 LNBH24 Product Page
Together with the LNBH23 (single tuner solution)
already in full production, the new LNBH24 represents
the latest generation of ICs for supplying/interfacing
two LNB down-converters, with two independent fully
integrated current-mode boost PWMs and two very
low-drop linear regulators. Control is through a single
I2C interface, giving all the additional functions required
for satellite international standards (DTV, Eutelsat).
Using ST's proprietary advanced BCD process, this
monolithic linear and switching-voltage regulator works
with high efficiency, extremely low noise and ripple
figures, due to the high levels of component integration.
The device includes two completely independent
sections separately controlled, except for the Vcc and
I2C inputs. |
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 Built-in DC/DC converter for single 12 V supply operation, and high efficiency (typ. 93 %@0.5 A)
Single I2C Interface for both output control functions and diagnostics
Very low-drop post regulators and high-efficiency
STEP-UP PWM with integrated power N-MOS allow
low power losses
Built-in 22 kHz tone generator and detector
(supporting bidirectional DiSEqC 2.0)
New tone generator (Enabled by TTX I2C bit or TTX
pin) with dedicated VoTX push-pull output pin for
22 kHz Tone generator to bypass the external RL
filter during DiSEqC 22 kHz transmission
Fine tuning output current limit by external resistor
Output voltage, output current, 22 kHz tone
frequency and amplitude diagnostic functions
Overload and over temperature protection with I2C
diagnostic bits
Fully integrated Itest circuit for
minimum current
diagnostic
Low profile
PSSO-36
exposed Pad
The LNBH24 provides up to 750 mA continuous load
current for each channel, while the highest current limit
threshold can be fine-tuned up to a typical value of
1 A through an external resistor connected to the
Isel pin. Two output pins are also dedicated to bypass
the RL filter during 22 kHZ tone transmission, reducing
the external component count across the filter.
The diagnostic features detect the output voltage level,
a minimum current output shows a correct LNB
connection on the bus or the cable status connection
to the IRD, and the DiSEqC tone output.
These diagnostic functions are available through the
I2C bus reading 8 bits on the system register. Each
section (A/B) has two addresses selectable respectively
by the ADDR-A and ADDR-B pins.
LNBH24 application circuit showing the typical configuration
for a dual LNB power supply
Part number
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Package
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PSSO-36 ePAD |
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