8281
AND
8282
A8282SLB
NC
OLF
VBULK
NC
NC
GND
GND
SENSE
LNB
LX
VIN
TCAP
1
2
3
24
23
22
EXTM
VINT
PUMPX
VPUMP
CPUMP
GND
GND
ENT
EN
VSEL0
VSEL1
LLC
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
Intended for analog and digital satellite receivers, these low-noise
block converter regulators (LNBRs) are monolithic linear and switching
voltage regulators specifically designed to provide the power and
interface signals to the LNB down converter via the coaxial cable. If the
device is in standby mode (EN terminal low), the regulator output is
disabled, allowing the antenna down converters to be supplied or
controlled by other satellite receivers sharing the same coaxial cable. In
this mode, the device will limit the output reverse current.
The A8281SLB output is set to 13 or 18
-
V by the VSEL terminal. It
is supplied in a 16-lead SOIC power-tab package. The power tabs are at
ground potential and need no electrical isolation.
The A8282SLB output is set to 12, 13, 18, or 20
-
V by the VSEL
terminals. Additionally, it is possible to increase the selected voltage by
1
-
V to compensate for the voltage drop in the coaxial cable (LLC
terminal high). It is supplied in a 24-lead SOIC power-tab package.
The power tabs are at ground potential and need no electrical isolation.
The A8282SLB is an improved version of the A8283SLB, without a
bypass switch.
Data Sheet
27448.2c
CHARGE
PUMP
BUCK
REG.
4
5
6
7
8
9
9
10
11
12
21
20
19
18
17
16
15
14
13
VOLTAGE
CONTROL
Dwg. PP-072-2
FEATURES
s
LNB selection and standby function
s
Built-in tone oscillator factory trimmed to 22
-
kHz, facilitates
DiSEqC™ (a trademark of EUTELSAT) encoding
s
Tracking switch-mode power converter for lowest dissipation
s
Externally adjustable short-circuit protection
s
LNB short-circuit protection and diagnostics
s
Auxiliary modulation input
s
Internal over-temperature protection
s
Reverse-current protection
s
Cable length compensation (A8282SLB only)
ABSOLUTE MAXIMUM RATINGS
at T
A
= +25
°
C
Supply Voltage, V
IN
...........................
47-V
Output Current, I
LNB
....
Internally Limited
Output Voltage Range, V
LNB
..
-1-V to +22-V
Logic Input Voltage Range,
V
I
...................................
-0.3-V to +7-V
Flag Output Voltage, V
OLF
...................
7-V
Operating Temperature Range,
T
A
.................................
-20
°
C to +85
°
C
Junction Temperature, T
J
................
+150
°
C
Storage Temperature Range,
T
S
..............................
-55
°
C to +150
°
C
These devices incorporate features that have patents pending.
Always order by complete part number, e.g.,
A8282SLB
.
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
