National CP3BT26 - Manual (Page 261)

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CP3
BT26
30.13 USB PORT AC CHARACTERISTICS
30.14 MULTI-FUNCTION TIMER (MFT) TIMING
Figure 129. Multi-Function Timer Input Timing
Table 90 USB Port Signals
Symbol Description Conditions a Min Typ Max Units
T
R
Rise Time C
L
= 50 pF 4 20 ns
T
F
Fall Time C
L
= 50 pF 4 20 ns
T
RFM
Fall/Rise Time Matching (T
R
/T
F
) C
L
= 50 pF 90 110 %
V
CRS
Output Signal Crossover Voltage C
L
= 50 pF 1.3 2.0 V
Z
DRV
Driver Output Impedance C
L
= 50 pF 28 43 ohms
a. Waveforms measured at 10% to 90%.
Table 91 Multi-Function Timer Input Signals
Symbol Figure Description Reference Min (ns) Max (ns)
t
TAH
129 TA High Time Rising Edge (RE) on CLK T
CLK
+ 5
t
TAL
129 TA Low Time RE on CLK T
CLK
+ 5
t
TBH
129 TB High Time RE on CLK T
CLK
+ 5
t
TBL
129 TB Low Time RE on CLK T
CLK
+ 5
t TAL /t TBL
CLK
TA/TB
DS169
t TAL /t TBH