Fairchild NC7WB3125 service manual
NC7WB3125
2-Bit Low Power Bus Switch
NC7WB3125 2-Bit Low Power Bus Switch
May 2000
Revised December 2005
General Description
The NC7WB3125 is a 2-bit ultra high-speed CMOS FET bu s
switch with TTL-compatible active LOW control inputs. The low
On Resistance of the switch allows inputs to be connected to
outputs with minimal propagation delay and without generating
additional ground bounce noise. The device is organized as a 2bit switch with independent bus enable (OE
is LOW, the switch is ON and Port A is connected to Port B.
When OE
state exists between the two ports. Control inputs tolerate voltages up to 5.5V independent of V
is HIGH, the switch is OPEN and a high-impedance
CC
) controls. When OE
.
Features
O
Space saving US8 surface mount package
O
MicroPak¥ Pb-Free leadless package
O
Typical 3: switch resistance at 5.0V V
O
Minimal propagation delay through the switch
O
Power down high impedance input/output
O
Zero bounce in flow through mode
O
TTL compatible active LOW control inputs
O
Control inputs are overvoltage tolerant
O
Bus switch replacement for Logic x125 part
CC
Ordering Code:
Product
Package Description Supplied AsOrder Package Code
Number Number Top Mark
NC7WB3125K8X MAB08A WB25 8-Lead US8, JEDEC MO-187, Variation CA 3.1mm Wide 3k Units on Tape and Reel
NC7WB3125L8X
(Preliminary)
Pb-Free package per JEDEC J-STD-020B.
MAC08A T4 Pb-Free 8-Lead MicroPak, 1.6 mm Wide 5k Units on Tape and Reel
MircoPak¥ is a trademark of Fairchild Semiconductor Corporation.
© 2005 Fairchild Semiconductor Corporation DS500376 www.fairchildsemi.com
Logic Diagram
NC7WB3125
Pin Descriptions
Pin Name Description
Function Table
Connection Diagrams
ABus A
BBus B
OE
Bus Enable Input
(Top View)
Pin One Orientation Diagra m
Bus Enable Input OE Function
L B Connected to A
H Disconnected
AAA represents Product Code Top Mark - see ordering code
Note: Orientation of Top Mark determines Pin One location. Read the top product
code mark left to right, Pin One is the lower left pin (see diagram).
Pad Assignments for MicroPak
(Top Through View)
www.fairchildsemi.com 2
NC7WB3125
Absolute Maximum Ratings(Note 1)
Supply Voltage (VCC)
DC Switch Voltage (V
DC Output Voltage (V
)
S
) (Note 2)
IN
DC Input Diode Current
) VIN 0V
(I
IK
DC Output (I
or Ground Current
DC V
CC
(I
CC/IGND
Storage Temperature Range (T
) Current 128 mA
OUT
)
STG
Junction Temperature under Bias (T
Junction Lead Temperature (T
)
L
(Soldering, 10 Seconds)
Power Dissipation (P
) @ 85qC 250 mW
D
)
J
0.5V to 7.0V
0.5V to 7.0V
0.5V to 7.0V
65q
C to 150qC
)
50 mA
r
100 mA
150qC
260qC
Recommended Operating
Conditions
Supply Operating (V
Control Input Voltage (V
Switch Input Voltage (V
Output Voltage (V
Operating Temperature (T
Input Rise and Fall Time (t
Switch Control Input 0 ns/V to 5 ns
Switch I/O 0 ns/V to DC
Thermal Resistance (
Note 1: The “Absolute Maximum Ratings” are those values beyond which the safety
of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not
guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation.
Note 2: The input and output negative voltage ratings may be exceeded if the input
and output diode current ratings are observed.
Note 3: Unused logic inputs must be held HIGH or LOW. They may not float.
(Note 3)
) 4.0V to 5.5V
CC
)0V to 5.5V
IN
)0V to 5.5V
IN
)0V to 5.5V
OUT
)
A
, tf)
r
T
) 250qC/W
JA
DC Electrical Characteristics
V
Symbol Parameter
V
IK
V
IH
V
IL
V
OH
I
IN
I
OFF
R
ON
I
CC
'
I
CC
Note 4: Measured by the voltage drop between A and B pins at the indicated current through the switch. On Resistance is determined by the lower of the
voltages on the two (A or B) pins.
Note 5: Per TTL driven input (VIN 3.4V, control input only). A and B pins do not contribute to ICC.
Clamp Diode Voltage 4.5
HIGH Level Input Voltage 4.0 to 5.5 2.0 V
LOW Level Input Voltage 4.0 to 5.5 0.8 V
HIGH Level Output Voltage 4.0 to 5.5 See Figure 3 V VIN V
Input Leakage Current 5.5
Switch OFF Leakage Current 5.5
Switch On Resistance 4.5 3.0 7.0
(Note 4) 4.5 3.0 7.0 VIN 0V, IIN 30 mA
Quiescent Supply Current 5.5 3.0
Increase in ICC per Input (Note 5) 5.5 1.0 2.5 mA VIN 3.4V, One OE Input only,
CC
(V) Min Typ Max
4.5 6.0 15.0 V
4.0 10.0 20.0 V
TA 40qC to 85qC
Units Conditions
1.2 V IIN 18 mA
r
1.0
r
1.0
P
A0 d VIN d 5.5V
P
A0 d A, B d V
VIN 0V, IIN 64 mA
:
P
2.4V, IIN 15 mA
IN
2.4V, IIN 15 mA
IN
AVIN VCC or GND
I
0
OUT
Other OE V
CC
CC
CC
40q
C to 85qC
3 www.fairchildsemi.com
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