TIGER ELECTRONIC CO.,LTD MAX485 Low-Power, Slew-Rate-Limited RS-485/RS-422 Transceivers General Description The MAX485 is low-power transceivers for RS-485 and RS422 communication. IC contains one driver and one receiver. The driver slew rates of the MAX485 is not limited, allowing them to transmit up to 2.5Mbps. These transceivers draw between 120µA and 500µA of supply current when unloaded or fully loaded with disabled drivers. All parts operate from a single 5V 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. The MAX485 is designed for half-duplex applications. Features Low Quiescent Current: 300µA -7V to +12V Common-Mode Input Voltage Range Three-State Outputs 30ns Propagation Delays, 5ns Skew Full-Duplex and Half-Duplex Versions Available Operate from a Single 5V Supply Allows up to 32 Transceivers on the Bus Data rate: 2,5 Mbps Current-Limiting and Thermal Shutdown for Driver Overload Protection The transmitter outputs and receiver inputs are protected to ±15kV Air ESD. ORDERING INFORMATION MAX485CPA Plastic DIP MAX485CSA SOIC MAX485 ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC) 12V Control Input Voltage -0.5V to (VCC + 0.5V) Driver Input Voltage (DI) -0.5V to (VCC+ 0.5V) Driver Output Voltage (A, B) -8V to +12.5V Receiver Input Voltage (A, B) -8V to +12.5V Receiver Output Voltage (RO) -0.5V to (VCC+0.5V) Continuous Power Dissipation (TA= +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) 727mW 8-Pin SOP (derate 5.88mW/°C above +70°C) 471mW Operating Temperature Ranges 0°C to +70°C Storage Temperature Range -65°C to +160°C Lead Temperature (soldering, 10sec) +300°C DC ELECTRICAL CHARACTERISTICS (VCC = 5V ±5%, 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 ∆VOD CONDITIONS R = 50Ω (RS-422) R = 27Ω (RS-485), Figure 4 R = 27Ω or 50Ω, Figure 4 TY P 2 1.5 MAX UNITS 5 V V 5 0.2 V VOC R = 27Ω or 50Ω, Figure 4 3 V ∆VOD R = 27Ω or 50Ω, Figure 4 0.2 V VIH DE, DI, RE Input Low Voltage VIL DE, DI, RE Input Current Input Current (A, B) IIN1 IIN2 DE, DI, RE DE = 0V; VCC = 0V or 5.25V, -7V ≤ VCM ≤12V 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 MIN VTH ∆VTH VOH VOL IOZR RIN 2.0 0.8 VIN = 12V VIN = -7V VCM = 0V IO = -4mA, VID = 200mV IO = 4mA, VID = -200mV 0.4V ≤ VO ≤ 2.4V -7V ≤ VCM ≤ 12V V -0.2 V ±2 µA 1.0 -0.8 0.2 mA 70 3.5 0.4 ±1 V mV V V µA kΩ MAX485 DC ELECTRICAL CHARACTERISTICS (continued) (VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER No-Load Supply Current (Note 3) SYMBOL ICC CONDITIONS MIN DE = VCC RE = 0V or VCC TY P MAX UNITS 500 300 900 500 µA DE = 0V Driver Short-Circuit Current, IOSD1 -7V ≤ VO ≤ 12V (Note 4) 35 250 mA IOSD2 -7V ≤ VO ≤12V (Note 4) 35 250 mA IOSR 0V ≤ VO ≤ VCC 7 95 mA VO = High Driver Short-Circuit Current, VO = Low Receiver Short-Circuit Current SWITCHING CHARACTERISTICS (VCC = 5V ±5%, TA = TMIN to TMAX, unless otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Driver Input to Output tPLH tPHL 10 10 tSKEW tZH tZL tLZ tHZ tSKD 30 30 5 40 40 40 40 13 60 60 10 70 70 70 70 ns Driver Output Skew to Output Driver Enable to Output High Driver Enable to Output Low Driver Disable Time from Low Driver Disable Time from High | tPLH - tPHL | Differential Receiver Skew Receiver Enable to Output Low Receiver Enable to Output High Receiver Disable Time from Low Receiver Disable Time from High Maximum Data Rate tZL tZH tLZ RDIFF = 54Ω CL1 = CL2 = 100pF RDIFF = 54Ω, CL1 = CL2 = 100pF CL= 100pF, S2 closed CL= 100pF, S1 closed CL= 15pF, S1 closed CL= 15pF, S2 closed RDIFF = 54Ω CL1 = CL2 = 100pF CRL = 15pF, S1 closed CRL = 15pF, S2 closed CRL = 15pF, S1 closed 20 20 20 50 50 50 ns ns ns tHZ CRL = 15pF, S2 closed 20 50 ns fMAX 2.5 ns ns ns ns ns ns Mbps MAX485 MAX485 Operation timing diagrams of MAX 485 Table of MAX 485 operation Transmitting RE X X 0 1 Inputs DE 1 1 0 0 X-don’t care Z-high impedance DI 1 0 X X Outputs X Z Y 0 1 1 0 Z Z Z Z RE 0 0 0 1 Receiving Inputs DE A-B 0 +0.2V 0 -0.2V 0 open 0 X Outputs RO 1 0 1 Z MAX485 N SUFFIX PLASTIC DIP (MS – 001BA) A Dimension, mm 5 8 B 1 4 MIN MAX A 8.51 10.16 B 6.1 7.11 5.33 C L F Symbol C D 0.36 0.56 F 1.14 1.78 -T- SEATING PLANE N G M K 0.25 (0.010) M J H D 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. 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 D SUFFIX SOIC (MS - 012AA) Dimension, mm A 8 5 B H 1 G P 4 D K 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 R x 45 C -T- Symbol SEATING PLANE J F 0.25 (0.010) M T C M M G 1.27 H 5.72 J 0° 8° K 0.1 0.25 1. Dimensions A and B do not include mold flash or protrusion. M 0.19 0.25 2. Maximum mold flash or protrusion 0.15 mm (0.006) per side for A; for B ‑ 0.25 mm (0.010) per side. P 5.8 6.2 R 0.25 0.5 NOTES: