• Complete integrated solution for LNB and I²C interface
• DiSEqC 2.x, and DiSEqC 1.x compatible
• Supports 5-V, 12-V, and 15-V power rail
• Up to 1000-mA accurate output current limit adjustable by external resistor
• Boost switch peak current limit proportional to LDO current limit
• Boost converter with 140-mΩ low R_ds(on) internal power switch
• Boost switching frequency 1-MHz or 500-kHz selectable
• Audible noise avoided at force PWM mode
• Dedicated enable pin for non-I²C application
• Low-dropout (LDO) regulator with push-pull output stage for VLNB output
• Built-in accurate 22-kHz tone generator and external tone input support
• Supports both external 44-kHz and 22-kHz tone input
• Adjustable soft start and 13-V to 18-V voltage transition time
• 650-mV to 750-mV 22-kHz tone amplitude selection
• I²C registers accessible with EN low
• Short circuit dynamic protection
• Diagnostics for output voltage level, DiSEqC tone input and output, current level, and cable connection
• Thermal protection available
• 20-pin WQFN 3-mm × 3-mm (RUK) package

• Set top box satellite receiver
• TV satellite receiver
• PC card satellite receiver
• Satellite TV

Designed for analog and digital satellite receivers, the TPS65235-1 is a monolithic voltage regulator with I²C interface; specifically to provide the 13-V to 18-V power supply and the 22-kHz tone signal to the LNB down converter in the antenna dish or to the multi-switch box. The device offers a complete solution with minimum component count, low power dissipation together with simple design and I²C standard interface.

The TPS65235-1 features high power efficiency. The boost converter integrates a 140-mΩ power MOSFET running at 1-MHz or 500-kHz selectable switching frequency. Drop out voltage at the linear regulator is 0.8 V to minimize power loss. The TPS65235-1 provides multiple ways to generate the 22-kHz signal. Integrated linear regulator with push-pull output stage generates 22-kHz tone signal superimposed at the output even at zero loading. Current limit of linear regulator can be programmed by external resistor with ±10% accuracy. Full range of diagnostic read by I²C is available for system monitoring.

The TPS65235-1 has a special design at FCCM mode to avoid the audible noise especially when VIN is higher or closer to the VLNB output.

The TPS65235-1 supports advanced DiSEqC 2.x standard with 22-kHz tone detection circuit and output interface.

Simplified Schematic