LED driver provides engineers with design flexibility

It is in stock at Anglia Components

The device guarantees 5 V output driving capability and has 12 low-side current generators allowing each channel to provide up to 20 mA output current with a headroom voltage of just 350 mV (typ.)

This LED driver offers maximum design flexibility by allowing separate output current adjustment for each channel by 8-bit analogue and 12-bit digital dimming control.

This allows the driver to deliver smoother more realistic lighting effects.

The driver is part of STMicroelectronics Sustainable Technology program and features low quiescent current of 4 uA (typ.) making it suitable for use in portable battery powered applications such as wearables.

The device features a slow turn-on and turn-off time which improves the system low noise generation performance, phase shifting between channels is implemented to help to reduce the inrush current.

Eight different patterns can be stored in the internal volatile memory on the device for automatic sequencing without the need for MCU intervention reducing overhead on the system.

The device supports two main methods for dimming the LEDs: changing the output DC current value (analogue dimming) or modifying the output current duty-cycle (digital dimming). The two methods are not mutually exclusive and can be used at the same time to generate a specific channel by channel 20-bit depth dimming.

The pattern sequence can be also configured for duration time and number of repetitions, each pattern output can be configured for PWM duty-cycle (on 4096 steps) and analogue dimming (on 256 steps) per channel is common to all patterns.

An I²C interface on the LED1202 is based on fast mode specification and works up to 400 kHz.

For multi-device applications that require more than 12 channels, a common clock domain can be shared for timing synchronization and eight I²C addresses are possible using the two configuration pins (A0/A1), the I2C interface also features a global address allowing multiple drivers to be synchronised together.

When connecting multiple LED1202 devices in a cascade or matrix, each device in the cascade needs to have a separately controlled local register area for full independent functionality. It is possible to define up to eight different I²C addresses with only two pins. The whole interface (SDA, SCL, IRQn) is connected in parallel.

The LED1202 also includes inbuilt thermal shutdown protection and open LED detection and is included in STMicroelectronics 10-year Longevity Program giving developers the reassurance to use the product in new designs.

The driver is supported by the X-NUCLEO-LED12A1 LED driver STM32 Nucleo expansion board.

This board features four LED1202 devices that can drive up to 48 LEDs allowing developers to experiment with the full capabilities of the device.

The expansion board comes with an additional LED panel board that houses two LEDs matrices: a 6x8 white LED matrix and a 4x4 RGB matrix.

LED matrices can be supplied via an external power supply connected to J13 connector and by selecting the right path through J15 jumper to reach the maximum luminosity available.

The LED1202 is available in a choice of packages, WLCSP20 measuring 1.71 x 2.16 x 0.5 mm with 0.4 mm pitch and a QFN20 package measuring 3 x 3 x 0.6 mm with 0.5 mm pitch. The device has an operating temperature range of -40°C to +85°C.

Applications include general lighting, signage, small appliances and wearables

Anglia are offering customers a FREE evaluation board and samples of the LED1202 12-Channel low quiescent current LED driver