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19-3274; Rev 0; 5/04 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver General Description The MAX3051 interfaces between the CAN protocol controller and the physical wires of the bus lines in a controller area network (CAN). The MAX3051 provides differential transmit capability to the bus and differential receive capability to the CAN controller. The MAX3051 is primarily intended for +3.3V single-supply applications that do not require the stringent fault protection specified by the automotive industry (ISO 11898). The MAX3051 features four different modes of operation: high-speed, slope-control, standby, and shutdown mode. High-speed mode allows data rates up to 1Mbps. The slope-control mode can be used to program the slew rate of the transmitter for data rates of up to 500kbps. This reduces the effects of EMI, thus allowing the use of unshielded twisted or parallel cable. In standby mode, the transmitter is shut off and the receiver is pulled high, placing the MAX3051 in lowcurrent mode. In shutdown mode, the transmitter and receiver are switched off. The MAX3051 input common-mode range is from -7V to +12V, exceeding the ISO 11898 specification of -2V to +7V. These features, and the programmable slew-rate limiting, make the part ideal for nonautomotive, harsh environments. The MAX3051 is available in 8-pin SO and SOT23 packages and operates over the -40C to +85C extended temperature range. Low +3.3V Single-Supply Operation Wide -7V to +12V Common-Mode Range Small SOT23 Package Four Operating Modes High-Speed Operation Up to 1Mbps Slope-Control Mode to Reduce EMI (Up to 500kbps) Standby Mode Low-Current Shutdown Mode Thermal Shutdown Current Limiting Features MAX3051 Ordering Information PART MAX3051ESA MAX3051EKA-T TEMP RANGE -40C to +85C -40C to +85C PINPACKAGE 8 SO 8 SOT23-8 TOP MARK -- AEKF Applications Printers JetLink Industrial Control and Networks Telecom Backplane Consumer Applications TXD 1 GND VCC 2 Pin Configuration TOP VIEW 8 7 RS CANH CANL SHDN MAX3051 3 6 5 RXD 4 SO/SOT23 Typical Operating Circuit at end of data sheet. ________________________________________________________________ Maxim Integrated Products 1 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. +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 ABSOLUTE MAXIMUM RATINGS VCC to GND ..............................................................-0.3V to +6V TXD, RS, SHDN to GND ...........................................-0.3V to +6V RXD to GND .............................................................-0.3V to +6V CANH, CANL to GND..........................................-7.5V to +12.5V Continuous Power Dissipation (TA = +70C) 8-Pin SO (derate 5.9mW/C above +70C)...................470mW 8-Pin SOT23 (derate 9.7mW/C above +70C).............774mW Operating Temperature Range ...........................-40C to +85C Maximum Junction Temperature .....................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature Range (soldering, 10s)......................+300C 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%, RL = 60, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 1) PARAMETER Supply Current Shutdown Current Thermal-Shutdown Threshold Thermal-Shutdown Hysteresis TXD INPUT LEVELS High-Level Input Voltage Low-Level Input Voltage Input Capacitance Pullup Resistor CANH, CANL TRANSMITTER Recessive Bus Voltage Off-State Output Leakage Input Leakage Current CANH Output Voltage CANL Output Voltage VCANH VCANL (VCANH VCANL) VCANH, VCANL VTXD = VCC, no load VTXD = VCC, no load, VRS = VCC (standby mode) -2V < VCANH, VCANL < +7V, SHDN = HIGH VCC = 0V, VCANH = VCANL = 5V VTXD = 0V VTXD = 0V VTXD = 0V Differential Output VTXD = 0V, RL = 45 VTXD = VCC, no load VTXD = VCC, RL = 60 1.5 1.2 -500 -120 2 -100 -250 -250 2.45 1.25 3.0 3.0 +50 +12 2.3 3 +100 +250 +250 V mV A A V V V mV VIH VIL CIN RINTXD 50 5 100 2 VCC + 0.3V 0.8 V V pF k SYMBOL Dominant IS ISHDN VTSH Recessive Standby VSHDN = VCC, TXD = VCC or floating +160 25 CONDITIONS MIN TYP 35 2 8 MAX 70 5 15 1 UNITS mA A A C C 2 _______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver ELECTRICAL CHARACTERISTICS (continued) (VCC = +3.3V 5%, RL = 60, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) (Note 1) PARAMETER CANH Short-Circuit Current CANL Short-Circuit Current RXD OUTPUT LEVELS RXD High Output-Voltage Level RXD Low Output-Voltage Level VOH VOL I = -1mA I = 4mA 0.8 x VCC VCC 0.4 V V SYMBOL ICANHSC ICANLSC CONDITIONS -7V VCANH 0V Minimum foldback current VCC VCANL 12V MIN -200 -35 200 TYP MAX UNITS mA mA MAX3051 DC BUS RECEIVER (VTXD = VCC; CANH and CANL externally driven; -7V VCANH, VCANL +12V, unless otherwise specified) -7V VCM +12V 0.5 Differential Input Voltage VDIFF V (Recessive) VRS = VCC (standby mode) 0.5 Differential Input Voltage (Dominant) Differential Input Hysteresis CANH and CANL Input Resistance Differential Input Resistance MODE SELECTION (RS) Input Voltage for High Speed Input Voltage for Standby Slope-Control Mode Voltage High-Speed Mode Current SHUTDOWN (SHDN) SHDN Input Voltage High SHDN Input Voltage Low SHDN Pulldown Resistor VSHDNH VSHDNL RINSHDN 50 2 0.8 100 V V k VSLP VSTBY VSLOPE IHS RRS = 25k to 200k VRS = 0 0.75 x VCC 0.4 x VCC 0.6 x VCC -500 0.3 x VCC V V V A VDIFF VDIFF(HYST) RI RDIFF 20 40 Dominant VRS = VCC (standby mode) 20 50 100 0.9 1.1 V mV k k _______________________________________________________________________________________ 3 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 TIMING CHARACTERISTICS (VCC = +3.3V 5%, RL = 60, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +3.3V and TA = +25C.) PARAMETER Delay TXD to Bus Active (Figure 1) SYMBOL tONTXD CONDITIONS VRS = 0V (1Mbps) RRS = 25k (500kbps) RRS = 100k (125kbps) Delay TXD to Bus Inactive (Figure 1) VRS = 0V (1Mbps) tOFFTXD RRS = 25k (500kbps) RRS = 100k (125kbps) Delay Bus to Receiver Active (Figure 1) VRS = 0V (1Mbps) tONRXD RRS = 25k (500kbps) RRS = 100k (125kbps) Delay Bus to Receiver Inactive (Figure 1) VRS = 0V (1Mbps) tOFFRXD RRS = 25k (500kbps) RRS = 100k (125kbps) VRS = 0V (1Mbps) Differential-Output Slew Rate SR RRS = 25k (500kbps) RRS = 100k (125kbps) RRS = 200k (62.5kbps) Bus Dominant to RXD Active Standby to Receiver Active SHDN to Bus Inactive SHDN to Receiver Active SHDN to Standby tDRXDL tSBRXDL tOFFSHDN tONSHDN tSHDNSB VRS > 0.8 x VCC, standby, Figure 2 BUS dominant, Figure 2 TXD = GND, Figure 3 (Note 2) BUS dominant, Figure 3 (Note 3) Figure 4 20 245 800 96 12.5 2.9 1.6 1 4 1 4 s s s s s V/s 200 730 100 ns 226 834 80 ns 183 770 70 ns MIN TYP MAX 50 ns UNITS Note 1: All currents into device are positive; all currents out of the device are negative. All voltages are referenced to device ground, unless otherwise noted. Note 2: No other devices on the BUS. Note 3: BUS externally driven. 4 _______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 Timing Diagrams TXD RS VCC /2 VCC /2 VCC x 0.75 BUS EXTERNALLY DRIVEN tONTXD tOFFTXD 0.9V 0.5V tONRXD tOFFRXD RXD VCC /2 VCC /2 tDRXDL VDIFF tSBRXDL 1.1V VDIFF RXD VCC /2 VCC /2 Figure 1. Timing Diagram Figure 2. Timing Diagram for Standby Signal SHDN VCC /2 VCC /2 SHDN VCC /2 tOFFSHDN tONSHDN VDIFF 0.5V BUS EXTERNALLY DRIVEN RS RXD VCC /2 tSHDNSB 0.75V x VCC Figure 3. Timing Diagram for Shutdown Signal Figure 4. Timing Diagram for Shutdown-to-Standby Signal _______________________________________________________________________________________ 5 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 Typical Operating Characteristics (VCC = +3.3V, RL = 60, CL = 100pF, TA = +25C, unless otherwise specified.) SLEW RATE vs. RRS AT 100kbps MAX3051toc01 SUPPLY CURRENT vs. DATA RATE MAX3051toc02 SHUTDOWN SUPPLY CURRENT vs. TEMPERATURE (SHDN = VCC) SHUTDOWN SUPPLY CURRENT (nA) MAX3051toc03 35 30 SLEW RATE (V/s) 25 20 15 10 5 0 0 25 TA = -40C 120 100 80 60 40 20 0 22 SUPPLY CURRENT (mA) 19 16 TA = +25C TA = +85C 13 10 20 40 60 80 100 120 140 160 180 200 RRS (k) 0 200 400 600 800 1000 DATA RATE (kbps) -40 -15 10 35 60 85 TEMPERATURE (C) STANDBY SUPPLY CURRENT vs. TEMPERATURE (RS = VCC) MAX3051toc04 RECEIVER PROPAGATION DELAY vs. TEMPERATURE RECEIVER PROPAGATION DELAY (ns) 45 40 35 30 25 20 15 10 5 RRS = GND -40 -15 10 35 60 85 TEMPERATURE (C) DOMINANT RECESSIVE MAX3051toc05 11.0 STANDBY SUPPLY CURRENT (A) 10.5 10.0 9.5 9.0 8.5 8.0 -40 -15 10 35 60 50 0 85 TEMPERATURE (C) DRIVER PROPAGATION DELAY vs. TEMPERATURE MAX3051toc06 RECEIVER OUTPUT LOW vs. OUTPUT CURRENT 1.4 1.2 VOLTAGE RXD (V) 1.0 0.8 0.6 0.4 0.2 TA = +25C TA = -40C TA = -85C MAX3051toc07 50 DRIVER PROPAGATION DELAY (ns) 1.6 40 30 RECESSIVE 20 DOMINANT RRS = GND, DATA RATE = 100kbps 0 -40 -15 10 35 60 85 TEMPERATURE (C) 10 0 0 5 10 15 20 25 30 35 40 45 OUTPUT CURRENT (mA) 6 _______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 Typical Operating Characteristics (continued) (VCC = +3.3V, RL = 60, CL = 100pF, TA = +25C, unless otherwise specified.) RECEIVER OUTPUT HIGH vs. OUTPUT CURRENT MAX3051toc08 DIFFERENTIAL VOLTAGE vs. DIFFERENTIAL LOAD TA = -40C TA = -85C TA = +25C MAX3051toc09 1.8 RECEIVER OUTPUT HIGH (VCC - RXD) (V) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 1 2 3 4 5 6 7 8 OUTPUT CURRENT (mA) 3.5 3.0 DIFFERENTIAL VOLTAGE (V) 2.5 2.0 1.5 1.0 0.5 0 0 100 200 300 DIFFERENTIAL LOAD RL () RECEIVER PROPAGATION DELAY MAX3051toc10 DRIVER PROPAGATION DELAY MAX3051toc11 RS = GND CAHN - CANL TXD 2V/div RRS = 24k RXD 1v/div RRS = 75k RRS = 100k 200ns/div 200ns/div DRIVER PROPAGATION DELAY MAX3051toc12 LOOPBACK PROPAGATION DELAY vs. RRS LOOPBACK PROPAGATION DELAY (ns) MAX3051toc13 1200 TXD 1V/div 1000 800 600 400 200 0 CAHN - CANL RS = GND 200ns/div 0 20 40 60 80 100 120 140 160 180 200 RRS (k) _______________________________________________________________________________________ 7 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 Detailed Description PIN 1 2 3 4 5 6 7 8 NAME TXD GND VCC RXD SHDN CANL CANH RS FUNCTION Transmit Data Input. TXD is a CMOS/TTL-compatible input from a CAN controller. TXD has an internal 75k pullup resistor. Ground Supply Voltage. Bypass VCC to GND with a 0.1F capacitor. Receive Data Output. RXD is a CMOS/TTL-compatible output. Shutdown Input, CMOS/TTL-Compatible. Drive SHDN high to put the MAX3051 in shutdown. SHDN has an internal 75k pulldown resistor to GND. CAN Bus Line Low CAN Bus Line High Mode-Select Input. Drive RS low or connect to GND for high-speed operation. Connect a resistor between RS and GND to control output slope. Drive RS high to put into standby mode (see the Mode Selection section). VCC MAX3051 THERMAL SHUTDOWN VCC CANH TXD TRANSMITTER CONTROL CANL RS MODE SELECTION GND RXD RECEIVER SHUTDOWN SHDN 0.75V Figure 5. MAX3051 Functional Diagram 8 _______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver Detailed Description The MAX3051 interfaces between the CAN protocol controller and the physical wires of the bus lines in a CAN. It provides differential transmit capability to the bus and differential receive capability to the CAN controller. It is primarily intended for +3.3V single-supply applications that do not require the stringent fault protection specified by the automotive industry (ISO 11898) The MAX3051 features four different modes of operation: high-speed, slope-control, standby, and shutdown mode. High-speed mode allows data rates up to 1Mbps. The slope-control mode can be used to program the slew rate of the transmitter for data rates of up to 500kbps. This reduces the effects of EMI, thus allowing the use of unshielded twisted or parallel cable. In standby mode, the transmitter is shut off and the receiver is pulled high, placing the MAX3051 in lowcurrent mode. In shutdown mode, the transmitter and receiver are switched off. The MAX3051 input common-mode range is from -7V to +12V, exceeding the ISO 11898 specification of -2V to +7V. These features, and the programmable slew-rate limiting, make the part ideal for nonautomotive, harsh environments. The transceivers operate from a single +3.3V supply and draw 35A of supply current in dominant state and 2A in recessive state. In standby mode, supply current is reduced to 8A. In shutdown mode, supply current is less than 1A. CANH and CANL are output 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. Receiver The receiver reads differential inputs from the bus lines (CANH, CANL) and transfers this data as a singleended output (RXD) to the CAN controller. It consists of a comparator that senses the difference VDIFF = (CANH - CANL) with respect to an internal threshold of +0.75V. If this VDIFF is greater than 0.75, a logic-low is present at RXD. If VDIFF is less than 0.75V, a logic-high is present. The receiver always echoes the CAN BUS data. The CANH and CANL common-mode range is -7V to +12V. RXD is logic-high when CANH and CANL are shorted or terminated and undriven. MAX3051 Mode Selection High-Speed Mode Connect RS to ground to set the MAX3051 to highspeed mode. When operating in high-speed mode, the MAX3051 can achieve transmission rates of up to 1Mbps. In high-speed mode, use shielded twisted pair cable to avoid EMI problems. Slope-Control Mode Connect a resistor from RS to ground to select slopecontrol mode (Table 2). In slope-control mode, CANH and CANL slew rates are controlled by the resistor connected to the RS pin. Maximum transmission speeds are controlled by R RS and range from 40kbps to 500kbps. Controlling the rise and fall slopes reduces EMI and allows the use of an unshielded twisted pair or a parallel pair of wires as bus lines. The equation for selecting the resistor value is given by: RRS (k) 12000 / (maximum speed in kbps) See the Slew Rate vs. RRS graph in the Typical Operating Characteristics. Standby Mode If a logic-high is applied to RS, the MAX3051 enters a low-current standby mode. In this mode, the transmitter Transmitter The transmitter converts a single-ended input (TXD) from the CAN controller to differential outputs for the bus lines (CANH, CANL). The truth table for the transmitter and receiver is given in Table 1. Table 1. Transmitter and Receiver Truth Table When Not Connected to The Bus TXD Low High or float X X RS VRS < 0.75 x VCC VRS < 0.75 x VCC VRS > 0.75 x VCC X SHDN Low Low Low High CANH High 5k to 25k to VCC / 2 5k to 25k to GND Floating CANL Low 5k to 25k to VCC / 2 5k to 25k to GND Floating BUS STATE Dominant Recessive Recessive Floating RXD Low High High High _______________________________________________________________________________________ 9 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver is switched off and the receiver is switched to a lowcurrent/low-speed state. If dominant bits are detected, RXD switches to low level. The microcontroller should react to this condition by switching the transceiver back to normal operation. When the MAX3051 enters standby mode, RXD goes high for 4s (max) regardless of the BUS state. However, after 4s, RXD goes low only when the BUS is dominant, otherwise RXD remains high (when the BUS is recessive). For proper measurement of standbyto-receiver active time (tSBRXDL), the BUS should be in dominant state (see Figure 2). Shutdown Drive SHDN high to enter shutdown mode. Connect SHDN to ground or leave floating for normal operation. MAX3051 Applications Information Reduced EMI and Reflections In slope-control mode, the CANH and CANL outputs are slew-rate limited, minimizing EMI and reducing reflections caused by improperly terminated cables. In multidrop CAN applications, it is important to maintain a direct point-to-point wiring scheme. A single pair of wires should connect each element of the CAN bus, and the two ends of the bus should be terminated with 120 resistors (Figure 6). A star configuration should never be used. Any deviation from the point-to-point wiring scheme creates a stub. The high-speed edge of the CAN data on a stub can create reflections back down the bus. These reflections can cause data errors by eroding the noise margin of the system. Although stubs are unavoidable in a multidrop system, care should be taken to keep these stubs as small as possible, especially in high-speed mode. In slope-control mode, the requirements are not as rigorous, but stub length should still be minimized. Thermal Shutdown If the junction temperature exceeds +160C, the device is switched off. The hysteresis is approximately 25C, disabling thermal shutdown once the temperature drops below 135C. In thermal shutdown, CANH and CANL go recessive and all IC functions are disabled. Power Supply and Bypassing The MAX3051 requires no special layout considerations beyond common practices. Bypass VCC to GND with a 0.1F ceramic capacitor mounted close to the IC with short lead lengths and wide trace widths. Table 2. Mode Selection Truth Table CONDITION FORCED AT PIN RS VRS < 0.3 x VCC 0.4 x VCC 10 ______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 MAX3051 CANH TXD RXD CANL RL = 120 STUB LENGTH KEEP AS SHORT AS POSSIBLE TWISTED PAIR RL = 120 TRANSCEIVER 3 TRANSCEIVER 1 TRANSCEIVER 2 Figure 6. Multiple Receivers Connected to CAN Bus Typical Operating Circuit VCC 120 0.1F VCC CAN CONTROLLER CANH MAX3051 TX0 RX0 TXD RXD CANL RS GND 25k TO 200k GND 120 Chip Information TRANSISTOR COUNT: 1024 PROCESS: BiCMOS ______________________________________________________________________________________ 11 +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver MAX3051 Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) SOICN .EPS INCHES DIM A A1 B C e E H L MAX MIN 0.069 0.053 0.010 0.004 0.014 0.019 0.007 0.010 0.050 BSC 0.150 0.157 0.228 0.244 0.016 0.050 MILLIMETERS MAX MIN 1.35 1.75 0.10 0.25 0.35 0.49 0.25 0.19 1.27 BSC 3.80 4.00 5.80 6.20 0.40 1.27 N E H VARIATIONS: 1 INCHES MILLIMETERS MIN 4.80 8.55 9.80 MAX 5.00 8.75 10.00 N MS012 8 AA 14 AB 16 AC TOP VIEW DIM D D D MIN 0.189 0.337 0.386 MAX 0.197 0.344 0.394 D A e B A1 L C 0-8 FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, .150" SOIC APPROVAL DOCUMENT CONTROL NO. REV. 21-0041 B 1 1 12 ______________________________________________________________________________________ +3.3V, 1Mbps, Low-Supply-Current CAN Transceiver Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to www.maxim-ic.com/packages.) SOT23, 8L .EPS REV. MAX3051 SEE DETAIL "A" b e C L SYMBOL A A1 A2 b C D E E1 L L2 e e1 MIN 0.90 0.00 0.90 0.28 0.09 2.80 2.60 1.50 0.30 MAX 1.45 0.15 1.30 0.45 0.20 3.00 3.00 1.75 0.60 0.25 BSC. C L E C L E1 PIN 1 I.D. DOT (SEE NOTE 6) e1 D C C L 0 0.65 BSC. 1.95 REF. 0 8 L2 A A2 A1 SEATING PLANE C GAUGE PLANE NOTE: 1. ALL DIMENSIONS ARE IN MILLIMETERS. 2. FOOT LENGTH MEASURED FROM LEAD TIP TO UPPER RADIUS OF HEEL OF THE LEAD PARALLEL TO SEATING PLANE C. 3. PACKAGE OUTLINE EXCLUSIVE OF MOLD FLASH & METAL BURR. 4. PACKAGE OUTLINE INCLUSIVE OF SOLDER PLATING. 5. COPLANARITY 4 MILS. MAX. 6. PIN 1 I.D. DOT IS 0.3 MM y MIN. LOCATED ABOVE PIN 1. 7. SOLDER THICKNESS MEASURED AT FLAT SECTION OF LEAD BETWEEN 0.08mm AND 0.15mm FROM LEAD TIP. 8. MEETS JEDEC MO178. L 0 DETAIL "A" PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, SOT-23, 8L BODY APPROVAL DOCUMENT CONTROL NO. 21-0078 D 1 1 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 ____________________ 13 (c) 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
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