OCT 2010 HG3085E General Description Features The HG3085E +5V, half-duplex, ±15kV ESDprotected RS-485/RS-422-compatible transceivers feature one driver and one receiver. The HG3085E include a hot-swap capability to eliminate false transitions on the bus during power-up or live insertion. TheHG3085E features reduced slew-rate drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing errorfree transmission up to 500kbps. The HG3085E feature a 1/8-unit load receiver input impedance, allowing up to 256 transceivers on the bus. These devices are intended for halfduplex communications. All driver outputs are protected to ±15kV ESD using the Human Body Model. TheHG3085 is available in an 8-pin SO package. The devices operate over the extended -40°C to +85°C temperature range. ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND.) Supply Voltage VCC...............................................................+6V DE, RE, DI..............................................................-0.3V to +6 A, B........................................................................... -8V to +13V Short-Circuit Duration (RO, A, B) to GND ..................Continuous +5V Operation Hot-Swappable for Telecom Applications Enhanced Slew-Rate Limiting Facilitates ErrorFree Data Transmission Extended ESD Protection for RS-485 I/O Pins ±15kV Human Body Model 1/8Unit Load ， Allowing Up to 256Transceivers on the Bus 8 Pin-SOP/DIP Package Applications Isolated RS-485 Interfaces Utility Meters Industrial Controls Industrial Motor Drives Automated HVAC Systems Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Continuous Power Dissipation (TA = +70°C) 8-Pin SO (derate 5.9mW/°C above +70°C)..................471mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering 10s) ..................................+300°C 1/7 www.hgsemi.net OCT 2010 HG3085E DC ELECTRICAL CHARACTERICS (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN Differential Driver Output (no load) VOD1 Figure1 Differential Driver Output VOD2 Figure1,R = 50Ω (RS422) Figure1,R = 27Ω (RS485) TYP MAX UNITS 5 V DRIVER 2.0 V 1.5 Change in Magnitude of Differential Output Voltage (Note 2) ∆VOD Figure1,R =50Ωor R= 27Ω 0.2 V Driver Common-Mode Output Voltage VOC Figure1,R=50Ωor R = 27Ω 3 V Change In Magnitude of Common-Mode Voltage (Note 2) ∆VOC Figure1,R=50Ωor R = 27Ω 0.2 V Input High Voltage VIH1 DE, DI, RE, 2.0 V Input Low Voltage VIL1 DE, DI, RE, 0.8 V DI Input Hysteresis VHYS WS3085 100 mV Input Current IIN1 DE, DI, RE ±2 µA Input Current (A and B) IIN4 Driver Short-Circuit Output Current (Note 3) VOD1 DE = GND, VCC=GND or 5.25V VIN=12V 125 VIN = -7V -75 -7V ≤ VOUT ≤ VCC µA mV -250 RECEIVER Receiver Differential Threshold Voltage VTH Receiver Input Hysteresis ∆VTH Receiver Output High Voltage VOH Receiver Output Low Voltage -7V ≤ VCM ≤ +12V -125 -50 mV 25 mV IO = 4mA, VID = -200mV; Vcc-1.5 V VOL IO = -4mA, VID = -50mV 0.4 V Three-State Output Current at Receiver IOZR 0.4V ≤ VO ≤ 2.4V ±1 µA Receiver Input Resistance RIN -7V ≤ VCM ≤ +12V 96 kΩ Receiver Output Short-Circuit Current IOSR 0V ≤ VRO ≤ VCC -200 ±7 ±95 mA SUPPLY CURRENT Supply Current ICC No load, RE =DI=GND or VCC DE = VCC 530 900 DE = GND 500 600 µA 2/7 www.hgsemi.net OCT 2010 HG3085E SWITCHING CHARACTERISTICS (VCC = +5V ±5%, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) PARAMETER Driver Input to Output SYMBOL tDPLH tDPHL CONDITIONS Figures3 and 5, RDIFF = 54Ω, CL1 = CL2 = 100pF Driver Output Skew | tDPLH - tDPHL | tDSKEW Figures 3 and 5, RDIFF = 54Ω, CL1 = CL2 = 100pF Driver Rise or Fall Time tDR, tDF Figures 3 and 5, RDIFF = 54Ω, CL1 = CL2 = 100pF Maximum Data Rate fMAX Driver Enable to Output High tDZH Driver Enable to Output Low tDZL Driver Disable Time from Low tDLZ Driver Disable Time from High tDHZ Receiver Input to Output tRPLH, tRPHL | tRPLH - tRPHL | Differential tRSKD Receiver Skew Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low tRZL tRZH tRLZ MIN TYP MAX 250 720 1000 250 720 1000 -3 200 ±100 530 UNITS ns ns 750 ns 500 kbps Figures4 and 6, CL = 100pF, S2 closed 2500 ns Figures4 and 6,CL= 100pF, S1 closed 2500 ns 100 ns 100 ns Figures 4 and 6, CL = 15pF, S1 closed Figures 4 and 6, CL = 15pF, S2 closed Figures 7 and 9; | VID | ≥ 2.0V;rise and fall time of VID ≤ 15ns Figures 7 and 9; | VID | ≥ 2.0V;rise and fall time of VID ≤ 15ns Figures 2 and 8, CL = 100pF, S1 closed Figures 2 and 8, CL = 100pF, S2 closed Figures 2 and 8 , CL = 100pF, S1 closed Figures 2 and 8, CL = 100pF, S2 closed 127 200 ns 3 ±30 ns 20 50 ns 20 50 ns 20 50 ns 20 50 ns Receiver Disable Time from High tRHZ Time to Shutdown Driver Enable from Shutdown to tSHDN (Note 4) tDZH(SHD Figures 4 and 6, CL = 15pF, S2 closed 4500 ns Figures 4 and 6, CL = 15pF, S1 closed 4500 ns Figures 2 and 8, CL = 100pF, S2 closed 3500 ns Figures 2 and 8, CL = 100pF, S1 closed 3500 ns N) Output High Driver Enable from Shutdown to tDZL(SHDN ) 50 200 600 ns Output Low Receiver Enable from Shutdown to Output High tRZH(SHD Receiver Enable from Shutdown to Output Low tRZL(SHDN N) ) Note 4: The device is put into shutdown by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the device is guaranteed not to enter shutdown. If the enable inputs are in this state for at least 600ns, the device is guaranteed to have entered 3/7 www.hgsemi.net OCT 2010 HG3085E 4/7 www.hgsemi.net OCT 2010 HG3085E Pin Description PIN NAME FUNCTION 1 RO Receiver Output. When RE is low and if A - B ≥ -50mV, RO will be high; if A - B ≤ -200mV, RO will be low. 2 RE 3 DE 4 DI Driver Output Enable. Drive DE high to enable driver outputs. These outputs are high impedance when DE is low. Drive RE high and DE low to enter low-power shutdown mode. DE is a hot-swap input (see the Hot-Swap Capability section for more details). Driver Input. With DE high, a low on DI forces non-inverting output low and inverting output high. Similarly, a high on DI forces non-inverting output high and inverting output low. 5 GND Ground 6 A Non-inverting Receiver Input and Non-inverting Driver Output 7 B Inverting Receiver Input and Inverting Driver Output 8 Vcc Positive Supply, VCC = +5V ±5%. Bypass VCC to GND with a 0.1µF capacitor. Receiver Output Enable. Drive RE low to enable RO; RO is high impedance when RE is high. Drive RE high and DE low to enter low-power shutdown mode. RE is a hot-swap input (see the Hot-Swap Capability section for more details). 5/7 www.hgsemi.net OCT 2010 HG3085E Function Table TRANSMITTING INPUTS RE X X 0 1 OUTPUTS DE 1 1 0 0 DI 1 0 X X B/Z 0 1 High-Z A/Y 1 0 High-Z Shutdown RECEIVING RE 0 0 0 1 1 INPUTS DE X X X 1 0 A-B ≥ -0.05V ≤ -0.2V Open/shorted X X OUTPUTS RO 1 0 1 High-Z Shutdown Applications Information 256 Transceivers on the Bus The standard RS-485 receiver input impedance is 12kΩ (one-unit load), and the standard driver can drive up to 32 unit loads. The HG3085 E family of transceivers have a 1/8-unit-load receiver input impedance (96kΩ), allowing up to 256 transceivers to be connected in parallel on one communication line. Any combination of these devices and/or other RS-485 transceivers with a total of 32 unit loads or less can be connected to the line. Driver Output Protection Two mechanisms prevent excessive output current and power dissipation caused by faults or by bus contention. The first, a fold-back current limit on the output stage, provides immediate protection against short circuits over the whole common-mode voltage range (see Typical Operating Characteristics). The second, a thermal shutdown circuit, forces the driver outputs into a high-impedance state if the die temperature becomes excessive. Low-Power Shutdown Mode Low-power shutdown mode is initiated by bringing both RE high and DE low. In shutdown, the devices typically draw only 2uA of supply current. RE and DE may be driven simultaneously; the parts are guaranteed not to enter shutdown if RE is high and DE is low for less than 50ns. If the inputs are in this state for at least 600ns, the parts are guaranteed to enter shutdown. Reduced EMI and Reflections HG3085E is slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. 6/7 www.hgsemi.net OCT 2010 HG3085E 7/7 www.hgsemi.net