AMIS-42700

AMIS-42700 Dual High Speed CAN Transceiver General Description 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. Key Features http://onsemi.com PIN CONFIGURATION NC EN2 Text Tx0 GND GND Rx0 Vref1 Rint EN1 1 2 3 20 19 18 NC CANH2 CANL2 GND GND GND CANL1 CANH1 VCC NC AMIS−42700 4 5 6 7 8 9 10 17 16 15 14 13 12 11 SOIC 20 WC SUFFIX CASE 751AQ • • • • • • • • • • • 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 ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 12 of this data sheet. © Semiconductor Components Industries, LLC, 2009 January, 2009 − Rev. 5 1 Publication Order Number: AMIS−42700/D AMIS−42700 Table 1. Technical Characteristics Symbol VCANHx VCANLx Vo(dif)(bus_dom) CM−range VCM−peak VCM−step Parameter DC voltage at pin CANH1/2 DC voltage at pin CANL1/2 Differential bus output voltage in dominant state Input common−mode range for comparator Common−mode peak Common−mode step Conditions 0 < VCC < 5.25 V; no time limit 0 < VCC < 5.25 V; no time limit 42.5 W < RLT < 60 W Guaranteed differential receiver threshold and leakage current See Figures 9 and 10 (Note 1) See Figures 9 and 10 (Note 1) Min. −45 −45 1.5 −35 −1000 −250 Max. +45 +45 3 +35 1000 250 Unit V V V V mV mV 1. The parameters VCM−peak and VCM−step guarantee low EME. VCC 12 Thermal shutdown POR clock CANH1 CANL1 13 Feedbeck Surpression Timer 14 Driver control AMIS− 42700 Feedbeck Surpression Timer Driver control 19 18 CANH2 CANL2 Logic Unit Vcc/2 Ri(cm) + COMP Ri(cm) COMP + Vcc/2 Ri(cm) VCC VCC VCC VCC Ri(cm) 8 10 3 4 7 9 2 5 6 15 16 17 VREF ENB1 Text Tx0 Rx0 Rint ENB2 GND Figure 1. Block Diagram Typical Application Application Description 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: • Dual CAN • A CAN−bus extender • A CAN−bus repeater http://onsemi.com 2 AMIS−42700 Application Schematics VBAT 5V−reg VCC EN1 10 12 EN2 2 Rx0 7 Tx0 Text Rint 4 3 9 5 CAN BUS 1 CD 100 nF Vref 8 13 CANH1 CAN BUS 2 RLT 14 19 CANL1 CANH2 60 W AMIS−42700 RLT 6 15 16 17 18 CANL2 60 W GND Figure 2. Application Diagram CAN−bus Repeater VBAT 5V−reg VCC CAN BUS 1 CD 100 nF VCC EN1 10 EN2 2 Rx0 12 CAN BUS 2 CD 100 nF Vref 8 13 CANH1 RLT mC CAN con− troller GND 7 4 3 9 Tx0 Text Rint AMIS−42700 14 19 CANL1 CANH2 60 W RLT 5 6 15 16 17 18 CANL2 60 W GND Figure 3. Application Diagram Dual−CAN http://onsemi.com 3 AMIS−42700 VBAT 5V−reg VCC CAN BUS 1 CD 100 nF VCC EN1 10 12 EN2 2 CD 100 nF Vref +5 CAN BUS 2 8 13 CANH1 RLT 14 19 mC CAN con− troller GND Rx0 7 Tx0 Text Rint 4 3 9 CANL1 CANH2 60 W AMIS−42700 RLT 5 6 15 16 17 18 CANL2 60 W GND +5 CAN BUS 3 CAN BUS 4 CD 100 nF VCC EN1 10 12 EN2 2 Rx0 Tx0 Text Rint 7 4 3 9 5 6 15 16 17 18 Vref 8 13 CANH1 RLT 14 19 CANL1 CANH2 60 W AMIS−42700 RLT CANL2 60 W GND Figure 4. Application Diagram CAN−bus Extender Table 2. Pin Out Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Name NC ENB2 Text Tx0 GND GND Rx0 VREF1 Rint ENB1 NC VCC CANH1 CANL1 GND GND GND CANL2 CANH2 NC Not connected Enable input, bus system 2; internal pull−up Multi−system transmitter Input; internal pull−up Transmitter input; internal pull−up Ground connection (Note 2) Ground connection (Note 2) Receiver output Reference voltage Multi−system receiver output Enable input, bus system 1; internal pull−up Not connected Positive supply voltage CANH transceiver I/O bus system 1 CANL transceiver I/O bus system 1 Ground connection (Note 2) Ground connection (Note 2) Ground connection (Note 2) CANL transceiver I/O bus system 2 CANH transceiver I/O bus system 2 Not connected Description 2. In order to ensure the chip performance, all these pins need to be connected to GND on the PCB. http://onsemi.com 4 AMIS−42700 Functional Description Overall Functional Description 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. Logic Unit and CAN Controller Interface 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. Transmitters 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 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. Table 3. Function of the Logic Unit (bold letters describe input signals) EN1B 0 0 0 0 0 0 0 0 0 0 0 EN2B 0 0 0 0 0 0 1 1 1 1 1 TX0 0 0 1 1 1 1 0 0 1 1 1 TEXT 0 1 0 1 1 1 0 1 0 1 1 Bus 1 State dominant dominant dominant recessive dominant (Note 3) dominant dominant dominant dominant recessive dominant (Note 3) Bus 2 State dominant dominant dominant recessive dominant dominant (Note 3) recessive recessive recessive recessive recessive RX0 0 0 0 1 0 0 0 0 0 1 0 RINT 0 0 1 1 0 0 0 0 1 1 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 0 1 1 1 1 1 1 1 1 1 1 1 1 EN2B 1 0 0 0 0 0 0 1 1 1 1 1 1 TX0 1 0 0 1 1 1 1 0 0 1 1 1 1 TEXT 1 0 1 0 1 1 1 0 1 0 1 1 1 Bus 1 State recessive recessive recessive recessive recessive dominant (Note 3) recessive recessive recessive recessive recessive dominant (Note 3) recessive Bus 2 State dominant (Note 3) dominant dominant dominant recessive recessive dominant (Note 3) recessive recessive recessive recessive recessive dominant (Note 3) RX0 1 0 0 0 1 1 0 0 0 0 1 1 1 RINT 1 0 0 1 1 1 0 0 0 1 1 1 1 3. Dominant detected by the corresponding receiver. Receivers 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. Time−out Counters 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. 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 Over Temperature Detection 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. Feedback Suppression 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. 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. 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. 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). Table 4. Absolute Maximum Ratings Symbol VCC VCANHx VCANLx VdigIO VREF Vtran(CANHx) Vtran(CANLx) Vesd(CANLx/CANHx) Vesd Latch−up Tstg Tamb Tjunc 4. 5. 6. 7. Supply voltage DC voltage at pin CANH1/2 DC voltage at pin CANL1/2 DC voltage at digital IO pins (EN1B, EN2B, Rint, Rx0, Text, Tx0) DC voltage at pin VREF Transient voltage at pin CANH1/2 Transient voltage at pin CANL1/2 ESD voltage at CANH1/2 and CANL1/2 pins ESD voltage at all other pins Static latch−up at all pins Storage temperature Ambient temperature Maximum junction temperature Parameter 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. 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. Conditions Min. −0.3 Max. +7 +45 +45 VCC + 0.3 VCC + 0.3 +150 +150 +4 +500 +2 +250 100 Unit V V V V V V V kV V kV V mA °C °C °C 0 < VCC < 5.25 V; no time limit 0 < VCC < 5.25 V; no time limit −45 −45 −0.3 −0.3 (Note 4) (Note 4) (Note 5) (Note 7) (Note 5) (Note 7) (Note 6) −150 −150 −4 −500 −2 −250 −55 −40 −40 +155 +125 +150 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 Rth(vj−a) Rth(vj−s) Parameter Thermal resistance from junction to ambient in SO20 package Thermal resistance from junction to substrate of bare die Conditions In free air In free air Value 85 45 Unit K/W K/W Table 6. DC and Timing Characteristics (VCC = 4.75 to 5.25 V; Tjunc = −40 to +150°C; RLT = 60 W unless specified otherwise.) Symbol SUPPLY (pin VCC) ICC PORL_VCC Supply current, no loads on digital outputs, both busses enabled Power−on−reset level on VCC High−level input voltage Low−level input voltage High−level input current Low−level input current Input capacitance VIN = VCC VIN = 0 V Not tested Dominant transmitted Recessive transmitted 2.2 45 137.5 19.5 4.7 mA V Parameter Conditions Min. Typ. Max. Unit DIGITAL INPUTS (Tx0, Text, EN1B, EN2B) VIH VIL IIH IIL Ci Ioh Iol VREF VREF_CM 0.7 x VCC −0.3 −5 −75 − − − 0 −200 5 VCC 0.3 x VCC +5 −350 10 V V mA mA pF DIGITAL OUTPUTS (pin Rx0, Rint) High−level output current Low−level output current Vo = 0.7 x VCC Vo = 0.3 x VCC −50 mA < IVREF < +50 mA −35 V