MAX3485CSA+

Click here for production status of specific part numbers. MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers General Description The MAX3483, MAX3485, MAX3486, MAX3488, MAX3490, and MAX3491 are 3.3V, low-power transceivers for RS-485 and RS-422 communication. Each part contains one driver and one receiver. The MAX3483 and MAX3488 feature slew-rate-limited drivers that minimize EMI and reduce reflections caused by improperly terminated cables, allowing error-free data transmission at data rates up to 250kbps. The partially slew-rate-limited MAX3486 transmits up to 2.5Mbps. The MAX3485, MAX3490, and MAX3491 transmit at up to 10Mbps. 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 both inputs are open circuit. The MAX3488, MAX3490, and MAX3491 feature fullduplex communication, while the MAX3483, MAX3485, and MAX3486 are designed for half-duplex communication. Applications ● ● ● ● Low-Power RS-485/RS-422 Transceivers Telecommunications Transceivers for EMI-Sensitive Applications Industrial-Control Local Area Networks Features ● Operate from a Single 3.3V Supply— No Charge Pump! ● Interoperable with +5V Logic ● 8ns Max Skew (MAX3485/MAX3490/MAX3491) ● Slew-Rate Limited for Errorless Data Transmission (MAX3483/MAX3488) ● 2nA Low-Current Shutdown Mode (MAX3483/MAX3485/MAX3486/MAX3491) ● -7V to +12V Common-Mode Input Voltage Range ● Allows up to 32 Transceivers on the Bus ● Full-Duplex and Half-Duplex Versions Available ● Industry Standard 75176 Pinout (MAX3483/MAX3485/MAX3486) ● Current-Limiting and Thermal Shutdown for Driver Overload Protection Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX3483CPA 0°C to +70°C 8 Plastic DIP MAX3483CSA 0°C to +70°C 8 SO MAX3483C/D 0°C to +70°C Dice* MAX3483EPA -40°C to +85°C 8 Plastic DIP MAX3483ESA -40°C to +85°C 8 SO MAX3485CPA 0°C to +70°C 8 Plastic DIP MAX3485CSA 0°C to +70°C 8 SO MAX3485C/D 0°C to +70°C Dice* MAX3485EPA -40°C to +85°C 8 Plastic DIP MAX3485ESA -40°C to +85°C 8 SO Ordering Information continued at end of data sheet. * Contact factory for for dice specifications. Selection Table PART NUMBER GUARANTEED DATA RATE (Mbps) MAX3483 HALF/FULL DUPLEX SLEW-RATE LIMITED DRIVER/ RECEIVER ENABLE SHUTDOWN CURRENT (nA) PIN COUNT 0.25 Half Yes Yes 2 8 MAX3485 10 Half No Yes 2 8 MAX3486 2.5 Half Yes Yes 2 8 MAX3488 0.25 Full Yes No — 8 MAX3490 10 Full No No — 8 MAX3491 10 Full No Yes 2 14 19-0333; Rev 1; 5/19 SUPPLY VOLTAGE (V) 3.0 to 3.6 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Absolute Maximum Ratings Supply Voltage (VCC)..............................................................7V Control Input Voltage (RE, DE)..................................-0.3V to 7V Driver Input Voltage (DI).............................................-0.3V to 7V Driver Output Voltage (A, B, Y, Z).........................-7.5V to 12.5V Receiver Input Voltage (A, B)................................-7.5V to 12.5V Receiver Output Voltage (RO).................. -0.3V to (VCC + 0.3V) Continuous Power Dissipation (TA = +70°C) 8-Pin Plastic DIP (derate 9.09mW/°C above +70°C)...727mW 8-Pin SO (derate 5.88mW/°C above +70°C)................471mW 14-Pin Plastic DIP (derate 10mW/°C above +70°C)....800mW 14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW Operating Temperature Ranges MAX34_ _C_ _....................................................0°C to +70°C MAX34_ _E_ _................................................ -40°C to +85°C Junction Temperature.......................................................+160°C Storage Temperature Range .............................-65°C to +160°C Lead Temperature (soldering, 10sec) .............................+300°C Package Information 14 SOIC PACKAGE CODE S14+1 Outline Number 21-0041 Land Pattern Number 90-0112 Thermal Resistance, Single-Layer Board: Junction to Ambient (θJA) 120 Junction to Case (θJA) 37 Thermal Resistance, Four-Layer Board: Junction to Ambient (θJA) 84 Junction to Case (θJA) 34 For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. www.maximintegrated.com Maxim Integrated │  2 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers DC Electrical Characteristics (VCC = 3.3V ±0.3V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C) PARAMETER Differential Driver Output SYMBOL VOD CONDITIONS MIN RL = 100Ω (RS-422), Figure 4 2.0 RL = 54Ω (RS-485), Figure 4 1.5 RL = 60Ω (RS-485), VCC = 3.3V, Figure 5 1.5 TYP MAX UNITS V Change in Magnitude of Driver Differential Output Voltage for Complementary Output States (Note 1) ΔVOD RL = 54Ω or 100Ω, Figure 4 0.2 V Driver Common-Mode Output Voltage VOC RL = 54Ω or 100Ω, Figure 4 3 V ΔVOC RL = 54Ω or 100Ω, Figure 4 0.2 V Change in Magnitude of Common-Mode Output Voltage (Note 1) Input High Voltage VIH DE, DI, RE 2.0 V Input Low Voltage VIL DE, DI, RE 0.8 V Logic Input Current IIN1 DE, DI, RE ±2 μA Input Current (A, B) IIN2 DE = 0V, VCC = 0V or 3.6V VIN = 12V 1.0 VIN = -7V -0.8 Output Leakage (Y, Z) IO DE = 0V, RE = 0V, VCC = 0V or 3.6V, MAX3491 VOUT = 12V 20 VOUT = -7V -20 Output Leakage (Y, Z) in Shutdown Mode IO DE = 0V, RE = VCC, VCC = 0V or 3.6V, MAX3491 VOUT = 12V 1 VOUT = -7V -1 Receiver Differential Threshold Voltage VTH -7V ≤ VCM ≤ 12V -0.2 0.2 μA μA V Receiver Input Hysteresis ΔVTH VCM = 0V Receiver Output High Voltage VOH IOUT = -1.5mA, VID = 200mV, Figure 6 Receiver Output Low Voltage VOL IOUT = 2.5mA, VID = 200mV, Figure 6 0.4 V Three-State (High Impedance) Output Current at Receiver IOZR VCC = 3.6V, 0V ≤ VOUT ≤ VCC ±1 μA Receiver Input Resistance RIN -7V ≤ VCM ≤ 12V ICC No load, DI = 0V or VCC Supply Current Supply Current in Shutdown Mode ISHDN Driver Short-Circuit Output Current IOSD Receiver Short-Circuit Output Current IOSR www.maximintegrated.com 50 mA mV VCC - 0.4 V 12 kΩ DE = VCC, RE = 0V or VCC 1.1 2.2 DE = 0V, RE = 0V 0.95 1.9 0.002 1 mA DE = 0V, RE = VCC, DI = VCC or 0V VOUT = -7V -250 VOUT = 12V 250 0V ≤ VRO ≤ VCC ±8 ±60 µA mA mA Maxim Integrated │  3 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Driver Switching Characteristics—MAX3485, MAX3490, and MAX3491 (VCC = 3.3V, TA = +25°C) MIN TYP MAX UNITS Driver Differential Output Delay PARAMETER SYMBOL tDD RL = 60Ω, Figure 7 CONDITIONS 1 22 35 ns Driver Differential Output Transition Time tTD RL = 60Ω, Figure 7 3 8 25 ns Driver Propagation Delay, Low-to-High Level tPLH RL = 27Ω, Figure 8 7 22 35 ns Driver Propagation Delay, High-to-Low Level tPHL RL = 27Ω, Figure 8 7 22 35 ns |tPLH - tPHL| Driver Propagation Delay Skew (Note 2) tPDS RL = 27Ω, Figure 8 8 ns DRIVER OUTPUT ENABLE/DISABLE TIMES (MAX3485/MAX3491 only) Driver Output Enable Time to Low Level tPZL RL = 110Ω, Figure 10 45 90 ns Driver Output Enable Time to High Level tPZH RL = 110Ω, Figure 9 45 90 ns Driver Output Disable Time from High Level tPHZ RL = 110Ω, Figure 9 40 80 ns Driver Output Disable Time from Low Level tPLZ RL = 110Ω, Figure 10 40 80 ns Driver Output Enable Time from Shutdown to Low Level tPSL RL = 110Ω, Figure 10 650 900 ns Driver Output Enable Time from Shutdown to High Level tPSH RL = 110Ω, Figure 9 650 900 ns MIN TYP MAX UNITS Driver Switching Characteristics—MAX3486 (VCC = 3.3V, TA = +25°C) PARAMETER SYMBOL CONDITIONS Driver Differential Output Delay tDD RL = 60Ω, Figure 7 24 48 70 ns Driver Differential Output Transition Time tTD RL = 60Ω, Figure 7 15 35 60 ns Driver Propagation Delay, Low-to-High Level tPLH RL = 27Ω, Figure 8 20 48 70 ns Driver Propagation Delay, High-to-Low Level tPHL RL = 27Ω, Figure 8 20 48 70 ns |tPLH - tPHL| Driver Propagation Delay Skew (Note 2) tPDS RL = 27Ω, Figure 8 11 ns Driver Output Enable Time to Low Level tPZL RL = 110Ω, Figure 10 55 100 ns Driver Output Enable Time to High Level tPZH RL = 110Ω, Figure 9 55 100 ns Driver Output Disable Time from High Level tPHZ RL = 110Ω, Figure 9 45 80 ns Driver Output Disable Time from Low Level tPLZ RL = 110Ω, Figure 10 45 80 ns Driver Output Enable Time from Shutdown to Low Level tPSL RL = 110Ω, Figure 10 700 1000 ns Driver Output Enable Time from Shutdown to High Level tPSH RL = 110Ω, Figure 9 700 1000 ns www.maximintegrated.com Maxim Integrated │  4 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Driver Switching Characteristics—MAX3483 and MAX3488 (VCC = 3.3V, TA = +25°C) MIN TYP MAX UNITS Driver Differential Output Delay PARAMETER SYMBOL tDD RL = 60Ω, Figure 7 CONDITIONS 600 900 1400 ns Driver Differential Output Transition Time tTD RL = 60Ω, Figure 7 400 700 1200 ns Driver Propagation Delay, Low-to-High Level tPLH RL = 27Ω, Figure 8 700 1000 1500 ns Driver Propagation Delay, High-to-Low Level tPHL RL = 27Ω, Figure 8 700 1000 1500 ns |tPLH - tPHL| Driver Propagation Delay Skew (Note 2) tPDS RL = 27Ω, Figure 8 100 ns DRIVER OUTPUT ENABLE/DISABLE TIMES (MAX3485/MAX3491 only) Driver Output Enable Time to Low Level tPZL RL = 110Ω, Figure 10 900 1300 ns Driver Output Enable Time to High Level tPZH RL = 110Ω, Figure 9 600 800 ns Driver Output Disable Time from High Level tPHZ RL = 110Ω, Figure 9 50 80 ns Driver Output Disable Time from Low Level tPLZ RL = 110Ω, Figure 10 50 80 ns Driver Output Enable Time from Shutdown to Low Level tPSL RL = 110Ω, Figure 10 1.9 2.7 ns Driver Output Enable Time from Shutdown to High Level tPSH RL = 110Ω, Figure 9 2.2 3.0 ns Receiver Switching Characteristics (VCC = 3.3V, TA = +25°C) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Time to Shutdown tSHDN MAX3483/MAX3485/MAX3486/MAX3491 only (Note 3) 80 190 300 ns Receiver Propagation Delay, Low-to-High Level tRPLH VID = 0V to 3.0V, CL = 15pF, Figure 11 25 65 90 MAX3483/MAX3488 25 75 120 Receiver Propagation Delay, High-to-Low Level tRPHL VID = 0V to 3.0V, CL = 15pF, Figure 11 25 65 90 MAX3483/MAX3488 25 75 120 |tPLH - tPHL| Receiver Propagation Delay Skew tRPDS Receiver Output Enable Time to Low Level tPRZL CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 25 50 ns Receiver Output Enable Time to High Level tPRZH CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 25 50 ns Receiver Output Disable Time from High Level tPRHZ CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 25 45 ns Receiver Output Disable Time from Low Level tPRLZ CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 25 45 ns Receiver Output Enable Time from Shutdown to Low Level tPRSL CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 720 1400 ns Receiver Output Enable Time from Shutdown to High Level tPRSH CL = 15pF, Figure 12, MAX3483/MAX3485/MAX3486/MAX3491 only 720 1400 ns VID = 0V to 3.0V, CL = 15pF, Figure 11 10 MAX3483/MAX3488 20 ns ns ns Note 1: ΔVOD and ΔVOC are the changes in VOD and VOC, respectively, when the DI input changes state. Note 2: Measured on |tPLH (Y) - tPHL (Y)| and |tPLH (Z) - tPHL (Z)|. Note 3: The transceivers are put into shutdown by bringing RE high and DE low. If the inputs are in this state for less than 80ns, the parts are guaranteed not to enter shutdown. If the inputs are in this state for at least 300ns, the parts are guaranteed to have entered shutdown. See Low-Power Shutdown Mode section. www.maximintegrated.com Maxim Integrated │  5 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Typical Operating Characteristics (VCC = 3.3V, TA = +25°C, unless otherwise noted.) 15 10 -16 -14 -12 -10 -8 -6 -4 5 3.30 0.5 1.0 1.5 2.0 2.5 0 3.5 3.10 0 0.5 1.0 1.5 2.0 2.5 3.0 3.00 3.5 -40 -20 0 20 40 60 80 TEMPERATURE (°C) RECEIVER OUTPUT LOW VOLTAGE vs. TEMPERATURE DRIVER OUTPUT CURRENT vs. DIFFERENTIAL OUTPUT VOLTAGE DRIVER DIFFERENTIAL OUTPUT VOLTAGE vs.TEMPERATURE OUTPUT CURRENT (mA) 0.6 90 0.5 0.4 0.3 0.2 80 70 60 50 40 30 20 0.1 10 0 20 40 60 80 0 100 0 0.5 TEMPERATURE (°C) 1.0 1.5 2.0 2.5 3.0 3.5 DIFFERENTIAL OUTPUT VOLTAGE (V) 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 -40 -20 0 20 40 -100 MAX3483-07 125 100 75 50 60 80 100 -80 -60 -40 -20 25 0 2.4 OUTPUT CURRENT vs. DRIVER OUTPUT HIGH VOLTAGE OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 150 R = 54Ω 2.5 TEMPERATURE (°C) OUTPUT CURRENT vs. DRIVER OUTPUT LOW VOLTAGE 175 100 MAX3483-08 -20 2.6 DIFFERENTIAL OUTPUT VOLTAGE (V) 100 MAX3483-05 IRO = 2.5mA -40 3.15 OUTPUT HIGH VOLTAGE (V) 0.7 0 3.20 OUTPUT LOW VOLTAGE (V) 0.8 OUTPUT LOW VOLTAGE (V) 3.0 MAX3483-04 0 3.25 3.05 -2 0 IRO = 1.5mA MAX3483-03 -18 OUTPUT HIGH VOLTAGE (V) 20 RECEIVER OUTPUT HIGH VOLTAGE vs. TEMPERATURE MAX3483-02 MAX3483-01 -20 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 25 OUTPUT CURRENT vs. RECEIVER OUTPUT HIGH VOLTAGE MAX3483-06 OUTPUT CURRENT vs. RECEIVER OUTPUT LOW VOLTAGE 0 2 4 6 8 OUTPUT LOW VOLTAGE (V) www.maximintegrated.com 10 12 0 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 OUTPUT HIGH VOLTAGE (V) 4 5 Maxim Integrated │  6 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Typical Operating Characteristics (continued) (VCC = 3.3V, TA = +25°C, unless otherwise noted.) SUPPLY CURRENT vs. TEMPERATURE 90 1.1 DE = VCC, RE = X 1.0 DE = 0, RE = 0 0.9 MAX3483-10 100 MAX3483-09 X = DON’T CARE SHUTDOWN CURRENT (nA) SUPPLY CURRENT (mA) 1.2 SHUTDOWN CURRENT vs. TEMPERATURE 0.8 80 70 60 50 40 30 20 10 0.7 -40 -20 0 20 40 60 80 0 100 -40 -20 0 20 40 60 80 100 TEMPERATURE (°C) TEMPERATURE (°C) Pin Description PIN MAX3483/ MAX3485/ MAX3486 MAX3488/ MAX3490 MAX3491 1 2 2 RO Receiver Output. If A > B by 200mV, RO will be high; if A < B by 200mV, RO will be low. 2 — 3 RE Receiver Output Enable. RO is enabled when RE is low; RO is high impedance when RE is high. If RE is high and DE is low, the device will enter a low-power shutdown mode. NAME FUNCTION 3 — 4 DE Driver Output Enable. The driver outputs are enabled by bringing DE high. They are high impedance when DE is low. If RE is high and DE is low, the device will enter a low-power shutdown mode. If the driver outputs are enabled, the parts function as line drivers. While they are high impedance, they function as line receivers if RE is low. 4 3 5 DI Driver Input. A low on DI forces output Y low and output Z high. Similarly, a high on DI forces output Y high and output Z low. 5 4 6, 7 GND — 5 9 Y Noninverting Driver Output — 6 10 Z Inverting Driver Output Ground 6 — — A Noninverting Receiver Input and Noninverting Driver Output — 8 12 A Noninverting Receiver Input 7 — — B Inverting Receiver Input and Inverting Driver Output — 7 11 B Inverting Receiver Input 8 1 13, 14 VCC Positive Supply: 3.0V ≤ VCC ≤ 3.6V — — 1, 8 N.C. No Connect—not internally connected www.maximintegrated.com Maxim Integrated │  7 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers TOP VIEW R VCC RO RE 2 7 B RE 2 DE 3 6 A DE 3 5 GND DI 4 D R 1 8 1 RO DI 4 MAX3483 MAX3485 MAX3486 8 VCC 7 B Rt 6 A 5 GND D DE D B Rt A DI RO R RE DIP/SO NOTE: PIN LABELS Y AND Z ON TIMING, TEST, AND WAVEFORM DIAGRAMS REFER TO PINS A AND B WHEN DE IS HIGH. Figure 1. MAX3483/MAX3485/MAX3486 Pin Configuration and Typical Operating Circuit TOP VIEW VCC 8 A RO 2 7 B DI 3 6 Z 5 Y VCC 1 GND 4 R D DI RO 3 5 Y D Rt 6 Z 8 A 2 VCC MAX3488 MAX3490 1 R 7 R RO Rt D DI B DIP/SO 4 GND GND Figure 2. MAX3488/MAX3490 Pin Configuration and Typical Operating Circuit TOP VIEW DE 4 N.C. 1 RO 2 RE 3 12 A DE 4 11 B DI 5 10 Z GND 6 GND 7 VCC 13, 14 14 V CC R D DIP/SO 13 V CC 9 Y 8 N.C. DI RO N.C. 5 9 D 10 12 2 R 11 1, 8 3 VCC RE MAX3491 Y Rt R RO Z A Rt D DI B 6, 7 RE GND GND DE Figure 3. MAX3491 Pin Configuration and Typical Operating Circuit www.maximintegrated.com Maxim Integrated │  8 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers 375Ω RL 2 VOD D RL VCC 2 D VOC VCC Figure 4. Driver VOD and VOC VID VCM = -7V to +12V RL VOD 375Ω Figure 5. Driver VOD with Varying Common-Mode Voltage R 0V VOL IOL (+) VOH IOH (-) Figure 6. Receiver VOH and VOL 3V IN 1.5V 1.5V CL D GENERATOR (NOTE 4) 0V RL = 60Ω OUT tDO 50Ω VCC OUT CL CL = 15pF (NOTE 5) 50% 10% tTD tDO 90% 90% ≈ 2.0V 50% 10% ≈ -2.0V tTD Figure 7. Driver Differential Output Delay and Transition Times www.maximintegrated.com Maxim Integrated │  9 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers 3V VOM IN 1.5V 1.5V RL = 27Ω 0V S1 GENERATOR (NOTE 4) tPLH OUT D 50Ω CL = 15pF (NOTE 5) VCC VOM = VOH + VOL 2 tPHL VOH Y OUT VOM VOM VOL tPHL ≈ 1.5V tPLH VOH Z OUT VOM VOM VOL Figure 8. Driver Propagation Times 3V S1 0V OR 3V GENERATOR (NOTE 4) OUT D IN 0V RL = 110Ω CL = 50pF (NOTE 5) 1.5V 1.5V tPZH tPHZ 50Ω OUT VOM = VOH + VOL 2 0.25V VOM ≈ 1.5V VOH 0V Figure 9. Driver Enable and Disable Times (tPZH, tPSH, tPHZ) VCC S1 0V OR 3V 3V RL = 110Ω IN 1.5V 1.5V 0V OUT D tPSL GENERATOR (NOTE 4) CL = 50pF (NOTE 5) 50Ω tPLZ VCC OUT VOM 0.25V VOL Figure 10. Driver Enable and Disable Times (tPZL, tPSL, tPLZ) www.maximintegrated.com Maxim Integrated │  10 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers VID GENERATOR (NOTE 4) 3.0V OUT R IN 50Ω CL = 15pF (NOTE 5) 1.5V 1.5V 0V tRPLH tRPHL VCC 1.5V VOM = 0V VOM OUT VCC 2 VOM 0V Figure 11. Receiver Propagation Delay S1 S3 1.5V -1.5V VID GENERATOR (NOTE 4) R 50Ω 1.5V 0V tPRZH tPRSH OUT S2 CL (NOTE 5) 3V IN VCC 1k S1 OPEN S2 CLOSED S3 = 1.5V 3V IN 1.5V 0V tPRZL tPRSL VOH OUT 1.5V IN 1.5V 0V VCC 1.5V 0V 3V S1 CLOSED S2 OPEN S3 = -1.5V VOL S1 OPEN S2 CLOSED S3 = 1.5V 3V IN 1.5V 0V S1 CLOSED S2 OPEN S3 = -1.5V tPRHZ OUT 0.25V tPRLZ VOH OUT 0V VCC 0.25V VOL Figure 12. Receiver Enable and Disable Times Note 4: The input pulse is supplied by a generator with the following characteristics: PRR = 250kHz, 50% duty cycle, tr ≤ 6.0ns, ZO = 50Ω. Note 5: CL includes probe and stray capacitance. www.maximintegrated.com Maxim Integrated │  11 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Function Tables Applications Information Devices with Receiver/Driver Enable (MAX3483/MAX3485/MAX3486/MAX3491) Table 1. Transmitting RE INPUTS OUTPUTS MODE DE DI B* A* X 1 1 0 1 Normal X 1 0 1 0 Normal 0 0 X High-Z High-Z Normal 1 0 X High-Z High-Z Shutdown * B and A outputs are Z and Y, respectively, for full-duplex part (MAX3491). X = Don’t care; High-Z = High impedance Table 2. Receiving INPUTS OUTPUTS MODE RE DE A, B B* 0 0* ≥ +0.2V 1 Normal 0 0* ≤ -0.2V 0 Normal 0 0* Inputs Open 1 Normal 1 0 X High-Z Shutdown * DE is a “don’t care” (x) for the full-duplex part (MAX3491). X = Don’t care; High-Z = High impedance Devices without Receiver/Driver Enable (MAX3488/MAX3490) Table 3. Transmitting INPUT Table 4. Receiving INPUTS OUTPUT DI Z OUTPUTS Y A, B RO 1 0 1 ≥ +0.2V 1 0 1 0 ≤ -0.2V 0 Inputs Open 1 500kHz/div 5MHz Figure 13. Driver Output Waveform and FFT Plot of MAX3485/ MAX3490/MAX3491 Transmitting a 125kHz Signal www.maximintegrated.com Reduced EMI and Reflections (MAX3483/MAX3486/MAX3488) The MAX3483/MAX3488 are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. Figure 13 shows both the driver output waveform of a MAX3485/MAX3490/MAX3491 transmitting a 125kHz signal and the Fourier analysis of that waveform. High-frequency harmonics with large amplitudes are evident. Figure 14 shows the same information, but for the slew-rate-limited MAX3483/MAX3488 transmitting the same signal. The high-frequency harmonics have much lower amplitudes, and the potential for EMI is significantly reduced. Low-Power Shutdown Mode (MAX3483/MAX3485/MAX3486/MAX3491) A low-power shutdown mode is initiated by bringing both RE high and DE low. The devices will not shut down unless both the driver and receiver are disabled (high impedance). In shutdown, the devices typically draw only 2nA of supply current. For these devices, the tPSH and tPSL enable times assume the part was in the low-power shutdown mode; the tPZH and tPZL enable times assume the receiver or driver was disabled, but the part was not shut down. 10dB/div 10dB/div 0Hz The MAX3483/MAX3485/MAX3486/MAX3488/MAX3490/ MAX3491 are low-power transceivers for RS-485 and RS-422 communications. The MAX3483 and MAX3488 can transmit and receive at data rates up to 250kbps, the MAX3486 at up to 2.5Mbps, and the MAX3485/MAX3490/ MAX3491 at up to 10Mbps. The MAX3488/MAX3490/ MAX3491 are full-duplex transceivers, while the MAX3483/ MAX3485/MAX3486 are half-duplex. Driver Enable (DE) and Receiver Enable (RE) pins are included on the MAX3483/MAX3485/MAX3486/MAX3491. When disabled, the driver and receiver outputs are high impedance. 0Hz 500kHz/div 5MHz Figure 14. Driver Output Waveform and FFT Plot of MAX3483/ MAX3488 Transmitting a 125kHz Signal Maxim Integrated │  12 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers B 1V/div DI 2V/div A 1V/div Z 1V/div RO 2V/div Y 1V/div 20ns/div 20ns/div Figure 15. MAX3485/MAX3490/MAX3491 Driver Propagation Delay Figure 16. MAX3485/MAX3490/MAX3491 Receiver Propagation Delay Driven by External RS-485 Device B 1V/div DI 2V/div A 1V/div Z 1V/div Y 1V/div RO 2V/div 1ms/div 1ms/div Figure 17. MAX3483/MAX3488 Driver Propagation Delay Figure 18. MAX3483/MAX3488 Receiver Propagation Delay DI 5V/div DI 5V/div VY - VZ 2V/div VY - VZ 2V/div RO 5V/div RO 5V/div 2µs/div Figure 19. MAX3483/MAX3488 System Differential Voltage at 125kHz Driving 4000 ft of Cable www.maximintegrated.com 2ms/div Figure 20. MAX3485/MAX3490/MAX3491 System Differential Voltage at 125kHz Driving 4000 ft of Cable Maxim Integrated │  13 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers 120Ω DI DE B D D DE RO RE 120Ω B A B A B A DI A R R RO RE R R D D MAX3483 MAX3485 MAX3486 DI DE RO RE DI DE RO RE Figure 21. MAX3483/MAX3485/MAX3486 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 (see Typical Operating Characteristics). In addition, a thermal shutdown circuit forces the driver outputs into a high-impedance state if the die temperature rises excessively. Propagation Delay Figures 15–18 show the typical propagation delays. 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 (20ns for the MAX3483/MAX3488). The driver skew times are 8ns for the MAX3485/MAX3490/MAX3491, 11ns for the MAX3486, and typically under 100ns for the MAX3483/MAX3488. www.maximintegrated.com Line Length vs. Data Rate The RS-485/RS-422 standard covers line lengths up to 4000 feet. For line lengths greater than 4000 feet, see Figure 23. Figures 19 and 20 show the system differential voltage for parts driving 4000 feet of 26AWG twisted-pair wire at 125kHz into 120Ω loads. Typical Applications The MAX3483, MAX3485, MAX3486, MAX3488, MAX3490, and MAX3491 transceivers are designed for bidirectional data communications on multipoint bus transmission lines. Figures 21 and 22 show typical network applications circuits. These parts can also be used as line repeaters, with cable lengths longer than 4000 feet, as shown in Figure 23. 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. The slew-rate-limited MAX3483/MAX3488 and the partially slew-rate-limited MAX3486 are more tolerant of imperfect termination. Maxim Integrated │  14 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 A R RO RE DE Y 120Ω 120Ω D B Z Z B D DI 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers 120Ω 120Ω Y Z Y B A Y Z R A DE RERO DE RE RO R A R MAX3488 MAX3490 MAX3491 D D DI B DI DI DE RERO NOTE: RE AND DE ON MAX3491 ONLY. Figure 22. MAX3488/MAX3490/MAX3491 Full-Duplex RS-485 Network A RO RE R B MAX3488 MAX3490 MAX3491 120Ω DATA IN DE DI Z D Y 120Ω DATA OUT NOTE: RE AND DE ON MAX3491 ONLY. Figure 23. Line Repeater for MAX3488/MAX3490/MAX3491 www.maximintegrated.com Maxim Integrated │  15 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Ordering Information (continued) MAX3486CPA 0°C to +70°C 8 Plastic DIP MAX3486CSA 0°C to +70°C 8 SO MAX3486C/D 0°C to +70°C Dice* MAX3486EPA -40°C to +85°C 8 Plastic DIP MAX3486ESA -40°C to +85°C 8 SO MAX3488CPA 0°C to +70°C 8 Plastic DIP MAX3488CSA 0°C to +70°C 8 SO MAX3488C/D 0°C to +70°C Dice* MAX3488EPA -40°C to +85°C 8 Plastic DIP MAX3488ESA -40°C to +85°C 8 SO MAX3490CPA 0°C to +70°C 8 Plastic DIP MAX3490CSA 0°C to +70°C 8 SO MAX3490C/D 0°C to +70°C Dice* MAX3490EPA -40°C to +85°C 8 Plastic DIP MAX3490ESA -40°C to +85°C 8 SO MAX3491CPD 0°C to +70°C 14 Plastic DIP MAX3491CSD 0°C to +70°C 14 SO MAX3491C/D 0°C to +70°C Dice* MAX3491EPD -40°C to +85°C MAX3491ESD -40°C to +85°C * Contact factory for for dice specifications. Chip Topography V CC RO A RE B Z/B 0.146" (3.71mm) DE DI Y/A 14 Plastic DIP 14 SO GND GND 0.086" (2.18mm) TRANSISTOR COUNT: 810 SUBSTRATE CONNECTED TO GROUND www.maximintegrated.com Maxim Integrated │  16 MAX3483/MAX3485/ MAX3486/MAX3488/ MAX3490/MAX3491 3.3V-Powered, 10Mbps and Slew-Rate-Limited True RS-485/RS-422 Transceivers Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 12/94 Initial release 1 5/19 Updated Absolute Maximum Ratings and Selection table, added Package Information section DESCRIPTION — 1, 2 For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. ©  2021 Maxim Integrated Products, Inc. │  17