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

The ISL6405 is a highly integrated voltage regulator and interface IC, specifically designed for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise blocks (LNBs) of two antenna ports. The device is comprised of two independent currentmode boost PWMs and two low-noise linear regulators along with the circuitry required for 22kHz tone generation, modulation and I2C device interface. The device makes the total LNB supply design simple, efficient and compact with low external component count.

Features

• Single Chip Power solution

- True Dual Operation for 2-Tuner/2-Dish Applications

- Both Outputs May be Enabled Simultaneously at Maximum Power

- Integrated DC-DC Converter and I2C Interface

• Switch-Mode Power Converter for Lowest Dissipation

- Boost PWMs with > 92 Efficiency

- Selectable 13V or 18V Outputs

- Digital Cable Length Compensation (1V)

• I2C Compatible Interface for Remote Device Control

- Registered Slave Address 0001 00XX

- Full 3.3V/5V Operation up to 400kHz

• External Pins to Select 13V/18V Options

- Available with QFN Package Only

• Built-In Tone Oscillator Factory Trimmed to 22kHz

- Facilitates DiSEqCTM (EUTELSAT) Encoding

• Internal Over-Temperature Protection and Diagnostics

• Internal Overload and Overtemp Flags (Visible on I2C)

• 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

• Pb-free Packaging Available

- Designated with “Z” Suffix (Refer to Note Below)

Applications

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