehensive application tools are available, including command compiler for easy LED sequence programming.
Applications
| • | Fun / indicator lights |
| • | LCD sub-display backlighting |
| • | Keypad RGB backlighting and phone cosmetics |
| • | Vibra, speakers, waveform generator |
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LP5521
