contact factory data sheet 27448.1 8283 lnb supply and control-voltage regulator always order by complete part number, e.g., A8283SLB . 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. 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 compen- sate 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 (v sel0 , v sel1 , 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 main- tains constant voltage drop across the linear regulator while permitting ad- equate 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. absolute maximum ratings supply voltage, v in .......................... 47 v output current, i o ............................ 1.0 a logic input voltage range, v i ................................... -0.5 v to +7 v bypass switch current, i sw ........................ internally limited flag output voltage, v olf .................. 7 v operating temperature range, t a ............................... -20 c to +85 c storage temperature range, t s ............................. -40 c to +150 c 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. 23 17 8 1 2 3 4 5 6 7 9 12 16 14 13 24 22 21 20 19 18 11 10 9 extm vint pumpx vpump cpump gnd gnd ent en vsel0 vsel1 llc osel olf vbulk miout mi gnd gnd sense lnb lx vin tcap charge pump voltage control reg. buck dwg. pp-072a 15 note that the a8283sb (dual in-line package) and A8283SLB (small-outline ic package) are electrically identical and share a common terminal number assignment. A8283SLB preliminary information (subject to change without notice) june 18, 2002
8283 lnb supply and control-voltage regulator 115 northeast cutoff, box 15036 worcester, massachusetts 01615-0036 (508) 853-5000 2 vref over- current tsd + 352 khz over- current r s 150 mv 800 mv 176 khz 22 khz tone ent pumpx c pump v pump olf v sel0 v sel1 llc tcap extm sense v in lx v bulk 5 k ? 1 k ? osel boost voltage 7 v 47 v max charge pump buck conv. 2 8 & waveshaping + + + + + mi dwg. fp-051-1 v int en 5 v voltage reg. 0 1 25 k ? 5 k ? mi out lnb r extm functional block diagram vsel0 vsel1 llc v lnb(typ) 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 ? 2002 allegro microsystems, inc. output voltage select table
8283 lnb supply and control-voltage regulator 3 www.allegromicro.com electrical characteristics at t a = 70 c, ent = l, en = h, osel = h, llc = l, i o = 50 ma (unless otherwise noted). limits characteristic symbol test conditions min. typ. max. units supply voltage v in i o = 500 ma, vsel0 = l, vsel1 = l, llc = l 5.5 + v o 47 v output voltage v o i o = 500 ma, vsel0 = l, vsel1 = l, llc = l 12.5 13 13.8 v i o = 500 ma, vsel0 = l, vsel1 = l, llc = h 13.4 14 14.9 v i o = 500 ma, vsel0 = l, vsel1 = h, llc = l 17.3 18 18.7 v i o = 500 ma, vsel0 = l, vsel1 = h, llc = h 18.2 19 19.8 v i o = 500 ma, vsel0 = h, vsel1 = l, llc = l 11.5 12 12.8 v i o = 500 ma, vsel0 = h, vsel1 = l, llc = h 12.5 13 13.8 v i o = 500 ma, vsel0 = h, vsel1 = h, llc = l 19.2 20 20.8 v i o = 500 ma, vsel0 = h, vsel1 = h, llc = h 20.2 21 21.8 v load regulation ? v o v o = 13 or 18 v, i o = 50 to 500 ma 80 220 mv current-limiting threshold v om(th) 125 145 160 mv tone frequency f tone ent = h 20 22 24 khz tone amplitude v tone(pp) ent = h, v o = 13 or 18 v, i o = 500 ma 400 680 800 mv external modulation v mod(out) ent = l, i o = 500 ma, r extm = 200 k ? , 400 500 800 mv output v mod(pp) = 130 mv, f = 22 khz tone duty cycle dc tone ent = h 50 % tone rise or fall time t r , t f ent = h 10 s external modulation gain a mod r extm = 200 k ? , v mod(pp) = 130 mv, f = 22 khz 4.6 v/v external modulation v mod(pp) ac coupling 160 mv input voltage external modulation z mod f = 22 khz 4.0 7.0 10 k ? input impedance continued next page ...
8283 lnb supply and control-voltage regulator 115 northeast cutoff, box 15036 worcester, massachusetts 01615-0036 (508) 853-5000 4 electrical characteristics at t a = 25 c, ent = l, en = h, osel = h, llc = l, v in = 24 v, v o = 13 v or 18 v, i o = 50 ma, r extm = open (unless otherwise noted). limits characteristic symbol test conditions min. typ. max. units overload flag logic low v ol i ol = 8 ma 0.28 0.8 v overload flag leakage current i oz v oh = 6 v <1.0 10 a logic input voltage v il 0.8 v v ih 2.0 v logic input current i il v il = 0 v <-1.0 -10 a i ih v ih = 5 v <1.0 10 a supply current i in output disabled (en = l) 0.2 1.0 ma output enabled, ent = h, i o = 0, v o = 13 v 7.5 15 ma thermal shutdown temp. t j 165 c linear regulator voltage drop ? v buck v bulk C v o 0.8 v switching frequency f o 16 x f tone 320 352 384 khz bypass switch current limit i swm osel = l 400 900 ma bypass switch voltage drop v sw osel = l, i sw = 300 ma 0.15 v (mi to lnb) 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 fre- quency. 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. to improve design flexibility and to allow implemen- tation 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 termi- nal. if external modulation is not used, the extm termi- nal should be decoupled with a 0.1 f capacitor. 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.
8283 lnb supply and control-voltage regulator 5 www.allegromicro.com functional description (contd) 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. this can be accomplished by connecting a 200 k ? resistor from the external modulation terminal (24) to ground. this will reduce the lnb output voltage by typically 300 mv without effecting the v bulk voltage. the output voltage can be restored to the programmed value by connecting a 1 m ? resistor from the v int terminal (23) to the t cap terminal (12). this raises both v bulk and v o by typically 300 mv. the output linear regulator will sink and source current. this feature allows full modulation capability into capacitive loads as high as 0.25 f. the programmed output voltage rise and fall times can be set by an internal 25 k ? resistor and an external capacitor located on the tcap terminal. typical values are 0.0047 f to 0.047 f. this feature only affects the turn on and programmed voltage rise and fall times. modulation is unaffected by the choice of tcap. 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, r s , between terminals 3 and 8. r s = v om(th) /i om where v om(th) is the current-limiting threshold voltage and i om is the desired current limit value. the minimum recommended value for r s is 0.15 ? . in operation, the short-circuit protection produces current fold-back at the input due to the tracking con- verter. if the output is shorted, the linear regulator will limit the output current to i om . 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 (i om x 0.8 v). short-circuit or thermal-shutdown activation will cause the olf terminal, an open-drain diagnostic output flag, to go low. thermal resistance: dip r ja = 40 c/w, r jt = 6 c/w, or soic r ja = 77 c/w, r jt = 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. r ja is measured on typical two-sided pcb with minimal copper ground area. for the soic, adding 3.57 2 in copper ground area will reduce the thermal resistance to 49 c/w. see application note 29501.5, improving batwing power dissipation .
8283 lnb supply and control-voltage regulator 115 northeast cutoff, box 15036 worcester, massachusetts 01615-0036 (508) 853-5000 6 symbol terminal function osel 1 logic input: selects between lnb on (when high) and bypass switch closed (when low) olf 2 overload flag output: low when i o > i om or i o > i swm or t j > 165 c, high when i o < i om and i o < i swm and t j < 130 c v bulk 3 tracking supply voltage to linear regulators mi out 4 output voltage from mi (connect to terminal 9) mi 5 master input gnd 6, 7 ground sense 8 current limit setup resistor lnb 9 output voltage (v o ) to lnb (connect to terminal 4) lx 10 inductor drive point v in 11 supply input voltage (minimum, v lnb + 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 v sel1 14 logic input: output voltage select v sel0 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 ground c pump 20 high side of charge-pump capacitor v pump 21 gate supply voltage for high-side drivers pumpx 22 charge-pump drive v int 23 bypass capacitor for internal voltage reference extm 24 external modulation input terminal configuration
8283 lnb supply and control-voltage regulator 7 www.allegromicro.com a8283sb dimensions in inches (controlling dimensions) dimensions in millimeters (for reference only) 0.014 0.008 0.300 bsc dwg. ma-001-25a in 0.430 max 24 16 12 0.280 0.240 0.210 max 0.070 0.045 0.015 min 0.022 0.014 0.100 bsc 0.005 min 0.150 0.115 13 1.280 1.230 note 1 7 0.355 0.204 7.62 bsc dwg. ma-001-25a mm 10.92 max 24 1 12 7.11 6.10 5.33 max 1.77 1.15 0.39 min 0.558 0.356 2.54 bsc 0.13 min 3.81 2.93 13 32.51 31.24 note 1 67 notes: 1. webbed lead frame. leads 6, 7, 18, and 19 are internally one piece. 2. exact body and lead configuration at vendors option within limits shown. 3. lead spacing tolerance is non-cumulative. 4. lead thickness is measured at seating plane or below. 5. supplied in standard sticks/tubes of 15 devices.
8283 lnb supply and control-voltage regulator 115 northeast cutoff, box 15036 worcester, massachusetts 01615-0036 (508) 853-5000 8 A8283SLB dimensions in inches (for reference only) dimensions in millimeters (controlling dimensions) 0 to 8 1 2 3 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 24 13 note 1 note 3 0.050 0.016 0 to 8 1 2 3 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 dwg. ma-008-25a mm 1.27 bsc 24 13 note 1 note 3 1.27 0.40 notes: 1. exact body and lead configuration at vendors 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 numbr for tape and reel.
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