The World’s First 4-Channel Intelligent High-Current LED Driver

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Future Lighting Solutions and NEC Electronics America Introduce the World’s First Intelligent Constant High-Current Driver with a Microcontroller

 

 

LED lighting designers and engineers are constantly looking for ways to reduce the cost and size of power management solutions for multi-LED applications. NEC Electronics’ solution is a 4-channel constant-current driver with an embedded 8-bit flash microcontroller integrated into a single package to maximize savings of both cost and space.

The µPD78F8024 has a wide input voltage range from 9 to 38V and supports both buck and boost topologies to drive up to 40 high-power LEDs at currents reaching over 1.5A (see Figures 1 and 2). Each constant-current drive implements an individual hardware hysteretic regulator controller with switching frequency up to 1MHz, while the flash microcontroller can control each channel through PWM signals to enable dimming, flashing, and strobing sequences.

 

Figure 1. Buck topology with µPD78F8024

Figure 2. Boost topology with µPD78F8024

 

Engineers who want to maximize control, reliability and power savings for their solid-state lighting applications can also leverage the four analog-to-digital converters and I²C interface to dynamically change the average LED current by having the µPD78F8024 communicate with a temperature or ambient light sensor.

 

Integrating Power and Intelligence

 

4 KEY BENEFITS 1. High Integration Integrated power and microcontroller solution for reduced board space and cost 2. High Flexibility Wide input voltage range (9 – 38V) Step-up (boost) or step-down (buck) topologies Wide current range (350mA to above 1.5A) with external FETs Large strings of LEDs per channel (up to 10 LEDs) Combined channels to increase total number of LEDs (up to 40) Can be used for motor control and solenoid driver applications, among others 3. High Efficiency and Reliability Switching-based constant current driver Reduced inductor size due to high switching frequency Distributed LEDs across multiple channels for redundancy LED failure detection 4. High Intelligence Four independent channels to control multi-LED applications Dimming control (8-bit PWM dimming) Custom flashing sequences Gradual LED light-up Color management algorithms DMX512 support via UART Thermal management with temperature sensor Power management via ambient light sensor

FEATURES High-Performance 8-Bit 78K0 Flash MCU 8KB flash memory, 512-byte SRAM 4-channel 8-bit PWM timers 3-channel serial interfaces (UART, UART/CSI, I2C) Internal 8MHz oscillator 4-channel 10-bit A/D converter Watchdog timer 16-bit capture/compare timer Figure 3. Two-die SiP Solution in 64-Pin LQFP Constant High-Current Driver 4-channel buck or boost current regulators Up to 1MHz switching frequency 350mA – 1.5A per channel with external FETs 9 – 38V supply voltage Soft start (for reduced EMI) Thermal shutdown Under-voltage lockout   APPLICATIONS Architectural and entertainment lighting Area lighting, street and tunnel lights Emergency and warning vehicles Gaming systems, including slot machines Interior and exterior aerospace lighting Light box sign backlighting Signaling and obstruction lighting White LED LCD backlighting

 

Applilet EZ for HCD Development Tool (EV-K0-HCD)

The Applilet EZ for HCD (see Figure 4) code generator is a free, user-friendly development tool that generates software automatically to control the four channels of the µPD78F8024 microcontroller.

There are two simple steps to program and evaluate the generated code from the Applilet EZ for HCD program:

 

There are four LED Dimmer Program options: Fix duty output mode, which sets the fixed duty value for each channel Variable value output mode, which sets the duty value for each channel by drawing pattern data (see Figure 5) Analog Input value output mode, which controls the duty value for each channel by A/D conversion result (temperature sensor or ambient light sensor) Serial Command output mode, which controls the duty value for each channel by serial communication (I2C or UART) Figure 4. Applilet EZ for HCD screenshot

This unique feature allows the user to set the duty value for each channel by drawing pattern data. Figure 5. Variable output mode screenshot

 

 

Step 1: Select LED control mode via the Applilet EZ for HCD GUI interface and generate automatic software code for the µPD78F8024 microcontroller.

Step 2: Program the µPD78F8024 microcontroller via USB cable (see Figure 6) and evaluate the generated software code using the associated µPD78F8024 microcontroller evaluation board.

For additional support, NEC Electronics offers a full range of software and hardware tools, including a C compiler, full-function emulator and integrated debugger for design and development, and a PG-FP4 flash programmer for programming user code into the MCU’s flash memory.

The EV-K0-HCD evaluation kit is intended to be just as flexible and intelligent as the µPD78F8024 product itself.

 

KIT INCLUDES µPD78F8024 microcontroller Applilet EZ for HCD GUI-based development software Power supply USB cable

 

The µPD78F8024 HCD/LED MCU is available in a 64-pin LQFP. Samples are available now! Prices start at $3.50 US/1000 unit quantities. Evaluation boards are also available now with a limited time discount of $25 US. For more information, visit www.FutureLightingSolutions.com/NEC or www.FutureElectronics.com/NEC.

 

 Featured Products

Part Number		Description	Data Sheet	App. Notes
EV-K0-HCD		µPD78F8024 Evaluation Kit
UPD78F8024GK-SSA-AX		8-Bit Single Chip Microcontroller

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