30.13USB PORT AC CHARACTERISTICS

Table 90 USB Port Signals

Symbol

Description

Conditionsa

Min

Typ

Max

Units

TR

Rise Time

CL = 50 pF

4

 

20

ns

TF

Fall Time

CL = 50 pF

4

 

20

ns

TRFM

Fall/Rise Time Matching (TR/TF)

CL = 50 pF

90

 

110

%

VCRS

Output Signal Crossover Voltage

CL = 50 pF

1.3

 

2.0

V

ZDRV

Driver Output Impedance

CL = 50 pF

28

 

43

ohms

a. Waveforms measured at 10% to 90%.

30.14MULTI-FUNCTION TIMER (MFT) TIMING

Table 91 Multi-Function Timer Input Signals

Symbol

Figure

Description

Reference

Min (ns)

Max (ns)

 

 

 

 

 

 

tTAH

129

TA High Time

Rising Edge (RE) on CLK

TCLK + 5

 

tTAL

129

TA Low Time

RE on CLK

TCLK + 5

 

tTBH

129

TB High Time

RE on CLK

TCLK + 5

 

tTBL

129

TB Low Time

RE on CLK

TCLK + 5

 

CLK

tTAL /tTBL

 

tTAL /tTBH

TA/TB

DS169

Figure 129. Multi-Function Timer Input Timing

CP3BT26

261

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National CP3BT26 manual USB Port AC Characteristics, MULTI-FUNCTION Timer MFT Timing