PRELIMINARY INFORMATION LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR (subject to change without notice) June 18, 2002 A8283SLB 1 24 EXTM OLF 2 23 VINT VBULK 3 22 PUMPX MIOUT 4 21 VPUMP MI 5 20 CPUMP GND 6 19 GND GND 7 18 GND SENSE 8 17 ENT LNB 99 16 EN LX 10 15 VSEL0 VIN 11 14 VSEL1 TCAP 12 13 LLC CHARGE PUMP OSEL REG. VOLTAGE CONTROL BUCK 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 down converter via the coaxial cable. If the device is in stand-by mode (EN terminal LOW), the regulator output is disabled, allowing the antenna downconverters to be supplied or controlled by other satellite receivers sharing the same coaxial cable. Similar two-output LNB supply and control voltage regulators are the A8284SB/SLB. For slave operation in single-dish dual-receiver systems, the bypass function is implemented by an electronic switch between the master input terminal (MI) and the LNB terminal, leaving all LNB power and control functions to the master receiver. This electronic switch is closed if the device is powered, EN is HIGH, and OSEL is LOW. ABSOLUTE MAXIMUM RATINGS Supply Voltage, VIN .......................... 47 V Output Current, IO ............................ 1.0 A Logic Input Voltage Range, VI ................................... -0.5 V to +7 V Bypass Switch Current, ISW ........................ Internally Limited Flag Output Voltage, VOLF .................. 7 V Operating Temperature Range, TA ............................... -20°C to +85°C Storage Temperature Range, TS ............................. -40°C to +150°C Y R O T C A F 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 regulator. Logic inputs (VSEL0, VSEL1, and LLC) select the desired output voltage. A tracking current-mode buck converter provides the linear regulator with an input voltage that is set to the output voltage plus typically 0.8 V. This maintains constant voltage drop across the linear regulator while permitting adequate voltage range for tone injection. The device is supplied in a 24-pin plastic DIP with batwing tabs (A8283SB), or a 24-lead SOIC power-tab package (A8283SLB). In both cases, the power tab is at ground potential and needs no electrical isolation. T C A T N O C Dwg. PP-072A Note that the A8283SB (dual in-line package) and A8283SLB (small-outline IC package) are electrically identical and share a common terminal number assignment. Data Sheet 27448.1 8283 FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Short-Circuit Protected Bypass Function for Slave Operation 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., A8283SLB . 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR SENSE LX VIN + VBULK RS 47 V MAX VPUMP CPUMP PUMPX FUNCTIONAL BLOCK DIAGRAM MI MIOUT BOOST VOLTAGE CHARGE PUMP 0 1 – 5V 176 kHz – BUCK CONV. OVERCURRENT + 7V VREF + 352 kHz ÷2 – 150 mV + 25 kΩ – + ENT 800 mV – EN VOLTAGE REG. + VINT LNB ÷8 & WAVESHAPING 5 kΩ 22 kHz TONE EXTM TSD 5 kΩ OLF OVERCURRENT REXTM TCAP LLC VSEL1 VSEL0 OSEL 1 kΩ Dwg. FP-051-1 Output Voltage Select Table VSEL0 L L L L H H H H 2 VSEL1 L L H H L L H H 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 Copyright © 2002 Allegro MicroSystems, Inc. LLC L H L H L H L H VLNB(typ) 13 V 14 V 18 V 19 V 12 V 13 V 20 V 21 V 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR ELECTRICAL CHARACTERISTICS at TA = 70°C, ENT = L, EN = H, OSEL = H, LLC = L, IO = 50 mA (unless otherwise noted). Limits Characteristic Symbol Supply Voltage VIN Output Voltage VO Load Regulation Current-Limiting Threshold ∆VO Test Conditions Min. Typ. Max. Units IO = 500 mA, VSEL0 = L, VSEL1 = L, LLC = L 5.5 + VO — 47 V IO = 500 mA, VSEL0 = L, VSEL1 = L, LLC = L 12.5 13 13.8 V IO = 500 mA, VSEL0 = L, VSEL1 = L, LLC = H 13.4 14 14.9 V IO = 500 mA, VSEL0 = L, VSEL1 = H, LLC = L 17.3 18 18.7 V IO = 500 mA, VSEL0 = L, VSEL1 = H, LLC = H 18.2 19 19.8 V IO = 500 mA, VSEL0 = H, VSEL1 = L, LLC = L 11.5 12 12.8 V IO = 500 mA, VSEL0 = H, VSEL1 = L, LLC = H 12.5 13 13.8 V IO = 500 mA, VSEL0 = H, VSEL1 = H, LLC = L 19.2 20 20.8 V IO = 500 mA, VSEL0 = H, VSEL1 = H, LLC = H 20.2 21 21.8 V — 80 220 mV 125 145 160 mV ENT = H 20 22 24 kHz VO = 13 or 18 V, IO = 50 to 500 mA VOM(th) Tone Frequency ftone Tone Amplitude Vtone(PP) ENT = H, VO = 13 or 18 V, IO = 500 mA 400 680 800 mV External Modulation Output Vmod(out) ENT = L, IO = 500 mA, REXTM = 200 kΩ, Vmod(PP) = 130 mV, f = 22 kHz 400 500 800 mV Tone Duty Cycle dctone ENT = H — 50 — % Tone Rise or Fall Time t r, t f ENT = H — 10 — µs External Modulation Gain Amod REXTM = 200 kΩ, Vmod(PP) = 130 mV, f = 22 kHz — 4.6 — V/V AC coupling — — 160 mV f = 22 kHz 4.0 7.0 10 kΩ External Modulation Input Voltage Vmod(PP) External Modulation Input Impedance Zmod continued next page ... www.allegromicro.com 3 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR ELECTRICAL CHARACTERISTICS at TA = 25°C, ENT = L, EN = H, OSEL = H, LLC = L, VIN = 24 V, VO = 13 V or 18 V, IO = 50 mA, REXTM = open (unless otherwise noted). Limits Characteristic Symbol Test Conditions Min. Typ. Max. Units Overload Flag Logic Low VOL IOL = 8 mA — 0.28 0.8 V Overload Flag Leakage Current IOZ VOH = 6 V — <1.0 10 µA Logic Input Voltage VIL — — 0.8 V VIH 2.0 — — V Logic Input Current Supply Current Thermal Shutdown Temp. Linear Regulator Voltage Drop Switching Frequency IIL VIL = 0 V — <-1.0 -10 µA IIH VIH = 5 V — <1.0 10 µA IIN Output disabled (EN = L) — 0.2 1.0 mA Output enabled, ENT = H, IO = 0, VO = 13 V — 7.5 15 mA — 165 — °C — 0.8 — V 16 x ftone 320 352 384 kHz 400 900 — mA — 0.15 — V TJ ∆VBUCK fO VBULK – VO Bypass Switch Current Limit IswM OSEL = L Bypass Switch Voltage Drop (MI to LNB) Vsw OSEL = L, Isw = 300 mA FUNCTIONAL DESCRIPTION The ENT (Tone Enable) terminal activates the internal tone signal, modulating the dc output with a ±0.3 V, 22 kHz symmetrical waveform. The internal oscillator is factory-trimmed to provide a tone of 22 kHz ±2 kHz. No further adjustment is required. The internal oscillator operates the buck converter at 16 times the tone frequency. 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. If external modulation is not used, the EXTM terminal should be decoupled with a 0.1 µF capacitor. Burst coding of the 22 kHz tone can be accomplished due to the fast response of the ENT input and rapid tone response. This allows implementation of the DiSEqC™ protocols. Applications that are required to deliver more than 400 mA and use the external modulation terminal should be rebiased to increase the voltage drop across the linear regulator. This will allow full modulation under all conditions. 4 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR FUNCTIONAL DESCRIPTION (cont’d) This can be accomplished by connecting a 200 kΩ resistor from the external modulation terminal (24) to ground. This will reduce the LNB output voltage by typically 300 mV without effecting the VBULK voltage. The output voltage can be restored to the programmed value by connecting a 1 MΩ resistor from the VINT terminal (23) to the TCAP terminal (12). This raises both VBULK and VO by typically 300 mV. Two terminals are dedicated to the over-current protection/monitoring: SENSE and OLF. The LNB output is current limited. The short-circuit protection threshold is set by the value of an external resistor, RS, between terminals 3 and 8. RS = VOM(th)/IOM where VOM(th) is the current-limiting threshold voltage and IOM is the desired current limit value. The minimum recommended value for RS is 0.15 Ω. The output linear regulator will sink and source current. This feature allows full modulation capability into capacitive loads as high as 0.25 µF. In operation, the short-circuit protection produces current fold-back at the input due to the tracking converter. If the output is shorted, the linear regulator will limit the output current to IOM. The tracking converter will maintain a constant voltage drop of 0.8 V across the linear regulator. This condition results in typically 550 mW dissipation (IOM x 0.8 V). Short-circuit or thermal-shutdown activation will cause the OLF terminal, an open-drain diagnostic output flag, to go LOW. The programmed output voltage rise and fall times can be set by an internal 25 kΩ resistor and an external capacitor located on the TCAP terminal. Typical values are 0.0047 µF to 0.047 µF. This feature only affects the turn on and programmed voltage rise and fall times. Modulation is unaffected by the choice of TCAP. Thermal resistance: DIP — RθJA = 40°C/W, RθJT = 6°C/W, or SOIC — RθJA = 77°C/W, RθJT = 6°C/W. The device junction temperature should be kept below 150°C. Thermal shut-down circuitry turns off the device if junction temperature exceeds +165°C typically. RθJA is measured on typical two-sided PCB with minimal copper ground area. For the SOIC, adding 3.572 in copper ground area will reduce the thermal resistance to 49°C/W. See Application Note 29501.5, Improving Batwing Power Dissipation. 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. www.allegromicro.com 5 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR TerminalConfiguration Symbol Function OSEL 1 Logic input: selects between LNB on (when high) and bypass switch closed (when low) OLF 2 Overload flag output: low when IO > IOM or IO > ISWM or TJ > 165°C, high when IO < IOM and IO < ISWM and TJ < 130°C VBULK 3 Tracking supply voltage to linear regulators MIOUT 4 Output voltage from MI (connect to terminal 9) MI 5 Master input GND 6 Terminal 6, 7 Ground SENSE 8 Current limit setup resistor LNB 9 Output voltage (VO) to LNB (connect to terminal 4) LX 10 Inductor drive point VIN 11 Supply input voltage (minimum, VLNB + 2.5 V) TCAP 12 Capacitor for setting the rise and fall time of the outputs LLC 13 Logic input: when high, increases output voltage by 1 V for line length compensation VSEL1 14 Logic input: output voltage select VSEL0 15 Logic input: output voltage select EN 16 Logic input: when high, enables device ENT 17 Logic input: when high, enables internal 22 kHz modulation GND 18, 19 CPUMP 20 High side of charge-pump capacitor VPUMP 21 Gate supply voltage for high-side drivers PUMPX 22 Charge-pump drive VINT 23 Bypass capacitor for internal voltage reference EXTM 24 External modulation input Ground 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR A8283SB Dimensions in Inches (controlling dimensions) 24 0.014 0.008 13 NOTE 1 0.430 MAX 0.280 0.240 0.300 BSC 1 0.070 0.045 7 6 0.100 1.280 1.230 12 BSC 0.005 MIN 0.210 MAX 0.015 0.150 0.115 MIN 0.022 0.014 Dwg. MA-001-25A in Dimensions in Millimeters (for reference only) 24 0.355 0.204 13 NOTE 1 10.92 MAX 7.11 6.10 7.62 BSC 1 1.77 1.15 6 7 2.54 32.51 31.24 12 BSC 0.13 MIN 5.33 MAX 0.39 3.81 2.93 MIN 0.558 0.356 NOTES: 1. 2. 3. 4. 5. Dwg. MA-001-25A mm 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. Supplied in standard sticks/tubes of 15 devices. www.allegromicro.com 7 8283 LNB SUPPLY AND CONTROL-VOLTAGE REGULATOR A8283SLB 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 0.050 0.6141 0.5985 0° TO 8° BSC NOTE 1 NOTE 3 0.0926 0.1043 0.0040 MIN. Dwg. MA-008-25A in Dimensions in Millimeters (controlling dimensions) 24 13 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. 8 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 numbr for tape and reel. 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000