AMIS42671ICAB1G

AMIS-42671 High Speed Autobaud CAN Transceiver General Description The AMIS−42671 CAN transceiver with autobaud is the interface between a controller area network (CAN) protocol controller and the physical bus. It may be used in both 12 V and 24 V systems. The transceiver provides differential transmit capability to the bus and differential receive capability to the CAN controller. Due to the wide common−mode voltage range of the receiver inputs, the AMIS−42671 is able to reach outstanding levels of electromagnetic susceptibility (EMS). Similarly, extremely low electromagnetic emission (EME) is achieved by the excellent matching of the output signals. The AMIS−42671 is primarily intended for industrial network applications where long network lengths are mandatory. Examples are elevators, in−building networks, process control and trains. To cope with the long bus delay the communication speed needs to be low. AMIS−42671 allows low transmit data rates down 10 kbit/s or lower. The autobaud function allows the CAN controller to determine the incoming baud rate without influencing the CAN communication on the bus. Features http://onsemi.com PIN ASSIGNMENT TxD GND VCC RxD 1 2 3 4 8 7 6 5 AUTB CANH CANL VREF (Top View) AMIS− 42671 PC20070929.1 • • • • • • • • • • • • • • • Fully compatible with the ISO 11898−2 standard Autobaud function Wide range of bus communication speed (0 up to 1 Mbit/s) Allows low transmit data rate in networks exceeding 1 km Ideally suited for 12 V and 24 V industrial and automotive applications Low electromagnetic emission (EME), common−mode choke is no longer required Differential receiver with wide common−mode range ($35 V) for high EMS No disturbance of the bus lines with an un−powered node Thermal protection Bus pins protected against transients Silent mode in which the transmitter is disabled Short circuit proof to supply voltage and ground Logic level inputs compatible with 3.3 V devices ESD protection for CAN bus at $8 kV These are Pb−Free Devices* ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 12 of this data sheet. *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. © Semiconductor Components Industries, LLC, 2009 January, 2009 − Rev. 3 1 Publication Order Number: AMIS−42671/D AMIS−42671 Table 1. TECHNICAL CHARACTERISTICS Symbol VCANH VCANL Vo(dif)(bus_dom) tpd(rec−dom) tpd(dom−rec) CM−range VCM−peak VCM−step Parameter DC Voltage at Pin CANH DC Voltage at Pin CANL Differential Bus Output Voltage in Dominant State Propagation Delay TxD to RxD Propagation Delay TxD to RxD Input Common−Mode Range for Comparator Common−Mode Peak Common−Mode Step Condition 0 < VCC < 5.25V; no time limit 0 < VCC < 5.25V; no time limit 42.5W < RLT < 60W See Figure 7 See Figure 7 Guaranteed differential receiver threshold and leakage current See Figures 8 and 9 (Note 1) See Figures 8 and 9 (Note 1) Max −45 −45 1.5 70 100 −35 −500 −150 Max +45 +45 3 245 245 +35 500 150 Unit V V V ns ns V mV mV 1. The parameters VCM−peak and VCM−step guarantee low electromagnetic emission. http://onsemi.com 2 AMIS−42671 VCC AUTB 8 Thermal shutdown VCC 3 TxD 1 Slope Control 7 Driver control 6 CANH CANL Autobaud Control AMIS−42671 COMP RxD VREF 4 Ri(cm) + Vcc/2 5 Ri(cm) 2 PC20070930.2 Figure 1. Block Diagram GND Table 2. PIN DESCRIPTION Pin 1 2 3 4 5 6 7 8 Name TxD GND VCC RxD VREF CANL CANH AUTB Description Transmit Data Input; Low Input → Dominant Driver; Internal Pullup Current Ground Supply Voltage Receive Data Output; Dominant Transmitter → Low Output Reference Voltage Output Low−Level CAN Bus Line (Low in Dominant Mode) High−Level CAN Bus Line (High in Dominant Mode) Autobaud Mode Control Input; Internal Pulldown Current http://onsemi.com 3 AMIS−42671 Table 3. ABSOLUTE MAXIMUM RATINGS Symbol VCC VCANH VCANL VTxD VRxD VAUTB VREF Vtran(CANH) Vtran(CANL) Vesd Latch−up Tstg TA TJ Supply Voltage DC Voltage at Pin CANH DC Voltage at Pin CANL DC Voltage at Pin TxD DC Voltage at Pin RxD DC Voltage at Pin AUTB DC Voltage at Pin VREF Transient Voltage at Pin CANH Transient Voltage at Pin CANL Electrostatic Discharge Voltage at All Pins Static Latch−up at all Pins Storage Temperature Ambient Temperature Maximum Junction Temperature Note 2 Note 2 Note 3 Note 4 Note 5 −55 −40 −40 0 < VCC < 5.25 V; No Time limit 0 < VCC < 5.25 V; No Time Limit Parameter Conditions Min −0.3 −45 −45 −0.3 −0.3 −0.3 −0.3 −150 −150 −4 −500 Max +7 +45 +45 VCC + 0.3 VCC + 0.3 VCC + 0.3 VCC + 0.3 +150 +150 +4 +500 100 +155 +125 +150 Unit V V V V V V V V V kV V mA °C °C °C Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 2. Applied transient waveforms in accordance with ISO 7637 part 3, test pulses 1, 2, 3a, and 3b (see Figure 3). 3. Standardized human body model ESD pulses in accordance to MIL883 method 3015.7. 4. Static latch−up immunity: static latch−up protection level when tested according to EIA/JESD78. 5. Standardized charged device model ESD pulses when tested according to EOS/ESD DS5.3−1993. Table 4. THERMAL CHARACTERISTICS Symbol Rth(vj−a) Rth(vj−s) Parameter Thermal Resistance from Junction−to−Ambient in SO−8 package Thermal Resistance from Junction−to−Substrate of Bare Die Conditions In Free Air In Free Air Value 150 45 Unit k/W k/W http://onsemi.com 4 AMIS−42671 APPLICATION INFORMATION VBAT IN 5V− reg OUT VCC AUTB 3 8 4 1 2 7 60 W VCC CANH VREF CANL 60 W GND 60 W 47 nF CAN controller RxD TxD AMIS− 42671 5 6 CAN BUS 60 W 47 nF GND PC20071001.1 Figure 2. Application Diagram http://onsemi.com 5 AMIS−42671 FUNCTIONAL DESCRIPTION Operating Modes The behavior of AMIS−42671 under various conditions is illustrated in Table 5 below. In case the device is powered, one of two operating modes can be selected through Pin AUTB. Table 5. FUNCTIONAL TABLE OF AMIS−42671 WHEN NOT CONNECTED TO THE BUS; x = don’t care VCC 4.75 to 5.25 V 4.75 to 5.25 V 4.75 to 5.25 V VCC < PORL (unpowered) PORL < VCC < 4.75 V Pin TxD 0 1 (or floating) 1 (or floating) x >2 V Pin AUTB 0 (or floating) 1 x x x Pin CANH High VCC/2 VCC/2 0 V < CANH < VCC 0 V < CANH < VCC Pin CANL Low VCC/2 VCC/2 0V < CANL < VCC 0V < CANL < VCC Bus State Dominant Recessive Recessive Recessive Recessive Pin RxD 0 1 1 1 1 High−Speed Mode Autobaud Mode If pin AUTB is pulled low (or left floating), the transceiver is in its high−speed mode and is able to communicate via the bus lines. The signals are transmitted and received to the CAN controller via the pins TxD and RxD. The slopes on the bus line outputs are optimized to give extremely low electromagnetic emissions. If Pin AUTB is pulled high, AMIS−42671 is in Autobaud mode. The transmitter is disabled while the receiver remains active. All other IC functions also continue to operate. Normal bus activity can be monitored at the RxD pin and transmit data on TxD is looped back to RxD without influencing the CAN communication. TxD CANH CANL RxD AUTB PC20071002.4 Figure 3. Simplified Schematic Diagram of Autobaud Function In Autobaud mode the local CAN controller is able to detect the used communication speed of other transmitting network nodes. Bus communication is received and via the RxD pin sent to the CAN controller. If the CAN controller operates at the wrong baud rate, it will transmit an error frame. This message will be looped back to the CAN controller which will increment its error counter. The CAN controller will be reset with another baud rate. When an error−free message is received, the correct baud rate is detected. A logic low may now be applied to Pin AUTB, returning to the high−speed mode. Overtemperature Detection A thermal protection circuit protects the IC from damage by switching off the transmitter if the junction temperature exceeds a value of approximately 160°C. Because the transmitter dissipates most of the power, the power dissipation and temperature of the IC is reduced. All other IC functions continue to operate. The transmitter off−state resets when pin TxD goes high. The thermal protection circuit is particularly necessary when a bus line short−circuits. http://onsemi.com 6 AMIS−42671 High Communication Speed Range The transceiver is primarily intended for industrial applications. It allows very low baud rates needed for long bus length applications. But also high speed communication is possible up to 1 Mbit/s. Fail−safe Features either positive or negative supply voltage, although power dissipation increases during this fault condition. The Pins CANH and CANL are protected from automotive electrical transients (according to “ISO 7637”; see Figure 4). Pin TxD is pulled high internally should the input become disconnected. A current−limiting circuit protects the transmitter output stage from damage caused by an accidental short−circuit to http://onsemi.com 7 AMIS−42671 ELECTRICAL CHARACTERISTICS Definitions All voltages are referenced to GND (Pin 2). Positive currents flow into the IC. Sinking current means the current is flowing into the pin; sourcing current means the current is flowing out of the pin. Table 6. DC CHARACTERISTICS VCC = 4.75 V to 5.25 V, TA = −40°C to +150°C; RLT = 60 W unless specified otherwise. Symbol SUPPLY (Pin VCC) ICC Supply current Dominant; VTXD = 0V Recessive; VTXD = VCC 25 2 45 4 65 8 mA Parameter Conditions Min Typ Max Unit TRANSMITTER DATA INPUT (Pin TxD) VIH VIL IIH IIL Ci VIH VIL IIH IIL VOH VOL VREF VREF_CM High−Level Input Voltage Low−Level Input Voltage High−Level Input Current Low−Level Input Current Input Capacitance Output Recessive Output Dominant VTxD = VCC VTxD = 0V Not Tested 2.0 −0.3 −1 −75 − − − 0 −200 5 VCC+ 0.3 +0.8 +1 −350 10 V V mA mA pF MODE SELECT (Pin AUTB) High−Level Input Voltage Low−Level Input Voltage High−Level Input Current Low−Level Input Current Autobaud Mode High−Speed Mode VS = 2 V VS = 0.8 V IRXD = −10 mA IRXD = 6 mA 0.45 x VCC 0.40 x VCC 2.0 −0.3 20 15 − − 30 30 VCC+ 0.3 +0.8 50 45 V V mA mA Receiver Data Output (Pin RxD) High−Level Output Voltage Low−Level Output Voltage 0.6 x VCC 0.75 x VCC 0.25 0.45 V V REFERENCE VOLTAGE OUTPUT (Pin VREF) Reference Output Voltage Reference Output Voltage for Full Common Mode Range −50 mA < IVREF < +50 mA −35 V