A8281 and A8282: LNB Supply and Control Voltage Regulator

A8281 and A8282
LNB Supply and Control-Voltage Regulators
Discontinued Product
This device is no longer in production. The device should not be
purchased for new design applications. Samples are no longer available.
Date of status change: November 1, 2010
Recommended Substitutions:
For existing customer transition, and for new customers or new applications, contact your local Allegro Sales Representative.
NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan
for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The
information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.
Data Sheet
27448.2E
8281 AND
8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
A8282SLB
1
24
EXTM
OLF
2
23
VINT
3
22
PUMPX
21
VPUMP
VBULK
CHARGE
PUMP
NC
NC
4
NC
5
20
CPUMP
GND
6
19
GND
GND
7
18
GND
8
17
ENT
LNB
99
16
EN
LX
10
15
VSEL0
VIN
11
14
VSEL1
TCAP
12
13
LLC
BUCK
REG.
VOLTAGE
CONTROL
SENSE
Dwg. PP-072-2
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 internallyfused 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.
FEATURES
■ LNB selection and standby function
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
■ 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.
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.
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
FUNCTIONAL BLOCK DIAGRAM
and typical application
100 µH
4.7 µF
VINT
(A8282 ONLY)
VOLTAGE
REG.
5V
176 kHz
–
BUCK
CONV.
+
OVERCURRENT
7V
–
VREF
+
SENSE
LX
VIN
–
EN
+
100 µF
100 µF
BOOST
VOLTAGE
CHARGE
PUMP
RS 200 mΩ
VIN
47 V MAX
+
VPUMP
PUMPX
CPUMP
0.1 µF
VBULK
0.1 µF
135 mV
+
DiSEqC TERMINATION
352 kHz
25 kΩ
900 mV
15 Ω
+
÷2
–
+
ENT
–
5 kΩ
22 kHz TONE
0.22 µF
100 nF
÷8 &
WAVESHAPING
180 µH
LNB
EXTM
TSD
OVERCURRENT
1
OLF
2
VBULK
3
CHARGE
PUMP
EXTM
16
PUMPX
15
VPUMP
14
CPUMP
13
SENSE
5
12
ENT
LNB
6
11
EN
LX
7
10
VSEL1
VIN
8
9
TCAP
VOLTAGE
CONTROL
4
GND
REG.
VSEL1
TCAP
10 nF
Dwg. FP-051-2
A8281SLB Output Voltage Select Table
GND
BUCK
VSEL0
(A8282 ONLY)
LLC
(A8282 ONLY)
1 kΩ
A8281SLB
Dwg. PP-072-3
2
0.1 µF
5 kΩ
OLF
VSEL1
L
H
VLNB
13 V
18 V
A8282SLB Output Voltage Select Table
VSEL0
L
L
L
L
H
H
H
H
VSEL1
L
L
H
H
L
L
H
H
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 2003 Allegro MicroSystems, Inc.
LLC
L
H
L
H
L
H
L
H
VLNB
13 V
14 V
18 V
19 V
12 V
13 V
20 V
21 V
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
ELECTRICAL CHARACTERISTICS: unless otherwise noted at TJ < 125°C, CLNB = 0.1 µF,
4.5-V + VLNB < VIN < 47-V
Limits
Characteristic
Supply Voltage Range
Symbol
VIN
Max.
Units
—
47
V
—
0
±4.5
%
12 mA ≤ ILNB ≤ 750 mA, ENT = H,
average VLNB
—
0
±4.5
%
IRLNB
EN = L, VLNB = 22 V, VIN = 22 V or floating
—
1
5
mA
rDS(on)
TJ = 25°C, ILNB = 750 mA
—
0.57
0.67
Ω
TJ = 125°C, ILNB = 750 mA
—
0.84
0.94
Ω
1
—
2.5
A
16 x ftone
320
352
384
kHz
VSENSE – VLNB, ENT = L, ILNB = 750 mA
700
900
1100
mV
VIL
—
—
0.8
V
VIH
2
—
—
V
Output Reverse Current
Buck Switch On Resist.
IBSM
Switching Frequency
fO
Linear Reg. Volt. Drop
∆VBUCK
Logic Input Voltage
Typ.
4.5 +VLNB
EVLNB
Operating
Min.
6 mA ≤ ILNB ≤ 750 mA, ENT = L
Output Voltage Error
(reference Output Voltage
Select table)
Buck Switch Current Limit
Test Conditions
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
ENT = H
20
22
24
kHz
650
900
mV
Tone Characteristics
Tone Frequency
ftone
Tone Amplitude
Vtone(PP)(ENT)
ENT = H, 12 mA ≤ ILNB ≤ 750 mA
400
Tone Duty Cycle
dctone
ENT = H, 12 mA ≤ ILNB ≤ 750 mA
40
—
60
%
tr, tf
ENT = H, 12 mA ≤ ILNB ≤ 750mA
5
10
15
µs
400
550
800
mV
100
—
125
mV
4
—
10
kΩ
Tone Rise or Fall Time
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
External Modulation Input
Voltage Range
VEXTM(PP)
External Modulation Input
Impedance
ZEXTM
AC coupled
f = 22 kHz
continued next page
NOTES: 1. Typical data is for design information only.
2. Negative current is defined as coming out of (sourcing) the specified device terminal.
www.allegromicro.com
3
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
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
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
Protection Circuitry
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.
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
FUNCTIONAL DESCRIPTION
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 frequency, nominally 352-kHz.
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.
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.
In operation, the short-circuit protection produces
current limiting at the input due to the tracking converter. If the output is shorted, the linear regulator
will limit the output current to ILNBM.
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 voltage 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 capacitor 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)).
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 accomplished, 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 external modulation is not used, the EXTM terminal
should be decoupled to ground with a 0.1-µF ceramic
capacitor.
RS = 0.135/ILNBM
where ILNBM is the desired current-limit value. The
sense resistor should be chosen based on the maxi-
www.allegromicro.com
5
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
APPLICATIONS INFORMATION
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)
of the 22-kHz tone. Operating points above the line
in the following graph will not have excessive overshoot.
125
100
OUTPUT CURRENT IN mA
Component selection:
75
MINIMAL OVERSHOOT
50
EXCESSIVE OVERSHOOT
25
0
0
0.5
1.0
1.5
OUTPUT CAPACITANCE IN µF
Layout notes:
Dwg. GP-074
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.
where Iripple(max) = VBULK(min) x (1 – [VBULK(min)/VIN(max)]) /
(L1 x 352-kHz).
3. Keep the sense resistor traces as short and as wide
as possible to lower trace resistance.
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.
4. Connect the bypass capacitors as close to the
device as possible. The lower value ceramic capacitors 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.
Also, because the linear regulator sink current is
limited, high values of output capacitance combined
with low levels of output current can cause overshoot
6
5. Place the TCAP capacitor as close to the device as
possible.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
APPLICATIONS INFORMATION (cont’d)
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 reference terminal. Keep the PWB traces short and location 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-kHztone transmission.
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.
VOLTAGE
REG.
VINT
1 MΩ
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.
TCAP
25 kΩ
VOLTAGE
SELECT
–
X6
+
LNB
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))
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7
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
APPLICATIONS INFORMATION (cont’d)
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-tohigh change of the LNB voltage. For high-to-low
transitions, the output voltage will be slew limited by
TCAP.
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
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 comprised 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
8
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
APPLICATIONS INFORMATION (cont’d)
+5 V
CBULK
2
3
4
CINT
C1
R1
TCAP
23
22
C2
C3
21
5
20
6
19
7
18
8
17
ENT
99
16
ENB
15
VSEL0
14
VSEL1
13
LLC
VIN
10
D1
CIN
BUCK
REG.
11
+
VOLTAGE
CONTROL
CBYP
L1
RS
+
24
CHARGE
PUMP
OLF
1
A8282SLB
NŸ
12
ANALOG
GROUND
CTCAP
Dwg. EP-072
VIN
+30 V
Ÿ
180 μH
D2
POWER
GROUND
CLNB
0.22 μF
L2
DiSEqC TERMINATION
Typical application
www.allegromicro.com
9
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
APPLICATIONS INFORMATION (cont’d)
Parts list for typical application
Description
C1, C2, C3,
Representative Component
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 trademark of EUTELSAT (European Telecommunications
Satellite Corporation), Paris, France.
DirecTV is a trademark of DirecTV, Inc., a unit of Hughes
Electronics Corp., El Segundo, CA
10
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
Terminal List
A8281SLB
Terminal Terminal
Name
Number
A8282SLB
Terminal
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
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
www.allegromicro.com
Ground and substrate
11
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
A8281SLB
Dimensions in Inches
(for reference only)
16
9
0.0125
0.0091
0.419
0.394
0.2992
0.2914
0.050
0.016
0.020
0.013
1
2
0.050
3
0° TO 8°
BSC
0.4133
0.3977
0.0926
0.1043
Dwg. MA-008-16A in
0.0040 MIN.
Dimensions in Millimeters
(controlling dimensions)
16
9
0.32
0.23
10.65
10.00
7.60
7.40
1.27
0.40
0.51
0.33
1
2
1.27
3
10.50
10.10
BSC
0° TO 8°
2.65
2.35
0.10 MIN.
NOTES: 1.
2.
3.
4.
12
Dwg. MA-008-16A mm
Exact body and lead configuration at vendor’s option within limits shown.
Lead spacing tolerance is non-cumulative.
Leads 4 and 13 are internally one piece.
Supplied in standard sticks/tubes of 47 devices or add “TR” to part number for tape and reel.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
A8282SLB
Dimensions in Inches
(for reference only)
24
13
0.0125
0.0091
0.419
0.394
0.2992
0.2914
0.050
0.016
0.020
0.013
1
2
3
0.6141
0.5985
0.050
BSC
0° TO 8°
NOTE 1
NOTE 3
0.0926
0.1043
0.0040 MIN.
Dwg. MA-008-25A in
Dimensions in Millimeters
(controlling dimensions)
24
0.32
0.23
10.65
10.00
7.60
7.40
1.27
0.40
0.51
0.33
1
2
3
15.60
15.20
1.27
BSC
0° TO 8°
NOTE 1
NOTE 3
2.65
2.35
0.10 MIN.
NOTES: 1.
2.
3.
4.
Dwg. MA-008-25A mm
Exact body and lead configuration at vendor’s option within limits shown.
Lead spacing tolerance is non-cumulative.
Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece.
Supplied in standard sticks/tubes of 31 devices or add “TR” to part number for tape and reel.
www.allegromicro.com
13
8281 AND 8282
LNB SUPPLY AND
CONTROL-VOLTAGE REGULATORS
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 responsibility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.
14
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
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