september 1994 7-69 philips semiconductors objective speci?cation can controller interface pca82C250 features fully compatible with the iso/dis 11898 standard high speed (up to 1 mbaud) bus lines protected against transients in an automotive environment slope control to reduce radio frequency interference (rfi) differential receiver with wide common-mode range for high immunity against electromagnetic interference (emi) thermally protected short-circuit proof to battery and ground low current standby mode an unpowered node does not disturb the bus lines at least 110 nodes can be connected. applications high-speed applications (up to 1 mbaud) in cars. general description the pca82C250 is the interface between the can protocol controller and the physical bus. the device provides differential transmit capability to the bus and differential receive capability to the can controller. quick reference data ordering information symbol parameter conditions min. max. unit v cc supply voltage 4.5 5.5 v i cc supply current - 170 m a 1/t bit maximum transmission speed non-return-to-zero 1 - mbaud v can canh, canl input/output voltage - 8 +18 v d v differential bus voltage 1.5 3.0 v t pd propagation delay high-speed mode - 50 ns t amb operating ambient temperature - 40 +125 c type number package pins pin position material code pca82C250 8 dip8 plastic sot97-1 pca82C250t 8 so8 plastic sot96-1
september 1994 7-70 philips semiconductors objective speci?cation can controller interface pca82C250 block diagram fig.1 block diagram. pinning symbol pin description txd 1 transmit data input gnd 2 ground v cc 3 supply voltage rxd 4 receive data output v ref 5 reference voltage output canl 6 low level can voltage input/output canh 7 high level can voltage input/output rs 8 slope resistor input fig.2 pin configuration.
september 1994 7-71 philips semiconductors objective speci?cation can controller interface pca82C250 functional description the pca82C250 is the interface between the can protocol controller and the physical bus. it is primarily intended for high-speed applications (up to 1 mbaud) in cars. the device provides differential transmit capability to the bus and differential receive capability to the can controller. it is fully compatible with the iso/dis 11898 standard. a current limiting circuit protects the transmitter output stage against short-circuit to positive and negative battery voltage. although the power dissipation is increased during this fault condition, this feature will prevent destruction of the transmitter output stage. if the junction temperature exceeds a value of approximately 160 c, the limiting current of both transmitter outputs is decreased. because the transmitter is responsible for the major part of the power dissipation, this will result in a reduced power dissipation and hence a lower chip temperature. all other parts of the ic will remain in operation. the thermal protection is particularly needed when a bus line is short-circuited. the canh and canl lines are also protected against electrical transients which may occur in an automotive environment. pin 8 (rs) allows three different modes of operation to be selected: high-speed, slope control or standby. for high-speed operation, the transmitter output transistors are simply switched on and off as fast as possible. in this mode, no measures are taken to limit the rise and fall slope. use of a shielded cable is recommended to avoid rfi problems. the high-speed mode is selected by connecting pin 8 to ground. for lower speeds or shorter bus length, an unshielded twisted pair or a parallel pair of wires can be used for the bus. to reduce rfi, the rise and fall slope should be limited. the rise and fall slope can be programmed with a resistor connected from pin 8 to ground. the slope is proportional to the current output at pin 8. if a high level is applied to pin 8, the circuit enters a low current standby mode. in this mode, the transmitter is switched off and the receiver is switched to a low current. if dominant bits are detected (differential bus voltage >0.9 v), rxd will be switched to a low level. the microcontroller should react to this condition by switching the transceiver back to normal operation (via pin 8). because the receiver is slow in standby mode, the first message will be lost. table 1 truth table of can transceiver. table 2 rs (pin 8) summary. supply txd canh canl bus state rxd 4.5 to 5.5 v 0 high low dominant 0 4.5 to 5.5 v 1 (or ?oating) ?oating ?oating recessive 1 <2 v (not powered) x ?oating ?oating recessive x 2v0.75v cc ?oating ?oating recessive x 2v 0.75v cc ?oating if v rs > 0.75v cc recessive x condition forced at rs mode resulting voltage or current at rs v rs > 0.75v cc standby i rs < |10 m a| - 10 m a september 1994 7-72 philips semiconductors objective speci?cation can controller interface pca82C250 limiting values in accordance with the absolute maximum rating system (iec 134). all voltages are referenced to pin 2; positive input current. note 1. in accordance with iec 747-1 . an alternative definition of virtual junction temperature t vj is: t vj =t amb +p d r th vj-amb , where r th vj-amb is a fixed value to be used for the calculation of t vj . the rating for t vj limits the allowable combinations of power dissipation (p d ) and ambient temperature (t amb ). handling classification a: human body model; c = 100 pf; r = 1500 w ; v = 2000 v. classification b: machine model; c = 200 pf; r = 0 w ; v = 200 v. quality specification quality specification snw-fq-611 part e is applicable and can be found in the quality reference pocket-book (ordering number 9398 510 34011). thermal characteristics symbol parameter conditions min. max. unit v cc supply voltage - 0.3 +9.0 v v n dc voltage at pins 1, 4, 5 and 8 - 0.3 v cc + 0.3 v v 6,7 dc voltage at pins 6 and 7 0v82C250 100 k/w pca82C250t 160 k/w
september 1994 7-73 philips semiconductors objective speci?cation can controller interface pca82C250 characteristics v cc = 4.5 to 5.5 v; t amb = - 40 to +125 c; r l =60 w ; i 8 > - 10 m a; unless otherwise speci?ed. all voltages referenced to ground (pin 2); positive input current; all parameters are guaranteed over the ambient temperature range by design, but only 100% tested at +25 c. symbol parameter conditions min. typ. max. unit supply i 3 supply current dominant; v 1 =1v -- 70 ma recessive; v 1 =4v; r 8 =47k w -- 14 ma recessive; v 1 =4v; v 8 =1v -- 18 ma standby; t amb <90 c; note 1 - 100 170 m a dc bus transmitter v ih high level input voltage output recessive 0.7v cc - v cc + 0.3 v v il low level input voltage output dominant - 0.3 - 0.3v cc v i ih high level input current v 1 =4v - 200 - +30 m a i il low level input voltage v 1 = 1 v 100 - 600 m a v 6,7 recessive bus voltage v 1 = 4 v; no load 2.0 - 3.0 v i lo off-state output leakage current - 2v<(v 6, v 7 )<7v - 2 - +1 ma - 5v<(v 6, v 7 ) < 18 v - 5 - +12 ma v 7 canh output voltage v 1 = 1 v 2.75 - 4.5 v v 6 canl output voltage v 1 = 1 v 0.5 - 2.25 v d v 6,7 difference between output voltage at pins 6 and 7 v 1 = 1 v 1.5 - 3.0 v v 1 = 1 v; r l =45 w ; v cc 3 4.9 v 1.5 -- v v 1 = 4 v; no load - 500 - +50 mv i sc7 short-circuit canh current v 7 = - 5 v; v cc 5v -- 105 ma v 7 = - 5 v; v cc = 5.5 v -- 120 ma i sc6 short-circuit canl current v 6 =18v -- 160 ma dc bus receiver: v 1 = 4 v; pins 6 and 7 externally driven; - 2v<(v 6, v 7 ) < 7 v; unless otherwise speci?ed v diff(r) differential input voltage (recessive) - 1.0 - 0.5 v - 7v<(v 6, v 7 ) < 12 v; not standby mode - 1.0 - 0.4 v v diff(d) differential input voltage (dominant) 0.9 - 5.0 v - 7v<(v 6, v 7 ) < 12 v; not standby mode 1.0 - 5.0 v v diff(hys) differential input hysteresis see fig.5 - 150 - mv v oh high level output voltage (pin 4) i 4 = - 100 m a 0.8v cc - v cc v v ol low level output voltage (pin 4) i 4 =1ma 0 - 0.2v cc v i 4 =10ma 0 - 1.5 v r i canh, canl input resistance 5 - 25 k w
september 1994 7-74 philips semiconductors objective speci?cation can controller interface pca82C250 note 1. i 1 =i 4 =i 5 = 0 ma; 0v september 1994 7-75 philips semiconductors objective speci?cation can controller interface pca82C250 fig.3 test circuit for characteristics. fig.4 timing diagram for dynamic characteristics.
september 1994 7-76 philips semiconductors objective speci?cation can controller interface pca82C250 fig.5 hysteresis. fig.6 timing diagram for wake-up from standby. v 1 =1v.
september 1994 7-77 philips semiconductors objective speci?cation can controller interface pca82C250 fig.7 timing diagram for bus dominant to rxd low. v 1 = 4 v; v 8 = 4 v. fig.8 test circuit for schaffner pulses.
september 1994 7-78 philips semiconductors objective speci?cation can controller interface pca82C250 application information fig.9 application of the can transceiver.
september 1994 7-79 philips semiconductors objective speci?cation can controller interface pca82C250 b b fig.10 application with galvanic isolation.
september 1994 7-80 philips semiconductors objective speci?cation can controller interface pca82C250 internal pin configuration b b fig.11 internal pin configuration.
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