tc7wb66cfk TOSHIBA Semiconductor CORPORATION, tc7wb66cfk Datasheet - Page 8

• Manufacturer Part Number: tc7wb66cfk
• Description: Low Capacitance Dual Bus Switch Analog
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Rise and Fall Time (tr / tf) of the TC7WB66C
The tr(out) and tf(out) values of the output signals are affected by the CR time constant of the input, which consists of
the switch terminal capacitance (C
In practice, the tr(out) and tf(out) values are also affected by the circuit’s capacitance and resistance components other
than those of the TC7WB66C, 67C.
The tr / tf(out) values can be approximated as follows. (Figure 3 shows the test circuit.)
tr / tf(out) (approx) = – (C
Calculation example:
Calculation conditions:
tr / tf(out) (approx) = –( 10 + 15 )E–12･(120 + 4)･ln (((4.5 – 0) – 2.25 ) / (4.5 – 0))
V
Output voltage of the previous IC = digital (i.e., high-level voltage = V
CC
= 4.5 V, C
Previous IC
R
DRIVE
R
L
DRIVE
= 15 pF, R
= output impedance of the previous IC
≈ 2.1 ns
I/O
DRIVE
+ C
A/B
L
)･(R
I/O
= 120 Ω (output impedance of the previous IC), V
) and the on-resistance (R
DRIVE
(Switch On)
Previous IC
TC7WB66C
TC7WB67C
R
DRIVE
C
R
I/O
+ R
where, R
ON
R
DRIVE
Figure 3 Test Circuit
ON
= output impedance of the previous IC
)･ln (((V
DRIVE
B/A
8
Parameter
OH
,
is the output impedance of the previous-stage circuit.
67C I/O Signals
V
– V
M
ON
OL
) of the input.
Measure
Measure
) – V
CC
5.0 ± 0.5 V
Waveform generated without the TC7WB66C,67C
V
M
; low-level voltage = GND)
CC
) / (V
/ 2
OH
– V
tr(out)
M
3.3 ± 0.3 V
= 2.25 V (V
OL
V
V
TC7WB66C,67CFK
M
CC
))
/ 2
V
CC
CC
/ 2)
2.5 ± 0.2 V
tf(out)
V
2011-07-01
CC
V
M
/ 2
V
GND
CC
1.8 ± 0.15 V
V
V
OH
V
OL
CC
/ 2