Integrated Device Technology, Inc.
20-BIT BUS SWITCH
IDT74FST163384
IDT74FST1632384
ADVANCE INFORMATION
FEATURES:
• Bus switches provide zero delay paths
• Extended commercial range of –40°C to +85°C
• Low switch on-resistance:
FST163xxx – 5Ω
FST1632xxx — 28Ω
• TTL-compatible input and output levels
• ESD > 2000V per MIL-STD-883, Method 3015;
> 200V using machine model (C = 200pF, R = 0)
• Available in SSOP, TSSOP and TVSOP
DESCRIPTION:
The FST163384/1632384 belong to IDT's family of Bus
switches. Bus switch devices perform the function of connecting or isolating two ports without providing any inherent
FUNCTIONAL BLOCK DIAGRAM
A
0
B
0
current sink or source capability. Thus they generate little or
no noise of their own while providing a low resistance path for
an external driver. These devices connect input and output
ports through an n-channel FET. When the gate-to-source
junction of this FET is adequately forward-biased the device
conducts and the resistance between input and output ports
is small. Without adequate bias on the gate-to-source junction
of the FET, the FET is turned off, therefore with no VCC
applied, the device has hot insertion capability.
The low on-resistance and simplicity of the connection
between input and output ports reduces the delay in this path
to close to zero.
The FST1632xxx integrates terminating resistors in the
device, thus eliminating the need for external 25Ω series
resistors.
The FST163384 and FST1632384 are 20-bit TTL-compatible bus switches. The BEx pins provide enable control.
A
10
B
10
A
4
A
5
A
9
BEA
BEB
PIN DESCRIPTION
Pin Names I/O Description
A
0-19
B
0-19
BEA, BEB
BEC, BED
,
,
I/O Bus A
I/O Bus B
I Bus Switch Enable (Active LOW)
A
A
A
BEC
BED
14
15
19
B
14
B
15
B
19
3473 drw 01
B
4
B
5
B
9
3473 tbl 01
The IDT logo is a registered trademark of Integrated Device Technology, Inc.
COMMERCIAL TEMPERATURE RANGE FEBRUARY 1997
1997 Integrated Device Technology, Inc. DSC-3473/4
1
IDT74FST163384, IDT74FST1632384
20-BIT BUS SWITCH COMMERCIAL TEMPERATURE RANGE
PIN CONFIGURATION
BEA
GND
BEC
GND
1
2
B
0
A
0
3
4
A
1
5
B
1
B
2
6
7
A
2
8
A
3
9
B
3
10
4
B
A
4
11
SO48-1
12
SO48-2
SO48-3
13
14
B
5
A
5
15
16
A
6
17
B
6
B
7
18
19
A
7
20
A
8
21
B
8
22
9
B
9
A
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
Vcc
19
B
A
19
A
18
B
18
B
17
A
17
A
16
B
16
B
15
A
15
BEB
Vcc
14
A
B
14
A
13
B
13
B
12
A
12
A
11
B
11
B
10
A
10
BED
ABSOLUTE MAXIMUM RATINGS
(1)
Symbol Description Max. Unit
(2)
VTERM
Terminal Voltage with Respect
–0.5 to +7.0 V
to GND
TSTG Storage Temperature –65 to +150 °C
IOUT Maximum Continuous Channel
128 mA
Current
NOTES:
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RAT-
INGS may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions
above those indicated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating condiitions for extended
periods may affect reliability.
2. VCC, Control and Switch terminals.
3473 tbl 02
FUNCTION TABLE
BEA
BEA
H H Hi-Z Hi-Z Disconnect
LHA
H L Hi-Z A
LLA
BEC
BEC
H H Hi-Z Hi-Z Disconnect
LHA
H L Hi-Z A
LLA
CAPACITANCE
Symbol Parameter Conditions
CIN Control Input Capacitance 4 pF
CI/O
NOTES:
1. Capacitance is characterized but not tested
2. TA = 25°C, f = 1MHz, VIN = 0V, VOUT = 0V
BEB
BEB
BED
BED
B
B
0-4
0-4
0-4
10-14
10-14
10-14
(1)
Switch Input/Output
Capacitance
B
5-9
Description
Hi-Z Connect
B
5-9
A
5-9
15-19
Connect
Connect
Description
Hi-Z Connect
A
15-19
15-19
Connect
Connect
Switch Off
(2)
Typ. Unit
3473 tbl 03
pF
3473 tbl 04
SSOP/
TSSOP/TVSOP
TOP VIEW
3473 drw 02
2