Fairchild Semiconductor 74ABT16543CMTD, 74ABT16543CSSCX, 74ABT16543CSSC, 74ABT16543CMTDX Datasheet

October 1993
Revised January 1999

74ABT16543
16-Bit Registered Transceiver with 3-STATE Outputs

74ABT16543 16-Bit Registered Transceiver with 3-STATE Outputs

General Description

The ABT16543 16-bit trans ceiver contains two sets of D­type latches for temporar y st orage o f data flowing in either
direction. Separate Latch Enable and Output Enable inputs
are provided for each register to permit indep endent con­trol of inputting and out putting in either direction of data
flow. Each byte has separate control inputs, which can be
shorted together for full 16-bit operation.

Features

■ Back-to-back registers for storage

■ Bidirectional data path

■ A and B outputs have current sourcing capability of 32

mA and current sinking capability of 64 mA

■ Separate control logic for each byte

■ 16-bit version of the ABT543

■ Separate controls for data flow in each direction

■ Guaranteed latchup protection

■ High impedance glitch free bus loading during entire

power up and power down cycle

■ Nondestructive hot insertion capability

Ordering Code:

Order Number Package Number Package Description

74ABT16543CSSC MS56A 56-Lead Shrink Small Outline Package (SSOP), JEDEC MO-118, 0.300” Wide
74ABT16543CMTD MTD56 56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide

Devices also available on Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Pin Assignment for SSOP and TSSOP

Pin Descriptions

Pin Names Description

OEAB
OEBA
CEAB
CEBA
LEAB
LEBA
A

0–A15

B

0–B15

A-to-B Output Enable Input (Active LOW)

n

B-to-A Output Enable Input (Active LOW)

n

A-to-B Enable Input (Active LOW)

n

B-to-A Enable Input (Active LOW)

n

A-to-B Latch Enable Input (Active LOW)

n

B-to-A Latch Enable Input (Active LOW)

n

A-to-B Data Inputs or
B-to-A 3-STATE Outputs
B-to-A Data Inputs or
A-to-B 3-STATE Outputs

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Logic Symbol Data I/O Control Table

Inputs Latch Status Output Buffers

LEABnOEAB

CEAB

74ABT16543

n

H X X Latched HIGH Z

n

X H X Latched —
L L X Transparent —
XXH — HIGH Z
L X L — Driving

H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial
A-to-B data flow shown;

B-to-A flow control is the s am e, except us ing CEBA

Functional Description

The ABT16543 con tains two sets of D-type la tches, with
separate input and output control s for each. For data flow
from A to B, for example, the A to B Enable (CEAB

) input
must be low in order to enter data from the A port or take
data from the B-Port as indicated in the Data I/O Contr ol
Table. With CEAB

low, a low signal on (LEAB) input makes
the A to B latches transparent; a su bsequent low to high
transit ion of the LEAB

line puts the A latches in the storage

mode and their outputs no longer change with the A inputs.
With CEAB

and OEAB both low, the B output buffers are
active and reflect the data present on th e output of the A
latches. Control of data flow from B to A is similar, but using
the CEBA

, LEBA and OEBA. Each byte has separate co n­trol inputs, allowing the device to be used as two 8-bit
transceivers or as one 16-bit transceiver.

Logic Diagrams

(Byte n) (Byte n)

, LEBAn and OEBA

n

n

Byte 1 (0:7)

Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimate propagation delays.

Byte 2 (8:15)

Please note that this diagram is provided only for the understanding of logic
operations and should not be used to estimat e propagation delays.

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Absolute Maximum Ratings(Note 1)

Storage Temperature −65°C to +150°C
Ambient Temperature under Bias −55°C to +125°C
Junction Temperature under Bias −55°C to +150°C

Pin Potential to

V

CC

Ground Pin −0.5V to +7.0V
Input Voltage (Note 2) −0.5V to +7.0V
Input Current (Note 2) −30 mA to +5.0 mA
Voltage Applied to Any Output

in the Disable or

Power-Off State −0.5V to +5.5V

in the HIGH State −0.5V to V
Current Applied to Output

in LOW State (Max) twice the rated I

OL

(mA)

DC Electrical Characteristics

DC Latchup Source Current −500 mA
Over Voltage Latchup (I/O) 10V

Recommended Operating
Conditions

Free Air Ambient Temperature −40°C to +85°C
Supply Voltage +4.5V to +5.5V
Minimum Input Edge Rate (∆V/∆t)

Data Input 50 mV/ns
Enable Input 20 mV/ns
Clock Input 100 mV/ns

Note 1: Absolute maximum ratin gs are values beyond which the device

CC

may be damaged or have its useful life impaired. Functional operation
under these condit ions is not implied.

Note 2: Either voltage limit or current limi t is s uf f ic ient to protect inputs.

74ABT16543

Symbol Parameter Min Typ Max Units

V
V
V
V

V
V

I

I
I

I

IIH + I

IIL + I

I
I
I
I
I
I

I

I

Input HIGH Voltage 2.0 V Recognized HIGH Signal

IH

Input LOW Voltage 0.8 V Recognized LOW Signal

IL

Input Clamp Diode Voltage −1.2 V Min IIN = −18 mA (Non I/O Pins)

CD

Output HIGH Voltage 2.5 IOH = −3 mA, (An, Bn)

OH

Output LOW Voltage 0.55 V Min IOL = 64 mA, (An, Bn)

OL

Input Leakage Test 4.75 V 0.0 IID = 1.9 µA, (Non-I/O Pins)

ID

Input HIGH Current 1 µAMaxVIN = 2.7V (Non-I/O Pins) ((Note 3)

IH

Input HIGH Current Breakdown Test 7 µAMaxVIN = 7.0V (Non-I/O Pins)

BVI

Input HIGH Current 100 µAMaxVIN = 5.5V (An, Bn)

BVIT

Breakdown Test (I/O)
Input LOW Current −1 µAMaxVIN = 0.5V (Non-I/O Pins) (Note 3)

IL

Output Leakage Current 10 µA 0V–5.5V V

OZH

Output Leakage Current −10 µA 0V–5.5V V

OZL

Output Short-Circuit Current −100 −275 mA Max V

OS

Output HIGH Leakage Current 50 µAMaxV

CEX

Bus Drainage Test 100 µA0.0VV

ZZ

Power Supply Current 1.0 mA Max All Outputs HIGH

CCH

Power Supply Current 60 mA Max All Outputs LOW

CCL

Power Supply Current 1.0 mA Max Outputs 3-STATE

CCZ

Additional ICC/Input 2.5 mA Max VI = VCC − 2.1V

CCT

Dynamic I

CCD

Note 3: Guaranteed but not tested.

CC

(Note 3) 0.25 mA/MHz Max

No Load

2.0 IOH = −32 mA, (An, Bn)

1V

−1V

V

CC

All Other Pins Grounded

= VCC (Non-I/O Pins)

IN

= 0.0V (Non-I/O Pins)

IN
OUT

OEAB or CEAB = 2V

OUT

OEAB or CEAB = 2V

OUT
OUT
OUT

All Others at VCC or GND

All Others at VCC or GND
Outputs Open, CEAB, OEAB, LEAB = GND,
CEBA = VCC, One Bit Toggling,
50% Duty Cycle

Conditions

= 2.7V (An, Bn);

= 0.5V (An, Bn);

= 0V (An, Bn)
= VCC (An, Bn)
= 5.5V (An, Bn); All Others GND

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