UNIVERSAL SERIAL BUS INTERFACE

(see Chapter 7 of USB rev 1.0 for complete Electrical Specification)

Nominal DC Characteristics (D+, D-)

Symbol

Parameter

Min.

Typ.

Max.

Unit

Differential Input Sensitivity [(D+) - (D-)]

0.2

V

Differential Common Mode Range

0.8

2.5

V

Single Ended Receiver Threshold

0.8

2

V

High Level Output Static Voltage (RL of 15k

Ω to GND)

Low Level Output Static Voltage (RL of 1.5k

Ω to 3.6V)

2.8

3.6

0.3

V

V

±10

µA

Transceiver Capacitance (Pin to GND)

20

pF

Driver Output Resistance (steady state drive)

TBD

TBD

Ω

Note 2 :

Excludes external resistor. In order to comply with USB Specifications 1.0, external series resistors of 27

Ω ±1% each on D+ and D-

are recommended

AC Characteristics (D+, D-) (see Figure 5 for test scheme)

Symbol

Parameter

Min.

Typ.

Max.

Unit

Average bit rate (12 M/s

± 0.05%)

11.97

12.03

Mbps

Rise Time between 10% and 90% (see Figure 6)

4

20

ns

Fall Time 10% and 90% (see Figure 6)

4

20

ns

Output Signal Crossover Voltage

1.3

2

V

1

2

15k

W

50pF

15k

W

50pF

Test

1.5k

W

V

REGD

27

W

Test

D+

D-

27

W

Figure 5 : Test Scheme for D+/D-

t

R

t

F

90%

10%

90%

10%

Figure 6 : Rise and Fall Time Measures

ST7554

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