B10011S

Features • Capability of Single-wire Operation • Hardware Fault Recognition • Inputs with High Common-mode and Differential-mode Interference Rejection Above 100 VPP due to External Filters at the Receiver Input • Immunity Against Electromagnetic Interference • Immunity Against Ground-voltage Offsets < 6V • Ruggedized Against ESD by MIL-STD-883C, Method 3015 Benefits Systems which employ this device have the following benefits compared to solutions using discrete components: • High Reliability Can Transceiver IC B10011S Applications • Especially Suited for Truck and Van Applications • Interface Between Truck and Trailer • Interface Between Dashboard and Engine 1. Description The CAN driver IC B10011S is a low-speed, high-level interface for 24V (27V) operation with transmission levels according to ISO WD 11992-1 (point-to-point interface between trucks and trailers). It is developed for signal levels of 8V/16V and a speed of up to 250 kbits/s. This device allows transmission, that is insensitive to electromagnetic interference. Such interferences may especially occur in truck applications where (due to the length of the wires) high common-mode voltages (e.g., 50) can be coupled into the lines. This device contains a fault recognition circuit that detects faults on one of the two wires, which are normally used for transmission. If a fault occurs the operation can be switched from double-wire to single-wire mode thus, allowing proper operation even if one wire is broken, has a short-cut or a high series resistance. 4749D–AUTO–10/07 Figure 1-1. Block Diagram 1 2 3 4 5 6 7 8 VDD VSS 2.5 V Error control +4.3 V VCC Select control Comparators 16 15 14 13 12 11 10 GND 9 Output control B10011S 2 B10011S 4749D–AUTO–10/07 B10011S 2. Pin Configuration Figure 2-1. Pinning SO16 ASEL BSEL ER RX1 RX0 TX0 VDD VSS 1 2 3 4 5 6 7 8 16 15 14 13 12 11 10 9 F1 F0 S+ VCC H' L' GND S- Table 2-1. Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Pin Description 16-lead SOIC (SO16), Small Outline Gull - Wing Symbol ASEL BSEL ER RX1 RX0 TX0 VDD VSS SGND L’ H’ VCC S+ F0 F1 Function Select control input Select control input Error signal output Reference voltage 2.5V Receiver output Transmitter input Controller supply voltage 5V Controller supply voltage 0V Collector of internal NPN switch Vehicle ground 0V Data out driver Data out driver Vehicle power supply 24V Control output for external PNP Receiver input Receiver input 3 4749D–AUTO–10/07 3. Absolute Maximum Ratings Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameters Supply voltage Controller supply voltage Input voltage at any input Junction temperature Storage temperature range Soldering temperature (for 10s maximum) Symbol VCC VDD Vin Tj Tstg Tsld Value –0.5 to +36 –0.5 to +5.5 –0.5 to VDD 150 –55 to +150 260 Unit V V V °C °C °C Operating Conditions Parameters Supply voltage car battery Controller supply voltage Control input voltage Input voltage Operating temperature Symbol VCC VDD Asel, Bsel Tx0 Tamb Value 7 to 32 4.75 to 5.25 0 to VDD 0 to VDD –40 to +105 Unit V V V V °C 4. Operating Modes 0 = 0V, 1 = 5V Asel 0 1 0 1 Bsel 0 0 1 1 Rx0 3.8V From H From L From L-H Mode H, L drivers disabled, L load disabled, S-, S+ disabled station not in operation, but consuming current Single-wire H, L driver, L load, S-, S+ disabled Single-wire L, H driver disabled Two-wire operation, normal mode ER (error signal) is low when normal operation is disturbed by line faults (interruption, short to ground or to VCC, H to L short disturbance by high voltage transients). After a waiting period due to transient delays, the controller is asked to test if single-wire operation is possible by changing the Asel and Bsel state. Asel and Bsel have an internal pull-up resistor. Therefore, the no-connect state is 1, but connection to VDD is recommended when not in use. 4 B10011S 4749D–AUTO–10/07 B10011S 5. Pulse Diagram The pulse diagram for two connected, identical stations is shown below. The resistor levels have to be kept constant when additional stations are connected. Figure 5-1. Pulse Diagram TX0 5V dominant 0V 4 ms min(1) 5V RX0 recessive t 0V t 27 V L 18 V H 9V 0V t 27 V L' 18 V H' 9V 0V (1) Filter t has to be changed if short distances are to be allowed 5 4749D–AUTO–10/07 6. Electrical Characteristics Test condition: Test circuit (see Figure 6-1 on page 7), 0 = 0V, 1 = 5V VCC = 27V, VDD = 5V, VSS = 0V, Tamb = –40°C to +105°C, unless otherwise specified. Parameters Test Conditions Tx0 = 0, Asel = 1, Bsel = 1 Supply current Tx0 = 0, Asel = 0, Bsel = 0 Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 1 Input current Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 0, Asel = 1, Bsel = 0 VIL(F0) = 1.9V, VIH(F1) = 2.7V Tx0 = 1, Asel = 1, Bsel = 1 VIL(F1) = 1.9 V, VIH(F0) = 2.7 V Tx0 = 0, Asel = 1, Bsel = 1 Output voltage Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 0, Asel = 1, Bsel = 1 No fault Fault on line Symbol ICC IDD ICC IDD I(Tx0) I(Asel, Bsel) Rx0 Rx0 U(H’) U(H’) U(L’) U(L’) ER ER 4.7 100 26 1.0 3.8 24.5 1.0 Min. Typ. Max. 15 22 26 16 650 150 1.0 Unit mA mA mA mA µA µA V V V V V V V mV VCC = 7V, VDD = 4.75V, VSS = 0V, Tamb = 25°C, unless otherwise specified. Parameters Test Conditions Tx0 = 0, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 0 Output voltage Tx0 = 0, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 0 VIL(F1) = 1.0V, VIH(F0) = 1.15V Tx0 = 0, Asel = 1, Bsel = 0 VIL(F0) = 1.0V, VIH(F1) = 1.15V Symbol U(H’) U(H’) U(L’) U(L’) Rx0 Rx0 3.3 1.0 6.5 1.0 Min. 4.5 100 Typ. Max. Unit V mV V V V V VCC = 32V, VDD = 5.25V, VSS = 0V, Tamb = 25°C, unless otherwise specified. Parameters Test Conditions Tx0 = 0, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 0 Output voltage Tx0 = 0, Asel = 1, Bsel = 1 Tx0 = 1, Asel = 1, Bsel = 0 VIL(F1) = 1.6V, VIH(F0) = 2.7V Tx0 = 0, Asel = 1, Bsel = 0 VIL(F0) = 1.6V, VIH(F1) = 2.7V Symbol U(H’) U(H’) U(L’) U(L’) Rx0 Rx0 4.0 1.0 31.5 1.0 Min. 29 500 Typ. Max. Unit V mV V V V V 6 B10011S 4749D–AUTO–10/07 B10011S Figure 6-1. Test Circuit 470 H/L VDD H/L 150k VDD 1k8 220 470 1k8 VDD H/L 470 1 2 3 4 5 6 7 8 Asel Bsel ER 2.5 V Rx0 Tx0 VDD VSS B10011S Error control Output control Select control +4.3V Comparators F1 F0 S+ VCC H' 16 15 14 13 12 11 580 620 VCC VIL VCC VCC VIH L' GND 10 S9 2k5 VCC Figure 6-2. Application Circuit +5 V Asel Bsel ER Rx1 Rx0 Tx0 VDD + VSS 10 µF 150k 2n2 1 2 3 4 2.5 V 5 6 7 VDD 8 VSS GND Output control 12 10µ + 11 40 V 10 1k8 9 0µ1 M Resistors: MELF 0204, 1%, 0.6 W 02075, 1%, TK50 Chip capacitors NPO 0805, 1206, 10% Ferrite bead BLM 31A601S (Murata) Common-mode choke coils (SMD): B82790 S0513 N201 (Siemens) F2 2x50 µH (Vogt) ST2001 (Vogt) Cable LiYY 4 x 1 mm2 Battery ground L H 1k8 1k8 1k8 220 270 VCC Error control Select control +4.3 V VCC Comparators Filter for 125 kbit/s operation 16k 16 VDD 15 14 BCX 17 13 1k8 1k8 24k 5k6 82p 16k 47p 22k 24k 5k6 82p 22k 47p to CAN controller Filter ground The implementation of a power filter and overvoltage clamp as follows is highly recommended: 7 4749D–AUTO–10/07 Figure 6-3. Implementation of a Power Filter and Over Clamps 10 From battery (cl. 15) 33V Ground To pin 10 To VCC (pin 13) + 22 µF 7. Application Hints As an interface between CAN controllers and a two-wire data bus system for serial data interchange, this device is adapted to a special high-level, low-speed transmission system, which is useful in harsh environments. High immunity against ground offset and interference voltages on the bus have been the design goals for this device, rather than low power consumption or a minimum of external components. An error detection scheme is implemented in the receiver part to give quick information to the controller in case of faults occurring on the bus. Thus, the controller is able to start a search cycle in order to look for the possibility of single-wire operation or to disable the station from the bus. An automatic error-signal end is not feasible because parts of the system are disabled during single-wire operation. Therefore, the controller has to carry out short tests by switching to the two-wire state and checking, whether the error signal is still present or not. Errors due to dirty contacts, shorts between high and low line, or interruptions may not be recognized at all, because this device does not contain a complete fault computer. Two control inputs Asel and Bsel enable four operation modes (see Table “Operating Modes” on page 4’). Depending on the nature of the error, the error signal ER is internally generated partly in the recessive or partly in the dominant transmission state. In order to avoid watching the error bits bitwise, an open-collector output driver (with a 1-kΩ series resistor) discharges a storage capacitor, which is charged by a time constant, long enough to hold the 0 state for, e.g., 200 µs, thus, giving the controller enough time to recognize this status during idle times. Only the charging resistor may be changed and not the 2.2-nF capacitor. In order to perform a faster error-end test, the charging resistor may be shorted by an NPN emitter follower or by a tristate output high for approximately 1 to 2 µs. The pinout of the device shows a controller side (pins 1 to 8) and a bus side (pins 9 to 16). The application circuit utilizes an input filter section which is necessary for every station and a bias section which is needed in two master stations only. Additional slave stations only contain the driving resistors at pins 11 and 12 (270Ω and 220Ω), the choke coil, and capacitor between pins 13 and 10. A power filter and overvoltage clamp is highly recommended in order to avoid transmission errors due to spikes on the 24-V battery voltage. The input filter is designed as an 2-RC filter for 125 kbit/s and may be changed to 250 kbit/s. Its good pulse response and good suppression of high frequencies should not be weakened by omitting one of the capacitors. 8 B10011S 4749D–AUTO–10/07 B10011S All the logical and sensing functions in the device are powered by VDD = 5V. Therefore, the filter section also acts as a level shifter to the input comparator range (approximately 1 to 3.3V). The diagram (see Figure 7-1) shows how the battery voltage, VCC, influences the comparator input voltages, F0 and F1, in relation to the internal reference voltage, Vref, in the recessive state. The lower VCC, the lower the bus level. Taking this into account the comparator input levels are F1 – Vref for single-wire H respectively F1 – F0 for two-wire operation. The comparator’s offset voltage is ≤10 mV. Matching the filter biasing to the internal reference is essentially for safe operation even at low battery voltages during motor start. The level investigations and tests described in the following description have been carried out within the temperature range of –40°C to +105°C with two B10011S on a bus line, one of them always in the recessive state (see Figure 7-2 on page 10). In case of line shorts to VCC or to ground or in case of H to L shorts, all participants on the bus are intended to switch to single-wire operation and to disable their drivers not in use. The dynamic behavior of the circuit depends on the line capacitances to ground. Approximately 200 pF/m and a maximum of 6 nF have to be taken into account. The transition from the dominant to the recessive state enables the bias network to recharge the line through a driving resistor of approximately 300 Ω. The transition from the recessive to the dominant state is approximately twice as fast. This is probably the source of emitted radiation having no capacitance on the line. The choke coil enables the suppression of this radiation in the frequency range above 5 MHz to 7 MHz. Care should be taken not to feed noise from VDD or VCC to the line. Therefore, they should be properly blocked by low-inductance capacitors. Data loss by externally induced interference is avoided by careful PCB layout and EMC design for this circuit as well as by providing appropriate overvoltage protection. It is very essential to separate battery ground and filter ground as indicated in the application circuit (see Figure 6-2 on page 7). Especially important is that the filter ground must be connected to pin 8 by a short connection not subject to disturbing currents from external sources. The ground wire of the “starquad” cable may introduce such currents and should be connected to battery ground via a 0.1-µF capacitor in a way as short as possible, perhaps to the metal housing. In order to avoid thermal problems, the voltage divider and driving resistors should be kept away from the IC. Otherwise they would heat up the environment of the small IC and might reduce its life expectancy. Figure 7-1. Comparator Thresholds V 5 RxN 4 3 2 1 0 5 10 15 20 25 30 35 VCC F1 F0 not ER Uref 9 4749D–AUTO–10/07 Figure 7-2. Test Circuit Equivalents VCC H' 300 H 300 2/3 VCC Switches are closed in the dominant state 1/3 VCC 300 L' L 300 Ideal test circuit equivalent 38k F1 VCC 4k54 0.946 V 220 H 300 2/3 VCC Switches are closed in the dominant state 1/3 VCC 270 L 300 38k F0 4k54 0.946 V Real test circuit equivalent 2CHL H CH0 L CL0 Capacitance H: CHgnd = CH0 + 2 CHL