Texas Instruments

Category: Power Management ICs

Efficient and high-performance LED response effects, such as blinking, breathing, and chasing, are critical to improving end-user experience in many human machine interface (HMI) applications.

The LP503x device is a 30- or 36-channel constant-current-sink LED driver. The LP503x has a 29 kHz, 12-Bit PWM generator for each channel, as well as channel/module independent color mixing and intensity control, formerly called brightness control registers to enable vivid LED effects with zero audible noise. Users can benefit from the device’s ultra-low shutdown Iq Power Saving Mode, while designers will appreciate the incredibly straightforward software coding of the LP503x’s three programmable R G B banks.

The LP503x device controls each LED output with a 12-bit PWM resolution at 29-kHz switching frequency. This control helps get an intensity that decreases smoothly and stops audible noise. Having different color-mixing and intensity-control registers makes writing the software code straightforward. When targeting fade-in, fade-out type breathing effects, the global R, G, B bank control reduces the microcontroller loading significantly. The LP503x device also implements a PWM phase-shifting function to help reduce the input power budget when LEDs turn on simultaneously.

The LP503x device has an automatic power-saving mode to get the ultra-low quiescent current. When channels are all off for 30 ms, the device total power consumption is down to 10 µA, making the LP503x device a possible alternative for battery-powered end equipment.

Features:

• Operating Voltage Range:
  • V_CC Range: 2.7 V to 5.5 V
  • EN, SDA, and SCL Pins Compatible With 1.8-V, 3.3-V, and 5-V Power Rails
  • Output Maximum Voltage: 6 V
• 36 Constant-Current Sinks With High Precision
  • 25.5 mA Maximum per Channel When V_CC in Full Range
  • 35 mA Maximum per Channel When V_CC ≥ 3.3 V
  • Device-to-Device Error ±5%; Channel-to-Channel Error ±5%
• Ultralow Quiescent Current:
  • Shutdown Mode: 1 µA (Maximum) When EN Low
  • Power Saving Mode: 12 µA (Maximum) When EN High and All LEDs Off for > 30 ms
• Integrated 12-Bit, 29-kHz PWM Generator for Each Channel:
  • Independent Color-Mixing Register Per Channel
  • Independent Brightness-Control Register Per RGB LED Module
  • Optional Logarithmic- or Linear-Scale Brightness Control
  • Integrated 3-Phase-Shifting PWM Scheme
• 3 Programmable Banks (R, G, B) for Easy Software Control of Each Color
• 2 External Hardware Address Pins Allow Connecting up to 4 Devices
• Broadcast Slave Address Allows Configuring Multiple Devices Simultaneously
• Auto-Increment Allows Writing or Reading Consecutive Registers Within One Transmission
• Up to 400-kHz Fast-Mode I²C Speed

$2.56