View ST491ABDR_5146227.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1/11 november 2002 n low supply current: 5ma max n designed for rs485 interface applications n -7 to 12 common mode input voltage range n 70mv typical input hysteresis n designed for 25mbps operation n operate from single 5 supply n 4kv esd protection n current limiting and thermal shutdown for driver overload protection description the st491a is a low power transceiver for rs-485 and rs-422 communications. the device contains one driver and one receiver in full duplex configuration. the st491a draws 5ma (typ.) of supply current when unloaded and operates from a single 5v supply. driver is short-circuit current limited and is protected against excessive power dissipation by thermal shutdown circuitry that place the driver outputs into a high-impedance state. the receiver input has a fail-safe feature that guarantees a logic high output if both inputs are open circuit. ordering codes ty pe temperature range package comments st491acn 0 to 70 c dip-14 25parts per tube / 40tube per box st491abn -40 to 85 c dip-14 25parts per tube / 40tube per box st491acd 0 to 70 c so-14 (tube) 50parts per tube / 20tube per box st491abd -40 to 85 c so-14 (tube) 50parts per tube / 20tube per box st491acdr 0 to 70 c so-14 (tape & reel) 2500 parts per reel ST491ABDR -40 to 85 c so-14 (tape & reel) 2500 parts per reel st491a low power high speed rs-485/rs-422 transceiver this is preliminary information on a new product now in development are or undergoing evaluation. details subject to change without notice. dip sop preliminary data
st491a 2/11 pin configuration pin description truth table (driver) x= dont care; z=high impedance truth table (receiver) ?= irrelevant; x= dont care; z=high impedance pln n symbol name and function 1 nc not connected 2 ro receiver output. 3 re receiver output enable 4 de driver output enable 5 di inverting driver input. 6 gnd ground 7 gnd ground 8 nc not connected 9 y non-inverting driver output 10 z inverting driver output 11 b inverting receiver input 12 a non-inverting receiver input 13 nc not connected 14 v cc supply voltage input outputs di de y z lhlh hhhl xlzz input output a-b re ro 3 -0.2v l h between -0.2v to 0.2v l ? -0.2v l l open l h xhz
st491a 3/11 absolute maximum ratings absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these condition is not implied. electrical characteristics v cc =4.5vto5.5v,t a = -40 to 85c, unless otherwise specified. typical values are referred to t a =25c) transmitter electrical characteristics v cc = 4.5v to 5.5v, t a = -40 to 85c, unless otherwise specified. typical values are referred to t a = 25c) symbol parameter value unit v cc supply voltage 7v v di driver input voltage -0.5 to 7 v v y ,v z driver output voltage -7.5 to 12.5 v v a ,v b receiver input voltage -7.5 to 12.5 v v ro receiver output voltage -0.3 to (v cc + 0.3) v esd human boby model 3.5 kv symbol parameter test conditions min. typ. max. unit i supply no load supply current 2 5 ma c in input capacitance 1.8 pf c yz driver output capacitance 1.2 pf c out output capacitance 2.3 pf symbol parameter test conditions min. typ. max. unit v od1 differential drive output (no load) v cc v v od2 differential drive output (with load) r l =54 w (rs-422) (figure 1) 1.5 2.6 5 v v od3 differential drive output (with load) r l = 100 w (rs-422) (figure 1) 2 3 v d v od change in magnitude of driver differential output voltage for complementary output states (note1) r l =54 w or 100 w (figure 1) 0 0.2 v v oc driver common mode output voltage r l =54 w (figure 1) 1 3 v d v oc change in magnitude of driver common mode output voltage (note1) r l =54 w (figure 1) 0 0.2 v i off power off output current v cc =0v v o =-7v to 12v 100 m a i osd driver short circuit output current v o =-7v to 12v 35 250 ma v il input logic threshold low 0.8 v v ih input logic threshold high 2 v
st491a 4/11 receiver electrical characteristics v cc = 4.5v to 5.5v, t a = -40 to 85c, unless otherwise specified. typical values are referred to t a = 25c) driver switching characteristics v cc =4.5vto5.5v,t a = -40 to 85c, unless otherwise specified. typical values are referred to t a = 25c) receiver switching characteristics v cc =4.5vto5.5v,t a = -40 to 85c, unless otherwise specified. typical values are referred to t a = 25c) symbol parameter test conditions min. typ. max. unit i in input current (a, b) other input=0v v cc = 0 or 5.25v v in =12v 0.5 1 ma v in =-7v -0.35 -0.8 ma v th receiver differential threshold voltage v cm = -7v to 12v -0.2 0.2 v d v th receiver input hysteresis v cm =0v 70 mv v oh receiver output high voltage i out = -8ma, v id = 200mv 3.5 4.7 v v ol receiver output low voltage i out = 8ma, v id = -200mv 0.3 0.5 v r rin receiver input resistance v cm = -7v to 12v 12 24 k w symbol parameter test conditions min. typ. max. unit d r maximum data rate jitter <5% 25 50 mbps t plh t phl propagation delay input to output r l =54 w c l1 =c l2 =50pf, (figure 1) 10 16 ns t skew differential output delay skew r l =54 w c l1 =c l2 =50pf, (figure 1) 1 3 ns t tlh t thl rise or fall differential time r l =54 w c l1 =c l2 =50pf, (figure 1) 8 12 ns t pzl output enable time c l = 50pf s1 closed 14 25 ns t pzh output enable time c l = 50pf s2 closed 14 25 ns t phz output disable time c l = 15pf s2 closed 10 25 ns t plz output disable time c l = 15pf s1 closed 16 25 ns symbol parameter test conditions min. typ. max. unit t plh t phl propagation delay input to output c l = 15pf (figures 2,4) 19 30 ns t skd |t plh - t phl | receiver output skew c l = 15pf (figures 2,4) 1 3 ns t tlh t thl rise or fall time c l = 15pf (figures 2,4) 6 ns t pzl output enable time c rl = 15pf s1 closed 6 12 ns t pzh output enable time c rl = 15pf s2 closed 7 12 ns t phz output disable time c rl = 15pf s2 closed 6 12 ns t plz output disable time c rl = 15pf s1 closed 6 12 ns
st491a 5/11 test circuits and typical characteristics figure 1 : driver dc test load figure 2 : receiver timing test load figure 3 : driver/receiver timing test circuit
st491a 6/11 figure 4 : driver timing test load figure 5 : driver propagation delay
st491a 7/11 figure 6 : receiver propagation delay figure 7 : receiver output current vs output voltage (output low) figure 8 : receiver output current vs output voltage (output high) figure 9 : driver diff. output voltage vs common mode voltage (diff. output low) figure 10 : driver diff. output voltage vs common mode voltage (diff. output high)
st491a 8/11 figure 11 : driver short circuit current vs line voltage (output high) figure 12 : driver short circuit current vs. line voltage (output low) figure 13 : receiver input current vs input voltage
st491a 9/11 dim. mm. inch min. typ max. min. typ. max. a1 0.51 0.020 b 1.39 1.65 0.055 0.065 b 0.5 0.020 b1 0.25 0.010 d 20 0.787 e 8.5 0.335 e 2.54 0.100 e3 15.24 0.600 f 7.1 0.280 i 5.1 0.201 l 3.3 0.130 z 1.27 2.54 0.050 0.100 plastic dip-14 mechanical data p001a
st491a 10/11 dim. mm. inch min. typ max. min. typ. max. a 1.75 0.068 a1 0.1 0.2 0.003 0.007 a2 1.65 0.064 b 0.35 0.46 0.013 0.018 b1 0.19 0.25 0.007 0.010 c 0.5 0.019 c1 45? (typ.) d 8.55 8.75 0.336 0.344 e 5.8 6.2 0.228 0.244 e 1.27 0.050 e3 7.62 0.300 f 3.8 4.0 0.149 0.157 g 4.6 5.3 0.181 0.208 l 0.5 1.27 0.019 0.050 m 0.68 0.026 s ? (max.) so-14 mechanical data po13g 8
st491a 11/11 information furnished is believed to be accurate and reliable. however, stmicroelectronics assumes no res ponsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result f rom its use. no license is granted by implication or otherwise under any patent or patent rights of stmicroelectronics. specificati ons mentioned in this publication are subject to change without notice. this publication supersedes and replaces all information previously supplied. stmicroelectronics products are not authorized for use as critical components in life support devi ces or systems without express written approval of stmicroelectronics. ? the st logo is a registered trademark of stmicroelectronics ? 2002 stmicroelectronics - printed in italy - all rights reserved stmicroelectronics group of companies australia - brazil - canada - china - finland - france - germany - hong kong - india - israel - italy - japan - malaysia - malt a - morocco singapore - spain - sweden - switzerland - united kingdom - united states. ? http://www.st.com

▲Up To Search▲

Price & Availability of ST491ABDR

	To Download ST491ABDR Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .