19-1703; Rev 1; 8/01 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers Features The MAX3171/MAX3173 are three-driver/three-receiver multiprotocol transceivers that operate from a single +3.3V supply. The MAX3171/MAX3173, along with the MAX3170 and MAX3172/MAX3174, form a complete software-selectable data terminal equipment (DTE) or data communications equipment (DCE) interface port that supports V.28 (RS-232) and V.10/V.11 (RS-449, V.36, EIA-530, EIA-530-A, X.21, RS-423) protocols. The MAX3171/MAX3173 transceivers carry the serial interface control signaling; the MAX3170 transceivers carry the clock and data signals. The MAX3172/ MAX3174 have an extra transceiver for applications requiring four transceivers for control signaling. An internal charge pump and proprietary low-dropout transmitter output stage allow V.28, V.11, and V.10 compliant operation from a single +3.3V supply. A nocable mode is entered when all mode pins (M0, M1, and M2) are pulled high or left unconnected. In nocable mode, supply current decreases to 2mA and all transmitter and receiver outputs are disabled (high impedance). Short-circuit limiting and thermal-shutdown circuits protect the drivers against excessive power dissipation. The MAX3171 features 10s deglitching on the V.10/V.11/V.28 receiver inputs. The MAX3173 is available for applications that do not require deglitching on the serial handshake signals. These parts require only four surface-mount capacitors for charge-pump operation in addition to supply bypassing. Industry's First +3.3V Multiprotocol Transceiver Certified TBR-1 and TBR-2 Compliant (NET1 and NET2) Supports V.28 (RS-232) and V.10/V.11 (RS-449, V.36, EIA-530, EIA-530-A, X.21, RS-423) Protocols 3V/5V Logic Compatibility MAX3171 MAX3173 CTS DSR R3 R2 R1 DCD DTR RTS D3 D2 D1 Software-Selectable DCE/DTE True Fail-Safe Receiver Operation Available in Small 28-Pin SSOP Package 10s Receiver Input Deglitching (MAX3171 only) All Transmitter Outputs Fault Protected to 15V, Tolerate Cable Miswiring ________________________Applications Data Networking PCI Cards CSU and DSU Telecommunications Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX3171CAI 0C to +70C 28 SSOP MAX3173CAI 0C to +70C 28 SSOP Routers appears at end of data sheet PinData Configuration Typical Operating Circuit LL RXD RXC R3 R2 TXC R1 D3 SCTE TXD D2 D1 MAX3170 MAX3172 MAX3174 R4 12 15 11 24 14 2 TXD B TXD A 9 17 SCTE B SCTE A DB-25 CONNECTOR 16 3 TXC B TXC A 18 RXD B RXD A RXC B RXC A 7 LL A DCD B DCD A 1 SG DSR B DSR A 23 20 19 4 SHIELD 22 6 RTS B RTS A 10 8 DTR B DTR A 13 5 CTS B CTS A D4 ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX3171/MAX3173 General Description MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND unless otherwise noted.) Supply Voltages VCC ......................................................................-0.3V to +4V V+ (Note 1) ..........................................................-0.3V to +7V V- (Note 1) ...........................................................+0.3V to -7V V+ to V- (Note 1) ...............................................................13V Logic Input Voltages M0, M1, M2, DCE/DTE, T_IN ...............................-0.3V to +6V Logic Output Voltages R_OUT ...................................................-0.3V to (VCC + 0.3V) Short-Circuit Duration............................................Continuous Transmitter Outputs T_OUT_...............................................................-15V to +15V Short-Circuit Duration ........................................................60s Receiver Inputs R_IN_ ..................................................................-15V to +15V Continuous Power Dissipation (TA = +70C) 28-Pin SSOP (derate 11.1mW/C above +70C) ........889mW Operating Temperature Range MAX3171CAI/MAX3173CAI ...............................0C to +70C Storage Temperature Range ............................-65C to +150C Lead Temperature (soldering, 10s) ................................+300C Note 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V. 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. ELECTRICAL CHARACTERISTICS (VCC = 3.3V 5%; C1 = C2 = 1F, C3 = C4 = C5 = 3.3F, and TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DC CHARACTERISTICS V.11/V.10 modes Supply Current (DCE Mode, Digital Inputs = GND or VCC, Transmitter Outputs Static) Internal Power Dissipation ICC PD 220 300 V.11/V.10 modes (no load) 6 23 V.28 mode 24 40 V.28 mode (no load) 6 23 No-cable mode 2 8 V.11/V.10 modes (no load) 20 V.11/V.10 modes (full load) 450 V.28 mode (full load) 40 No-cable mode V.11/V.10 modes (no load) V+ Output Voltage V+ V- 6.6 V.11/V.10 modes (full load) 4.2 V.28 mode 5.55 V 4.6 V.11/V.10 modes (no load) -4.0 V.11/V.10 modes (full load) -3.8 V.28 mode -5.45 No-cable mode Charge-Pump Enable Time mW 4.4 No-cable mode V- Output Voltage mA V -4.2 Delay until V+ and V- specifications met 1 ms LOGIC INPUTS (M0, M1, M2, DCE/DTE, T_IN) Input High Voltage VIH Input Low Voltage VIL 2.0 V 0.8 Logic Input Current IIH, IIL 2 1 M0, M1, M2, DCE / DTE = VCC M0, M1, M2, DCE / DTE = GND V 1 T_IN 30 50 _______________________________________________________________________________________ 100 A +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers (VCC = 3.3V 5%; C1 = C2 = 1F, C3 = C4 = C5 = 3.3F, and TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 0.4 V LOGIC OUTPUTS (R_OUT) Output High Voltage VOH ISOURCE = 1.0mA Output Low Voltage VOL ISINK = 1.6mA Rise or Fall Time tr, tf 10% to 90%, Figure 4 R_OUT = GND Output Leakage Current (Receiver Output Three-Stated) VCC - 1.0 V 15 30 50 ns 100 1 R_OUT = VCC A TRANSMITTER OUTPUTS Output Leakage Current IZ -0.25V VOUT +0.25V, power off or no-cable mode -100 100 V.28 240 Data Rate V.10 115 Receiver Glitch Rejection (MAX3171 only) Minimum pulse width passed V.11 Receiver Input Resistance RIN 10 20 40 -15V VA +15V, V.28 mode 3 5 Data Rate MAX3173 Mbps 15 -10V VAB +10V, VA or VB grounded, V.11/V.35, no-cable mode MAX3171 kbps 5 Minimum pulse width rejected V.10/V.28 64 V.11 64 V.10/V.28 240 V.11 10 A s K 7 kbps Mbps V.11 TRANSMITTER Unloaded Differential Output Voltage VODO R = 1.95k, Figure 1 Loaded Differential Output Voltage VODL R = 50, Figure 1 Change in Magnitude of Output Differential Voltage VOD R = 50, Figure 1 0.2 V Common-Mode Output Voltage VOC R = 50, Figure 1 3.0 V Change in Magnitude of Output Common-Mode Voltage VOC R = 50, Figure 1 0.2 V Short-Circuit Current ISC T_OUTA/B = GND 60 150 mA Rise or Fall Time tr, tf 10% to 90%, Figure 2 10 25 ns Figure 2 50 80 ns | tPHL - tPLH | Figure 2 2 10 Transmitter Input to Output Data Skew Output-to-Output Skew tPHL, tPLH tSKEW 4.0 6.0 0.5 VODO Figure 2 Channel-to-Channel Skew V V ns 2 ns 2 ns V.11 RECEIVER Differential Threshold Voltage Input Hysteresis VTH -7V VCM +7V -200 -100 VTH -7V VCM +7V 5 15 -25 mV mV _______________________________________________________________________________________ 3 MAX3171/MAX3173 ELECTRICAL CHARACTERISTICS (continued) MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers ELECTRICAL CHARACTERISTICS (continued) (VCC = 3.3V 5%; C1 = C2 = 1F, C3 = C4 = C5 = 3.3F, and TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25C.) (Note 2) PARAMETER Receiver Input to Output Data Skew V.10 TRANSMITTER Unloaded Output Voltage Loaded Output Voltage Swing SYMBOL tPHL, tPLH | tPHL - tPLH | VODO VODL CONDITIONS MIN TYP MAX UNITS 5 10 15 s MAX3173 60 120 ns MAX3171 0.5 4 s MAX3173 5 16 ns 4.4 6.0 V MAX3171 RL = 3.9k, Figure 3 4.0 RL = 450, Figure 3 0.9 VODO V 100 150 Short-Circuit Current ISC T_OUTA = GND Transmitter Rise or Fall Time tr, tf RL = 450, CL = 100pF, Figure 3 2 s tPHL, tPLH RL = 450, CL = 100pF, Figure 3 2 s | tPHL - tPLH | RL = 450, CL =100pF, Figure 3 50 ns Transmitter Input to Output Data Skew mA V.10 RECEIVER Threshold Voltage Input Hysteresis Receiver Input to Output Data Skew VTH +25 VTH tPHL, tPLH | tPHL - tPLH | +100 +300 15 MAX3171, Figure 4 5 mV mV 10 15 s MAX3173, Figure 4 60 120 ns MAX3171, Figure 4 0.5 4 s MAX3173, Figure 4 5 16 ns V.28 TRANSMITTER Output Voltage Swing VO Short-Circuit Current ISC All transmitters loaded with RL = 3k Data Skew 6.5 25 T_OUTA = GND 4 60 V mA 30 V/s SR RL = 7k, CL = 150pF, measured from +3V to -3V or from -3V to +3V, Figure 3 Transmitter Input to Output 5.4 No load RL = 3k, CL = 2500pF, measured from +3V to -3V or from -3V to +3V, Figure 3 Output Slew Rate 5.0 6 30 tPHL, tPLH Figure 3 1 s | tPHL - tPLH | Figure 3 100 ns V.28 RECEIVER Input Threshold Low VIL Input Threshold High VIH Input Hysteresis Propagation Delay Data Skew 0.8 2.0 VHYS tPLH, tPHL | tPHL - tPLH | V 0.5 MAX3171, Figure 4 5 MAX3173, Figure 4 MAX3171, Figure 4 MAX3173, Figure 4 V 10 V 15 200 0.5 4.0 100 s s ns Note 2: V+ and V- are also used to supply the MAX3172/MAX3174. The MAX3171/MAX3173 are tested with additional current load on V+ and V- to capture the effect of loading from the MAX3172/MAX3174 in all operation modes. 4 _______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers 70 150 100 60 50 40 30 FULL LOAD 20 50 0.01 0.1 1k 10k 100k 1 0 -1 -2 NO LOAD 0 0.001 1000k VOUT- -4 0.01 0.1 1k 10k 100k 1000k -40 -15 10 35 60 85 DATA RATE (kbps) TEMPERATURE (C) V.28 LOADED OUTPUT VOLTAGE vs. TEMPERATURE V.10 LOADED OUTPUT VOLTAGE vs. TEMPERATURE V.10/V.11 RECEIVER INPUT CURRENT vs. INPUT VOLTAGE VOUT+ 2 0 -2 VOUT+ RL = 450 3 OUTPUT VOLTAGE (V) 4 4 VOUT- 2 1 0 -1 -2 -3 -6 0.3 MAX3171 toc06 6 5 0.2 INPUT CURRENT (mA) RL = 3k MAX3171 toc05 8 -4 -3 DATA RATE (kbps) MAX3171 toc04 0 0.001 VOUT- 0.1 0 -0.1 -0.2 -4 -5 -8 -15 10 35 60 -0.3 -40 85 -15 10 35 60 85 -5 0 5 10 TEMPERATURE (C) INPUT VOLTAGE (V) V.28 RECEIVER INPUT CURRENT vs. INPUT VOLTAGE V.28 SLEW RATE vs. LOAD CAPACITANCE V.10 TRANSMITTER RISE AND FALL TIMES vs. LOAD CAPACITANCE 3 16 SLEW RATE (V/s) 0 -1 12 +SLEW -SLEW 10 8 6 -2 4 -3 2 -10 -5 0 5 INPUT VOLTAGE (V) 10 15 FALL 1.5 RISE 1.0 0.5 0 0 -4 2.0 14 2 1 2.5 MAX3171toc12 18 MAX3171 toc07 4 -15 -10 TEMPERATURE (C) RISE/FALL TIME (s) -40 MAX3171toc11 OUTPUT VOLTAGE (V) VOUT+ 2 NO LOAD 10 INPUT CURRENT (mA) RL = 100 3 OUTPUT VOLTAGE (V) SUPPLY CURRENT (mA) 200 4 MAX3171 toc02 FULL LOAD SUPPLY CURRENT (mA) 80 MAX3171 toc01 250 V.11 LOADED DIFFERENTIAL OUTPUT VOLTAGE vs. TEMPERATURE V.28 MODE SUPPLY CURRENT vs. DATA RATE MAX3171 toc03 V.10/V.11 MODE SUPPLY CURRENT vs. DATA RATE 0 500 1000 1500 2000 CAPACITANCE (pF) 2500 3000 0 500 1000 1500 2000 2500 3000 CAPACITANCE (pF) _______________________________________________________________________________________ 5 MAX3171/MAX3173 Typical Operating Characteristics (VCC = +3.3V, C1 = C2 = 1.0F, C3 = C4 = C5 = 3.3F, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +3.3V, C1 = C2 = 1.0F, C3 = C4 = C5 = 3.3F, TA = +25C, unless otherwise noted.) ROUT 5V/div 5V/div TIN ROUT2 TOUT2/ RIN2 TOUT/ RIN TOUT/ RIN MAX3171 toc10 MAX3171 toc09 ROUT MAX3173 LOOPBACK SCOPE PHOTO 530A MODE (UNLOADED) MAX3171 LOOPBACK SCOPE PHOTO V.28 MODE (RL = 3k) MAX3173 LOOPBACK SCOPE PHOTO V.11 MODE (UNLOADED) MAX3171 toc08 MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers 5V/div TIN2 TIN 10s/div 10s/div 10s/div Test Circuits 100pF R Tx VOD Rx 100 50pF R VOC 100pF Figure 1. V.11 DC Test Circuit 6 Figure 2. V.11 AC Test Circuit _______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceiver Tx Tx CL Rx RL Figure 3. V.10/V.28 Driver Test Circuit 50pF Figure 4. V.10/V.28 Receiver Test Circuit Pin Description PIN NAME FUNCTION 1 V+ 2 C2+ Positive Terminal of the Inverting Charge-Pump Capacitor. Connect C2+ to C2- with a 1F ceramic capacitor. 3 C2- Negative Terminal of the Inverting Charge-Pump Capacitor. Connect C2+ to C2- with a 1F ceramic capacitor. 4 V- Negative Supply Generated by the Charge Pump (connect to V- pin of MAX3172/MAX3174). Bypass V- to ground with a 3.3F ceramic capacitor. 5, 6, 7 T_IN 8, 9, 10 R_OUT 11, 12, 13 M_ 14 DCE/DTE 15, 18 R_INB Noninverting Receiver Inputs (R3INB, R2INB) 16, 17 R_INA Inverting Receiver Inputs (R3INA, R2INA) 19 T3OUTB/R1INB Noninverting Transmitter Output/Noninverting Receiver Input 20 T3OUTA/R1INA Inverting Transmitter Output/Inverting Receiver Input 21, 23 T_OUTB Noninverting Transmitter Outputs (T2OUTB, T1OUTB) 22, 24 T_OUTA Inverting Transmitter Outputs (T2OUTA, T1OUTA) 25 C1- 26 GND Ground 27 VCC +3.3V Supply Voltage (5%). Bypass VCC to ground with a 3.3F ceramic capacitor. 28 C1+ Positive Terminal of the Voltage-Doubler Charge-Pump Capacitor. Connect C1+ to C1- with a 1F ceramic capacitor. Positive Supply Generated by the Charge Pump (connect to V+ pin of MAX3172/MAX3174). Bypass V+ to ground with a 3.3F ceramic capacitor. Transmitter CMOS Inputs (T1IN, T2IN, T3IN) Receiver CMOS Outputs (R1OUT, R2OUT, R3OUT) Mode Select Inputs (M0, M1, M2). Internally pulled up to VCC. See Table 1 for detailed information. DCE/DTE Mode Select Input. Logic level high selects DCE interface; logic level low selects DTE interface. Internally pulled up to VCC. Negative Terminal of the Voltage-Doubler Charge-Pump Capacitor. Connect C1+ to C1- with a 1F ceramic capacitor. _______________________________________________________________________________________ 7 MAX3171/MAX3173 Test Circuits (continued) MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers Table 1. Mode Selection LOGIC INPUTS PROTOCOL TRANSMITTERS RECEIVERS M2 M1 M0 DCE/DTE T1 T2 T3 R1 R2 R3 V.11 0 0 0 0 V.11 V.11 Z V.11 V.11 V.11 RS-530A 0 0 1 0 V.11 V.10 Z V.11 V.10 V.11 RS-530 0 1 0 0 V.11 V.11 Z V.11 V.11 V.11 X.21 0 1 1 0 V.11 V.11 Z V.11 V.11 V.11 V.35 1 0 0 0 V.28 V.28 Z V.28 V.28 V.28 RS-449/V.36 1 0 1 0 V.11 V.11 Z V.11 V.11 V.11 V.28/RS-232 1 1 0 0 V.28 V.28 Z V.28 V.28 V.28 No cable 1 1 1 0 Z Z Z Z Z Z V.11 0 0 0 1 V.11 V.11 V.11 Z V.11 V.11 RS-530A 0 0 1 1 V.11 V.10 V.11 Z V.10 V.11 RS-530 0 1 0 1 V.11 V.11 V.11 Z V.11 V.11 X.21 0 1 1 1 V.11 V.11 V.11 Z V.11 V.11 V.35 1 0 0 1 V.28 V.28 V.28 Z V.28 V.28 RS-449/V.36 1 0 1 1 V.11 V.11 V.11 Z V.11 V.11 V.28/RS-232 1 1 0 1 V.28 V.28 V.28 Z V.28 V.28 No cable 1 1 1 1 Z Z Z Z Z Z Z = High impedance 1 C3 3.3F 2 C2 1F 3 4 MAX3171 28 V+ MAX3173 C1+ C2+ VCC C2- GND V- C1- 27 26 C5 3.3F C1 1F Mode Selection 25 C4 3.3F Figure 5. Charge-Pump Connections Detailed Description The MAX3171/MAX3173 are three-driver/three-receiver multiprotocol transceivers that operate from a single +3.3V supply. The MAX3171/MAX3173, along with the MAX3170 and MAX3172/MAX3174, form a complete software-selectable DTE or DCE interface port that supports the V.28 (RS-232), V.10/V.11 (RS-449, V.36, EIA530, EIA-530-A, X.21, RS-423), and V.35 protocols. The MAX3171/MAX3173 carry the control signals, while the MAX3170 transceiver carries the high-speed clock and data signals. The MAX3172/MAX3174 provide termination for the clock and data signals and have an extra transceiver for applications requiring four transceivers for control handshaking. 8 The MAX3171/MAX3173 feature a 2mA no-cable mode, true fail-safe operation, and thermal shutdown circuitry. Thermal shutdown protects the drivers against excessive power dissipation. When activated, the thermal shutdown circuitry places the driver outputs into a highimpedance state. The state of mode select pins M0, M1, and M2 determines which serial interface protocol is selected (Table 1). The state of the DCE/DTE input determines whether the transceivers will be configured as a DTE serial port or a DCE serial port. When the DCE/DTE input is logic HIGH, driver T3 is activated and receiver R1 is disabled. When the DCE/DTE input is logic LOW, driver T3 is disabled and receiver R1 is activated. M0, M1, M2, and DCE/DTE are internally pulled up to VCC to ensure logic HIGH if left unconnected. The MAX3171/MAX3173's mode can be selected through software control of the M0, M1, M2, and DCE/DTE inputs. Alternatively, the mode can be selected by shorting the appropriate combination of mode control inputs to GND (the inputs left floating will be internally pulled up to VCC). If the M0, M1, and M2 mode inputs are all unconnected, the MAX3171/ MAX3173 will enter no-cable mode. _______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceiver Dual Charge-Pump Voltage Converter The MAX3171/MAX3173 internal power supply consists of a regulated dual charge pump that provides positive and negative output voltages from a +3.3V supply. The charge pump operates in discontinuous mode: If the output voltage is less than the regulated voltage, the charge pump is enabled; if the output voltage exceeds the regulated voltage, the charge pump is disabled. Each charge pump requires a flying capacitor (C1, C2) and a reservoir capacitor (C3, C4) to generate the V+ and V- supplies. See Figure 5 for charge-pump connections. The charge pump is designed to supply V+ and Vpower to the MAX3172/MAX3174 in addition to the MAX3171/MAX3173 internal transceivers. Connect the MAX3172/MAX3174 V+ and V- terminals to the MAX3171/MAX3173 V+ and V- terminals, respectively. Fail-Safe The MAX3171/MAX3173 guarantee a logic HIGH receiver output when the receiver inputs are shorted or open, or when they are connected to a terminated transmission line with drivers disabled. The V.11 receiver threshold is set between -25mV and -200mV to guarantee fail-safe operation. If the differential receiver input voltage (B - A) is -25mV, R_OUT is logic HIGH. In the case of a terminated bus with all transmitters disabled, the receiver's differential input voltage is pulled to 0 by the termination. With the MAX3171/MAX3173 receiver thresholds, this results in R_OUT logic HIGH with a 25mV (min) noise margin. The V.10 receiver threshold is set between +25mV and +300mV. If the V.10 receiver input voltage is +25mV, ROUT is logic HIGH. The V.28 receiver threshold is set between 0.8V and 2.0V. If the receiver input voltage is 0.8V, ROUT is logic HIGH. In the case of a terminated bus with transmitters disabled, the V.10/V.28 receiver's input voltage is pulled to ground by the termination. With the MAX3172/MAX3174 receiver thresholds, this results in R_OUT logic HIGH. Applications Information Capacitor Selection The capacitors used for the charge pumps, as well as the supply bypassing, should have a low-ESR and lowtemperature coefficient. Multilayer ceramic capacitors with an X7R dielectric offer the best combination of performance, size, and cost. The flying capacitors (C1, C2) should have a value of 1F, while the reservoir capacitors (C3, C4) and bypass capacitor (C5) should have a minimum value of 3.3F (Figure 5). To reduce the ripple present on the transmitter outputs, capacitors C3, C4, and C5 can be increased. Do not increase the value of C1 and C2. Local Loopback Control Signal For applications that require the use of local loopback (LL) signal routing, an extra transceiver is available for use on the MAX3172/MAX3174 multiprotocol termination network device. Cable-Selectable Mode Figure 6 shows a cable-selectable mulitprotocol interface. The mode control lines (M0, M1, M2, and DCE/DTE) are wired to the DB-25 connector. To select the serial interface mode, the appropriate combinations of M0, M1, M2, and DCE/DTE are grounded within the cable wiring. The control lines that are not grounded are pulled high by the internal pullups on the MAX3170. The serial interface protocol of the MAX3171/MAX3173 (MAX3170 and MAX3172/MAX3174) is now selected based on the cable connected to the DB-25 interface. V.11 (RS-422) Interface As shown in Figure 7, the V.11 protocol is a fully balanced differential interface. The V.11 driver generates 2V (min) between nodes A and B when 100 (min) resistance is presented at the load. The V.11 receiver is sensitive to 200mV differential signals at the receiver inputs A' and B'. The V.11 receiver input must comply with the impedance curve of Figure 8 and reject common-mode signals up to 7V developed across the cable (referenced from C to C' in Figure 7). The MAX3171/MAX3173 V.11 mode receiver has a differential threshold between -200mV and -25mV to ensure that the receiver has proper fail-safe operation (see Fail-Safe). To aid in rejecting system noise, the MAX3171/MAX3173 V.11 receiver has a 15mV (typ) hysteresis. Switch S3 in Figure 9 is open in V.11 mode to disable the V.28 5k termination at the inverting receiver input. Because the control signals are slow (64kbps), 100 termination resistance is generally not required for the MAX3171/MAX3173. _______________________________________________________________________________________ 9 MAX3171/MAX3173 No-Cable Mode The MAX3171/MAX3173 enter no-cable mode when the mode select pins are left unconnected or tied HIGH (M0 = M1 = M2 = 1). In this mode, the multiprotocol drivers and receivers are disabled and the supply current is less than 8mA. The receiver outputs enter a highimpedance state in no-cable mode, which allows these output lines to be shared with other receivers (the receiver outputs have an internal pullup resistor to pull the outputs HIGH if not driven). Also, in no-cable mode, the transmitter outputs enter a high-impedance state, so these output lines can be shared with other devices. MAX3171 MAX3173 R3 R2 RXD(DTE) TXD(DCE) RXC(DTE) SCTE(DCE) DTR(DTE) DSR(DCE) RTS(DTE) DCD(DTE) CTS(DCE) DCD(DCE) R1 D3 D2 D1 SCTE(DTE) RXC(DCE) TXC(DTE) TXD(DTE) TXC(DCE) RXD(DCE) MAX3172 MAX3174 R4 R3 R2 16 3 9 17 R1 D3 D2 D1 D4 MAX3170 M0 M1 M2 DCE/DTE CTS(DTE) RTS(DCE) DSR(DTE) DTR(DCE) M0 M1 M2 DCE/DTE MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers M0 M1 M2 DCE/DTE TXD B TXD A RXD RXD DB-25 CONNECTOR RXC SCTE B RXC SCTE A TXC B TXC A 12 15 11 24 14 2 TXC B TXC A 25 DCE/DTE RXD RXD RXC RXC SG 18 21 M0 M1 TXD B TXD A SCTE B SCTE A 7 SHIELD RTS B RTS A 1 CTS B CTS A DTR B DTR A DCD DCD 23 20 19 4 DSR DSR DSR DSR CABLE WIRING FOR MODE SELECTION MODE PIN 18 PIN 21 V.35 PIN 7 PIN 7 RS-449, V.36 N.C. PIN 7 RS-232 PIN 7 N.C. DCD DCD 22 6 DTR B DTR A 10 8 DCE RTS B RTS A 13 5 DTE CTS B CTS A VCC CABLE WIRING FOR DCE/DTE SELECTION MODE PIN 25 DTE PIN 7 DCE N.C. Figure 6. Cable-Selectable Multiprotocol DCE/DTE Port V.10 Interface BALANCED INTERCONNECTING CABLE GENERATOR A LOAD CABLE RECEIVER TERMINATION A 100 MIN B B C C Figure 7. Typical V.11 Interface 10 The V.10 interface (Figure 10) is an unbalanced singleended interface capable of driving a 450 load. The V.10 driver generates a 4V (min) VODO voltage across A' and C' when unloaded and a minimum of 0.9 VODO voltage with a 450 load. The V.10 receiver input trip threshold is defined between +300mV and -300mV with the input impedance characteristic shown in Figure 8. The MAX3171/MAX3173 V.10 mode receiver has a threshold between +25mV and +300mV to ensure that the receiver has proper fail-safe operation (see Fail- ______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceiver 3.25mA A A VZ +10V +3V MAX3171 MAX3173 R5 30k -3V -10V MAX3171/MAX3173 IZ R8 5k R6 10k RECEIVER -3.25mA S3 Figure 8. Receiver Input Impedance Curve A R7 10k A MAX3171 MAX3173 R5 30k R8 5k R4 30k B B S5 R6 10k C RECEIVER S4 GND S3 Figure 11. V.10 Internal Resistance Network R7 10k B R4 30k B A A MAX3171 MAX3173 R5 30k C R8 5k GND R6 10k Figure 9. V.11 Termination and Internal Resistance Networks RECEIVER S3 GENERATOR UNBALANCED INTERCONNECTING CABLE A LOAD CABLE TERMINATION R7 10k RECEIVER R4 30k A B B C C C Figure 10. Typical V.10/V.28 Interface GND Figure 12. V.28 Termination and Internal Resistance Networks ______________________________________________________________________________________ 11 CTS(DTE) RTS(DCE) DSR(DTE) DTR(DCE) RXD(DTE) TXD(DCE) LL(DTE) RXC(DTE) LL(DCE) SCTE(DCE) DTR(DTE) DSR(DCE) RTS(DTE) DCD(DTE) CTS(DCE) DCD(DCE) SCTE(DTE) RXC(DCE) TXC(DTE) TXD(DTE) TXC(DCE) RXD(DCE) MAX3171 MAX3173 R3 R2 R1 D3 D2 D1 M0 M1 M2 DCE/DTE MAX3172 MAX3174 R4 R3 R2 16 3 9 17 R1 D3 D2 D1 D4 MAX3170 M0 M1 M2 DCE/DTE MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers TXD B TXD A RXD B RXD A RXC B SCTE B RXC A SCTE A TXC B TXC A 12 15 11 24 14 2 TXC B TXC A DB-25 CONNECTOR TXD B TXD A SCTE B SCTE A SG LL A RXD B RXD A RXC B RXC A 7 18 LL A 1 SHIELD RTS B RTS A CTS B CTS A DTR B DTR A DCD B DCD A 23 20 19 4 DSR B DSR A DSR B DSR A DCD B DCD A 22 6 DTR B DTR A 10 8 DCE RTS B RTS A 13 5 DTE CTS B CTS A M0 M1 M2 DCE/DTE M0 M1 M2 DCE/DTE Figure 13. Multiprotocol DCE/DTE Port Safe). To aid in rejecting system noise, the MAX3171/MAX3173 V.10 receiver has 15mV (typ) hysteresis. Switch S3 in Figure 11 is open in V.10 mode to disable the 5k V.28 termination at the receiver input. Switch S4 is closed, and switch S5 is open to internally ground the receiver B input. V.28 Interface The V.28 interface is an unbalanced single-ended interface (Figure 12). The V.28 generator provides 5V (min) across the load impedance between A' and C'. The V.28 standard specifies input trip points at 3V. The MAX3171/MAX3173 V.28 mode receiver has a threshold between +0.8V and +2.0V to ensure that the receiver has proper fail-safe operation (see Fail-Safe). To aid in rejecting system noise, the MAX3171/MAX3173 V.28 receiver has a 500mV (typ) hysteresis. Switch S3 in 12 Figure 12 is closed in V.28 mode to enable the 5k V.28 termination at the receiver input. Receiver Glitch Rejection To facilitate operation in an unterminated or otherwise noisy system, the MAX3171 features 10s of receiver input glitch rejection in V.10, V.11, and V.28 modes. The glitch rejection circuitry blocks the reception of high-frequency noise (tB < 5s) while receiving a lowfrequency signal (tB > 15s), allowing glitch-free operation in unterminated systems at up to 64kbps. The MAX3173 does not have this feature and can be operated at data rates up to 240kbps if properly terminated. DTE vs. DCE Operation Figure 13 shows a DCE or DTE controller-selectable interface. The DCE/DTE input switches the port's mode of operation. A logic high selects DCE, which enables ______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceiver SERIAL CONTROLLER MAX3170 DCE MAX3172 MAX3174 MAX3172 MAX3174 TXD D1 TXD SCTE D2 SCTE 103 103 D3 TXC R1 RXC R2 RXD R3 MAX3170 SERIAL CONTROLLER R3 TXD R2 SCTE R1 103 103 103 D4 LL MAX3171/MAX3173 DTE TXC D3 TXC RXC D2 RXC RXD LL D1 RXD R4 R4 LL D4 MAX3171 MAX3173 MAX3171 MAX3173 RTS D1 RTS R3 RTS DTR D2 DTR R2 DTR D3 R1 DCD R1 DCD D3 DCD DSR R2 DSR D2 DSR CTS R3 CTS D1 CTS Figure 14. DCE-to-DTE X.21 Interface driver 3 on the MAX3171/MAX3173, driver 3 on the MAX3170, and driver 4 on the MAX3172/MAX3174. A logic low selects DTE, which enables receiver 1 on the MAX3171/MAX3173, receiver 1 on the MAX3170, and receiver 4 on the MAX3172/MAX3174. This application requires only one DB-25 connector. See Figure 13 for complete signal routing in DCE and DTE modes. For example, driver 3 routes the DCD (DCE) signal to pins 22 and 6 in DCE mode, while in DTE mode, receiver 1 routes pins 22 and 6 to DCD (DTE). Complete Multiprotocol X.21 Interface Figure 14 shows a complete DCE-to-DTE interface operating in X.21 mode. The MAX3171/MAX3173 generate the control signals, and the MAX3170 is used to generate the clock and data signals. The MAX3172/ MAX3174 generate local loopback and are used to terminate the clock and data signals to support the V.11 protocol for cable termination. The control signals do not need external termination. ______________________________________________________________________________________ 13 MAX3171/MAX3173 +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceivers Pin Configuration Compliance Testing A European Standard EN 45001 test report is available for the MAX3170-MAX3174 chipset. A copy of the test report will be available from Maxim. Chip Information TRANSISTOR COUNT: 1763 PROCESS: BiCMOS TOP VIEW V+ 1 28 C1+ C2+ 2 27 VCC C2- 3 26 GND V- 4 25 C1- T1IN 5 T2IN 6 24 T1OUTA MAX3171 MAX3173 23 T1OUTB T3IN 7 22 T2OUTA R1OUT 8 21 T2OUTB R2OUT 9 20 T3OUTA/R1INA R3OUT 10 19 T3OUTB/R1INB M0 11 18 R2INB M1 12 17 R2INA M2 13 16 R3INA DCE/DTE 14 15 R3INB SSOP 14 ______________________________________________________________________________________ +3.3V Multiprotocol 3Tx/3Rx Software-Selectable Control Transceiver SSOP.EPS Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 15 (c) 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. MAX3171/MAX3173 Package Information Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX3171CAI+ MAX3171CAI+T MAX3173CAI+ MAX3173CAI+T