Features • • • • • • • • Wide Power Supply Voltage Range Short-circuit Protected K-interface, ISO9141 Compatible Three Short-circuit Protected 40-mA Open-collector Buffers All Low-power Outputs with Built-in 28-V Clamping CMOS Compatible Digital Inputs with Hysteresis Digital 1-mA Push-pull "RxD" K-line Output Channel-specific Over-temperature Switch Off in Event of Short Circuit Load-dump Protection and Interference Protection According to ISO 7637-1/4 (DIN 40839) Description The U6812B is a bipolar monolithic K-line bus transceiver designed to provide bi-directional serial communication in automotive diagnostic applications. The standard K-line is ISO 9141 compatible for baud rates up to 250 kBaud. The IC provides three universally applicable 40-mA open-collector buffers, that can be used for signal decoupling. The U6812B is manufactured using Atmel’s bipolar process and fully complies to automotive industry specifications.The U6812B provides an ideal grouping of SO-packaged low-power drivers, thus meeting customers’ demand for space-saving and cost-effective circuit board assembly. Single-ended Bus Transceiver with Triple Buffer U6812B Figure 1. Block Diagram VS VCC VS K-diagnosis ISO 9141 TXD VCC K VS/2 GND TXD VCC/2 OUT 1 IN 1 VCC/2 GND VCC IN 2 Temperature control OUT 2 GND DIS OUT 3 IN 3 GND Rev. 4760A–AUTO–10/03 Pin Configuration Figure 2. Pinning SO16 GND 1 16 GND OUT 2 2 15 K IN 2 3 14 TXD DIS 4 13 RXD VS U6812B VCC 5 12 IN 3 6 11 IN 1 OUT 3 7 10 OUT 1 GND 8 9 GND Pin Description Pin 2 Symbol Type Function 1 GND Supply 2 OUT 2 Open-collector output Ground; all ground pins are directly connected to the lead frame 3 IN 2 Digital input Input of protected driver 2 (faced to: µP) 4 DIS Digital input Disable input for OUT 2 and OUT 3, “H”=enable, “L”=disable 5 VCC Supply 6 IN 3 Digital input 7 OUT 3 Open-collector output 8 GND Supply Protected output of driver 2 (faced to: outside) +5-V supply Input of protected driver 3 (faced to: µP) Protected output of driver 3 (faced to: outside) Ground 9 GND Supply 10 OUT 1 Open-collector output Ground 11 IN 1 Digital input 12 VS Supply/reference 13 RXD Digital output Diagnosis receive line (faced to: µP) 14 TXD Digital input Diagnosis transmit line (faced to: µP) 15 K 12-V input and O.C. output 16 GND Supply Protected output of driver 1 (faced to: outside) Input of protected driver 1 (faced to: µP) +12-V reference for K-line level Bi-directional diagnosis line (faced to: outside) Ground U6812B 4760A–AUTO–10/03 U6812B Figure 3. Basic Application Circuit VBatt D1 C1 10 µ + R1 1k K C2 TXD RXD IN 1 OUT 1 VS 16 15 14 13 12 11 10 9 6 7 8 U6812B 1 2 3 4 5 IN 2 OUT 3 DIS OUT 2 VCC IN 3 3 4760A–AUTO–10/03 Functional Description K-interface The K-interface is equipped with a 40-mA open-collector driver. The current is determined by the external pull-up resistor. The saturation voltage is below 0.6 V. The open-collector output is protected by a 28-V Z-diode. The collector current is permanently monitored for short circuits via a built-in shunt. In the event of a short circuit occurring at VBatt, the collector current is held at approximately Icreg = 80 mA; the chip temperature then rises due to power loss. This status is maintained until the detection of overtemperature which causes the K-line output to be disabled and stored to memory. The internal short-circuit detection threshold is Isc > 0.8 ´ Icreg. The output remains disabled until a falling edge of a pulse is available to its input. Any further attempt to connect while the short circuit is still present causes the above sequence to be repeated. The output can be activated normally once the short circuit has been removed. The maximum baud rate is 250 kBaud. The K-line allows bi-directional communication with the microcontroller. When the output K is disabled, information can be transferred to the processor via the input comparator at pin RxD. The digital output RxD is a push-pull output stage with a driver power of 1 mA. In the event of a line break at the K-line, the output K is connected to GND via the builtin 85-kW pull-down resistor, thus allowing the microcontroller to detect this fault. The maximum sampling frequency is 250 kBaud. Open-collector Driver OUTx The outputs are designed for a maximum static current of 40 mA, which is determined by the external pull-up resistor. The saturation voltage is below 0.6 V The three OUTx-driver outputs are activated with "active low" at the corresponding input. Outputs OUT2 and OUT3 can also be disabled with "active low" at the disable input, regardless of their input signal. The outputs are released by an open disable input or by using high potential. The open-collector outputs are connected to a 28-V Z-diode. The collector current is permanently monitored via a built-in shunt circuit to permit the detection of short circuits. If a short circuit occurs at V Batt , the collector current is held at approximately Icreg = 80 mA; accompanied with a rise of chip temperature due to power loss. This status is maintained until the detection of overtemperature which causes the output affected by the short circuit to be selectively disabled and stored to memory. The internal short-circuit detection threshold is I sc > 0.8 ´ Icreg . The affected output remains disabled until a falling edge of a pulse is available to its input. Any further attempt to connect while the short circuit is still present causes the above sequence to be repeated. The output can be activated normally once the short circuit has been removed. Power Supply The IC must be equipped with external RC circuitry to limit the voltage in the event of power surges (see Figure 3 on page 3). This prevents the circuit from being damaged or destroyed, and provides a buffer in case of power fluctuations at VBatt. The RxD comparator is powered via pin VS, producing its reference voltage of 1/2 V S, while all other blocks are supplied via VCC. The operating voltage can vary between VS= 7 V and 26 V. The resistor R1 at pin VS limits the current via the built-in 28-V Z-diode between VS and GND. 4 U6812B 4760A–AUTO–10/03 U6812B Application Note It is recommended to use the external components as shown in Figure 3 on page 3 with the reverse battery protection diode D1 and the buffer capacitor C1 = 10 µF. Digital Inputs (DIS, IN 1, IN 2, IN 3 and TxD) The digital inputs are CMOS-compatible and equipped with a built-in pull-up resistor with a typical rating of 85 kW to VCC. The input threshold totals VTH = 0.57 ´ VCC with a typical hysteresis of 100 mV. The inputs are designed for an input voltage of -0.2 V to VCC + 0.6 V. For proper activation of the output stages, it is mandatory that the inputs are kept low as long as the supply voltage is not applied. When the supply voltage has been applied, all inputs need to have a falling edge (see “Timing Diagrams” on page 6). Digital Output (RxD) The digital output RxD is a push-pull output stage with a driver power of IRxD = 1 mA. Interference Voltages The U6812B is protected against interference pulses (usually present in the wiring) by and Load Dump (Defined the recommended R1C1 circuitry and the integrated elements (28-V Z-diodes, both at in DIN40839 or ISO7637) the supply pin and at the output pins and two diodes connected to VCC and GND at the digital inputs). All transient pulses, which appear on the supply line (VBatt), should not affect the function of the IC (see Table 1). Table 1. Transient Test Conditions Name Voltage Source Resistance Rise Time Pulse Duration Pulse Amount DIN/ISO 1 -110 V 10 W 100 V/µs 2 ms 15000 DIN/ISO 2 110 V 10 W 100 V/µs 0.05 ms 15000 DIN/ISO 3a -160 V 50 W 30 V/ns 0.1 µs 1 h (reference to ISO) DIN/ISO 3b 150 V 50 W 20 V/ns 0.1 µs 1 h (reference to ISO) DIN/ISO 5 55 V (total) 2W 10 V/ms 500 ms 20 Table 2. Truth Table WSI-1 WSI-2 WSI-R EN TXD K WSO-1 WSO-2 WSO-R RXD L L X H X X L L X X H H X X X X Open Open X X L L X L X X Open Open X X X X H X H Open X X Open H X X L X L L L X L L X X X X X H X X X H 5 4760A–AUTO–10/03 Timing Diagrams Figure 4. IN2/IN3 - Pulse Diagram VS IN2/IN3 DIS OUT2/OUT3 Short 150°C Temperature 140°C Figure 5. IN1 - Pulse Diagram VS IN1 OUT1 Short 150°C Temperature 140°C Figure 6. K-interface Pulse Diagram VS TxD K RxD Short 150°C Temperature 6 140°C U6812B 4760A–AUTO–10/03 U6812B 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 Symbol Value Unit Operating voltage VS 26 V Operating voltage VCC 3 to 6 V Voltage at pins IN1,2,3; RxD, TxD, DIS Vi -0.2 to +6 V Voltage at pins OUT1, 2, 3; K Vo -1 to +26 V Static collector current at pins OUT1,2,3; K Ix 45 mA Ambient temperature Tamb -40 to +125 °C Storage temperature range Tstg -55 to +150 °C Tj 150 °C Symbol Value Unit Junction to case RthJC 36 K/W Junction to ambient; strongly depending on the assembly RthJA 65 to 80 K/W Maximum junction temperature Thermal Resistance Parameters Electrical Characteristics Tamb = -40 to +125°C, VCC = 4.75 V to 5.25 V (unless otherwise specified), reference point is GND (pin 1, 7, 8, 16). IC with recommended external components (see Figure 3 on page 3). Parameters Test Conditions Symbol Min. Max. Unit Supply voltage VS 7 26 V Supply voltage VCC 4.5 5.5 V Vsat = 0.6 V at IX = 20 mA VCC 3.0 4.5 V All inputs open or high at VCC = 5.25 V IS 6 mA All inputs on (= low) at VCC = 5.25 V IS 20 mA Supply Reduced supply voltage Current consumption Pin Typ. 5, 12 Protective resistor R1 1 kW Smoothing capacitor C1 10 µF Integrated Z-diode IS = 20 mA VS Quiescent current All outputs low or open at VS = 18 V IVS Inputs IN 1, IN 2, IN 3, DIS, TxD 26 28 30 V 0.75 mA VCC + 0.6 V 170 kW 3, 4, 6, 11, 14 Input voltage Vi -0.2 Internal pull-up resistor Ri 30 85 7 4760A–AUTO–10/03 Electrical Characteristics (Continued) Tamb = -40 to +125°C, VCC = 4.75 V to 5.25 V (unless otherwise specified), reference point is GND (pin 1, 7, 8, 16). IC with recommended external components (see Figure 3 on page 3). Parameters Test Conditions Pin Symbol Min. Typ. Max. Unit Switchover threshold ViTH 0.57 ´ VCC V Hysteresis ViHYS 100 mV Outputs OUT 1, OUT 2, OUT 3 Integrated Z-diode 2, 7, 10 IOUTx = 20 mA Current regulation Saturation voltage IOUTx = 40 mA Output open, VS = 21 V 28 -1.0 ILeak 30 V 130 mA 0.6 V 26 V 2 µA 30 V 1 mA 13 IRxD = 20 mA VRxD Output current Saturation voltage IO 45 Vout Output RxD Integrated Z-diode 26 VOSAT Maximum voltage Leakage current VO 26 28 IRxD IRxD = 1 mA VRxDSAT Rise time tR 0.01 Fall time tF 0.01 K-line 0.5 V 5 µs 5 µs 15 0.57 ´ VS V Threshold VK Internal pull-down resistor RK 30 85 170 kW VK 26 28 30 V IK 45 130 mA 0.6 V 26 V Integrated Z-diode IK = 20 mA Current regulation Saturation voltage IK = 40 mA Maximum voltage Maximum baud rate 8 VKsat Vout IK = 40 mA, C2 = 20 nF C2 = 470 pF -1.0 14.4 250 kBaud kBaud U6812B 4760A–AUTO–10/03 U6812B Ordering Information Extended Type Number Package U6812B Remarks SO16/150 mil – Package Information Package SO16 Dimensions in mm 5.2 4.8 10.0 9.85 3.7 1.4 0.25 0.10 0.4 1.27 6.15 5.85 8.89 16 0.2 3.8 9 technical drawings according to DIN specifications 1 8 9 4760A–AUTO–10/03 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Regional Headquarters Europe Atmel Sarl Route des Arsenaux 41 Case Postale 80 CH-1705 Fribourg Switzerland Tel: (41) 26-426-5555 Fax: (41) 26-426-5500 Asia Room 1219 Chinachem Golden Plaza 77 Mody Road Tsimshatsui East Kowloon Hong Kong Tel: (852) 2721-9778 Fax: (852) 2722-1369 Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Atmel Operations Memory 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 RF/Automotive Theresienstrasse 2 Postfach 3535 74025 Heilbronn, Germany Tel: (49) 71-31-67-0 Fax: (49) 71-31-67-2340 Microcontrollers 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 La Chantrerie BP 70602 44306 Nantes Cedex 3, France Tel: (33) 2-40-18-18-18 Fax: (33) 2-40-18-19-60 ASIC/ASSP/Smart Cards 1150 East Cheyenne Mtn. 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