Single Output LNB Supply and Control Voltage Regulator with I2C Interface for Advanced Satellite Set-top Box Designs

The ISL6421A is a highly integrated solution for providing power and control signals from advanced satellite set-top box (STB) modules to the low noise block (LNB). The internal architecture of this device contains a current-mode boost PWM 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.

Features
• Switch-Mode Power Converter for Lowest Dissipation
    - Boost PWM with >92% Efficiency
    - Selectable 13V or 18V Outputs
    - Digital Cable Length Compensation (1V)
    - Vsw tracks Vout ensures low dissipation
• I2C Compatible Interface for Remote Device Control
    - Registered Slave Address 0001 00XX
    - Fully Functional 3.3V, 5V Operation up to 400kHz
• Built-In Tone Oscillator Factory Trimmed to 22kHz
    - Facilitates DiSEqC™ (EUTELSAT) Encoding
    - External Modulation input DSQIN
• Internal Over Temperature Protection and Diagnostics
• Internal Overload and Over Temperature Flags (Visible on I2C)
• Output Back-Bias Protection to 24V
• LNB Short-Circuit Protection and Diagnostics
• QFN Package
    - Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Product Outline
    - Near Chip-Scale Package Footprint
• External Pins to Select 13V/18V Options
• Pb-Free Available (RoHS Compliant)

Applications
• LNB Power Supply and Control for Satellite Set-Top Box