1
PS8391A 06/10/99
Function
BE
X
A
19-A0
Disconnect
H
Hi-Z
Connect
L
B
19-B0
Truth Table
(1)
Note:
1. H = High Voltage Level
L = Low Voltage Level
Hi-Z = High Impedance
Pin Name
Description
BEx
Bus Enable Inputs (Active LOW)
A
19-A0
Bus A
B
19-B0
Bus B
Product Pin Description
Product Pin Configuration
Product Features
Near-zero propagation delay
5
switches connect inputs to outputs
Undershoot Protection up to 1V
Direct bus connection when switches are ON
32X384 function with flow through pinout make board
layout easier
Ultra-low quiescent power (120A typical)
ideally suited for notebook applications
Industrial operating temperature: 40C to +85C
Packages available:
48-pin 240-mil wide plastic TSSOP (A)
48-pin 150-mil wide plastic BQSOP (B)
Product Description
Pericom Semiconductors PI5C series of Bus Switch circuits are
produced using the Companys advanced submicron CMOS
technology, achieving industry leading speed.
The PI5C16862C is configured as a 20-bit, 2-port bus switch
designed with a low ON resistance (5
) allowing inputs to be
connected directly to outputs. The bus switch creates no additional
propagational delay or additional ground bounce noise. The
switches are turned ON by the Bus Enable (BEx) input signal.
The PI5C16862C can withstand undershoot of up to 1V.
Logic Block Diagram
48-Pin
A,B
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PI5C16862C
20-Bit, 2-Port Bus Switch
with Undershoot Protection
2
PS8391A 06/10/99
PI5C16862C
20-Bit, 2-Port Bus Switch
with Undershoot Protection
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DC Electrical Characteristics
(Over the Operating Range, T
A
= 40C to +85C, V
CC
= 5V 10%)
Parameters Description
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Units
V
IH
Input HIGH Voltage
Guaranteed Logic HIGH Level
2.0
--
--
V
V
IL
Input LOW Voltage
Guaranteed Logic LOW Level
0.5
--
0.8
V
I
IH
Input HIGH Current
V
CC
= Max., V
IN
= V
CC
--
--
1
A
I
IL
Input LOW Current
V
CC
= Max., V
IN
= GND
--
--
1
A
I
OZH
High Impedance Output Current
0
A, B
V
CC
--
--
1
A
V
IK
Clamp Diode Voltage
V
CC
= Min., I
IN
= 18mA
--
1.8
V
I
OS
Short Circuit Current
(3)
A (B) = 0V, B (A) = V
CC
100
--
--
mA
V
H
Input Hysteresis at Control Pins
--
150
--
mV
R
ON
Switch On Resistance
(4)
V
CC
= Min., V
IN
= 0.0V,
--
5.5
8
I
ON
= 48mA
V
CC
= Min., V
IN
= 2.4V,
--
9
16
I
ON
= 15mA
Storage Temperature............................................................65C to +150C
Ambient Temperature with Power Applied ........................... 40C to +85C
Supply Voltage to Ground Potential (Inputs & V
CC
Only) ... 0.5V to +7.0V
Supply Voltage to Ground Potential (Outputs & D/O Only) . 0.5V to +7.0V
DC Input Voltage................................................................... 0.5V to +7.0V
DC Output Current ..............................................................................120mA
Power Dissipation ................................................................................... 0.5W
Note:
Stresses greater than those listed under MAXIMUM
RATINGS may cause permanent damage to the
device. This is a stress rating only and functional
operation of the device at these or any other condi-
tions above those indicated in the operational sec-
tions of this specification is not implied. Exposure to
absolute maximum rating conditions for extended
periods may affect reliability.
Capacitance
(T
A
= 25C, f = 1 MHz)
Parameters
(5)
Description
Test Conditions
Typ.
Units
C
IN
Input Capacitance
V
IN
= 0V
6
pF
C
OFF
A/B Capacitance, Switch Off
V
IN
= 0V
6
pF
C
ON
A/B Capacitance, Switch On
V
IN
= 0V
10
pF
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device type.
2. Typical values are at V
CC
= 5.0V, T
A
= 25C ambient and maximum loading.
3. Not more than one output should be shorted at one time. Duration of the test should not exceed one second.
4. Measured by the voltage drop between A and B pin at indicated current through the switch. ON resistance is determined by the
lower of the voltages on the two (A,B) pins.
5. This parameter is determined by device characterization but is not production tested.
Maximum Ratings
(Above which the useful life may be impaired. For user guidelines, not tested.)
PI5C16862C
20-Bit, 2-Port Bus Switch
with Undershoot Protection
3
PS8391A 06/10/99
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Power Supply Characteristics
Parameters Description
Test Conditions
(1)
Min.
Typ.
(2)
Max.
Units
I
CC
Quiescent Power
V
CC
= Max.
V
IN
= GND or V
CC
120
200
A
Supply Current
I
CC
Supply Current per
V
CC
= Max.
V
IN
= 3.4V
(3)
2.5
mA
Input @ TTL HIGH
I
CCD
Supply Current per
V
CC
= Max.,
0.25
mA/
Input per MHz
(4)
A and B Pins Open
MHz
BE
X
= GND
Control Input Toggling
50% Duty Cycle
Notes:
1. For Max. or Min. conditions, use appropriate value specified under Electrical Characteristics for the applicable device.
2. Typical values are at V
CC
= 5.0V, +25C ambient.
3. Per TTL driven input (V
IN
= 3.4V, control inputs only); A and B pins do not contribute to I
CC
.
4. This current applies to the control inputs only and represent the current required to switch internal capacitance at the
specified frequency. The A and B inputs generate no significant AC or DC currents as they transition. This parameter
is not tested, but is guaranteed by design.
Notes:
1. See test circuit and waveforms.
2. This parameter is guaranteed but not tested on Propagation Delays.
3. The bus switch contributes no propagational delay other than the RC delay of the ON resistance
of the switch and the load capacitance. The time constant for the switch alone is of the order of
0.25ns for 50pF load. Since this time constant is much smaller than the rise/fall times of typical
driving signals, it adds very little propagational delay to the system. Propagational delay of the
bus switch when used in a system is determined by the driving circuit on the driving side of the
switch and its interaction with the load on the driven side.
PI5C16862C
Com.
Parameters Description
Conditions
(1)
Min.
Max.
Units
t
PLH
Propagation Delay
(2,3)
C
L
= 50pF
0.25
t
PHL
Ax to Bx, Bx to Ax
R
L
= 500
t
PZH
Bus Enable Time
1.5
6.5
ns
t
PZL
BE
X
to Ax or Bx
t
PHZ
Bus Disable Time
1.5
5.5
t
PLZ
BEx to Ax or Bx
Pericom Semiconductor Corporation
2380 Bering Drive San Jose, CA 95131 1-800-435-2336 Fax (408) 435-1100 http://www.pericom.com
PI5C16862 Switching Characteristics over Operating Range
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