National DS36C278 manual Parameter Measurement Information, Figures 12

Switching Characteristics (Continued)

Over Supply Voltage and Operating Temperature ranges, unless otherwise specified (Notes 3 and 8)

Symbol	Parameter	Conditions	Reference	Min	Typ	Max	Units
RECEIVER CHARACTERISTICS
tPHL	Propagation Delay	CL e 15 pF		30	210	400	ns
	High to Low
			Figures 12, 13
tPLH	Propagation Delay			30	190	400	ns
	Low to High
tSK	Skew, ltPHL b tPLHl			0	20	50	ns
tPLZ	Output Disable Time	CL e 15 pF		—	50	150	ns
tPHZ			Figures 14, 15, 16	—	55	150	ns
tPZL	Output Enable Time			—	40	150	ns
tPZH				—	45	150	ns

Note 1: ‘‘Absolute Maximum Ratings’’ are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the devices should be operated at these limits. The table of ‘‘Electrical Characteristics’’ specifies conditions of device operation.

Note 2: Current into device pins is defined as positive. Current out of device pins is defined as negative. All voltages are referenced to ground except VOD1 and VOD2.

Note 3: All typicals are given for: VCC e a5.0V, TA e a 25§C.

Note 4: Delta lVOD2l and Delta lVOCl are changes in magnitude of VOD2 and VOC, respectively, that occur when input changes state.

Note 5: Threshold parameter limits specified as an algebraic value rather than by magnitude.

Note 6: Hysteresis defined as VHST e VTH b VTL.

Note 7: IIN includes the receiver input current and driver TRI-STATE leakage current.

Note 8: CL includes probe and jig capacitance.

Note 9: For complete details of test, see RS-485.

Parameter Measurement Information

TL/F/12040 – 18

TL/F/12040 – 2	FIGURE 2. Driver VOD3
FIGURE 1. Driver VOD2 and VOC

	TL/F/12040 – 3	TL/F/12040 – 4
FIGURE 3. Driver VOH and VOL		Vtest e b7V to a12V
		FIGURE 4. Driver IOSD

TL/F/12040 – 5

	FIGURE 5. Driver Differential Propagation Delay Test Circuit
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