MAX14883E CAN Transceiver with ±60V Fault Protection and Selectable Polarity

Transcription

1 EALUATION KIT AAILABLE MAX14883E CAN Transceiver with ±6 General Description The MAX14883E fault-protected, high-speed Control Area Network (CAN) transceiver is optimized for industrial network applications. This device features ±6 fault protection, a ±25 functional common mode input range, and high ±1k ESD protection (contact discharge) on the CANH and CANL bus. The device operates from a single 5 supply ( CC ) and includes a logic-level supply input ( L ) for interfacing with 1.8 to 5 logic. The MAX14883E features a polarity selection input (POL) that swaps the CANH and CANL I/Os, allowing for software correction of cross-wired field cables. The MAX14883E operates at the maximum CAN highspeed data rate, allowing up to 1Mbps on small networks. The maximum speed on large networks may be limited by capacitive loading and other factors. The transceiver includes a transmitter dominant timeout (t DOM ) to prevent bus lockup caused by controller error or by a fault on the input. When remains in the dominant state (low) for longer than t DOM, the driver is switched to the recessive state, releasing the bus. The MAX14883E is available in a narrow, 8-pin SOIC package and operates over the -4 C to +125 C temperature range. Benefits and Features Integrated Protection for Robust Communication ±6 Fault Tolerant CANH and CANL High ESD Protection on CANH and CANL -- ±22k Human Body Model -- ±15k IEC Air Gap -- ±1k IEC Contact Discharge Flexible Logic Interface Simplifies Designs 1.71 to 5.5 Logic-Supply ( L ) Range High Integration Allows Simplified Network Configuration Polarity Control Dominant Timeout Protection Capable of Data Rates Up to 1Mbps Applications Industrial Controls Building Automation HAC Switch Gear Ordering Information appears at end of data sheet. Simplified Block Diagram DD -DOMINANT TIMEOUT DD MAX14883E PROTECTION CANH LEEL SHIFTER PROTECTION CANL POL POLARITY SELECT CONTROL GND ; Rev ; 12/16

2 Absolute Maximum Ratings (All voltages referenced to GND, unless otherwise noted) DD to +6 CANH or CANL (Continuous) to +63, POL to 6 L to ( DD +.5) to L +.3 Continuous Power Dissipation Single-Layer Board (T A = +7 C, derate 5.9mW/ C above +7 C.) mW Multilayer Board (T A = +7 C, derate 7.6mW/ C above +7 C.) mW Operating Temperature Range...-4 C to 125 C Junction Temperature C Storage Temperature Range C to +15 C Lead Temperature (soldering, 1s)...+3 C Soldering Temperature (reflow) C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Package Information 8 SOIC PACKAGE CODE S8+4 Outline Number Land Pattern Number 9-96 Thermal Resistance, Single-Layer Board: Junction to Ambient (θ JA ) 17 Junction to Case (θ JC ) 4 Thermal Resistance, Four-Layer Board: Junction to Ambient (θ JA ) 132 Junction to Case (θ JC ) 38 For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to Maxim Integrated 2

3 DC Electrical Characteristics ( DD = 4.5 to 5.5, L = 1.71 to DD, R L = 6Ω, C L = 15pF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at DD = 5, L = 3.3, and T A = +25 C, unless otherwise specified. (Note 1)) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS POWER Power Supply Input DD Logic-Level oltage Supply Input L 1.71 DD DD = 5, No load = low R L = 6Ω Supply Current I DD No load 3.2 ma DD = 5, = high CANH shorted 3.2 to CANL L = No load on Logic-Level Supply Current I L L = µa L = DD UO Threshold UO_R DD rising 4.25 UO_F DD falling 3.45 LOGIC INTERFACE (,, POL) Input High oltage IH.7 x L 2.25 L Input Low oltage IL 1.71 L < Output High oltage OH I SOURCE = 4mA L -.4 Output Low oltage OL I SINK = 4mA.4 Input Pullup Resistance R PU_ 1 25 kω POL Input Pulldown Resistance R PD_POL 1 25 kω Input Capacitance 5 pf CAN BUS DRIER Single-Ended oltage = low, CANH Ouptut (Dominant State) OD R L = 6Ω CANL Differential oltage Output (Dominant State) Single-Ended oltage Ouptut (Recessive State) Differential oltage Output (Recessive State) DIFF OR ODR = low, R L = 6Ω = high, no load = high R CM = 156Ω, -5 CM +1, Figure R CM is open CANH 2 3 CANL 2 3 R L = 6Ω No load m Maxim Integrated 3

4 DC Electrical Characteristics (continued) ( DD = 4.5 to 5.5, L = 1.71 to DD, R L = 6Ω, C L = 15pF, T A = T MIN to T MAX, unless otherwise noted. Typical values are at DD = 5, L = 3.3, and T A = +25 C, unless otherwise specified. (Note 1)) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS High-Side Short-Circuit Current Low-Side Short-Circuit Current I SC_H I SC_L = low = low RECEIER ( = High, CANH and CANL Externally Driven) Common Mode Input Range Differential Input oltage Threshold (Recessive) Differential Input oltage Threshold (Dominant) Differential Input Hysteresis CANH and CANL Input Resistance Differential Input Resistance CANH or CANL to GND, output valid POL = low, CANH is shorted to GND POL = high, CANL is shorted to GND POL= low, CANL is shorted to DD POL = high, CANH is shorted to DD ma ma DIFF_R = high.5 DIFF_D = high.9 DIFF(HYST) 13 m R IN = high 1 5 kω R DIFF = high 2 1 kω Input Leakage Current I LKG DD = L =, CAN_ = 5 31 ua Input Capacitance C IN CANH or CANL to GND (Note 2) pf Differential Input Capacitance C IN_DIFF CANH to CANL (Note 2) pf PROTECTION IEC Air Gap Discharge ±15 ESD Protection (CANH, CANL to GND) IEC Contact Discharge ±1 k Human Body Model ±22 ESD Protection Human Body Model ±4 k (All Other Pins) Machine Model ±4 Fault Protection Range FAULT CANH or CANL to GND Thermal Shutdown T SHDN Junction temperature rising 16 C Thermal Shutdown Hysteresis T HYST 2 C Maxim Integrated 4

5 AC Electrical Characteristics Switching ( DD = 4.5 to 5.5, L = 1.71 to 5.5, R L = 6Ω, C L = 15pF, T A = T MIN to T MAX, unless otherwise specified. Typical values are at DD = 5, L = 3.3, and T A = +25 C, unless otherwise specified. (Note 1)) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Driver Rise Time t R R L = 6Ω, C L = 1pF, R CM is open, Figure 1 Driver Fall Time t F R L = 6Ω, C L = 1pF, R CM is open, Figure 1 to Loop Delay t LOOP R L = 6Ω, Dominant to Recessive and Recessive to Dominant, Figure 2 Propagation Delay (Recessive to Dominant) Propagation Delay (Dominant to Recessive) Propagation Delay (Recessive to Dominant) Propagation Delay (Dominant to Recessive) t ON t OFF R L = 6Ω, C L = 1pF, R CM is open, Figure 1 R L = 6Ω, C L = 1pF, R CM is open, Figure 1 Note 1: All units are 1% production tested at T A = +25 C. Specifications over temperature are guaranteed by design. Note 2: Not production tested. Guaranteed at T A = 25 C. 2 ns 33 ns 3 ns 9 ns 9 ns t ON C L = 15pF, Figure 3 21 ns t OFF C L = 15pF, Figure 3 21 ns -Dominant TimeOut t DOM Figure ms RCM RL CL DIFF RCM CM 5% 5% DIFF ton.9 9% 1%.5 toff tr tf Figure 1. Transmitter Test Circuit and Timing Diagram Maxim Integrated 5

6 CANH RL CLD 5% CANL tloop2 5% tloop1 CL Figure 2. to Loop Delay + ID - CANH CANL CL ID ton toff OH 5% 5% OL Figure 3. Timing Diagram tdom TRANSMITTER DISABLED TRANSMITTER ENABLED CANH-CANL Figure 4. Transmitter-Dominant Timeout Timing Diagram Maxim Integrated 6

7 Typical Operating Characteristics ( DD = 5, L = 3.3, 6Ω load between CANH and CANL, T A = 25 C, unless otherwise noted.) IDD (ma) DD = 5 = DD DD SUPPLY CURRENT vs. TEMPERATURE = LOW, 6Ω LOAD = HIGH = LOW, NO LOAD toc TEMPERATURE (ºC) MEAN SUPPLY CURRENT (ma) DD SUPPLY CURRENT vs. DATA RATE SWITCHING AT 5% NO LOAD R L = 6Ω toc DATA RATE (kbps) CAN_ OUTPUT OLTAGE () CANH/CANL OUTPUT OLTAGE vs. TEMPERATURE = LOW TEMPERATURE (ºC) CANH, 6Ω LOAD CANL, 6Ω LOAD toc3 CANH SOURCE CURRENT (ma) CANH OUTPUT SHORT CIRCUIT CURRENT vs. OLTAGE = LOW CANH OLTAGE () toc4 CANL SINK CURRENT (ma) CANL OUTPUT SHORT CIRCUIT CURRENT vs. OLTAGE = LOW CANL OLTAGE () toc5 PROPAGATION DELAY (ns) PROPAGATION DELAY vs. TEMPERATURE TEMPERATURE (ºC) t ON t OFF toc6 PROPAGATION DELAY (ns) PROPAGATION DELAY vs. TEMPERATURE TEMPERATURE (ºC) t ON t OFF toc7 DIFFERENTIAL OLTAGE () (CANH-CANL) DIFFERENTIAL OUTPUT OLTAGE vs. LOAD toc DIFFERENTIAL LOAD RESISTANCE (Ω) RECEIER HYSTERESIS (m) RECEIER INPUT HYSTERESIS vs. TEMPERATURE TEMPERATURE (ºC) toc9 Maxim Integrated 7

8 Pin Configuration TOP IEW POL GND 2 MAX14883E 7 CANH DD 3 6 CANL 4 5 SOIC Pin Description PIN NAME FUNCTION 1 Transmit Data Input. Drive high to set the driver in the recessive state. Drive low to set the driver in the dominant state. has an internal pullup to L. 2 GND Ground. 3 DD Power Supply Input. Bypass DD to GND with a.1μf capacitor as close to the device as possible. 4 Receive Data Output. is high when CANH and CANL are in the recessive state. is low when CANH and CANL are in the dominant state. is referenced to L. Logic-Level oltage Supply Input. Bypass 5 L to GND with a.1μf capacitor as close to the device L as possible. 6 CANL CAN Bus Line Low. CANL is the low-side input/output of the receiver/driver. Drive POL high to set CANL as the high-side input/output of the receiver/driver. 7 CANH CAN Bus Line High. CANH is the high-side input/output of the differential receiver/driver. Drive POL high to set CANH as the low-side input/output. 8 POL Polarity Select Input. Drive POL low for normal CANH/CANL operation. Drive POL high to switch CANH/CANL operation. POL does not change the dominant and recessive states of and. POL has an internal 1kΩ (min) pulldown to GND. Maxim Integrated 8

9 Detailed Description The MAX14883E fault-protected CAN transceiver is optimized for industrial network applications and operates from a 5 supply. The MAX14883E features a ±25 common mode input range and is protected against shorts up to ±6 on the CAN bus (CANH, CANL), making it ideal for operating in harsh industrial environments. The MAX14883E operates at the maximum high-speed CAN data rate, allowing up to 1Mbps on small networks. The maximum speed on large networks may be limited by capacitive loading and other factors. Networks of up to 17 MAX14883E transceivers can operate up to 1Mbps. Larger networks of up to 12 MAX14883E transceivers can operate up to data rates of 125kbps. CANH and CANL outputs are short-circuit current-limited and are protected against excessive power dissipation by thermal shutdown circuitry that places the driver outputs in a high-impedance state. Transmitter The transmitter converts a single-ended input signal () from the CAN controller to differential outputs for the bus lines (CANH, CANL). The truth table for the transmitter and receiver is given in Table 1. Transmitter-Dominant Timeout The MAX14883E features a transmitter dominant timeout (t DOM ) that prevents erroneous CAN controllers from clamping the bus to a dominant level by maintaining a continuous low signal. When remains in the dominant state (low) for greater than t DOM, the transmitter is disabled, releasing the bus to a recessive state (Figure 4). After a dominant timeout fault, the transmitter is re-enabled when receiving a rising edge at. The transmitter dominant timeout limits the minimum possible data rate to 9kbps for standard CAN protocol. Driver Output Protection The MAX14883E protects the transmitter output stage against a short-circuit to a positive or negative voltage by limiting the driver current. Thermal shutdown further protects the MAX14883E from excessive temperatures that may result from a short. The transmitter returns to normal operation once the short is removed. Receiver The receiver reads the differential input from the bus (CANH, CANL) and transfers this data as a single-ended output () to the CAN controller. It consists of a comparator that senses the difference DIFF = (CANH- CANL), with respect to an internal threshold of.7. If DIFF >.9, a logic-low is present on. If DIFF <.5, a logic-high is present. The CANH and CANL common-mode range is ±25. is logic-high when CANH and CANL are shorted or terminated and undriven. Polarity Selection A polarity select input (POL) switches the state of the CANH and CANL drivers. Polarity selection allows for software correction of cross-wired field cables, ensuring that the transmitter continues to operate correctly in the field. See Table 1 for detailed operation. Thermal Shutdown If the junction exceeds +16 C (typ), the device is switched off. During thermal shutdown, CANH and CANL are high-impedance and all IC functions are disabled. The transmitter outputs are re-enabled and the device resumes normal operation when the junction temperature drops below 145 C (typ). Table 1. Transmitter and Receiver Truth Table (When Not Connected to the Bus) POL LOW TIME CANH CANL BUS STATE LOW LOW < t DOM HIGH LOW DOMINANT LOW LOW LOW > t DOM DD /2 DD /2 RECESSIE HIGH LOW HIGH X DD /2 DD /2 RECESSIE HIGH HIGH LOW < t DOM LOW HIGH DOMINANT LOW HIGH LOW > t DOM DD /2 DD /2 RECESSIE HIGH HIGH HIGH X DD /2 DD /2 RECESSIE HIGH Maxim Integrated 9

10 Applications Information Reduced EMI and Reflections In multidrop CAN applications, it is important to maintain a single linear bus of uniform impedance that is properly terminated at each end. See Figure 5 for an example network. A star configuration should never be used. Any deviation from the end-to-end wiring scheme creates a stub. High-speed data edges on a stub can create reflections back down the bus. These reflections can cause data errors by eroding the noise margin of the system. Although stubs are unavoidable in a multidrop system, care should be taken to keep these stubs as small as possible, especially when operating with high data rates. Typical Application Circuits Figure 5. Multidrop CAN Bus Ordering Information PART TEMP RANGE PIN- PACKAGE MAX14883EASA+ -4 C to +125 C 8 SOIC MAX14883EASA+T -4 C to +125 C 8 SOIC Maxim Integrated 1

11 Revision History REISION NUMBER REISION DATE DESCRIPTION PAGES CHANGED 12/16 Initial release For pricing, delivery, and ordering information, please contact Maxim Direct at , or visit Maxim Integrated s website at Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 216 Maxim Integrated Products, Inc. 11