特性和优势

• 16 LED drivers. Each output programmable at:
  • Off
  • On
  • Programmable LED brightness
  • Programmable group dimming/blinking mixed with individual LED brightness
  • Programmable LED output delay to reduce EMI and surge currents
• Off
• On
• Programmable LED brightness
• Programmable group dimming/blinking mixed with individual LED brightness
• Programmable LED output delay to reduce EMI and surge currents
• Gradation control for all channels
  • Each channel can assign to one of four gradation control groups
  • Programmable gradation time and rate for ramp-up and/or ramp-down operations
  • Programmable step time (6-bit) from 0.5 ms (minimum) to 512 ms (maximum)
  • Programmable hold-on time after ramp-up and hold-off time after ramp-down (3-bit) from 0 s to 6 s
  • Programmable final ramp-up and hold-on current
  • Programmable brightness current output adjustment, either linear or exponential curve
• Each channel can assign to one of four gradation control groups
• Programmable gradation time and rate for ramp-up and/or ramp-down operations
• Programmable step time (6-bit) from 0.5 ms (minimum) to 512 ms (maximum)
• Programmable hold-on time after ramp-up and hold-off time after ramp-down (3-bit) from 0 s to 6 s
• Programmable final ramp-up and hold-on current
• Programmable brightness current output adjustment, either linear or exponential curve
• 16 constant current output channels can sink up to 57 mA, tolerate up to 20 V when OFF
• Output current adjusted through an external resistor (REXT input)
• Output current accuracy
  • ±4 % between output channels
  • ±6 % between PCU9955A devices
• ±4 % between output channels
• ±6 % between PCU9955A devices
• Thermal shutdown for overtemperature
• 5 MHz Ultra Fast-mode I²C-bus interface
• 256-step (8-bit) linear programmable brightness per LED output varying from fully off (default) to maximum brightness fully ON 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 (bit 9, this bit is always set to 1 by I²C-bus master) or the STOP condition to update outputs byte-by-byte or all at the same time (default to ‘Change on STOP’).
• Active LOW Output Enable (OE) input pin allows for hardware blinking and dimming of the LEDs
• Three quinary hardware address pins allow 125 PCU9955A devices to be connected to the same I²C-bus and to be individually programmed
• 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 PCU9955As 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 USDA/USCL inputs
• No glitch on LEDn outputs 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
• ‑40 °C to +85 °C operation
• ESD protection exceeds 4000 V HBM per JESD22-A114
• Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
• Packages offered: HTSSOP28

应用

• Amusement products
• RGB or RGBA LED drivers
• LED status information
• LED displays
• LCD backlights
• Keypad backlights for cellular phones or handheld devices
• Fade-in and fade-out for breathlight control

产品图片