Features and Benefits
- 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
The LT8500 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.
- Large Screen Display LED Backlighting
- Mono-, Multi-, Full-Color LED Displays
- LED Billboards and Signboards
- Motor Control
- Industrial Control
- Automated Test Equipment
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
Demonstration circuit 1552 showcases the LT8500, a 48-channel PWM generator and serial interface. It operates from a 30V to 45V input power supply and drives 48 channels of LED strings at 30mA and up to 32V each, although it can be adjusted for 50mA per string. The LT8500 drives 48 PWM channels that are tied directly to the PWM inputs of three separate LT3595A 16-channel step-down LED drivers. Each LED Driver can operate up to 45V input and provide up to 50mA LED current per channel.
The input to the LT8500 is a serial interface that can run up to 50MHz. The DC1552A has both an input and output connector and can be cascaded in a chain of two or more while being driven from a single serial interface.
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Sample & Buy
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