HT3485EBRZ

HT3485EB Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers (compatible to MAX3485 (MAXIM) Description The 3485 is low-power transceivers for RS-485 and RS- 422 communication. IC contains one driver and one receiver. The driver slew rates of the HT3485 is not limited, allowing them to transmit up to 10Mbps. These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. All parts operate from a single 3.3V supply. Drivers are short-circuit current limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs into a high-impedance state. The receiver input has a fail-safe feature that guarantees a logic-high output if the input is open circuit. DIP8−8 N SUFFIX HT3485EBNZ SOP−8 R SUFFIX HT3485EBRZ MSOP−8 M SUFFIX HT3485EBRMZ TA = -40 to 85C for all packages. Features ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ ƒ Low Quiescent Current: 120µA -7V to +12V Common-Mode Input Voltage Range Three-State Outputs 80ns Propagation Delays, 5ns Skew Half-Duplex Versions Available Operate from a Single 3.3V Supply Allows up to 32 Transceivers on the Bus Data rate: 10 Mbps Current-Limiting and Thermal Shutdown for Driver Overload Protection Enhanced ESD Specifications: —15kV IEC61000-4-2 Air Discharge —8kV IEC61000-4-2 Contact Discharge Pin Description Rev. 01 HT3485EB ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) 7V Continuous Power Dissipation (TA= +70°C) Control Input Voltage -0.3V to 7V 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) 727mW Driver Input Voltage (DI) -0.3V to 7V 8-Pin SOP (derate 5.88mW/°C above +70°C) 471mW Driver Output Voltage (A, B) -7.5V to +12.5V Operating Temperature Ranges -40°C to +85°C Receiver Input Voltage (A, B) -7.5V to +12.5V Storage Temperature Range -65°C to +160°C Receiver Output Voltage (RO) -0.3V to (VCC+0.3V) Lead Temperature (soldering, 10sec) +300°C 6WUHVVHVEH\RQGWKRVHOLVWHGXQGHU³DEVROXWHPD[LPXPUDWLQJV´PD\FDXVHSHUPDQHQWGDPDJHWRWKHGHYLFH These are stress ratings only and functional operation of the device at these or any other conditions beyond those LQGLFDWHGXQGHU³UHFRPPHQGHGRSHUDWLQJFRQGLWLRQV´LVQRWLPSOLHG Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. DC ELECTRICAL CHARACTERISTICS (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL Differential Driver Output (no load) Differential Driver Output (with load) Change in Magnitude of Driver Differential Output Voltage for Complementary Output States Driver Common-Mode Output Voltage Change in Magnitude of Driver Common-Mode Output Voltage for Complementary Output States Input High Voltage VOD1 VOD2 CONDITIONS ¨VOD R = 10ȍ56-422) R = 54ȍ56-485), Figure 4 R = 54ȍ or 50ȍ, Figure 4 VOC ¨VOC MIN TYP MAX UNITS 3 V 1 0.8 V 0.2 V R = 54ȍ or 100ȍ, Figure 4 2 V R = 54ȍ or 100ȍ, Figure 4 0.2 V VIH DE, DI, RE Input Low Voltage VIL DE, DI, RE 0.8 V Input Current Input Current (A, B) IIN1 ±2 µA VTH 1.0 -0.8 0.2 mA Receiver Differential Threshold Voltage Receiver Input Hysteresis Receiver Output High Voltage Receiver Output Low Voltage Three-State (high impedance) Output Current at Receiver Receiver Input Resistance DE, DI, RE DE = 0V; VIN = 12V VCC = 0V or 3.35V VIN = -7V -9”9CM ”9 IIN2 ¨VTH VOH VOL IOZR RIN VCM = 0V IO = -1.5mA, VID = 200mV IO = 2.5mA, VID = -200mV 9”9O ”9 -9”9CM ”9 2.0 V -0.2 70 2.5 0.4 ±1 12 V mV V V µA Nȍ Rev. 01 HT3485EB DC ELECTRICAL CHARACTERISTICS (continued) (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER No-Load Supply Current (Note 3) SYMBOL ICC Driver Short-Circuit Current, IOSD1 VO = High Driver Short-Circuit Current VO = Low Receiver Short-Circuit Current IOSD2 CONDITIONS MIN DE = VCC RE = 0V or VCC DE = 0V -9”9O ”91RWH TYP MAX UNITS 500 300 800 400 µA 250 mA 250 mA 95 mA -9”9O ”91RWH IOSR 9”9O ”9CC ±6.5 A, B, Y and Z pins, tested using Human Body Model ESD Protection r15 kV SWITCHING CHARACTERISTICS (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER Driver Input to Output SYMBOL tPLH tPHL TYP MAX UNITS 10 10 80 80 5 100 100 10 ns 55 55 60 60 13 120 120 5 50 50 80 80 90 90 20 200 200 10 90 90 ns ns ns ns ns ns tZL tZH tLZ CRL = 15pF, S1 closed 40 80 ns tHZ CRL = 15pF, S2 closed 40 80 ns 5 10 Mbps tSKEW Driver Enable to Output High Driver Enable to Output Low Driver Disable Time from Low Driver Disable Time from High | tPLH - tPHL | Differential tZH tZL tLZ tHZ tSKD tPLH tPHL Receiver Skew | tPLH - tPHL | Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low Receiver Disable Time from High Maximum Data Rate MIN RDIFF = 54: CL1 = CL2 = 100pF RDIFF = 54:, CL1 = CL2 = 100pF CL= 100pF, S2 closed CL= 100pF, S1 closed CL= 15pF, S1 closed CL= 15pF, S2 closed RDIFF = 54: RDIFF = 54: CL1 = CL2 = 100pF CL1 = CL2 = 100pF CRL = 15pF, S1 closed CRL = 15pF, S2 closed Driver Output Skew to Output Receiver Input to Output CONDITIONS fMAX 20 20 2.5 ns ns ns Note 1: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified. Note 2: All typical specifications are given for VCC=3.3V and TA=+25°C. Note 3: Supply current specification is valid for loaded transmitters when DE=0V. Note 4: Applies to peak current. Rev. 01 HT3485EB TEST CIRCUITS Figure 1. Driver VOD and VOC Figure 2. Driver VOD with Varying Common-Mode Voltage Figure 3. Receiver VOH and VOL Figure 4. Driver Differential Output Delay and Transition Times Rev. 01 HT3485EB TEST CIRCUITS (continue) Figure 5. Driver Propagation Times Figure 6. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) Figure 7. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) Rev. 01 HT3485EB TEST CIRCUITS (continue) Figure 8. Receiver Propagation Delay Figure 9. Receiver Enable and Disable Times Note 5: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tr d6.0ns, ZO ȍ Note 6: CL includes probe and stray capacitance. Rev. 01 HT3485EB Function Tables Transmitting INPUTS RE DE X 1 X 1 0 0 1 0 DI 1 0 X X OUTPUTS X Z Y 0 1 1 0 Z Z Z Z Receiving INPUTS RE DE A-B 0 0 +0.2V 0 0 -0.2V 0 0 open 1 0 X OUTPUTS RO 1 0 1 Z X-GRQ¶WFDUH Z-high impedance Typical Information Figure 10. 3485 Typical RS-485 Network Driver Output Protection Excessive output current and power dissipation caused by faults or by bus contention are prevented by two mechanisms. A foldback current limit on the output stage provides immediate protection against short circuits over the whole common-mode voltage range. In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Skew time is simply the difference between the low-to-high and high-to-low propagation delay. Small driver/receiver skew times help maintain a symmetrical mark-space ratio (50% duty cycle). The receiver skew time, |tPRLH - tPRHL|, is under 10ns. The driver skew times are 5ns for the 3485. Typical Applications 3485 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figure 10 shows typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet. To minimize reflections, the line should be terminated at both ends in its characteristic impedance, and stub lengths off the main line should be kept as short as possible. Rev. 01 HT3485EB (DIP8) A Dimension, mm 5 8 B 1 4 F C -T- SEATING PLANE G M K 0.25 (0.010) M J H D MIN MAX A 8.51 10.16 B 6.1 7.11 5.33 C L N Symbol T NOTES: 1. Dimensions “A”, “B” do not include mold flash or protrusions. Maximum mold flash or protrusions 0.25 mm (0.010) per side. D 0.36 0.56 F 1.14 1.78 G 2.54 H 7.62 J 0° 10° K 2.92 3.81 L 7.62 8.26 M 0.2 0.36 N 0.38 (SOP8) Dimension, mm A 8 5 B H 1 G P 4 R x 45 C -TD K SEATING PLANE J F 0.25 (0.010) M T C M NOTES: 1. Dimensions A and B do not include mold flash or protrusion. 2. Maximum mold flash or protrusion 0.15 mm (0.006) per side for A; for B ‑ 0.25 mm (0.010) per side. M Symbol MIN MAX A 4.8 5 B 3.8 4 C 1.35 1.75 D 0.33 0.51 F 0.4 1.27 G 1.27 H 5.72 J 0° 8° K 0.1 0.25 M 0.19 0.25 P 5.8 6.2 R 0.25 0.5 Rev. 01