PCA9955中文资料恩XP数据手册PDF规格书

Features and benefits

• 16 LED drivers. Each output programmable at:

– Off

– On

– Programmable LED brightness

– Programmable group dimming/blinking mixed with individual LED brightness

– Programmable LEDn output enable delay to reduce EMI and surge currents

• 16 constant current output channels can sink up to 57 mA, tolerate up to 40 V when OFF

• Output current adjusted through an external resistor

• Output current accuracy

– ±6 % between output channels

– ±8 % between PCA9952/55 devices

• Open/short load/overtemperature detection mode to detect individual LED errors

• 1 MHz Fast-mode Plus compatible I2C-bus interface with 30 mA high drive capability on SDA output for

driving high capacitive buses

• 256-step (8-bit) linear programmable brightness per LEDn output varying from fully off (default) to maximum

brightness using a 31.25 kHz PWM signal

• 256-step group brightness control allows general dimming (using a 122 Hz PWM signal) from fully off to

maximum brightness (default)

• 256-step group blinking with frequency programmable from 15 Hz to 16.8 s and duty cycle from 0 % to 99.6 %

• Output state change programmable on the Acknowledge or the STOP Command to update outputs byte-bybyte

or all at the same time (default to ‘Change on STOP’).

• Active LOW Output Enable (OE) input pin (only on PCA9952) allows for hardware blinking and dimming of the

LEDs

• Four hardware address pins allow 16 PCA9955 devices to be connected to the same I2C-bus and to be

individually programmed

• Four software programmable I2C-bus addresses (one LED Group Call address and three LED Sub Call

addresses) allow groups of devices to be addressed at the same time in any combination (for example, one

register used for ‘All Call’ so that all the PCA9952/55s on the I2C-bus can be addressed at the same time and

the second register used for three different addresses so that 1⁄3 of all devices on the bus can be addressed at

the same time in a group). Software enable and disable for each programmable I2C-bus address.

• Unique power-up default Sub Call address allows mixing of devices with different channel widths

• Software Reset feature (SWRST Call) allows the device to be reset through the I2C-bus

• 8 MHz internal oscillator requires no external components

• Internal power-on reset

• Noise filter on SDA/SCL inputs

• No glitch on LED on power-up

• Low standby current

• Operating power supply voltage (VDD) range of 3 V to 5.5 V

• 5.5 V tolerant inputs on non-LED pins

• Operating temperature:

– -40 °C to +85 °C

• ESD protection exceeds 2000 V HBM per JESD22-A114, and 500 V CDM per JESD22-C101

• Latch-up testing is done to JEDEC Standard JESD78 Class II, Level B

• Packages offered: HTSSOP28

– PCA9952TW/Q900 for automotive

Applications

• Amusement products

• RGB or RGBA LED drivers

• LED status information

• LED displays

• LCD backlights

• Keypad backlights for cellular phones or handheld devices

• Automotive lighting