STMicroelectronics

The STEVAL-ILD003V2 demonstration board is designed to propose a low-cost analog dimmer topology using a sensitive SCR TS820-600FP. The dimmer can drive typical low-consumption lamps, particularly CFL and LED dimmable lamps. Through-hole technology is used for the most important components such as LC filter, gate resistor, turn-on delay capacitor, etc., in order to allow board modification, if needed. The STEVAL-ILD003V2 eliminates flickering thanks to its continuous current applied through the sensitive SCR gate. This dimmer could easily replace a standard low-cost analog Triac light dimmer using a Diac-controlled circuit.

The STEVAL-ILD005V1 evaluation board implements a simple and cost-effective MOS-based reverse phase cut dimming solution for analog wall dimmers using a pair of STF17N62K3 power MOSFETs controlled by a triple 3-input NOR gate to effectively dim either resistive or capacitive lighting loads (i.e. halogen lamps, electronic low voltage transformers and various dimmable CFL/LED lamps). The AC analog control dimming technique employed allows for both on/off power switching and up/down dimming functions through a single linear rotary potentiometer equipped with a mechanical switch which opens the circuit at minimum setting. Control of the board is achieved using a triple 3-input NOR gate (pin-to-pin compatible with a ST's HCF4025BE 14-lead dual in-line CMOS gate logic device in plastic SO-14 micropackage) which acts as a gate driving voltage signal source, performs zero crossing detection and timing through the use of a few other passive components and diodes.

This demonstration board provides a complete solution for driving 40 high-brightness green LEDs manufactured by Toshiba. The high-brightness LEDs are arranged on the board in a 5x8 matrix. The matrix is driven by five 8-channel STP08DP05 drivers which are controlled by the ST7FLITE3x 8-bit microcontroller. The innovative feature of STP08DP05 is the full output error detection function, which checks the status of the outputs without invasive tests (via software).

The STEVAL-ILL015V1 demonstration board provides a platform for the testing and evaluation of STMicroelectronics’ Power Logic LED driver STP24DP05. The STP24DP05 device is a 24-bit constant current LED sink driver with output error detection, suitable for applications such as largearea displays and full-color board panels where improvement in RGB LED resolution and reduction of system cost are important.

The STEVAL-ILL015V2 product evaluation board provides a platform to test and evaluate the power logic LED driver LED2472G from STMicroelectronics. The LED2472G is a 24-bit constant-current LED sink driver with output error detection, suitable for applications such as large-area displays and full-color board panels where improvement in RGB LED resolution and reduction of system cost are important.

This demonstration board is based on the LED7706 and implements a high efficiency monolithic boost converter and six controlled current generators (rows) specifically designed to supply LEDs arrays used in the backlight of LCD panels. The device can manage an output voltage up to 36 V (i.e. ten white-LEDs per row). The generators can be externally programmed to sink up to 30 mA and can be dimmed via a PWM signal (1% dimming duty cycle at 20 kHz can be managed). The device allows to detect and manage the open and shorted LED faults and to let unused rows floating. Basic protections (output overvoltage, internal MOSFET overcurrent and thermal shutdown) are provided.

This demonstration boards is based on the LED7707 and implements a high efficiency monolithic boost converter and six controlled current generators (rows) specifically designed to supply LEDs arrays used in the backlight of LCD panels. The device can manage an output voltage up to 36 V (i.e. ten white-LEDs per row). The generators can be externally programmed to sink up to 85 mA and can be dimmed via a PWM signal (1% of minimum dimming duty cycle at 1kHz can be managed). The device allows to detect and manage the open and shorted LED faults and to let unused rows floating. Basic protections (output overvoltage, internal MOSFET overcurrent and thermal shutdown) are provided.

The solar-LED streetlight controller is made up of one 80 W battery charger and one 25 W LED driver. When the sun is present the charger converts the electricity from the solar panel then charges the battery. In a dark ambient where no sun is present the battery powers on the LED lamp as a streetlight. When wet or cloudy weather persists for several days the battery gradually runs out of power. The controller then switches on the AC mains supply instead of the battery to power on the LED until the battery is fully charged again.

The progress made in the field of LEDs is visible on an almost day-by-day basis. Many high power LEDs are currently on the market, such as 0.7 A and 1 A devices. However, the most commonly used LEDs are those with a current of 0.350 A. This demonstration board is designed for 350 mA LEDs and is capable of driving three 1 W LEDs in series with high-precision constant current (± 5% tolerance). The design is based on the VIPer22AE, which combines a dedicated current mode PWM controller with a high voltage power MOSFET on the same silicon chip. The internal control circuit offers a large input voltage range on the VDDpin, accommodates changes in auxiliary supply voltage, and supports automatic burst mode in low load conditions. The board also features protections against overtemperature, overcurrent and overvoltage conditions.

The purpose of the STEVAL-ILL035V1 demonstration board is to provide an application example of a compact LED backlight driver using the LED7708 device. The board is equipped with a 16-channel LED driver with integrated boost controller (the LED7708), power section components, and an STM32 microcontroller to easily control all the features via a USB connection. The output voltage required by the LED strings connected to the output channels is derived from a single input rail and continuously adjusted to minimize the voltage drop (and power dissipation) across them, despite an independent PWM duty cycle for each one. The brightness of each LED string is digitally controlled with 12- or 16-bit dimming resolution. Embedded, programmable fault detection and management circuitry can be set to automatically disconnect faulty channels without the need for intervention by the host controller. The board has been designed as a demonstration of a solution for medium/large LCD panel backlight drivers, but is suitable for any application involving several LEDs assembled in strings (e.g. advertisement panels, signs, gaming, etc.).