Intersil IC has high integration, better reliability

Intersil Corp. disclosed that its latest power and control IC is a highly integrated solution for providing power and control signals from advanced STB units to the satellite dish low-noise block (LNB) down converter.
According to the company, the ISL6421A IC offers high integration to reduce space and costs, high power efficiency to reduce power dissipation and heat, and high reliability to ensure long service in customer premises equipment. Richard Powers, director of marketing for Intersil's Broadband Power Products, said, "Our ISL6405 dual-output LNB down-converter supply and control voltage regulator IC is the first of its kind and was specifically designed to save satellite STB manufacturers board space, parts count and costs for their STBs."

The new IC contains both a high-efficiency current-mode boost PWM converter and a low-noise linear regulator, along with the circuitry required for I2C device interfacing and for providing DiSEqC standard control signals to the LNB. A regulated output voltage is available at the output terminal (Vout) to support the operation of the antenna port in advanced satellite STB applications. This regulated output may be set to either 13V or 18V by use of an external pin (SEL18V) or the voltage select command bit (VSEL) through the I2C bus. Additionally, to compensate for the voltage drop in the coaxial cable, the voltage may be increased by 1V with the line length compensation bit (LLC) feature.

Other features
The ISL6421A can be put into a standby mode though the enable bit (EN) that disables the PWM and linear regulator combination and helps conserve power. The input to the linear regulator is derived from the current mode boost converter, such that the required voltage is the sum of the output voltage and the linear regulator drop (1V typical). Intersil said that this ensures that the power dissipation is minimized and maintains a constant voltage drop across the linear pass element, while permitting an adequate voltage range for tone injection. The device is capable of providing 450mA (typical), and the overcurrent limit is digitally programmable to static or dynamic mode.

Housed in a near-chip-scale 32-pad 5-by-5mm QFN package, and are available on tape and reel. Additional information are available online.