Illumination LED Driver with Built-in Display Patterns | New product new technology

Illumination LED Driver with Built-in Display Patterns

First utilized in mobile phones and car audio systems, LEDs are being increasing adopted in portable devices and consumer appliances.

Today’s devices need to provide greater functionality without placing additional burdens on existing systems.

Overview

　ROHM’s 6ch LED driver integrates 16 display patterns, enabling full management control with just a simple control signal from the CPU.

　In addition, a constant control circuit, 7bit gradation current DAC, and charge pump step-up circuit is built into each of the 6 channels. The result is significantly reduced forward voltage fluctuation and more than 2,000,000 possible colors.
Two types are available – with a charge pump (BD2812GU) and without (BD2802GU)

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Features(BD2812GU/BD2802GU)

Drives 6 LEDs (30.48mA max./ch)
16 illumination patterns built-in
128-step constant current driver
Integrated automatic switching charge pump step-up circuit (BD2812GU)
I²C BUS compatible
Expansion possible via address change function
Compact Wafer Level chip scale package (WL-CSP)

16 built-in illumination waveform patterns reduce CPU load

The BD2812GU and BD2802GU feature 16 illumination patterns that can be selected via CPU. Setting just the maximum/minimum drive currents and the slope reduces CPU load and allows for greater expression.

16 built-in illumination waveform patterns reduce CPU load

7bit gradation DAC built-in, resulting in more than 2,000,000 colors for rich, vivid expression

　The human eye is sensitive to LED brightness changes, making it imperative to minimize current fluctuations.
　ROHM’s BD2812GU and BD2802GU LED drivers feature a 7bit gradation DAC and 128-step RGB current control (0.2mA/step), minimizing fluctuations for high performance illumination.128-step RGB operation results in superior expressiveness with more than 2,000,000 colors possible.

7bit gradation DAC built-in, resulting in more than 2,000,000 colors for rich, vivid expression

Current DAC ensures low EMI

　Conventional PWM control is utilized for gradation operation. LED current is switched ON/OFF rapidly, reducing noise generation as well as power supply fluctuations.

　The BD2812GU and BD2802GU incorporate a current DAC that allows current changes in steps of as little as 0.2mA, reducing noise and supply fluctuations significantly.

Ultra-compact Wafer Level CSP (Chip Scale Package)

　Conventional discrete illumination lighting solutions require a resistor (to absorb the LED current differences due to forward voltage fluctuations) as well as a MOSFET (for switching the current ON/OFF) at each channel, along with PWM gradation control signals from the CPU.

In contrast, ROHM’s BD2812GU and BD2802GU integrate all required functions on a compact 2.8mm×2.8mm chip, allowing illumination by simply connecting the LEDs and inputting simple control signals from the CPU.

Ultra-compact wafer level CSP (Chip Scale Package)

Applications

Mobile phones, car audio systems, and other sets utilizing LED lighting

Product Lineup

Part No.	Supply Voltage(V)	LED Connection	DC/DC	AUX LED	Other	Control Interface	Package
BD2802GU	2.7 to 5.5	Parallel connection	－	6 LEDs Max. 30.48mA 128 steps Illumination function	Master/ Slave Selection	I²C BUS	VCSP85H2 (2.8×2.8) H=1.0Max.
BD2812GU	2.7 to 5.5	Parallel connection	Charge pump	6 LEDs Max. 30.48mA 128 steps Illumination function	Master/ Slave Selection	I²C BUS	VCSP85H3 (3.1×3.1) H=1.0Max.