ISL9492ERZ-T

The ISL9492 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 (LNB) of a single antenna port.
It also supports DiSEqC tone generation and modulation with
diagnostic status read-back. Controlling the ISL9492 is simple
via the I2C bus by writing 8 bit words onto the System
Registers (SR).
The device design makes the total LNB supply design simple,
efficient and compact with low external component count by
integrating Boost power MOSFET, current-mode boost PWM
and a low-noise linear regulator. The current-mode boost
converters provide the linear regulator with input voltage that
is set to the final output voltages, plus typically 0.9V to insure
minimum power dissipation across each linear regulator.
The LNB output voltage can be controlled in two ways; by full
control from I2C using the VTOP and VBOT bits or by setting the
I
2C to the lower range and switching to higher range with the
select VTOP pin.
The External modulation input EXTM accepts a modulated
DISEqC command and transfers it symmetrically to the output.
The EXTM pin can be used to modulate the continuous internal
tone. The fault signal serves as an interrupt for the processor
when any condition turns OFF the LNB controller
(over-temperature, overcurrent, disable). The states of these flags
to the faults can be thoroughly examined through the I2C
registers.