unisonic technologies co., ltd utrs458 preliminary cmos ic www.unisonic.com.tw 1 of 8 copyright ? 2016 unisonic technologies co., ltd qw-r113-016.b polarity free, fail-safe, 500kbps, rs-485 / rs-422 transceivers with 12kv esd-protected ? description the utc utrs458 is a polarity-free half-duplex transceiver designed for rs-485 data bus network, which contains one transmitter and one receiver. the utc utrs458 features a fail-safe receiver, which guarantees the receiver to output high when the receiver inputs are open, short or idle. the utc utrs458 can automatically detect the polarity for a and b pins when pull-high for a and pull-low for b have been designed on the rs485 bus. the detection functi on is real-time monitored the bus polarity without any data flow on the rs485 bus. the utc utrs458 also features a hot-swap glitch free protection circuits which guarantee outputs of both the transmitter and the receiver in a high impedance state dur ing the power up period. so that the large short current from power to ground will be disable by glitch free function, which will save the power and enhance the efficiency of the power up. the utc utrs458 is optimized for signal rates up to 500kbps with differential voltage of 2.3v. the utc utrs458 also has the thermal shutdown function when t he temperature is over 150c and the protection of the current limita tion in the transmitter to protect the itself from the damage by the sy stem-fault conditions during normal operation. ? features * meet the requirements of the eia/tia-485 standards. * 5.0v single power supply. * 1a low-current shutdown mode. * hbm 12kv esd protection. * true fail-safe receiver while maintaining eia/tia-485 compatibility. * hot-swap glitch free prot ection on control inputs. * up to 256 transceivers on the bus. * maximum baud rate up to 500kbps. * transmitter short circuit current limit. * thermal shutdown for overload protection. * polarity-free for rs485 bus pins. ? ordering information ordering number package packing UTRS458G-S08-R sop-8 tape reel
utrs458 preliminary cmos ic unisonic technologies co., ltd 2 of 8 www.unisonic.com.tw qw-r113-016.b ? marking ? pin configuration 1 2 3 4 8 7 6 5 ro reb de di v cc b a gnd ? pin description pin no. pin name description 1 ro receiver output. 2 reb receiver output enable: reb is low to enable the receiver; reb is high to disable the receiver. 3 de transmitter output enable: de is high to enable the transmitter; de is low to disable the transmitter. 4 di transmitter input: when de is high, a low on di forces an output low and b output high. similarly, a high on di forces an output high and b output low. 5 gnd ground pin. must be connected to 0v. 6 a non-inverting receiver input and non-inverting transmitter output 7 b inverting receiver input and inverting transmitter output 8 v cc power supply input 5.0v.
utrs458 preliminary cmos ic unisonic technologies co., ltd 3 of 8 www.unisonic.com.tw qw-r113-016.b ? block diagram 1 2 3 4 8 7 6 ro reb de di v cc b a gnd tx rx polarity detection circuit 5
utrs458 preliminary cmos ic unisonic technologies co., ltd 4 of 8 www.unisonic.com.tw qw-r113-016.b ? absolute maximum rating parameter symbol ratings unit power supply v cc v cc -0.3~7.0 v control input voltage reb, de -0.3~ v cc v receiver input voltage a, b 12.5 v receiver output voltage ro -0.3~ v cc v transmitter output voltage a, b 12.5 v transmitter input di -0.3~ v cc v operating temperature t op -40 ~ +85 c storage temperature t stg -65 ~ +150 c note: absolute maximum ratings are only stress ratings and it is not implied for functional device operation. absolute maximum ratings are the values beyond which the device will be damaged permanently. ? dc electrical characteristics (v cc =5.0v 5% with t a =t min to t max , unless otherwise noted. typical values are at v cc =5.0v and t a =25c) parameter symbol test conditions min typ max unit transmitter differential transmitter output v od1 no load 5.0 v differential transmitter output v od2 fig.1, r l =27 ? 1.5 v change in magnitude of differential output voltage ? v od fig.1, r l =27 ? 0.2 v transmitter common- mode output voltage v oc fig.1, r l =27 ? 3.0 v change in magnitude of common- mode voltage ? v oc fig.1, r l =27 ? 0.2 v input high voltage v ih de, di, reb 2.0 v input low voltage v il de, di, reb 0.8 v input current i in1 di 2.0 a input current i in2 de, reb 50 a di input hysteresis v hys 100 mv v in =12v 125 a input current (a and b) i in3 de=gnd, v cc =gnd or 5.25v v in =-7v -75 a -7v v out v cc -250 ma transmitter short-circuit output current i os 0v v out 12v 250 ma receiver receiver differential threshold voltage v th -7v v cm +12v -300 300 mv receiver input hysteresis ? v th 25 mv receiver output high voltage v oh i o =-4ma, v id =-50mv v cc -1.5 v receiver output low voltage v ol i o =4ma, v id =-200mv 0.5 v three- state output current at receiver i ozr 0.4v v cm 2.4v 1.0 a receiver input resistance r in -7v v cm +12v 96 k ? receiver output short-circuit current i osr fig.6, 0v v ro vcc 7 95 m supply current de=v cc 420 900 a supply current i cc no load, reb=gnd, di=v cc or gnd. de=gnd 320 600 a supply current in shutdown mode i shdn reb=v cc , de=gnd 1.0 10 a
utrs458 preliminary cmos ic unisonic technologies co., ltd 5 of 8 www.unisonic.com.tw qw-r113-016.b ? switching characteristics (v cc =5.0v 5% with t a =t min to t max , unless otherwise noted. typical values are at v cc =5.0v and t a =25c) parameter symbol test conditions min typ max unit transmitter input to output t dplh , t dphl fig.2 and 7, r diff =54 ? , c l1 =c l2 = 100pf 720 900 ns transmitter output skew | t dplh - t dphl | t dskew fig.2 and 7, r diff =54 ? , c l1 =c l2 = 100pf 10 ns transmitter rise or fall time t df , t dr fig.2 and 7, r diff =54 ? , c l1 =c l2 = 100pf 15 750 ns maximum data rate f max 500 kbps transmitter enable to output low t dzl fig.4 and 8, c dl =100pf, s1 closed 2500 ns transmitter enable to output high t dzh fig.4 and 8, c dl =100pf, s2 closed 2500 ns transmitter disable time from low t dlz fig.4 and 8, c dl =15pf, s1 closed 500 ns transmitter disable time from high t dhz fig.4 and 8, c dl =15pf, s2 closed 500 ns receiver input to output t rplh , t rphl fig.5 and 9 , |v id | 2.0v; rise and fall tim e of v id 15ns 200 ns | t rplh ? t rphl | different receiver skew t rskd fig.5 and 9 , |v id | 2.0v; rise and fall tim e of v id 15ns 100 ns receiver enable to output low t rzl fig.3 and 10, c rl =100pf, s1 closed 50 ns receiver enable to output high t rzh fig.3 and 10, c rl =100pf, s2 closed 50 ns receiver disable time from low t rlz fig.3 and 10, c rl =100pf, s1 closed 50 ns receiver disable time from high t rhz fig.3 and 10, c rl =100pf, s2 closed 50 ns time to shutdown t shdn 200 ns transmitter enable from shutdown to output low t dzl(shdn) fig.4 and 8, c dl =15pf, s1 closed 4500 ns transmitter enable from shutdown to output high t dzh(shdn) fig.4 and 8, c dl =15pf, s2 closed 4500 ns receiver enable from shutdown to output low t rzl(shdn) fig.3 and 10, c rl =100pf, s1 closed 4500 ns receiver enable from shutdown to output high t rzh(shdn) fig.3 and 10, c rl =100pf, s2 closed 4500 ns
utrs458 preliminary cmos ic unisonic technologies co., ltd 6 of 8 www.unisonic.com.tw qw-r113-016.b ? function table transmitting receiving inputs output reb de a-b ro 0 x -0.05v 1 0 x -0.2v 0 0 x open/shorted 1 1 1 x high-z 1 0 shutdown x = don?t care shutdown mode, transmitter and receiver outputs high impedance inputs outputs reb de di a b x 1 0 0 1 x 1 1 1 0 0 0 x high-z high-z 1 0 x shutdown
utrs458 preliminary cmos ic unisonic technologies co., ltd 7 of 8 www.unisonic.com.tw qw-r113-016.b ? test circuit rx a b reb c rl 1k s1 s2 1k vcc tx vdc de a b c dl 500 s1 s2 vcc fig. 3 receiver enable/disable timing test circuit fig. 4 transmitter enable/disable timing test circuit
utrs458 preliminary cmos ic unisonic technologies co., ltd 8 of 8 www.unisonic.com.tw qw-r113-016.b ? test circuit (cont.) voh vol ro a -1v b 1.5v output t rphl input 1.5v t rplh 3v 0v reb v cc ro v ol v oh ro 0 1.5v t rzl 1.5v 1.5v t rzh output normally low output normally high t rlz 1.5v v ol +0.5v v oh -0.5v t rhz fig. 9 receiver propagation delays fig. 10 receiver enable and disable times utc assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all utc products described or contained herein. utc products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. the information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice.
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