DS500374

www.fairchildsemi.com

May 2000

Revised April 2003

NC7WBD3125 T

i
nyLogi

UHS 2-

Bit
Lo

Power

Bus Swi

t
ch

i
t
h

Level

Shif

NC7WBD3125
TinyLogic

UHS 2-Bit Low Power Bus Switch

with Level Shifting

General Description

The NC7WBD3125 is a 2-bit ultra high-speed CMOS FET
bus switch with enhanced level shifting circuitry and 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 gener-
ating additional ground bounce noise. The device is orga-
nized as a 2-bit switch with independent bus enable (OE)
controls. When OE is LOW, the switch is ON and Port A is
connected to Port B. When OE is HIGH, the switch is
OPEN and a high-impedance state exists between the two
ports. Reduced voltage drive to the gate of the FET switch
permits nominal level shifting of 5V to 3V through the
switch. Control inputs tolerate voltages up to 5.5V indepen-
dent of V

Features

Space saving US8 surface mount package

MicroPak

leadless package

Typical 3

switch resistance at 5.0V V

, V

Level shift facilitates 5V to 3.3V interfacing

Minimal propagation delay through the switch

Power down high impedance input/output

Zero bounce in flow through mode

TTL compatible active LOW control inputs

Control inputs are overvoltage tolerant

Bus switch replacement for x125 logic part

Ordering Code:

TinyLogic

is a registered trademark of Fairchild Semiconductor Corporation.

MicroPak

is a trademark of Fairchild Semiconductor Corporation.

Package

Package Description

Supplied As

Order

Package

Code

Number

Number Top Mark

NC7WBD3125K8X MAB08A

WB5D

8-Lead US8, JEDEC MO-187, Variation CA 3.1mm Wide 3k Units on Tape and Reel

NC7WBD3125L8X
(Preliminary)

MAC08A

8-Lead MicroPak, 1.6 mm Wide

5k Units on Tape and Reel

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NC7W

BD3125

Logic Diagram

Pin Descriptions

Function Table

HIGH Logic Level

LOW Logic Level

Connection Diagrams

(Top View)

Pin One Orientation Diagram

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 Thru View)

Pin Name

Description

Bus A Switch I/O

Bus B Switch I/O

Bus Enable Input

Bus Enable Input (OE)

Function

B Connected to A

Disconnected

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NC7WBD3125

Absolute Maximum Ratings

(Note 1)

Recommended Operating
Conditions

(Note 3)

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.

DC Electrical Characteristics

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 (V

3.4V, control input only). A and B pins do not contribute to I

Supply Voltage (V

)

0.5V to

7.0V

DC Switch Voltage (V

)

0.5V to

7.0V

DC Output Voltage (V

) (Note 2)

0.5V to

7.0V

DC Input Diode Current

) V

50 mA

DC Output (I

OUT

) Current

128 mA

DC V

or Ground Current

GND

)

100 mA

Storage Temperature Range (T

STG

)

C to

150

Junction Temperature under Bias (T

)

150

Lead Temperature (T

)

(Soldering, 10 Seconds)

260

Power Dissipation (P

) @

250 mW

Supply Operating (V

)

4.5V to 5.5V

Control Input Voltage (V

)

0V to 5.5V

Switch Input Voltage (V

)

0V to 5.5V

Switch Output Voltage (V

OUT

)

0V to 5.5V

Operating Temperature (T

)

C to

Input Rise and Fall Time (t

, t

)

Control Input

0 ns/V to 5 ns/V

Switch I/O

0 ns/V to DC

Thermal Resistance (

)

250

C/W

Symbol

Parameter

C to

Units

Conditions

(V)

Min

Typ

Max

Clamp Diode Voltage

4.5

1.2

18 mA

HIGH Level Input Voltage

4.5 to 5.5

2.0

LOW Level Input Voltage

4.5 to 5.5

0.8

HIGH Level Output Voltage

4.5 to 5.5

See Figure 3

Input Leakage Current

5.5

1.0

5.5V

OFF

Power OFF Leakage Current

5.5

1.0

A, B

Switch On Resistance

4.5

0V, I

64 mA

(Note 4)

4.5

0V, I

30 mA

4.5

2.4V, I

15 mA

Quiescent Supply Current

5.5

or GND, I

OUT

1.1

1.5

GND

Increase in I

per Input

5.5

2.5

3.4V, One OE Input only,

(Note 5)

Other OE

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NC7W

BD3125

AC Electrical Characteristics

Note 6: This parameter is guaranteed. The bus switch contributes no propagation delay other than the RC delay of the typical On Resistance of the switch
and the 50 pF load capacitance, when driven by an ideal voltage source (zero output impedance). The specified limit is calculated on this basis.

Capacitance

AC Loading and Waveforms

Input driven by 50

source terminated in 50

includes load and stray capacitance

Input PRR

1.0 MHz; t

500 ns

FIGURE 1. AC Test Circuit

FIGURE 2. AC Waveforms

C to

Symbol

Parameter

50 pF, RU

500

Units

Conditions

Figure

(V)

Min

Typ Max

Number

PHL

Propagation Delay Bus-to-Bus

4.5 to 5.5

0.25

OPEN

Figures

1, 2

PLH

(Note 6)

PZL

Output Enable Time

4.5 to 5.5

1.0

3.5

5.8

7V for t

PZL

Figures

1, 2

PZH

0V for t

PZH

PLZ

Output Disable Time

4.5 to 5.5

0.8

3.0

4.8

7V for t

PLZ

Figures

1, 2

PHZ

0V for t

PHZ

Symbol Parameter

Typ

Max

Units

Conditions

Control Pin Input Capacitance

2.5

I/O

(OFF)

Port OFF Capacitance

5.0V

I/O

(ON)

Port ON Capacitance

5.0V, OE

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NC7W

BD3125

Tape and Reel Specification

TAPE FORMAT for US8

TAPE DIMENSIONS inches (millimeters)

TAPE FORMAT for MicroPak

TAPE DIMENSIONS inches (millimeters)

Package

Tape

Number

Cavity

Cover Tape

Designator

Section

Cavities

Status

Leader (Start End)

125 (typ)

Empty

Sealed

K8X

Carrier

250

Filled

Sealed

Trailer (Hub End)

75 (typ)

Empty

Sealed

Package

Tape

Number

Cavity

Cover Tape

Designator

Section

Cavities

Status

Leader (Start End)

125 (typ)

Empty

Sealed

L8X

Carrier

250

Filled

Sealed

Trailer (Hub End)

75 (typ)

Empty

Sealed

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NC7WBD3125 T

i
nyLogi

UHS 2-

Bit
Lo

Power

Bus Swi

t
ch

i
t
h

Level

Shif

Physical Dimensions

inches (millimeters) unless otherwise noted (Continued)

8-Lead MicroPak, 1.6 mm Wide

Package Number MAC08A

(Preliminary)

Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.

LIFE SUPPORT POLICY

FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or systems

which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be rea-
sonably expected to result in a significant injury to the
user.

2. A critical component in any component of a life support

device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.

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Part Number NC7WBD3125