LNBP8 ,LNB SUPPLY AND CONTROL VOLTAGE REGULATORLNBP8LNBP9LNB SUPPLY AND CONTROL VOLTAGE REGULATOR
LNBP8-LNBP8V7V-LNBP9
LNB SUPPLY AND CONTROL VOLTAGE REGULATOR
1/8November 2004 SIMPLEST INTEGRATED SOLUTION FOR
THE LNB REMOTE SUPPLY AND CONTROL 500mA GUARANTEED OUTPUT CURRENT DUAL INPUT SUPPLY FOR REDUCING
POWER DISSIPATION 22KHZ BUILT-IN TONE OSCILLATOR
(LNBP9 VERSION) FAST OSCILLATOR START-UP FOR
DiSEqCTM ENCODING (LNBP9 VERSION) AUXILIARY MODULATION INPUT FOR
MORE FLEXIBILITY (LNBP8 VERSION) STAND-BY FUNCTION SHORT CIRCUIT AND
OVERTEMPERATURE PROTECTION AVAILABLE IN THRU-HOLE PACKAGE
DESCRIPTIONIntended for analog and digital satellite receivers,
the LNBP is a monolithic linear voltage regulator,
assembled in HeptawattTM , specifically designed
to provide the powering voltages and the
interfacing signals to the LNB down-converter.
The regulator output can be logic controlled to be
13V or 18V (typ.) by mean of the VSEL pin for the
remote controlling of the LNB. In order to reduce
the power dissipation of the device when the
lowest output voltage is selected, the regulator
has 2 supply inputs (VCC1 and VCC2). They must
be powered respectively at 15V (min.) and 22V
(min.), and an internal switch will automatically
select the appropriate supply voltage according to
the selected output voltage.
The TONE pin (only for the LNBP9 version)
activates the internal oscillator so that the DC
output is modulated by a 22KHz square wave.
This internal oscillator is factory trimmed within a
tolerance of +/- 2KHz, thus no further adjustment
or external components are required.
A burst coding of the 22KHz tone can be
accomplished thanks to the fast response of the
TONE input and the prompt oscillator start-up.
This helps designers which want to implement the
DiSEqCTM protocols.
In order to improve design flexibility and to allow
implementation of other LNB remote control
standards, an analogic modulation input pin
(EXTM) is available (LNBP8 version only). An
appropriate DC blocking capacitor must be used
to couple the modulating signal source to the
EXTM pin.
Both versions integrate thermal and short circuit
protection.
The device is packaged in Heptawatt for an easy
thru-hole mounting. If an adequate Heatsink is
provided and higher power losses are acceptable,
both supply pins can be powered by the same 23V
source without affecting any other circuit
performance.
When the IC is powered and put in Stand-by (EN
pin LOW), the regulator output is disabled and the
IC power consumption is reduced to 300µA typ.
Table 1: Order Codes
LNBP8
LNBP9LNB SUPPLY AND CONTROL VOLTAGE REGULATOR
Rev. 1
LNBP8 - LNBP92/8
Figure 1: Pin Configuration (top view)
Table 2: Pin Descriptions
Table 3: Absolute Maximum Ratings Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.
Table 4: Thermal Data
LNBP8 - LNBP93/8
Figure 2: Block Diagram
Table 5: Electrical Characteristics (V CC1 = 16V, V CC2 = 22V, CI1 = CI2 = 0.22μF, CO =0.1μF,
ENABLE = H, TONE = L (LNBP9), EXTM floating (LNBP8), IO = 50mA, TJ = 0 to 85°C unless otherwise
specified.)
LNBP8 - LNBP94/8
TYPICAL APPLICATION CIRCUITS
Figure 3: LNBP9 with 22KHz Tone Control Pin
Figure 4: LNBP8 with external 22KHz Input Pin (EXTM)
LNBP8 - LNBP95/8
Figure 5: Single Supply Solution (1) In a single supply configuration the presence of the input resistor in the 12-15Ω range is suggested
only to reduce the device power dissipation during the 13V output condition. The resistor can be omitted
in spite of power dissipation increase.
(2) The input diodes are mandatory to protect the device from any reverse current.
