Always order by the following complete part number.
Part Number Pb-Free Package Packing*
A8281SLBTR – 16-pin SOICW 1000 pieces/13-in. reel
A8282SLBTR – 24-pin SOICW 1000 pieces/13-in. reel
A8282SLBTR-T Yes 24-pin SOICW 1000 pieces/13-in. reel
*Contact Allegro for additional packing options.
Data Sheet
27448.2E
8281
AND
8282
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 package with internally-fused leads for
enhanced thermal dissipation. The fused leads 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 package with internally-
fused leads for enhanced thermal dissipation. The fused leads are at
ground potential and need no electrical isolation The A8282SLB is an
improved version of the A8283SLB, without a bypass switch.The lead
(Pb) free version has 100 % matte tin leadframe plating.
ABSOLUTE MAXIMUM RATINGS
at TA = +25°C
Supply Voltage, VIN ........................... 47-V
Output Current, ILNB .... Internally Limited
Output Voltage Range, VLNB .. -1
-
V to +22
-
V
Logic Input Voltage Range,
VI................................... -0.3-V to +7-V
Flag Output Voltage, VOLF ................... 7-V
Operating Temperature Range,
TA................................. -20°C to +85°C
Junction Temperature, TJ................ +150°C
Storage Temperature Range,
TS.............................. -55°C to +150°C
FEATURES
■LNB selection and standby function
■Built-in tone oscillator factory trimmed to 22-kHz, facilitates
DiSEqC™ (a trademark of EUTELSAT) encoding
■Tracking switch-mode power converter for lowest dissipation
■Externally adjustable short-circuit protection
■LNB short-circuit protection and diagnostics
■Auxiliary modulation input
■Internal over-temperature protection
■Reverse-current protection
■Cable length compensation (A8282SLB only)
These devices incorporate features that have patents pending.
A8282SLB
23
17
8
1
2
3
4
5
9
12
16
14
13
24
22
21
20
11
10
9
EXTM
VINT
PUMPX
VPUMP
CPUMP
GND
GND
ENT
EN
VSEL0
VSEL1
LLC
NC
OLF
VBULK
NC
NC
GND
GND
SENSE
LNB
LX
VIN
TCAP
CHARGE
PUMP
REG.
BUCK
Dwg. PP-072-2
15
VOLTAGE
CONTROL
6
7
19
18
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
2
VREF
OVER-
CURRENT
TSD
+
352 kHz
OVER-
CURRENT
R
S
200 mΩ
135 mV
900 mV
176 kHz
22 kHz TONE
ENT
PUMPX
CPUMP
VPUMP
OLF
VSEL0
(
A8282 ONLY)
VSEL1
LLC
(
A8282 ONLY)
TCAP
EXTM
SENSE
VIN
LX
VBULK
5 kΩ
1 kΩ
BOOST
VOLTAGE
7 V
V
IN
47 V MAX
CHARGE
PUMP BUCK
CONV.
÷2
÷8
&
WAVESHAPING
–
+
–
+
–
+
–
+
–
+
Dwg. FP-051-2
VINT
(A8282 ONLY)
EN 5 V
VOLTAGE
REG.
25 kΩ
5 kΩ
LNB
0.1 µF0.1 µF
+100 µF100 µF
100 µH
100 nF
0.1 µF
10 nF
15 Ω
180 µH
0.22 µF
DiSEqC TERMINATION
4.7 µF
FUNCTIONAL BLOCK DIAGRAM
and typical application
A8281SLB Output Voltage Select Table
VSEL1 VLNB
L 13 V
H 18 V
A8282SLB Output Voltage Select Table
VSEL0 VSEL1 LLC VLNB
LLL13 V
L L H 14 V
L H L 18 V
L H H 19 V
H L L 12 V
H L H 13 V
H H L 20 V
HHH21 V
Copyright © 2003 Allegro MicroSystems, Inc.
A8281SLB
PUMPX
VPUMP
CPUMP
CHARGE
PUMP
15
98
1
2
3
4
5
6
7
16
14
13
12
11
10
EXTM
GND
ENT
EN
VSEL1
OLF
VBULK
GND
SENSE
LNB
LX
VIN TCAP
VOLTAGE
CONTROL
REG.
BUCK
Dwg. PP-072-3
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
www.allegromicro.com
3
ELECTRICAL CHARACTERISTICS: unless otherwise noted at TJ < 125°C, CLNB = 0.1 µF,
4.5-V + VLNB < VIN < 47-V
Characteristic Symbol Test Conditions
Limits
Min. Typ. Max. Units
Supply Voltage Range VIN Operating 4.5 +VLNB —47 V
Output Voltage Error
(reference Output Voltage
Select table)
EVLNB 6 mA ≤ ILNB ≤ 750 mA, ENT = L — 0 ±4.5 %
12 mA ≤ ILNB ≤ 750 mA, ENT = H,
average VLNB
— 0 ±4.5 %
Output Reverse Current IRLNB EN = L, VLNB = 22 V, VIN = 22 V or fl oating — 1 5 mA
Buck Switch On Resist. rDS(on) TJ = 25°C, ILNB = 750 mA — 0.57 0.67 Ω
TJ = 125°C, ILNB = 750 mA — 0.84 0.94 Ω
Buck Switch Current Limit IBSM 1 — 2.5 A
Switching Frequency fO16 x ftone 320 352 384 kHz
Linear Reg. Volt. Drop ∆VBUCK VSENSE – VLNB, ENT = L, ILNB = 750 mA 700 900 1100 mV
Logic Input Voltage VIL — — 0.8 V
VIH 2——V
Logic Input Current IIH VIH = 5 V — <1.0 10 µA
Supply Current IIN Outputs disabled (EN = L) — 0.25 1 mA
EN = H, ILNB = 0 — 6 10 mA
Tone Characteristics
Tone Frequency ftone ENT = H 20 22 24 kHz
Tone Amplitude Vtone(PP)(ENT) ENT = H, 12 mA ≤ ILNB ≤ 750 mA 400 650 900 mV
Tone Duty Cycle dctone ENT = H, 12 mA ≤ ILNB ≤ 750 mA 40 — 60 %
Tone Rise or Fall Time tr, tfENT = H, 12 mA ≤ ILNB ≤ 750mA 5 10 15 µs
External Modulation
Tone Amplitude
Vtone(PP)(EXTM) f = 22 kHz square wave, ILOAD = 12 mA to
450 mA, VIN = 100mV to 125 mV;
VPP ac coupled
400 550 800 mV
External Modulation Input
Voltage Range
VEXTM(PP) AC coupled 100 — 125 mV
External Modulation Input
Impedance
ZEXTM f = 22 kHz 4 — 10 kΩ
continued next page
NOTES: 1. Typical data is for design information only.
2. Negative current is defi ned as coming out of (sourcing) the specifi ed device terminal.
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
4
ELECTRICAL CHARACTERISTICS: unless otherwise noted at TJ ≤ 125°C, CLNB = 0.1-µF,
4.5-V + VLNB ≤ VIN ≤ 47-V.
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Protection Circuitry
Current-Limiting Threshold VILNB(th) VBULK – VSENSE 115 135 155 mV
Overload Flag Output Low VOLF IOLF = 8-mA — 0.28 0.5 V
Overload Flag Leakage Current IOLF VOLF = 5.5-V — <1.0 10 µA
Thermal Shutdown Temp. TJ— 165 — °C
Thermal Shutdown Hysteresis ∆TJ—20—°C
NOTES: 1. Typical data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULAT ORS
5
www.allegromicro.com
Buck regulator. A current-mode buck converter
provides the linear regulator a supply voltage that
tracks the selected LNB output voltage. The buck
converter operates at 16 times the internal tone fre-
quency, nominally 352-kHz.
The tracking regulator provides minimum power
dissipation across the range of output voltages by
adjusting the SENSE terminal voltage, nominally
900-mV above the LNB output voltage. The tracking
regulator also provides adequate headroom for tone
injection.
Linear regulator. The output linear regulator will
sink or source current. This allows tone modulation
into a capacitive load of 0.1-µF over the output
current range of 12-mA to 750-mA.
Slew rate control. The programmed output volt-
age rise and fall times can be set by an external
capacitor (with an internal 25-kΩ resistor) located on
the TCAP terminal. The range of acceptable capaci-
tor values is 4.7-nF to 47-nF. This feature only
affects the turn-on and programmed voltage rise and
fall times. Modulation is unaffected by the capacitor.
If LNB output voltage rise and fall time limiting is
not required, the TCAP terminal should use a 100-nF
ceramic as a default value to minimize output noise.
If a small value capacitor is used, the rise time will be
limited by the time required to charge the VBULK
capacitor.
Short-circuit limit regulator. The LNB output is
current limited. The short-circuit protection threshold
is set by the value of an external resistor, RS, in
conjunction with an internal 135-mV reference
voltage (VILNB(th)).
RS = 0.135/ILNBM
where ILNBM is the desired current-limit value. The
sense resistor should be chosen based on the maxi-
mum dc plus ac (tone) load current required, internal
VILNB(th) tolerance, and sense resistor accuracy. For
750-mA applications, a precision 140-mΩ resistor is
recommended. For 500-mA applications, the resistor
value can be raised to 200-mΩ.
In operation, the short-circuit protection produces
current limiting at the input due to the tracking con-
verter. If the output is shorted, the linear regulator
will limit the output current to ILNBM.
Fault output. Short-circuit or thermal shutdown
will cause the OLF terminal, an open-drain diagnostic
output flag, to go LOW.
Internal tone modulation. The ENT (tone enable)
terminal activates the internal tone signal, modulating
the dc output with a 650-mV peak-to-peak trapezoidal
waveform. The internal oscillator is factory trimmed
to provide a tone of 22-kHz. No further adjustment is
required. Burst coding of the tone can be accom-
plished, due to the fast response of the ENT input and
rapid tone response. This allows implementation of
the DiSEqC™ protocols.
External tone modulation. To improve design
flexibility and to allow implementation of proposed
LNB remote control standards, an analog modulation
input terminal is available (EXTM). An appropriate
dc-blocking capacitor must be used to couple the
modulating signal source to the EXTM terminal. The
peak-to-peak input amplitude should stay within
100-mV to 125-mV to ensure the DiSEqC amplitude
specification over the output current range. If exter-
nal modulation is not used, the EXTM terminal
should be decoupled to ground with a 0.1-µF ceramic
capacitor.
FUNCTIONAL DESCRIPTION
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
6
APPLICATIONS INFORMATION
Component selection:
Input capacitor, CIN. An electrolytic capacitor
should be located as close to the device VIN terminal
as possible. The input current is a square wave with
fast rise and fall times so the capacitor must be able to
handle the rms current without excessive temperature
rise. The value of this capacitor is not as important as
the ESR. The worst-case current is with maximum
load current, minimum VIN, and maximum VLNB
(highest switch duty cycle). Choose a capacitor with
a ripple current rating greater than
Icin = ILNB x 1.2 x VLNB(max)/VIN(min)
Buck inductor, L1. A 100-µH power inductor is
appropriate for all operating conditions. The rated
saturation current of the inductor must be greater than
1.3-A. To maximize efficiency, the dc resistance
should be less than 350-mΩ.
Clamp diode, D1. A Schottky diode is required at
the switching node LX. This diode should be rated at
1.5 times the maximum load current.
Output capacitor, CBULK. A low-ESR (<200-mΩ)
electrolytic capacitor is recommended to minimize
the ripple voltage. Less than 50-mV peak-to-peak is a
reasonable goal.
Vripple(PP) = ESR x Iripple(max)
where
I
ripple(max)
= V
BULK(min)
x (1 – [V
BULK(min)
/V
IN(max)
]) /
(L1 x 352
-
kHz).
Output capacitor, CLNB. Increasing the output
capacitance, CLNB, will attenuate noise. However,
this is limited by the requirement for low cable
capacitance for 22-kHz tone transmission.
Also, because the linear regulator sink current is
limited, high values of output capacitance combined
with low levels of output current can cause overshoot
of the 22-kHz tone. Operating points above the line
in the following graph will not have excessive over-
shoot.
0.5
Dwg. GP-074
1.0 1.5
OUTPUT CAPACITANCE IN µF
0
100
OUTPUT CURRENT IN mA
50
0
25
75
125
MINIMAL OVERSHOOT
EXCESSIVE OVERSHOOT
Layout notes:
1. The printed wiring board should use a heavy
ground plane. A two-sided board with ground planes
on both sides of the board is most desirable. Several
copper vias under the device can be used to connect
the ground planes and enhance thermal performance.
2. For optimum electrical and thermal performance,
the device should be soldered directly onto the board.
3. Keep the sense resistor traces as short and as wide
as possible to lower trace resistance.
4. Connect the bypass capacitors as close to the
device as possible. The lower value ceramic capaci-
tors should be closer to the device than the
electrolytics. The supply voltage, VIN, should be
decoupled with an electrolytic capacitor placed as
close to the device as possible.
5. Place the TCAP capacitor as close to the device as
possible.
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULAT ORS
7
www.allegromicro.com
Grounding. Use a star ground approach at the
device ground terminals. This allows the analog and
power grounds to be kept separate on the PWB up to
the device.
Noise immunity. LNB systems can have a 50-mV
peak specification for noise on the coaxial cable.
This is easily achievable with proper layout and
following a few guidelines:
1. Use a low-ESR capacitor for VBULK. A maximum
of 200-mΩ is recommended.
2. The LNB output is sensitive to the TCAP refer-
ence terminal. Keep the PWB traces short and loca-
tion of CTCAP close to the device. This terminal is a
high-impedance node and noise can be induced from
proximity to an unshielded inductor. If the inductor
can not be placed far enough away to avoid noise
pickup, it is important to ensure that the induced
voltage is out of phase with the switching node LX.
Rotating the inductor can change the phase of the
induced voltage.
3. Be sure to place a 1-µF to 10-µF capacitor on
internal reference VINT (A8282 only).
4. Bypass EXTM with a 0.1-µF ceramic capacitor to
ground.
5. Increasing the output capacitance will attenuate
noise. However, this must be traded off with the
requiremnent for low cable capacitance for 22-kHz-
tone transmission.
APPLICATIONS INFORMATION (cont’d)
DirecTV®. With the A8282, it is possible to raise
the LNB output voltage 440-mV from the nominal
13-V setting to comply with DirecTV requirements.
This is accomplished by connecting a 1-MΩ resistor
between the VINT and TCAP terminals, sourcing
approximately 2.76-µA into the TCAP node. The
LNB output voltage is approximately six times the
setting of the voltage-select DAC as shown in the
figure.
–
+
VINT
LNB
VOLTAGE
REG.
25 kΩ
TCAP
1 MΩ
VOLTAGE
SELECT
X6
Dwg. EP-074
DiSEqC™. The 22-kHz tone is specified to be
compatible with EUTELSAT coaxial cable bus
standards.
The LNB output will be able to drive the DiSEqC
termination network. The inductor must pass the dc
current with minimal loss while the parallel resistor
provides the recommended source impedance at
22-kHz. Unidirectional communication systems such
as DiSEqC 1.0 do not need this termination and the
LNB can be directly connected to the coaxial cable.
13-V to 18-V transition. The LNB output can be
rapidly switched between a high and a low setting as
a method of receiver-to-LNB communication. The
TCAP capacitor will control the slew rate based on
the RC charging.
tr or tf = 25 x 103 x CTCAP ln(VLNB(H)/VLNB(L))
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8
Small values of TCAP are used when the desired
transition time is less than a millisecond. In this case,
the minimum rise time is limited by the charge time
of the switching regulator output capacitor. This is
dependent on the LNB load current, peak current limit
in the buck switch, and the output amplitude change.
tr = CBULK (VLNB(H) – VLNB(L))/I(AV)
where I(AV) is the average current available to charge
the output capacitor and can be estimated by I(AV) =
1.4 – ILNB. Note that this is only a limitation due to
the ability to charge the output capacitor on a low-to-
high change of the LNB voltage. For high-to-low
transitions, the output voltage will be slew limited by
TCAP.
The minimum value for CTCAP is 4.7-nF.
Power dissipation. The power dissipated, and
operating junction temperature of the device, can be
estimated to ensure that the device is operating within
the desired thermal budget.
The total device power dissipation (PD) is com-
prised of three components:
PD = PD(bias) + PD(lin) + PD(buck)
where PD(bias) = VIN (IIN – 0.004),
PD(lin) = ∆VBUCK x ILNB,
PD(buck) = ILNB2 x rDS(on) x VBULK/VIN
where VBULK = ∆VBUCK + (ILNB x RS) + VLNB.
The device junction temperature can then be
estimated as
TJ = (PD x RθJA) + TA
or
TJ = (PD x RθJT) + TT
APPLICATIONS INFORMATION (cont’d)
where TT is the power tab temperature (leads 4 or 13
for the A8281SLB or leads 6, 7, 18, or 19 for the
A8282SLB) and RθJT is 6°C/W.
Package thermal resistances, RθJA, measured on
JEDEC standard “high-K” four layer board:
A8281SLB ..................................... 38°C/W
A8282SLB ..................................... 35°C/W
measured on two-sided PWB with 3 square inches
(1935 mm2) copper ground area on each side:
A8281SLB ..................................... 48°C/W
A8282SLB ..................................... 45°C/W
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
9
www.allegromicro.com
APPLICATIONS INFORMATION (cont’d)
Typical application
23
17
8
1
2
3
4
5
9
12
16
14
13
24
22
21
20
11
9
CHARGE
PUMP
REG.
BUCK
Dwg. EP-072
15
DiSEqC TERMINATION
ENT
ENB
VSEL0
VSEL1
LLC
OLF TCAP
VIN
VIN
+30 V
C1
C2
C3
R1
C
INT
0.22 μF
180 μH
+
C
BULK
L1
R
S
C
BYP
D1
C
IN
+
C
TCAP
C
LNB
D2
POWER
GROUND
ANALOG
GROUND
L2
A8282SLB
10
+5 V
N
6
7
19
18
VOLTAGE
CONTROL
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
10
APPLICATIONS INFORMATION (cont’d)
Parts list for typical application
Description Representative Component
C1, C2, C3, 0.1-µF/50-V ceramic X7R/X5R
CBYP, CLNB
CIN 100-µF/50-V low-ESR electrolytic Nichicon UHD1H101MPT
CBULK 100-µF/35-V low-ESR electrolytic Nichicon UHC1V101
CINT 4.7-µF/16-V tantalum electrolytic
D1 1-A/40-V Schottky diode Sanken EK04
D2 1.2-A/100-V fast-recovery diode Sanken EU 2YX
L1 100-µH (750-mA max. load) TDK TSL1112-101K1R4, or
Coilcraft D03316P-104LW
100-µH (500-mA max. load) TDK TSL0808-101KR80
L2 180-µH (750-mA max. load) TDK TSL1112S-181K1R0-PF
RS 140-mΩ to 200-mΩ/0.25-W Meritek CR04RxxxF
CTCAP 10-nF ceramic X7R/X5R
R1 1-MΩ, ±5% (optional, see page 7)
DiSEqC (Digital Satelite Equipment Control) is a trade-
mark of EUTELSAT (European Telecommunications
Satellite Corporation), Paris, France.
DirecTV is a trademark of DirecTV, Inc., a unit of Hughes
Electronics Corp., El Segundo, CA
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULAT ORS
11
www.allegromicro.com
A8281SLB A8282SLB
Terminal Terminal Terminal
Name Number Number Terminal Description
NC – 1 No (internal) connection
OLF 2 2 Overload flag output: low (fault) when ILNB > ILNBM or
TJ > 165°C, high when ILNB < ILNBM and TJ < 130°C
VBULK 3 3 Tracking supply voltage to linear regulator
NC – 4, 5 No (internal) connection
GND 4 6, 7 Ground and substrate
SENSE 5 8 Current limit setup resistor
LNB 6 9 Output voltage to LNB
LX 7 10 Inductor drive point
VIN 8 11 Supply input voltage (minimum, VLNB + 2.5-V)
TCAP 9 12 Capacitor for setting the rise and fall time of the outputs for
line-length compensation
LLC – 13 Logic input: output voltage select
VSEL1 10 14 Logic input: output voltage select
VSEL0 – 15 Logic input: output voltage select
EN 11 16 Logic input: when high, enables device
ENT 12 17 Logic input: when high, enables internal 22-kHz modulation
GND 13 18, 19 Ground and substrate
CPUMP 14 20 High side of charge-pump capacitor
VPUMP 15 21 Gate-supply voltage for high-side drivers
PUMPX 16 22 Charge-pump drive
VINT – 23 Bypass capacitor for internal voltage reference
EXTM 1 24 External modulation input
Terminal List
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
12
A8281SLB
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
1 2 3
0.2992
0.2914
0.4133
0.3977
0.419
0.394
0.020
0.013
0.0926
0.1043
0.0040 MIN.
0.0125
0.0091
0.050
0.016
0° TO 8°
Dwg. MA-008-16A in
0.050
BSC
16 9
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative.
3. Leads 4 and 13 are internally one piece.
4. Supplied in standard sticks/tubes of 47 devices or add “TR” to part number for tape and reel.
916
1 2 3
7.60
7.40
10.50
10.10
10.65
10.00
0.51
0.33
2.65
2.35
0.10
MIN.
0.32
0.23
1.27
0.40
0°
TO
8°
Dwg. MA-008-16A mm
1.27
BSC
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULAT ORS
13
www.allegromicro.com
A8282SLB
Dimensions in Inches
(for reference only)
Dimensions in Millimeters
(controlling dimensions)
0° TO 8°
1
24
13
23
0.2992
0.2914
0.6141
0.5985
0.419
0.394
0.020
0.013
0.0926
0.1043
0.0040
MIN.
0.0125
0.0091
Dwg. MA-008-25A in
0.050
BSC
NOTE 1
NOTE 3
0.050
0.016
0°
TO
8°
1
24
23
7.60
7.40
15.60
15.20
10.65
10.00
0.51
0.33
2.65
2.35
0.10
MIN.
0.32
0.23
1.27
BSC
NOTE 1
NOTE 3
1.27
0.40
Dwg. MA-008-25A mm
NOTES: 1. Exact body and lead configuration at vendor’s option within limits shown.
2. Lead spacing tolerance is non-cumulative.
3. Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece.
4. Supplied in standard sticks/tubes of 31 devices or add “TR” to part number for tape and reel.
8281
AND
8282
LNB SUPPLY AND
CONTROL-VOL TAGE REGULATORS
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
14
The products described here are manufactured under one or more
U.S. patents or U.S. patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be
required to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components
in life-support devices or systems without express written approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsi-
bility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.
