1 Features

• 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 Rds(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

2 Applications

• Set top box satellite receiver

• TV satellite receiver

• PC card satellite receiver

• Satellite TV

3 Description

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.