LED technology is progressing fast however a very controlled driver integrated modules and so on. was produced in the market HV9910 used to drive high power LEDs (high-efficiency PWM LED driver) and MIC3201 integrates computation programs prepared for this to be integrated with the design of the circuit pretty easy.
HV9910 Universal High Brightness LED Driver
HV9910 is a PWM high-efficiency LED driver control IC. It allows efficient operation of High Brightness (HB) LEDs from voltage sources ranging from 8VDC up to 450VDC. The HV9910 controls an external MOSFET at fixed switching frequency up to 300kHz. The frequency can be programmed using a single resistor. The LED string is driven at constant current rather than constant voltage, thus providing constant light output and enhanced reliability. The output current can be programmed between a few milliamps and up to more than 1.0Amp.
MIC3201 High Brightness LED Driver Current Sense
MIC3201 is a hysteretic step-down, constant-current, High-Brightness LED (HB LED) driver capable of driving up to four, 1A LEDs. It provides an ideal solution for interior/exterior lighting, architectural and ambient lighting, LED bulbs, and other general illumination applications. The MIC3201 operates with an input voltage range from 6V to 20V. The hysteretic control gives good supply rejection and fast response during load transients and PWM dimming. The high-side current sensing and on-chip current sense amplifier delivers LED current with ±5% accuracy. An external high-side current sense resistor is used to set the output current.
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Published: 2012/07/06 Tags: electronics software tools
Surge Protection Circuit Thyristor TIC126
The construction of the mentioned protection against overvoltage me besides the fact that most electronic components (active semiconductor components) is too high supply voltage is destroyed. Therefore Safety expensive electronic system or apparatus is therefore to protect against power surges, no unnecessary luxury. A prerequisite for the effectiveness of such protection is the speed of response. It does not make sense use a surge protector with a slow relays to disconnect power surges, because it’s long too late when we relay drops out. Therefore, for protection against surges thyristor TIC126 is used, which is much faster than conventional relay. If the surge and the thyristor lights and shorts the supply voltage. This has connected device is protected. As a result of a short circuit is melted fuse F1 and interrupts power supply. Threshold voltage can be set by the potentiometer P1 between 5V and 25V 5A.
Surge Protection Schematic Diagram