Features • Internal power-on reset • Active low reset • Internal precision oscillator • Variable dim rates (from 6.25 ms to 1.6s; 160 Hz-0.625 Hz) Description LP3944 is an integrated device capable of independently driving 8 LEDs. This device also contains an internal precision oscillator that provides all the necessary timing required for driving each LED. Two prescaler registers along with two PWM registers provide a versatile duty cycle control. The LP3944 contains the ability to dim LEDs in SMBUS/I2C applications where it is required to cut down on bus traffic. Traditionally, to dim LEDs using a serial shift register such as 74LS594/5 would require a large amount of traffic to be on the serial bus. LP3944 instead requires only the setup of the frequency and duty cycle for each output pin. From then on, only a single command from the host is required to turn each individual open drain output ON, OFF, or to cycle a programmed frequency and duty cycle. Maximum output sink current is 25 mA per pin and 200 mA per package. Any ports not used for controlling the LEDs can be used for general purpose input/output expansion. Key Specification • 8 LED driver (multiple programmable states-on, off, input, and dimming at a specified rate) • 8 Open drain outputs capable of driving up to 25 mA per LED Applications • Customized flashing LED lights for cellular phones • Portable Applications • Digital Cameras • Indicator Lamps • General purpose I/O expander • Toys

Also Recommended LP3943▲ 16 LEDs MY BRIEFCASE                                       Click any "Briefcase" icon to add an item

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance click for larger image

Datasheet

Title		Size	Date	Other Language
	LP3944 RGB/White/Blue 8-LED Fun Light Driver	249 Kbytes	11-Nov-03

Featured Application Notes

Title		Size	Date	Other Language
	AN-1344: Application Note 1344 LP3944 Evaluation Kit	366 Kbytes	20-Oct-04
	AN-1715: Application Note 1715 LP3943/LP3944 as a GPIO Expander	93 Kbytes	12-Oct-07	中文

More Application Notes

Title		Size	Date	Other Language
	AN-1296: Application Note 1296 LP3945/LP3946 Evaluation Kit	280 Kbytes	17-Sep-04
	AN-1300: Application Note 1300 LP3943 Evaluation Kit	466 Kbytes	20-Oct-04
	AN-1341: Application Note 1341 LP3947 Evaluation Board	584 Kbytes	18-Nov-04

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LP3944ISQ	CMOS7	0	18406	0	0	1089000	4	309006723
LP3944ISQX	CMOS7	0	18406	0	0	1089000	4	309006723

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.