AMIS-42700 Dual High Speed CAN Transceiver General Description http://onsemi.com PIN CONFIGURATION NC 1 20 NC EN2 2 19 CANH2 Text 3 18 CANL2 Tx0 4 17 GND GND 5 16 GND GND 6 15 GND Rx0 7 14 CANL1 Vref1 8 13 CANH1 Rint 9 12 VCC EN1 10 11 NC AMIS-42700 Controller area network (CAN) is a serial communication protocol, which supports distributed real-time control and multiplexing with high safety level. Typical applications of CAN-based networks can be found in automotive and industrial environments. The AMIS-42700 Dual-CAN transceiver is the interface between up to two physical bus lines and the protocol controller and will be used for serial data interchange between different electronic units at more than one bus line. It can be used for both 12 V and 24 V systems. The circuit consists of following blocks: * Two differential line transmitters * Two differential line receivers * Interface to the CAN protocol handler * Interface to expand the number of CAN busses * Logic block including repeater function and the feedback suppression * Thermal shutdown circuit (TSD) * Short to battery treatment circuit Due to the wide common-mode voltage range of the receiver inputs, the AMIS-42700 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. SOIC 20 WC SUFFIX CASE 751AQ Key Features * * * * * * * * * * * Fully compatible with the ISO 11898-2 standard Certified "Authentication on CAN Transceiver Conformance (d1.1)" High speed (up to 1 Mbit/s in function of the bus topology) Ideally suited for 12 V and 24 V industrial and automotive applications Low 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 Dominant time-out function Thermal protection Bus pins protected against transients in an automotive environment Short circuit proof to supply voltage and ground (c) Semiconductor Components Industries, LLC, 2009 January, 2009 - Rev. 5 1 ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 12 of this data sheet. Publication Order Number: AMIS-42700/D AMIS-42700 Table 1. Technical Characteristics Symbol Parameter Conditions Min. Max. Unit VCANHx DC voltage at pin CANH1/2 0 < VCC < 5.25 V; no time limit -45 +45 V VCANLx DC voltage at pin CANL1/2 0 < VCC < 5.25 V; no time limit -45 +45 V 42.5 W < RLT < 60 W 1.5 3 V Vo(dif)(bus_dom) Differential bus output voltage in dominant state CM-range Input common-mode range for comparator Guaranteed differential receiver threshold and leakage current -35 +35 V VCM-peak Common-mode peak See Figures 9 and 10 (Note 1) -1000 1000 mV VCM-step Common-mode step See Figures 9 and 10 (Note 1) -250 250 mV 1. The parameters VCM-peak and VCM-step guarantee low EME. VCC 12 Thermal shutdown Timer 14 Driver control Vcc/2 Ri(cm) + COMP 19 Timer Feedbeck Surpression CANL1 clock AMIS-42700 13 Feedbeck Surpression CANH1 POR Logic Unit 18 Driver control Ri(cm) + COMP Ri(cm) Vcc/2 Ri(cm) VCC 8 VREF VCC 10 VCC VCC 3 ENB1 Text 7 4 Rx0 Tx0 9 Rint 2 5 ENB2 Figure 1. Block Diagram Typical Application Application Description * Dual CAN * A CAN-bus extender * A CAN-bus repeater AMIS-42700 is especially designed to provide the link between a CAN controller (protocol IC) and two physical busses. It is able to operate in three different modes: http://onsemi.com 2 6 15 GND 16 17 CANH2 CANL2 AMIS-42700 Application Schematics VBAT CAN BUS 1 5V-reg CAN BUS 2 CD 100 nF Vref VCC 8 13 CANH1 EN1 10 12 EN2 2 Rx0 7 Tx0 Text Rint RLT AMIS-42700 4 14 19 CANL1 60 W CANH2 RLT 3 9 5 18 6 15 16 17 CANL2 60 W GND Figure 2. Application Diagram CAN-bus Repeater VBAT CAN BUS 1 5V-reg CD CD 100 nF 100 nF VCC VCC EN1 10 EN2 2 Rx0 mC CAN con- troller Tx0 Text Rint 7 4 Vref 8 13 CANH1 12 RLT AMIS-42700 14 19 CANL1 CANH2 RLT 3 9 60 W 5 6 15 16 17 18 CANL2 60 W GND GND Figure 3. Application Diagram Dual-CAN http://onsemi.com 3 CAN BUS 2 AMIS-42700 VBAT CAN BUS 1 5V-reg CD CD 100 nF 100 nF VCC 8 13 CANH1 EN1 10 12 EN2 2 mC Rx0 7 Tx0 CAN con- troller Text Rint +5 Vref VCC RLT AMIS-42700 4 CAN BUS 2 14 19 CANL1 60 W CANH2 RLT 3 9 5 18 6 15 16 17 CANL2 GND GND 60 W +5 CAN BUS 3 CD 100 nF Vref VCC 8 13 CANH1 EN1 10 12 EN2 2 Rx0 Tx0 Text Rint 7 4 RLT AMIS-42700 14 19 CANL1 CANH2 RLT 3 9 60 W 5 6 15 16 17 18 CANL2 60 W GND Figure 4. Application Diagram CAN-bus Extender Table 2. Pin Out Pin Name Description 1 NC 2 ENB2 Not connected 3 Text Multi-system transmitter Input; internal pull-up 4 Tx0 Transmitter input; internal pull-up 5 GND Ground connection (Note 2) 6 GND Ground connection (Note 2) 7 Rx0 Receiver output 8 VREF1 9 Rint 10 ENB1 11 NC Enable input, bus system 2; internal pull-up Reference voltage Multi-system receiver output Enable input, bus system 1; internal pull-up Not connected 12 VCC 13 CANH1 Positive supply voltage CANH transceiver I/O bus system 1 14 CANL1 CANL transceiver I/O bus system 1 15 GND Ground connection (Note 2) 16 GND Ground connection (Note 2) 17 GND Ground connection (Note 2) 18 CANL2 CANL transceiver I/O bus system 2 19 CANH2 CANH transceiver I/O bus system 2 20 NC Not connected 2. In order to ensure the chip performance, all these pins need to be connected to GND on the PCB. http://onsemi.com 4 CAN BUS 4 AMIS-42700 Functional Description Overall Functional Description not connected or is accidentally interrupted. A dominant state on the bus line is represented by a low-level at the digital interface; a recessive state is represented by a high-level. Dominant state received on any bus (if enabled) causes a dominant state on both busses, pin Rint and pin Rx0. Dominant signal on any of the input pins Tx0 and Text causes transmission of dominant on both bus lines (if enabled). Digital inputs Tx0 and Text are used for connecting the internal logic's of several IC's to obtain versions with more than two bus outputs (see Figure 4: Application Diagram CAN-bus Extender). They have also a direct logical link to pins Rx0 and Rint independently on the EN1x pins - dominant on Tx0 is directly transferred to both Rx0 and Rint pins, dominant on Text is only transferred to Rx0. AMIS-42700 is specially designed to provide the link between the protocol IC (CAN controller) and two physical bus lines. Data interchange between those two bus lines is realized via the logic unit inside the chip. To provide an independent switch-off of the transceiver units for both bus systems by a third device (e.g. the mC), enable-inputs for the corresponding driving and receiving sections are provided. As long as both lines are enabled, they appear as one logical bus to all nodes connected to either of them. The bus lines can have two logical states, dominant or recessive. A bus is in the recessive state when the driving sections of all transceivers connected to the bus are passive. The differential voltage between the two wires is approximately zero. If at least one driver is active, the bus changes into the dominant state. This state is represented by a differential voltage greater than a minimum threshold and therefore by a current flow through the terminating resistors of the bus line. The recessive state is overwritten by the dominant state. In case of a fault (like short circuit) is present on one of the bus lines, it remains limited to that bus line where it occurs. Data interchange from the protocol IC to the other bus system and on this bus system itself can be continued. AMIS-42700 can be also used for only one bus system. If the connections for the second bus system are simply left open it serves as a single transceiver for an electronic unit. For correct operation, it is necessary to terminate the open bus by the proper termination resistor. Transmitters The transceiver includes two transmitters, one for each bus line, and a driver control circuit. Each transmitter is implemented as a push and a pull driver. The drivers will be active if the transmission of a dominant bit is required. During the transmission of a recessive bit all drivers are passive. The transmitters have a built-in current limiting circuit that protects the driver stages from damage caused by accidental short circuit to either positive supply voltage or to ground. Additionally a thermal protection circuit is integrated. The driver control circuit ensures that the drivers are switched on and off with a controlled slope to limit EME. The driver control circuit will be controlled itself by the thermal protection circuit, the timer circuit and the logic unit. The enable signal ENBx allows the transmitter to be switched off by a third device (e.g. the mC). In the disabled state (ENBx = high) the corresponding transmitter behaves as in the recessive state. Logic Unit and CAN Controller Interface The logic unit inside AMIS-42700 provides data transfer from/to the digital interface to/from the two busses and from one bus to the other bus. The detailed function of the logic unit is described in Table 3. All digital input pins, including ENBx, have an internal pull-up resistor to ensure a recessive state when the input is Table 3. Function of the Logic Unit (bold letters describe input signals) EN1B EN2B TX0 TEXT Bus 1 State Bus 2 State RX0 RINT 0 0 0 0 dominant dominant 0 0 0 0 0 1 dominant dominant 0 0 0 0 1 0 dominant dominant 0 1 0 0 1 1 recessive recessive 1 1 0 0 1 1 dominant (Note 3) dominant 0 0 0 0 1 1 dominant dominant (Note 3) 0 0 0 1 0 0 dominant recessive 0 0 0 1 0 1 dominant recessive 0 0 0 1 1 0 dominant recessive 0 1 0 1 1 1 recessive recessive 1 1 0 1 1 1 dominant (Note 3) recessive 0 0 3. Dominant detected by the corresponding receiver. http://onsemi.com 5 AMIS-42700 Table 3. Function of the Logic Unit (bold letters describe input signals) EN1B EN2B TX0 TEXT Bus 1 State Bus 2 State RX0 RINT 0 1 1 1 recessive dominant (Note 3) 1 1 1 0 0 0 recessive dominant 0 0 1 0 0 1 recessive dominant 0 0 1 0 1 0 recessive dominant 0 1 1 0 1 1 recessive recessive 1 1 1 0 1 1 dominant (Note 3) recessive 1 1 1 0 1 1 recessive dominant (Note 3) 0 0 1 1 0 0 recessive recessive 0 0 1 1 0 1 recessive recessive 0 0 1 1 1 0 recessive recessive 0 1 1 1 1 1 recessive recessive 1 1 1 1 1 1 dominant (Note 3) recessive 1 1 1 1 1 1 recessive dominant (Note 3) 1 1 3. Dominant detected by the corresponding receiver. Receivers on that bus line, on which a dominant is actively transmitted. The reception becomes active again only with certain delay after the dominant transmission on this line is finished. Two bus receiving sections sense the states of the bus lines. Each receiver section consists of an input filter and a fast and accurate comparator. The aim of the input filter is to improve the immunity against high-frequency disturbances and also to convert the voltage at the bus lines CANHx and CANLx, which can vary from -12 V to +12 V, to voltages in the range 0 to 5 V, which can be applied to the comparators. The output signal of the comparators is gated by the ENBx signal. In the disabled state (ENBX = high), the output signal of the comparator will be replaced by a permanently recessive state and does not depend on the bus voltage. In the enabled state the receiver signal sent to the logic unit is identical to the comparator output signal. Power-on-Reset (POR) While Vcc voltage is below the POR level, the POR circuit makes sure that: * The counters are kept in the reset mode and stable state without current consumption * Inputs are disabled (don't care) * Outputs are high impedant; only Rx0 = high-level * Analog blocks are in power down * Oscillator not running and in power down * CANHx and CANLx are recessive * VREF output high impedant for POR not released Time-out Counters To avoid that the transceiver drives a permanent dominant state on either of the bus lines (blocking all communication), time-out function is implemented. Signals on pins Tx0 and Text as well as both bus receivers are connected to the logic unit through independent timers. If the input of the timer stays dominant for longer than parameter tdom, it's replaced by a recessive signal on the timer output. Over Temperature Detection Feedback Suppression Fault Behavior The logic unit described in Table 3 constantly ensures that dominant symbols on one bus line are transmitted to the other bus line without imposing any priority on either of the lines. This feature would lead to an "interlock" state with permanent dominant signal transmitted to both bus lines, if no extra measure is taken. Therefore a feedback suppression is included inside the logic unit of the transceiver. This block masks-out reception A fault like a short circuit is limited to that bus line where it occurs; hence data interchange from the protocol IC to the other bus system is not affected. When the voltage at the bus lines is going out of the normal operating range (-12 V to +12 V), the receiver is not allowed to erroneously detect a dominant state. A thermal protection circuit is integrated to prevent the transceiver from damage if the junction temperature exceeds thermal shutdown level. Because the transmitters dissipate most of the total power, the transmitters will be switched off only to reduce power dissipation and IC temperature. All other IC functions continue to operate. http://onsemi.com 6 AMIS-42700 Short Circuits Reverse Electronic Unit (ECU) Supply As specified in the maximum ratings, short circuits of the bus wires CANHx and CANLx to the positive supply voltage Vbat or to ground must not destroy the transceiver. A short circuit between CANHx and CANLx must not destroy the IC as well. The dedicated comparator (L2VBAT) on CANL pin detects the short to battery and after debounce time-out switches off the affected driver only. The receiver of the affected driver has to operate normally. If the connections for ground and supply voltage of an electronic unit (ECU) (max. 50 V) which provides Vcc for the transceiver are exchanged, this transceiver has a ground potential which may be up to 50 V higher than that of the other transceivers. In this case no transceiver must be destroyed even if several of them are connected via the bus system. Any exchange among the six connections CANH1, CANH2, CANL1, CANL2, ground, and supply voltage of the electronic unit at the connector of the unit must never lead to the destruction of any transceiver of the bus system. Faulty Supply In case of a faulty supply (missing connection of the electronic unit or the transceiver to ground, missing connection of the electronic unit to Vbat or missing connection of the transceiver to Vcc), the power supply module of the electronic unit will operate such that the transceiver is not supplied, i.e. the voltage Vcc is below the POR level. In this condition the bus connections of the transceiver must be in the POR state. If the ground line of the electronic unit is interrupted, Vbat may be applied to the Vcc pin (measured relative to the original ground potential, to which the other units on the bus are connected). Electrical Characteristics Definitions All voltages are referenced to GND. Positive currents flow into the IC. Sinking current means that the current is flowing into the pin. Sourcing current means that the current is flowing out of the pin. Absolute Maximum Ratings Stresses above those listed in Table 4 may cause permanent device failure. Exposure to absolute maximum ratings for extended periods may affect device reliability. Table 4. Absolute Maximum Ratings Symbol VCC Conditions Supply voltage Min. Max. Unit -0.3 +7 V VCANHx DC voltage at pin CANH1/2 0 < VCC < 5.25 V; no time limit -45 +45 V VCANLx DC voltage at pin CANL1/2 0 < VCC < 5.25 V; no time limit -45 +45 V VdigIO DC voltage at digital IO pins (EN1B, EN2B, Rint, Rx0, Text, Tx0) -0.3 VCC + 0.3 V VREF DC voltage at pin VREF -0.3 VCC + 0.3 V Vtran(CANHx) Transient voltage at pin CANH1/2 (Note 4) -150 +150 V Vtran(CANLx) Transient voltage at pin CANL1/2 (Note 4) -150 +150 V ESD voltage at CANH1/2 and CANL1/2 pins (Note 5) (Note 7) -4 -500 +4 +500 kV V ESD voltage at all other pins (Note 5) (Note 7) -2 -250 +2 +250 kV V Static latch-up at all pins (Note 6) 100 mA Vesd(CANLx/CANHx) Vesd Latch-up 4. 5. 6. 7. Parameter Tstg Storage temperature -55 +155 C Tamb Ambient temperature -40 +125 C Tjunc Maximum junction temperature -40 +150 C Applied transient waveforms in accordance with "ISO 7637 part 3", test pulses 1, 2, 3a, and 3b (see Figure 5). Standardized human body model (HBM) ESD pulses in accordance to MIL883 method 3015. Supply pin 8 is 2 kV. Static latch-up immunity: static latch-up protection level when tested according to EIA/JESD78. Standardized charged device model ESD pulses when tested according to EOS/ESD DS5.3-1993. http://onsemi.com 7 AMIS-42700 Table 5. Thermal Characteristics Symbol Parameter Conditions Value Unit Rth(vj-a) Thermal resistance from junction to ambient in SO20 package In free air 85 K/W Rth(vj-s) Thermal resistance from junction to substrate of bare die In free air 45 K/W Table 6. DC and Timing Characteristics (VCC = 4.75 to 5.25 V; Tjunc = -40 to +150C; RLT = 60 W unless specified otherwise.) Symbol Parameter Conditions Min. Typ. Max. Unit 45 137.5 19.5 mA 4.7 V SUPPLY (pin VCC) ICC PORL_VCC Supply current, no loads on digital outputs, both busses enabled Dominant transmitted Recessive transmitted Power-on-reset level on VCC 2.2 DIGITAL INPUTS (Tx0, Text, EN1B, EN2B) VIH High-level input voltage 0.7 x VCC - VCC V VIL Low-level input voltage -0.3 - 0.3 x VCC V IIH High-level input current VIN = VCC -5 0 +5 mA IIL Low-level input current VIN = 0 V -75 -200 -350 mA Ci Input capacitance Not tested - 5 10 pF DIGITAL OUTPUTS (pin Rx0, Rint) Ioh High-level output current Vo = 0.7 x VCC -5 -10 -15 mA Iol Low-level output current Vo = 0.3 x VCC 5 10 15 mA Reference output voltage -50 mA < IVREF < +50 mA 0.45 x VCC 0.50 x VCC 0.55 x VCC V Reference output voltage for full common mode range -35 V