The EVAL6520-1421 is a demonstration board able to drive either a 14 W or 21 W linear T5 fluorescent lamp with the L6520 low voltage ballast controller.

The half bridge consists of NPN high voltage power transistors driven by a suitable pulse transformer.

This design was developed to drive a TL fluorescent lamp of up to 58 W. It is composed of two sections: the PFC using the L6561 controller, and the ballast based on the L6574. The application includes a current feedback that can be used to control the power (and, if necessary, the dimming function) by varying the switching frequency during normal lamp operation. The application also features safety circuitry which activates when an open load or faulty lamp ignition is detected. The PFC pre-regulator allows connection of the application to a wide input voltage range (85 Vac to 265 Vac) providing a Power Factor higher than 0.99 and a THD lower than 10%.

The EVALHVLED805 is a demonstration board equipped with the new HVLED805 PWM current mode LED driver and is designed for European mains. It can control, with very good accuracy, from 1 to 3 LEDs having a nominal current of 350 mA. The HVLED805 has integrated high voltage startup and an 800 V power MOSFET. The high MOSFET's breakdown voltage allows very robust and reliable applications and reduces the size of the snubber and the relative power dissipation. Its accurate primary-current control eliminates the need of the optocoupler which impacts the cost, the compactness and the lifetime of the application while still maintaining a very good LED accuracy (below 5 %). Moreover, this converter, specifically designed for quasi-resonant (QR) flyback converters, enables very low turn-on losses and EMI emissions.

The STEVAL-ILB001V2 demonstration board is a complete reference system for a simple cost-effective PFC (power factor corrector) using bipolar transistors and is intended for low-to-medium power HF ballasts.

The proposed bipolar PFC solution targets the low-cost HF ballast market up to 80 W as it provides a simple cost-effective solution without sacrificing THD and PF levels. No additional ICs are required for the PWM signal as the device uses just a power bipolar transistor and a closed-loop feedback which performs the duty cycle modulation and output power regulation.

The active PFC solution with bipolar transistor adopts the boost topology operating in discontinuous-conduction mode.

The STEVAL-ILB008V1 is a wide-range lighting ballast capable of driving 4 x 18 W linear T8 fluorescent tubes.

The ballast is controlled by the L6585DE IC, which integrates PFC and half-bridge control circuits, relevant drivers, and the circuitry required to manage all lamp operating phases (pre-heating, ignition and run mode). Protection against failures such as lamp disconnection, anti-capacitive mode, and PFC overvoltage are guaranteed and achieved using a minimum number of external components.

An electronic ballast consumes less power and therefore dissipates less heat than an electromagnetic ballast. The energy saved is estimated to be in the range of 20-25% for a given lamp power. Moreover, an electronic solution allows for improved control of the filament current and lamp voltage during pre-heating, resulting in increased lamp life.

The STEVAL-ILB009V1 demonstration board is able to drive a 2 x 28 W electronic lamp ballast with active PFC. The ballast is formed by a PFC section and a self-oscillating half bridge converter.

The circuit has been designed for a nominal input voltage of 230 Vrms ± 15% and 50-60 Hz.

The key components are the power bipolar transistor (STD845DN40), MOSFET device (STD3N62K3) and ST power switching driver for the PFC section.

The purpose of the STEVAL-ILB009V1 is to show a simple and cheap lighting application optimized in terms of power factor (PFC), THD harmonic distortion, and electrical efficiency.

The STEVAL-ILD003V1 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-ILD003V1 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-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-ILH004V1 demonstration board implements a digital ballast for a 70 W HID lamp (sodium or metal halide) used in general lighting applications. The ballast is composed of a boost converter (power factor controller PFC) working in transition mode and an inverter composed of a half-bridge that drive the lamp in low-frequency square wave.

Both the half-bridge and the PFC stage are managed by the ST7LITE49K2 that controls the L6382D5, activating all the power switches.

This board was designed to drive super highbrightness multicolor RGB LEDs with current up to 700 mA per LED. The LED brightness and color are very easily changed by potentiometers, and an automatic color-change mode continuously modulates the color of the LED to generate multicolor light. A LED over-temperature protection is designed on this board, so the power delivered to the LED can be automatically limited to prevent LED overheating.

The STEVAL-ILL009V1 is a motherboard assembled without LEDs. To evaluate light effect features, it is necessary to order a load board.

Two load boards are available for easy performance evaluation. The first with a OSTAR projection module has ordering code STEVALILL009V3, and the second with Golden Dragon LEDs has ordering code STEVAL-ILL009V4

The STEVAL-ILL009V5 demonstration board was designed in order to allow evaluation and testing of the new DC-DC converter ST1S10 and new LED drivers STP04CM05 and STP08CP05. This board replaces the previous version STEVALILL009V1.

Thanks to the ST1S10 DC-DC converter, the size of the inductor and board dimensions are reduced. The dimensions of the STEVAL-ILL009V5 are 120 mm x 47 mm, instead of 151 mm x 47 mm for the STEVAL-ILL009V1.

The input voltage for this board ranges from 7 V to 18 V. The new LED drivers allow faster communications and higher output voltage. Other features such as software, brightness and color regulation, microcontroller and temperature protection, are identical on both the STEVALILL009V1 and the new STEVAL-ILL009V5.

The use of high power LEDs in lighting applications is becoming increasingly popular due to rapid improvements in lighting efficiency, longer life, higher reliability and overall cost effectiveness. Dimming funtions are more easily implemented in LEDs, and they are more robust and offer wider design flexibility compared to other light sources.

The STEVAL-ILL013V1 demonstration board is an 80 W offline dimmable LED driver with high power factor (PF) intended for 350 mA, 700 mA and 1 A LEDs.

The converter is designed as a constant current source to achieve the best lighting performance from the LEDs, and can be used for lighting applications from low power, low voltage to high power, high voltage. This allows designers to cover a wide range of different LED systems using a single topology.

Additionally, in lighting applications where the input active power is higher than 25 W and a high power factor is required, the high PF converter can be connected as the first stage, before the modified BUCK converter.

This demonstration board design is complaint with standard EN61000-3-2 (limits for harmonic current emissions).

The best way to power LEDs is to control the forward current in order to achieve good matching of light output. LED manufacturers specify the characteristics (such as lumens, beam pattern, color) of their devices at a specified forward current.

The STEVAL-ILL014V1 evaluation board demonstrates the operation of the STCS1 constant current LED driver. The STCS1 is capable of controlling the LED current under several application conditions, while also providing useful features that make it suitable for different applications such as advertising signs, automotive interior and exterior lighting, and emergency vehicle warning lights.

The STEVAL-ILL019V1 demonstration board implements an isolated high-PF flyback converter based on the L6562A transition-mode PFC controller, capable of supplying 4 constant-current outputs for 4 different RGGB LED modules.

Each module can contain 5 to 13 LEDs, with each current channel set to 350 mA.

It is possible to choose between automatic color change mode or manual color adjustment mode (in the latter case some external components are required).

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.

Rapid advances in LED technology has led to increases in their output current capabilities in recent years. 0.350 A LEDs, for example, were soon followed by 0.7 A LEDs, and then 1 A devices appeared shortly thereafter. Currently, LEDs with currents as high as several amps are present on the market. However, these high currents increase the requirements of the driving circuitry of the LEDs, particularly in terms of efficiency.

The STEVAL-ILL023V1 demonstration board is based on the L6726A single phase PWM controller, with two external MOSFETS for synchronous rectification. Designed for 2.8 A LEDs (1-3 in a series string), the main benefit of the solution is its exceptional efficiency. Ease of dimming and scalability to even higher currents are additional advantages of the design.

The solution is also much safer with regard to border conditions, since the current limit is based solely on the selection of the MOSFETS.

The STEVAL-ILL024V1 LED matrix control unit demonstrates the capabilities of the STP16DP05 LED driver to drive an LED matrix panel. The control unit is part of a complete LED matrix display demonstration system that includes the STEVAL-ILL025V1 LED matrix display panel.

The STM32F103VB microcontroller-based control unit can be configured to operate as master (responsible for sending the commands for display control) or as slave (responsible for receiving commands and executing them on the display unit).

The display can be configured with a PS2 keyboard for any of nine available display modes and nine different speeds, or the display settings can be configured through Windows® HyperTerminal™ using the serial interface included on the control unit.

A GPS module can be connected through a USART port to allow GPS data to be displayed with latitude, longitude and real-time clock information.

The system also includes audio output for playback of the prerecorded .wav file from the microSD card.

The STEVAL-ILL025V1 LED matrix display panel demonstrates the capabilities of the STP16DP05 LED driver to drive an LED matrix panel. This board is the display unit of a complete LED matrix display demonstration system that also includes the STEVAL-ILL024V1 LED matrix control unit.

The control unit is an STM32F103VB microcontroller-based system used for configuring the settings of the STP16DP05 display driver.

The display can be configured with a PS2 keyboard for any of nine available display modes and nine different speeds, and the display settings configured through Windows® HyperTerminal™ using the serial interface included on the control unit.

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 V_DD pin, 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 STEVAL-ILL027V2 implements a non-isolated, soft-switched, single-stage, high power factor offline LED driver.

The buck-boost converter is chosen for this application due to its simplicity and low cost.

The converter operates with constant peak current for constant power control and in transition mode (boundary mode between CCM and DCM), to achieve soft switching, using the L6562A controller.

This single-stage buck-boost converter provides a cost-effective solution for offline non-isolated LED applications and it also has open load and short-circuit protection.

The STEVAL-ILL029V1 front panel demonstration board provides an evaluation platform for the STLED325 advanced LED controller driver, and the STM8S 8-bit microcontroller as I²C master.

The features of the STLED325 that this front panel application demonstrates include key scanning, RTC, IR decoding, and standby management. These features are required to address the market segment for DVD players, DVD recorders, set-top boxes, washing machines and many others, while keeping system costs as low as possible.

The system can be operated using the front panel keys mounted on the board, or by remote control.

System I/Os are handled completely by the STLED325, with minimal load on the host processor.

The STEVAL-ILL032V1 is a demonstration board featuring the STP24DP05BTR RGB LED driver to drive the RGB LED matrix panel.

The STEVAL-ILL032V1 demonstration board is part of a complete system which includes at least one control board (STEVAL-ILL033V1) and one RGB LED matrix display panel.

The STEVAL-ILL033V1 demonstration board functions as the control board of a complete system which shows the capability of the STP24DP05 RGB LED driver to drive the RGB LED matrix display panel. The complete system includes one control board and one RGB LED matrix display panel.

The STEVAL-ILL033V1 control board employs the STM32F103VET6 microcontroller which is used to configure the display settings of the STP24DP05 display driver.

The control unit has a PS2 keyboard interface for data entry in which the color combinations of the display text and background can be configured during the run time.

The STEVAL-ILL034V1 demonstration board is able to implement a non-dimmable, non-isolated LED driver.

The physical design is small enough to fit inside the base of an A19 bulb outline.

The coupled inductor has a step-down winding to power the L6562A PFC driver.

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.).

The STEVAL-ILL037V1 demonstration board implements a 3.2 W (16 V / 0.2 A) wide range LED driver to support from 3 to 5 LEDs for LED lamps (e.g. E27 and GU10).

The HVLED805 is an offline all-primary sensing switching regulator, specific to offline LED drivers, based on quasi-resonant ZVS (zero voltage switching at switch turn-on) flyback topology, due to its simplicity and low cost.

The STEVAL-ILL038V1 demonstration board implements a 100 W LED switched-mode power supply (SMPS) based on the L6585DE. This device embeds a high-performance transition mode (TM) Power Factor Correction (PFC) controller, Half-Bridge (HB) controller and all the relevant drivers necessary to build a combo IC.

The L6585DE embeds a wide range of features to provide an energy-saving and cost-effective solution for LED SMPS.

The PFC section of this IC has superior performance in terms of harmonic content mitigation. High Power Factor (PF) and Total Harmonic Distortion (THD) reduction are obtained as required by international norms, especially concerning universal input voltage operations. The TM PFC operation and high-efficiency performance of the half-bridge topology provide very good overall circuit efficiency.

In order to guarantee maintenance-free operation required by this kind of application during the LED’s lifetime, the STEVAL-ILL038V1 board doesn’t use any electrolytic capacitors which have been replaced by safer film capacitors.

Other features, such as half-bridge overcurrent with frequency increase and PFC overvoltage, allow designers to build a reliable and flexible solution with a reduced component count.

The purpose of the STEVAL-ILL039V1 demonstration board is to provide an example for applications of an LED driver using the step-up controller STLDC08.

The STLDC08 is designed for handheld equipment supplied by AA or AAA batteries and provides a precise constant current starting from a variable input voltage source.

The LED current is set by an external sense resistor inserted between the feedback pin (FB) and GND.

A regulation loop holds the voltage drop at the sense resistor at a constant level (100 mV typ.).

The purpose of the STEVAL-ILL039V2 demonstration board is to provide an example for applications of an LED driver using the step-up controller STLDC08.

The STLDC08 is designed for handheld equipment supplied by AA or AAA batteries and provides a precise constant current starting from a variable input voltage source.

The LED current is set by an external sense resistor inserted between the feedback pin (FB) and GND.

A regulation loop holds the voltage drop at the sense resistor at a constant level (typ. 100 mV).

The STEVAL-ILL041V1 demonstration board implements an LED driver that meets the present requirements for the US market.

The STEVAL-ILL041V1 utilizes ST’s L6564 power factor controller in an unconventional circuit to regulate the input power to a step-down switching regulator. The circuit also compensates for variations in LED voltage drop, to maintain the average output current in a tight band over a wide range of line voltage and LED characteristics.

While the input current waveform is not perfectly sinusoidal, power factor and harmonic content are well within the requirements for the US commercial market.

The form factor was designed to fit into the PAR38 envelope and the driver and LEDs can be used to replace 65 W incandescent flood lamps.

The STEVAL-ILM001V1 is a plug-in module for the STM8S-DISCOVERY kit and SW DALI library, to create a fully working DALI slave application. The STM8S-DISCOVERY + STEVAL-ILM001V1 work as a DALI slave device and can be connected to and controlled by any DALI network.

The LD1 on the STM8S-DISCOVERY kit is used as a light source. Its brightness, fade-in/out times, etc., as defined by the DALI standard, can be controlled through DALI to simulate a normal lamp behavior.

The DALI (Digital Addressable Lighting Interface) standard is a communication protocol widely used in intelligent lighting applications. Its use is not limited to fluorescent tube lamp dimmable ballasts, for which it was initially designed, but also for future LED applications.

The user is expected to be familiar with the DALI standard and its details.

This evaluation board is based on the STLD40D that is a boost converter that operates from 3.0 V to 5.5 V and can provide an output voltage as 37 V and can drive up to 10 white LEDs in series. The converter is a PFM (pulse frequency modulation) inductor switches and can work in discontinuous (DCM) mode operation. A minimum OFF time of the embedded boost switch TSW is fixed internally and allows limiting the switching frequency. The output current capability is 20 mA with an output voltage of 37 V. The regulation is done by sensing the led current through the resistor R_LED. The device can be turned ON/OFF through the logic enable signal pin EN. Applying a low frequency PWM signal the LEDs can be dimmed. The maximum peak inductor current can be programmed.

This evaluation board is based on the STCF01, that is a white LED driver optimized for driving two to four LEDs from a Li-Ion battery input.

It provides up to 300 mA over an input voltage range of 2.6 V to 5.5 V and it features 16.5 V output voltage, 1.5 MHz internal power switch, internal soft start, open load voltage protection and optimized internal compensation.

Only an inductor, a Schottky diode, two capacitors and two resistors are required. Besides, a low output ripple is guaranteed by the current mode PWM topology and by the use of low E.S.R. SMD ceramic capacitors The STCF01 is ideal for camera flash in cellular phones requiring, small circuit size and very high efficiency (up to 90%).

This demonstration board implements a flash LED driver using the STCF06 device, which is a buck-boost current mode converter with an I²C interface.

The flash LED driver STCF06 has a high operating frequency (1.8 MHz) which allows the usage of small external components.

The demonstration board is designed for driving a single LED with a forward voltage range from 2.7 to 5 V.

For easy connection to a PC, the STEVALTLL006V1 uses a μPSD-based motherboard used as a bridge.

The STCF06 motherboard uses an USB human interface device to communicate with the PC. It is not necessary to install a driver, if the operating system in use is capable of enumerating USB human interface devices.

The STEVAL-TLL006V2 demonstration board implements a flash LED driver using the STCF06 device, which is a buck-boost current mode converter with an I²C interface.

As technology for external components has greatly improved, in this new version “V2” it was possible to shrink the original application and maintain the same level of performance or similar.

The flash LED driver STCF06 has a high operational frequency (1.8 MHz) which allows the use of small external components.

The STEVAL-TLL006V2 is designed for driving a single LED with a forward voltage range from 2.7 to 5 V.

For easy connection to the PC, a motherboard is supplied based on μPSD which is used as a bridge.

The STCF06 motherboard uses a USB human interface device class to communicate with the PC. It is not necessary to install any driver, if the operating system is able to enumerate USB human interface devices.

Connect the motherboard to the PC through the USB cable (AB type). Wait until the computer enumerates the control board and displays the message that new hardware has been found and is ready to use. It is then possible to run the data packet creator application by pressing the “Connect board” button.

This demonstration board is dedicated to the STCF05 flash LED driver IC, which is a boost current mode converter with an I²C interface and internal current source. The STCF05 is designed to drive two LEDs in series with a total forward voltage from 5.3 V to 10.2 V.

For easy connection to a PC, the STEVALTLL007V1 uses a μPSD-based motherboard used as a bridge.

The STCF05 motherboard uses a USB human interface device to communicate with the PC. It is not necessary to install a driver, if the operating system in use is capable of enumerating USB human interface devices.

The STEVAL-TLL008V1 demonstration board is a flash LED driver using the STCF04 device, which is a buck-boost converter with an I^²C interface dedicated to charging a SuperCap.

All LEDs with a forward voltage range from 2.5 V to 5 V are compatible with the STCF04. The forward voltage spread of any selected LED must, however, be within this range (2.5 V to 5 V). It is possible to set the level of the LED current in Flash mode and Torch mode by setting the dimming registers. The maximum level of the LED current in Flash mode can be set by changing the external flash resistor.

The STEVAL-TLL009V1 demonstration board demonstrates the performance of the STCF07, a dedicated and size-optimized solution for driving a power LED.

This device is a buck-boost converter which guarantees proper LED current control over all possible battery voltage and LED forward voltage conditions.

The output current control ensures good current regulation over the forward voltage spread characteristics of high-brightness LEDs.

The device also includes various functions to protect the chip and the power LEDs, such as an optional external NTC that is supported to protect the LEDs against overheating.

It is possible to separately program the current intensity in HIGH and LOW mode using the SEL pin.

The STEVAL-TLL010V1 demonstration board is based on the STLA02, a boost converter dedicated to powering and controlling the current of white LEDs in an LCD backlight. The device operates at a typical constant switching frequency of 2.3 MHz. It steps an input voltage ranging from 2.5 V to 18 V, up to 27 V. The output current is adjustable by the resistor RFB connected between the V_OUTand FB pins. The STLA02 device contains high-side sensing to simplify the PCB layout in terms of LED connection.

The output current is dimmable by the PWM signal applied to the EN pin with minimum PWM frequency equal 100 Hz.

The STEVAL-TLL011V1 demonstration board demonstrates the performance of the STLD41, a boost converter that operates from 3.0 V to 21 V and which can provide an output voltage as high as 38 V.

It can drive up to 40 white LEDs connected in 4 strings of 10 LEDs in series. The total output current capability is 120 mA at an output voltage of 38 V.

Regulation is performed by the internal error amplifier which works with the feedback voltage from the sensing resistor.

The device can be turned ON/OFF by way of the logic signal connected to the EN pin.

The LEDs can be dimmed by applying a PWM signal to the PWM input.

The STEVAL-TLL013V1 demonstration board was designed to demonstrate the performance of the STLED25, a fixed frequency, high-efficiency, boost DC-DC converter with five parallel high-side current sources.

The STLED25 is able to provide 125 mA of total current with a maximum voltage of 7.5 V on each channel.

Each current source supports single or dual LED connections. The output voltage of the step-up converter is automatically set at 100 mV above the highest voltage required on any driver to guarantee the proper operation of the linear current sources. The device implements a self-test feature to detect any failure of the LEDs and to disable the related channel.

The failure status is reset as soon the IC is disabled. This mode of failure detection allows the device to continue operating driver channels that are operating normally, while avoiding excessive power consumption or associated thermal issues.