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.