8284
ADVANCE INFORMATION
(Subject to change without notice) December 22, 2000
TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
Intended for analog and digital satellite receivers, the low noise block converter regulator (LNBR) is a monolithic linear and switching voltage regulator designed to provide power and interface signals to the LNB downconverter via the coaxial cable. Because most satellite receivers have two antenna ports, the output voltage of the regulator is available at one of two logic-selectable output terminals (LNBA, LNBB). If the device is in stand-by mode (EN terminal LOW), both regulator outputs are disabled, allowing the antenna downconverters to be supplied and controlled by other satellite receivers sharing the same coaxial cable. Similar single-output devices, with a bypass function for slave operation in single-dish dual-receiver systems, are the A8283SB/SLB. The regulator outputs are 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). The LNBR combines a tracking switching regulator and low-noise linear regulators. Logic inputs (VSEL0, VSEL1, and LLC) select the desired output voltage. A tracking current-mode buck converter provides the linear regulator input voltage that is set to the output voltage plus typically 0.8 V. This maintains constant voltage drop across the linear regulators while permitting adequate voltage range for tone injection. The device is supplied in a 24-pin plastic DIP with batwing tabs (A8284SB), or a 24-lead SOIC power-tab package (A8284SLB). In both cases, the power tab is at ground potential and needs no electrical isolation.
Data Sheet 27448.1
A8284SLB
OSEL OLF VBULK LNBB NC GND GND SENSE LNBA LX VIN TCAP 1 2 3 4 5 6 7 8 9 9 10 11 12 BUCK REG. 24 23 22 EXTM VINT PUMPX VPUMP CPUMP GND GND ENT EN VSEL0 VSEL1 LLC
21 20 19 18 17 16 15 14
Note that the A8284SB (dual in-line package) and A8284SLB (small-outline IC package) are electrically identical and share a common terminal number assignment.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, VIN .......................... 47 V Output Current, IO .... Internally Limited Logic Input Voltage Range, VI ................................... -0.5 V to +7 V Flag Output Voltage, VOLF .................. 7 V Operating Temperature Range, TA ............................... -20°C to +85°C Storage Temperature Range, TS ............................. -40°C to +150°C
T C A T N O C
13
Dwg. PP-072-1A
Y R O T C A F
VOLTAGE CONTROL
CHARGE PUMP
FEATURES
I I I I I I I I I I Complete Interface for Two LNBs Remote Supply and Control LNB Selection and Stand-By Function Built-In Tone Oscillator Factory Trimmed to 22 kHz, Facilitates DiSEqC™ (a trademark of EUTELSAT) Encoding Full Modulation With No Load Tracking Switch-Mode Power Converter for Lowest Dissipation Externally Adjustable Short-Circuit Protection LNB Short-Circuit Protection and Diagnostics Auxiliary Modulation Input Cable Length Compensation Internal Over-Temperature Protection
This device incorporates features that have patents pending.
Always order by complete part number, e.g., A8284SLB .
8284 TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
FUNCTIONAL BLOCK DIAGRAM
RS
CPUMP PUMPX VPUMP SENSE VBULK
47 V MAX
VIN LX
+
VINT
VOLTAGE REG.
CHARGE PUMP
BOOST VOLTAGE
EN
– 5V 176 kHz +
BUCK CONV. 7V VREF
– + OVERCURRENT – + 800 mV + 1 0 5 kΩ 150 mV LNBB
÷2 ENT
352 kHz 25 kΩ
– +
÷8 & WAVESHAPING
22 kHz TONE 5 kΩ 1 kΩ
TSD OLF OVER-CURRENT
VSEL1
VSEL0
OSEL
LLC
TCAP
OSEL VSEL0 L L L L L L L L H H H H H H H H L L L L H H H H L L L L H H H H
VSEL1 L L H H L L H H L L H H L L H H
LLC L H L H L H L H L H L H L H L H
VLNBA(typ) 13 V 14 V 18 V 19 V 12 V 13 V 20 V 21 V Low Low Low Low Low Low Low Low
VLNBB(typ) Low Low Low Low Low Low Low Low 13 V 14 V 18 V 19 V 12 V 13 V 20 V 21 V
Output Voltage Select Table
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 2000, Allegro MicroSystems, Inc.
–
EXTM
LNBA
Dwg. FP-051
8284 TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
ELECTRICAL CHARACTERISTICS at TA = 25°C, OSEL = H for LNBB, OSEL = L for LNBA (each output tested separately), ENT = L, EN = H, LLC = L, VIN = 24 V, IO = 50 mA (unless otherwise noted).
Limits Characteristic Supply Voltage Output Voltage Symbol VIN VO Test Conditions IO = 600 mA, VSEL0 = L, VSEL1 = L, LLC = L IO = 600 mA, VSEL0 = L, VSEL1 = L, LLC = L IO = 600 mA, VSEL0 = L, VSEL1 = L, LLC = H IO = 600 mA, VSEL0 = L, VSEL1 = H, LLC = L IO = 600 mA, VSEL0 = L, VSEL1 = H, LLC = H IO = 600 mA, VSEL0 = H, VSEL1 = L, LLC = L IO = 600 mA, VSEL0 = H, VSEL1 = L, LLC = H IO = 600 mA, VSEL0 = H, VSEL1 = H, LLC = L IO = 600 mA, VSEL0 = H, VSEL1 = H, LLC = H Line Regulation ∆VO ∆VO VOM(th) ftone Vtone(PP) dctone t r, t f Gmod Vmod(PP) Zmod ENT = H ENT = H ENT = H ENT = H ∆VO/∆Vmod, f = 10 Hz to 40 kHz AC coupling VO = 13 V, VI = 16 to 40 V VO = 18 V, VI = 21 to 40 V Load Regulation Current-Limiting Threshold Tone Frequency Tone Amplitude Tone Duty Cycle Tone Rise or Fall Time External Modulation Gain External Modulation Input Voltage External Modulation Impedance VO = 13 or 18 V, IO = 50 to 600 mA Min. Typ. Max. Units V V V V V V V V V mV mV mV mV kHz mV % µs V/V mV kΩ — 3.3 + ∆VBUCK 47 12.5 13.4 17.3 18.2 11.5 12.5 19.2 20.2 — — — 125 20 550 40 5.0 — — 13 14 18 19 12 13 20 21 4.0 4.0 80 135 22 680 50 10 5.0 — 13.5 14.6 18.7 19.8 12.5 13.5 20.8 21.8 40 40 180 145 24 800 60 15 — 160
f = 10 Hz to 40 kHz
—
5.0
—
continued next page ...
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8284 TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
ELECTRICAL CHARACTERISTICS at TA = 25°C, ENT = L, EN = H, LLC = L, VIN = 24 V, IOUT = 50 mA (unless otherwise noted).
Limits Characteristic Overload Flag Logic Low Overload Flag Leakage Current Logic Input Voltage Symbol VOL IOZ VIL VIH Logic Input Current Supply Current IIH IIN VIH = 5 V Outputs disabled (EN = L) ENT = H, IO = 600 mA, VO = 13 V Thermal Shutdown Temp. Linear Regulator Voltage Drop Switching Frequency TJ ∆VBUCK fO VBULK – VO 16 • ftone Test Conditions IOL = 8 mA VOH = 5.5 V Min. — — Typ. 0.28 165°C, high when IO < IOM and TJ < 130°C Tracking supply voltage to linear regulators Output voltage to LNBB No (internal) connection Ground Current limit setup resistor Output voltage to LNBA Inductor drive point Supply input voltage (minimum, VLNB + 2.5 V) Capacitor for setting the rise and fall time of the outputs Logic input: when high, increases output voltage by 1 V for line length compensation Logic input: output voltage select Logic input: output voltage select Logic input: when high, enables device (LNB on) Logic input: when high, enables internal 22 kHz modulation Ground High side of charge-pump capacitor Gate supply voltage for high-side drivers Charge-pump drive Bypass capacitor for internal voltage reference External modulation input
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115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
8284 TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
A8284SB
Dimensions in Inches (controlling dimensions)
0.014 0.008
24
NOTE 1
13
0.430 0.280 0.240
MAX
0.300
BSC
1
0.070 0.045
6
7 1.280 1.230
0.100
BSC
12
0.005
MIN
0.210
MAX
0.015
MIN
0.150 0.115 0.022 0.014
Dwg. MA-001-25A in
Dimensions in Millimeters (for reference only)
24
NOTE 1
13
0.355 0.204
10.92 7.11 6.10
MAX
7.62
BSC
1
1.77 1.15
6
7 32.51 31.24
2.54
BSC
12
0.13
MIN
5.33
MAX
0.39
MIN
3.81 2.93 0.558 0.356
Dwg. MA-001-25A mm
NOTES: 1. 2. 3. 4.
Webbed lead frame. Leads 6, 7, 18, and 19 are internally one piece. Exact body and lead configuration at vendor’s option within limits shown. Lead spacing tolerance is non-cumulative Lead thickness is measured at seating plane or below.
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8284 TWO-OUTPUT LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR
A8284SLB
Dimensions in Inches (for reference only)
24 13
0.0125 0.0091
0.2992 0.2914
0.491 0.394 0.050 0.016
0.020 0.013
1
2
3
0.6141 0.5985
0.050
BSC NOTE 1 NOTE 3
0° TO 8
0.0926 0.1043 0.0040 MIN.
Dimensions in Millimeters (controlling dimensions)
24 13
Dwg. MA-008-25 in
0.32 0.23
7.60 7.40
10.65 10.00 1.27 0.40
0.51 0.33
1
2
3
15.60 15.20
1.27
BSC NOTE 1 NOTE 3
0° TO 8
2.65 2.35 0.10 MIN.
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.
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
Dwg. MA-008-25A mm
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