描述 Description

The PCA9959 is a daisy-chain SPI-compatible 4-wire serial bus controlled by a 24-channel constant preset current LED driver optimized for dimming and blinking 63 mA Red/green/blue/amber (RGBA) LEDs.
Each LED output has its own 6-bit resolution (64 steps) preset current configuration, with an absolute accuracy of ±8 %.
PCA9959 supports up to four groups of LED gradation control, with each LED channel assigned to one of the groups. For each group, PCA9959 supports 64-grid brightness control, with the time duration of each grid adjustable from 2.5 μs to 1 ms. Each LED output can be off, on or set at its individual preset current value within each grid. Once gradation control enabled, PCA9959 will automatically change each LED preset current with the setup from grid0 to grid63. Once finished, it can hold grid63 or repeat from grid0 as configured.

特性 Features

General
? 24 constant preset current output channels can sink up to 63 mA, tolerate up to 5.5 V when OFF
? Output preset current adjusted through an external resistor (REXT input)
? Open/short load/overtemperature detection mode to detect individual LED errors
? 4-wire serial bus interface with 10 MHz data clock rate
? Active LOW output enable (OE) input pin
? Internal power-on reset
? No glitch on LEDn outputs on power-up
? Low standby preset current
? Operating power supply voltage (VDD) range of 2.7 V to 5.5 V
? 5.5 V tolerant inputs on non-LED pins
? -40 °C to +85 °C operation
? Latch-up performance exceeds 100 mA per JESD 78, Class II
? Package offered: HVQFN40
24 LED drivers
? Each output programmable at:
? Off
? On
? 6 bits programmable LED brightness
? Programmable LED output delay to reduce EMI and surge currents when off
Gradation control for all channels
? Each channel can be assigned to one of four gradation control groups
? 64 grids of gradation control for each channel
? Programmable grid duration time
? Four preset current options for each channel during gradation control
Output preset current accuracy
? ±8 % absolute accuracy with 60 mA output current
? ±6.5 % absolute accuracy with 30 mA output current
? Maximum ±5 % channel to channel variation
? Maximum ±7 % device to device variation
ESD protection exceeds per JESD22-A114
? 2000 V Human-Body Model (A114-A)
? 1000 V Charged-Device Model (C101)

應(yīng)用 Application

Industrial

? Fade-in and fade-out for breath light control

? LCD backlights

? LED displays

? LED status information

? RGB or RGBA LED drivers
?Smart Lighting