Constant LED Brightness and LDS8711

The LDS8711 is a fixed frequency current mode boost converter with internal rectifier and cycle-by- cycle switch current limit specifically designed to drive a string of up to 10 White LEDs.

Constant LED Brightness and LDS8711

Aa Switching Converter Chip with hardly any external components driving a HB LED chain. HB – High Brightness LED. This IC is from IXYS Power Devices.

High efficiency boost converter with the input voltage range from 2.7 to 5.5 V . Drives one LED string with 10 LEDs in series up to 32 mA.

  • 250 mV current sense voltage
  • No external Schottky Required
  • 0.7 MHz Switching Frequency
  • Efficiency greater than 83%
  • PWM LED Brightness Control
  • Low Shutdown Current (<1µA)

LED Current Setting – The maximum current value in the LED string may be factory preset in the range from 10 to 30mAin 0.125mA steps, or set by Smart OneWire interface in the range from 0.125to 32 mA.The average LED string current that determines LED brightness may be controlled applying PWM signal to the EN/PWM pin.

LED Drive using TPS61042 from TI

This Chip from TI is simple to integrate into your designs and this solution is good for production of lighting gadgets, here a consistent quality and predictable performance is easily obtained.

TPS61042 30-V, 500-mA Switch Boost Converter in QFN-8 for White LED Applications

LED-driver application that drives four LEDs with 20 mA of forward current and operates from an input voltage range of 1.8 to 6.0 V.

LED Drive using TPS61042

 

The entire circuit consists of the control IC, two small ceramic caps, an inductor, a diode, and a current sense resistor. The primary power-supply functions and the secondary features such as load disconnect, overvoltage protection, and PWM dimming have been implemented with a control IC and five small surface-mount passive components.

LED-driver considerations By Michael Day

MAX1910 White LED Charge Pumps – Maxim IC

Drives LEDs with a regulated output voltage or current (up to 120mA) from an unregulated input supply (2.7V to 5.3V). These are complete DC-DC converters requiring only four small ceramic capacitors and no inductors. 200mV Current-Sense Threshold Reduces Power Loss.

MAX1910 White LED Charge Pumps – Maxim IC

MAX1910 White LED Charge Pumps - Maxim IC

1.5x/2x High-Efficiency White LED Charge Pumps

Some Features

  • High-Efficiency 1.5x/2x Charge Pumps
  • Low Input Ripple with 750kHz Operation
  • Up to 120mA Output Current
  • 1µA Shutdown Current

Toshiba Electronic Components

Toshiba Electronics Europe (TEE) offers a wide IC and discrete product range. high-end memory, microcontrollers and ASIC. Optoelectronic Semiconductors include Light Emitting Diodes (LEDs) and Photocouplers.

Toshiba Electronic Components

Toshiba InGaAlP LED-devices feature high brightness as it employs four-element LED chip technology (InGaAlP). Higher Visibility, Low Power and Reliable LEDs for Lighting.

Toshiba News n-channel power MOSFET

Toshiba expands family of semi power devices with new n-channel power management MOSFET. – Toshiba News n-channel power MOSFET

Also see this page What’s Fuel Cell ? – “Fuel Cell is not a battery but a generator. The principle is the reverse of “electrolysis of water”

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Toshiba has a wide and very diverse range of components and advanced materials technologies.