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ISL6421
Single Output LNB Supply and Control Voltage Regulator with I2C Interface for Advanced Satellite Set-top Box Designs
FN9130 Rev 1.00 Jul 2004
The ISL6421 is a highly integrated solution for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise block (LNB). This device is comprised of a current-mode boost PWM and a low-noise linear regulator, along with the circuitry required for I2C device interfacing and for providing DiSEqCTM 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. The regulated output may be set to either 13V or 18V by use of the voltage select command (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 (LLC) feature. An enable command sent on the I2C.