USB 2.0 compliance measurements

As the Intona USB 2.0 Hi-Speed isolator is a design from scratch, not using any ready-made USB isolation chips, we were often asked about USB-compliance, signal quality and clock jitter. In the following, we have published our compliance tests for the isolated side.

For details on test setup, methodology, and performance criteria, please consult the signal quality test description at the USB-IF Compliance Program. We tested using a LeCroy Serial Data Analyzer. You can find the corresponding test sheet here.

USB Test No.	Description	Requirement	Result	Conclusion
EL_21	Sync Field	X = 31	X = 31	Passed
EL_22	Inter-packet Gap #2	X = 8 bits < X < 192 bits	same as host	Passed
EL_23	Inter-packet Gap #1	88 bits < X < 192 bits	same as host	Passed
EL_25	EOP Width	X > 7.5 bits	X = 7.97 bits	Passed
EL_33	Chirp Response time	X < 100us	X = 50.3us	Passed
EL_34	Chirp JK Duration	40us < X < 60us	X = 50us	Passed
EL_35	Chirp JK->SOF time	100us < X < 500us	X = 101.1483us	Passed
EL_39	Host Suspend time	3.0ms < X < 3.125ms	X = 3.052ms	Passed
EL_41	Host Resume time	X < 3ms	X = 1.369us	Passed
EL_55	SOF EOP Width	X > 40 bits	X = 40.1 bits	Passed
EL_28	Chirp-K Latency	2.5us < X < 6.0ms	X = 3.02us	Passed
EL_29	Chirp-K Duration	1.0ms < X < 7.0ms	X = 2.76ms	Passed
EL_31	Device Turn On	X < 500us	X = 573ns	Passed

Table 1: USB Compliance Electrical Test

Description	Result	Conclusion
Signal eye	see diagram	Passed
EOP width	7.97 bits	Passed
Measured signaling rate	479.9464 MHz	Passed
Rising Edge Rate	1233.48 V/us (518.86 ps equivalent risetime)	Passed
Falling Edge Rate	1256.71 V/us (509.27 ps equivalent risetime)	Passed

Table 2: USB Near End High Speed Signal Quality Test of Isolated Side

Description	Range Min	Range Max	RMS
Consecutive Jitter	-31.061ps	30.560ps	12.512ps
Paired JK Jitter	-30.454ps	32.848ps	8.833ps
Paired KJ Jitter	-41.908ps	32.871ps	9.087ps

Table 3: Additional Information (Isolated Side)

Overall result: pass!

Signal Eye (Isolated Side):