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.
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-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.
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.
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.
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.
“ROHM Co. Ltd. was established in Kyoto, Japan, in 1958. ROHM designs and manufactures semiconductors, integrated circuits and other electronic components. These components find a home in the dynamic and ever-growing wireless, computer, automotive and consumer electronics markets…..”
1954 – Toyo Electronics Industry established. Carbon film resistors developed and marketed. 1967 – Transistors and switching diode developed and marketed.
Exar Corporation based in Fremont, CA. designs, develops and markets high-performance, analog and mixed-signal silicon solutions for a variety of markets including networking, communications, and storage.
Other Areas are
Power solutions, power and system architecture, LED-Lighting.
Networking, UART and serial protocol transceiver solutions, Storage.
Royal Philips Electronics of the Netherlands is a global leader in healthcare, lifestyle and technology, delivering products, services and solutions through the brand promise of “sense and simplicity”.
The company was founded in 1891 by Gerard Philips, a maternal cousin of Karl Marx, in Eindhoven, the Netherlands. Its first products were light bulbs ‘and other electrotechnical equipment’. Its first factory remains as a museum. Koninklijke Philips Electronics N.V. – Wikipedia
Vintage Philips Tape Recorder Transistor based
(I have fixed some of these decades ago, if i remember right, it had only transistors, no chips. I am not sure if it was only germanium transistors, but i used both silicon and germanium devices to repair – ananth)