Silan launched hysteresis control mode of LED drive solutions

Silan recently launched a new high performance, high reliability, high power green lighting drive solutions the core chip, 6~36V input, 1A high power LED driver chip SD42525 hysteresis.

The chip uses a Silan "on the output current changes with input voltage compensation" and "input and output pressure is small with the maximum duty ratio limiting" patent technology based on Silan designed for high performance BCD technology of green energy products are developed, and integrated LDMOS power switch tube in single chip in the built-in PWM dimming module and multiple protection function. The chip is a step-down, constant current LED driver circuit, with high conversion efficiency, suitable for MR16 and other LED lighting field.

SD42525 using hysteresis control mode, with fast transient response without the need for additional loop compensation design, only a few external components, greatly reduce the cost of application. Generally speaking, hysteresis control mode LED driver circuit due to internal comparator and the system delay, thereby causing the output current with the input voltage and load LED the number of changes, changes in the input voltage range of 36V to 6V, the output current will change from 10% to 15%. While SD42525 uses the output current compensation Silan patented technology, can greatly reduce the output current as the input voltage changes, the range of output current can be controlled in the range of 3%. In addition, hysteresis control mode of the duty ratio of the input voltage and the load drop by LED, when the input voltage and load voltage is close to LED, the duty ratio can reach 100%, the output current is much greater than the normal operating current can be as high at this time, about 20%. Therefore, the chip is added to the maximum duty cycle module to ensure the maximum duty cycle is not more than 96%, thereby preventing the output current is too high, so that the output current is more stable.

Adopts advanced BCD technology, and the internal use of the trimming technology of high precision, the output current of the chip has good consistency and control within 3% of the chip can output current difference of different batches.

SD42525 can use the DIM pin PWM dimming or analog dimming, two dimming mode multiplexing a pin, allowing customers to be more simple and effective application. PWM dimming precision is high, compared with the analog dimming, there will be no LED color shift phenomenon, can meet the 100Hz ~ 20kHz range dimming requirements. The chip has a soft start function, and the soft start time is determined by setting the appropriate capacitor between the DIM pin and the ground.

The power switch of LDMOS advanced system architecture and a built-in low resistance pipe, which makes the system composed of SD42525 conversion efficiency can reach above 96%. Again, the chip integrated temperature protection, current limiting and other multiple protection circuit to ensure that the working environment of the LED lamp is normal, and its service life is prolonged. SD42525 has SOP-8, SOT-23-6L, SOT-89-5L three forms of packaging, convenient for customers to choose the appropriate package type.

The chip can be used in DC input and AC input and other typical applications. DC input typical applications, a wide input voltage range of up to 6V~36V, the maximum output current of 1A. When the input voltage is 24V, 6 LED can be connected in series, and the peripheral components of the system are very few, so it is very suitable for 24V power supply system.

In the typical application of MR16 lamp AC input in the input voltage range is AC12V, only need 8 peripheral devices.

Silan microelectronics is a special process in the field of integrated circuit chip design and manufacturing enterprise operation mode integration of design and manufacturing, has been the construction of two integrated circuit chip production line, has invested huge funds for the development of special technology, currently in the 0.8 micron BiCMOS/BCD technology platform, the new device structure has has been leading research and development achievements, has established a cross platform design process and construction technology. The construction of these advanced systems will be good comprehensive ability formed in Silan microelectronics in the field of power semiconductor technology product group. The launch SD42525, enrich the Silan's driving circuit of LED lighting product line. Before Silan has launched a series of drive products of different specifications, can meet a variety of LED lighting applications, such as for LED lamp SD42351, applied to the MR16 lamp SD42522, used in landscape lighting SD42524, used for lifting pressure environment SD42560.