Description

    The AT9635 is an I²C-bus controlled 16-bit LED driver optimized for Red/Green/Blue/Amber (RGBA) color mixing applications. Each LED output has its own 8-bit resolution (256 steps) fixed frequency individual PWM controller that operates at 97 kHz with a duty cycle that is adjustable froThe AT9635 is an I²C-bus controlled 16-bit LED driver optimized for Red/Green/Blue/Amber (RGBA) color mixing applications. Each LED output has its own 8-bit resolution (256 steps) fixed frequency individual PWM controller that operates at 97kHz with a duty cycle that is adjustable from 0% to 99.6% to allow the LED to be set to a specific brightness value. An additional 8-bit resolution (256 steps) group PWM controller has both a fixed frequency of 190 Hz and an adjustable frequency between 24 Hz to once every 10.73 seconds with a duty cycle that is adjustable from 0% to 99.6% that is used to either dim or blink all LEDs with the same value.m 0% to 99.6% to allow the LED to be set to a specific brightness value. An additional 8-bit resolution (256 steps) group PWM controller has both a fixed frequency of 190 Hz and an adjustable frequency between 24 Hz to once every 10.73 seconds with a duty cycle that is adjustable from 0 % to 99.6 % that is used to either dim or blink all LEDs with the same value.

Features

16 LED drivers. Each output programmable at:

Off/On

Programmable LED brightness

Programmable group dimming/blinking mixed with individual LED brightness

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 LED output varying from fully off (default) to maximum brightness using a 97 kHz PWM signal

256-step group brightness control allows general dimming (using a 190 Hz PWM signal) from fully off to maximum brightness (default)

256-step group blinking with frequency programmable from 24 Hz to 10.73 s and duty cycle from 0 % to 99.6 %

Sixteen totem-pole outputs (sink 25 mA and source 10 mA at 5 V) with software programmable open-drain LED outputs selection (default at totem-pole). No input function.

Output state change programmable on the Acknowledge or the STOP Command to update outputs byte-by-byte or all at the same time (default to ‘Change on STOP’)

Active LOW Output Enable (OE) input pin. LED outputs programmable to logic 1, logic 0 or ‘high-impedance’ (default at power-up) when OE is HIGH, thus allowing hardware blinking and dimming of the LEDs.

7 hardware address pins allow 126 devices to be connected to the same I2C-bus

4 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 AT9635s 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 I2C-bus address.

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

25 MHz internal oscillator requires no external components

Internal power-on reset

Noise filter on SDA/SCL inputs

Edge rate control on outputs

No glitch on power-up

Supports hot insertion

Low standby current

Operating power supply voltage range of 2.3 V to 5.5 V

5.5 V tolerant inputs

-40℃ to +85℃ operation

ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101

Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA

Packages offered: TSSOP28

APPLICATIONS

RGB or RGBA LED drivers

LED status information

LED displays

LCD backlights

Keypad backlights for cellular phones or handheld devices

Block diagram