SN65ELT21
www.ti.com ....................................................................................................................................................................................................... SLLS923–JUNE 2009
5-V PECL-to-TTL Translator
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FEATURES
PIN ASSIGNMENT
•
3ns (TYP) Propagation Delay
•
Operating Range: VCC = 4.2 V to 5.7 V with
GND = 0 V
D or DGK PACKAGE
(TOP VIEW)
•
•
24-mA TTL Output
Deterministic Output Value for Open Input
Conditions or When Inputs < 1.3 V
NC
D
V
CC
1
2
8
7
•
•
Built-In Temperature Compensation
Q
Drop-In Compatible to the MC10ELT21,
MC100ELT21
D
6
5
NC
3
4
APPLICATIONS
•
Data and Clock Transmission Over Backplane
GND
V
•
Signaling Level Conversion for Clock or Data
BB
DESCRIPTION
Table 1. Pin Descriptions
The SN65ELT21 is
a
differential PECL-to-TTL
translator. It operates on +5-V supply and ground
only. The device includes circuitry to maintain Q to a
low logic level when inputs are in an open condition
or < 1.3 V.
PIN
FUNCTION
PECL data inputs
TTL output
D, D
Q
VCC
VEE
VBB
Positive supply
The VBB pin is a reference voltage output for the
device. When the device is used in single-ended
mode, the unused input should be tied to VBB. This
reference voltage can also be used to bias the input
when it is ac coupled. When it is used, place a
Negative supply
Reference voltage output
0.01µF decoupling capacitor between VCC and VBB
Also limit the sink/source current to < 0.5 mA to VBB
Leave VBB open when it is not used.
.
.
The SN65ELT21 is housed in an industry standard
SOIC-8 package and is also available in an optional
TSSOP-8 package.
ORDERING INFORMATION(1)(2)
PART NUMBER
SN65ELT21D
PART MARKING
ELT21
SIII
PACKAGE
SOIC
SOIC-TSSOP
LEAD FINISH
NiPdAu
SN65ELT21DGK
NiPdAu
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com.
(2) Leaded device options are not initially available; contact a sales representative for further details.
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Copyright © 2009, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.