Features

• 3V to 5.5V Input Voltage
• 48 Independent PWM Outputs
• TTL/CMOS Logic 50MHz Serial Data Interface
• 12-Bit (4096 Steps) PWM Width Resolution
• 6-Bit (64 Steps) PWM Correction (±50% of Programmed PWM Width)
• Up to 6.1kHz PWM Frequency (PWMCK = 25MHz)
• Phase-Shift Option Reduces Switching Noise
• Directly Controls Three LT3595A 16-Channel LED Drivers
• Diagnostic Information: Sync Error/Open LED Flags
• 56-Pin (6mm × 6mm × 0.78mm) TLA QFN Package

Typical Application

Description

The LT®8500 is a pulse width modulation (PWM) generator with 48 independent channels. Each channel has an individually adjustable 12-bit (4096-step) PWM register and a 6-bit (64-step) ±50% correction register. All controls are programmable via a simple serial data interface. Three banks of 16-channels each can be configured such that they operate 120° out-of-phase with each other.

The LT8500 features two diagnostic information flags: synchronization error and open LED. The flags are sent, with additional state information, on the serial data interface during status read back. The 50MHz cascadable serial data interface includes buffering and skew-balancing, making the chip suitable for PWM intensive applications such as large screen LCD dynamic backlighting and mono-, multi- and full-color LED displays. The LT8500 is also ideally suited to control three LT3595A LED drivers.