Fairchild Semiconductor 74VCX16838MTDX, 74VCX16838MTD Datasheet

July 1997
Revised July 2000

74VCX16838
Low Voltage 16-Bit Selectable Register/Buffer

with 3.6V Tolerant Inputs and Outputs

74VCX16838 Low Voltage 16-Bit Selectable Register/Buffer with 3.6V Tolerant Inputs and Outputs

General Description

The VCX16838 contai ns sixteen non-inverting selectable
buffered or registered pa ths. T he dev ic e can be c onfi g ur ed
to operate in a regis tered, or flow throu gh buffer mode by
utilizing the register enable (REGE) and Clock (CP) sig­nals. The device operates in a 16-bit word wide mode. All
outputs can be placed in to 3-State through u se of the OE
Pin. These devices a re ide ally suited for buffere d or regis­tered 168 pin and 200 pin SDRAM DIMM me mory mod­ules.

The 74VCX16838 is designed for low voltage (1.65V to

3.6V) V
The 74VCX16838 i s fabricated with an advanc ed CMOS

technology to achieve high speed operation while maintain­ing low CMOS power dissipation.

applications with I/O compatibility up to 3.6V.

CC

Features

■ Compatible with PC100 and PC133 DIMM module
specifications

■ 1.65V–3.6V V

■ 3.6V tolerant inputs and outputs

■ t

(CP to On)

PD

3.0 ns max for 3.0V to 3.6V V

4.0 ns max for 2.3V to 2.7V VCC

8.0 ns max for 1.65V to 1.95V V

■ Power-off high impedance inputs and outputs

■ Supports live insertion and withdrawal (Note 1)

■ Static Drive (I

±24 mA @ 3.0V V
±18 mA @ 2.3V V
±6 mA @ 1.65V V

■ Uses patented noise/EMI reductio n circuitr y

■ Ideal for SDRAM DIMM modules

■ Latch-up performance exce eds 300 mA

■ ESD performance:

Human body model
Machine model

Note 1: To ensure the high-impedance state d uring power up or power
down, OE

should be tied to VCC through a pull-up r esistor; the min imum

value of the res istor is d eter mine d by the cu rre nt-sou rcin g ca pa bility of t he
driver.

supply operation

CC

)

OH/IOL

CC
CC

CC

> 2000V

> 200V

CC

CC

Ordering Code:

Order Number Package Number Package Description

74VCX16838MTD MTD48 48-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide

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

Logic Symbol Pin Descriptions

Pin Names Description

OE
I

0–I15

O

0–O15

CP Clock Pulse Input
REGE Register Enable Input

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Output Enable Input (Active LOW)
Inputs
Outputs

Connection Diagram Truth Table

CP REGE

74VCX16838

↑ HHL H
↑ HLL L

XLHLH
XLLLL
XXXHZ

H = HIGH Voltage Level
L = LOW Voltage Level
X = Immaterial (HIGH or LOW, inputs may not float)
Z = High Impedance

Functional Description

The 74VCX16838 consists of sixteen selectable non­inverting buffers or registers with word wide controls. Mode
functionality is sele cted through operation of th e CP and
REGE pin as shown by the truth table. When REGE is held
at a logic “1” the device operates as a 16-bi t regist er. Data
is transferred from I

When the REGE pin is held at a logic “0” the device oper­ates in a flow through mod e and data propagates dir ectly
from the I to the O outputs. All outpu ts can be 3 -STATE by
holding the OE

Logic Diagram

Inputs Outputs

I

n

to On on the rising edge of the CP pin.

n

pin at a logic “1.”

OE

O

n

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Absolute Maximum Ratings(Note 2) Recommended Operating

Supply Voltage (VCC) −0.5V to +4.6V
DC Input Voltage (V
Output Voltage (V

Outputs 3-STATE

Outputs Active (Note 3)
DC Input Diode Current (I
DC Output Diode Current (I

V

< 0V −50 mA

O

V

> V

O

CC

) −0.5V to +4.6V

I

)

O

−0.5V to +4.6V

−0.5V to V

) VI < 0V −50 mA

IK

)

OK

CC

+50 mA

+0.5V

DC Output Source/Sink Current

) ±50 mA

(I

OH/IOL

DC V

or GND Current per

CC

Supply Pin (I
Storage Temperature Range (T

or GND) ±100 mA

CC

) −65°C to +150°C

STG

Conditions

Power Supply

Operating 1.65V to 3.6V

Data Retention Only 1.2V to 3.6V
Input Voltage
Output Voltage (V

Output in Active States 0V to V

Output in “OFF” State 0.0V to 3.6V
Output Current in I

VCC = 3.0V to 3.6V ±24 mA

= 2.3V to 2.7V ±18 mA

V

CC

V

= 1.65V to 2.3V ±6 mA

CC

Free Air Operating Temperature (T
Minimum Input Edge Rate (

V

= 0.8V to 2.0V, VCC = 3.0V 10 ns/V

IN

Note 2: The Absolute Maxi mum Ratings are thos e values beyond which
the safety of the d evice cannot b e guaranteed . The device sh ould not be
operated at these limit s. The parametric values defi ned 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 .

Absolute Maximum Rating must be observed.

Note 3: I

O

Note 4: Floating or unused inputs must be held HIGH or LOW.

(Note 4)

)

O

OH/IOL

) −40°C to +85°C

A

∆t/∆V)

DC Electrical Characteristics (2.7V < VCC ≤ 3.6V)

V

Symbol Parameter Conditions

V

IH

V

IL

V

OH

V

OL

I

I

I

OZ

I

OFF

I

CC

∆I

Note 5: Outputs disabled or 3-STATE only.

HIGH Level Input Voltage 2.7–3.6 2.0 V
LOW Level Input Voltage 2.7–3.6 0.8 V
HIGH Level Output Voltage IOH = −100 µA2.7–3.6 VCC − 0.2 V

LOW Level Output Voltage IOL = 100 µA2.7–3.6 0.2 V

Input Leakage Current 0 ≤ VI ≤ 3.6V 2.7–3.6 ±5.0 µA
3-STATE Output Leakage 0 ≤ VO ≤ 3.6V

Power-OFF Leakage Current 0 ≤ (VI, VO) ≤ 3.6V 0 10 µA
Quiescent Supply Current VI = VCC or GND 2.7–3.6 20 µA

Increase in ICC per Input VIH = VCC −0.6V 2.7–3.6 750 µA

CC

IOH = −12 mA 2.7 2.2 V
I

= −18 mA 3.0 2.4 V

OH

= −24 mA 3.0 2.2 V

I

OH

I

= 12 mA 2.7 0.4 V

OL

= 18 mA 3.0 0.4 V

I

OL

IOL = 24 mA 3.0 0.55 V

VI = VIH or V

VCC ≤ (VI, VO) ≤ 3.6V (Note 5) 2.7–3.6 ±20 µA

IL

CC

(V)

2.7–3.6 ±10 µA

Min Max Units

74VCX16838

−0.3V to +3.6V

CC

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