SN74CBT3257
4 BIT 1 OF 2 FET MULTIPLEXER/DEMULTIPLEXER
SCDS017M − MAY 1995 − REVISED JANUARY 2004
switching characteristics over recommended operating free-air temperature range, C
L
= 50 pF
(unless otherwise noted) (see Figure 1)
PARAMETER
tpd†
tpd
ten
tdis
FROM
(INPUT)
A or B
S
S
OE
S
OE
TO
(OUTPUT)
B or A
A
B
A or B
B
A or B
VCC = 4 V
MIN
MAX
0.35
5.5
5.7
5.6
5.2
5.5
1.6
1.6
1.8
1
2.2
VCC = 5 V
±
0.5 V
MIN
MAX
0.25
5
5.2
5.1
5
5.5
ns
ns
ns
ns
UNIT
† The propagation delay is the calculated RC time constant of the typical on-state resistance of the switch and the specified load capacitance, when
driven by an ideal voltage source (zero output impedance).
PARAMETER MEASUREMENT INFORMATION
7V
From Output
Under Test
CL = 50 pF
(see Note A)
500
Ω
S1
Open
GND
500
Ω
TEST
tpd
tPLZ/tPZL
tPHZ/tPZH
S1
Open
7V
Open
3V
LOAD CIRCUIT
Output
Control
1.5 V
1.5 V
0V
tPZL
3V
Input
1.5 V
1.5 V
0V
tPLH
Output
1.5 V
VOLTAGE WAVEFORMS
PROPAGATION DELAY TIMES
tPHL
VOH
1.5 V
VOL
Output
Waveform 1
S1 at 7 V
(see Note B)
tPZH
Output
Waveform 2
S1 at Open
(see Note B)
1.5 V
tPLZ
3.5 V
VOL + 0.3 V
VOL
tPHZ
VOH
VOH − 0.3 V
0V
VOLTAGE WAVEFORMS
ENABLE AND DISABLE TIMES
1.5 V
NOTES: A. CL includes probe and jig capacitance.
B. Waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control.
Waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control.
C. All input pulses are supplied by generators having the following characteristics: PRR
≤
10 MHz, ZO = 50
Ω,
tr
≤
2.5 ns, tf
≤
2.5 ns.
D. The outputs are measured one at a time with one transition per measurement.
E. tPLZ and tPHZ are the same as tdis.
F. tPZL and tPZH are the same as ten.
G. tPLH and tPHL are the same as tpd.
H. All parameters and waveforms are not applicable to all devices.
Figure 1. Load Circuit and Voltage Waveforms
4
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•
DALLAS, TEXAS 75265
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