SN65ELT21 Datasheet, PDF (1/11 Pages) Texas Instruments – 5-V PECL-to-TTL Translator

SN65ELT21
www.ti.com....................................................................................................................................................................................................... SLLS923 – JUNE 2009
5-V PECL-to-TTL Translator
FEATURES
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• 3ns (TYP) Propagation Delay
• Operating Range: V_CC = 4.2 V to 5.7 V with
GND = 0 V
• 24-mA TTL Output
• Deterministic Output Value for Open Input
Conditions or When Inputs < 1.3 V
• Built-In Temperature Compensation
• Drop-In Compatible to the MC10ELT21,
MC100ELT21
APPLICATIONS
• Data and Clock Transmission Over Backplane
• Signaling Level Conversion for Clock or Data
PIN ASSIGNMENT
D or DGK PACKAGE
(TOP VIEW)
NC ₁
8 ^V_CC
D₂
7Q
D₃
V_BB ⁴
6 NC
5 GND
DESCRIPTION
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.
The V_BB 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 V_BB. This
reference voltage can also be used to bias the input
when it is ac coupled. When it is used, place a
0.01µF decoupling capacitor between V_CC and V_BB.
Also limit the sink/source current to < 0.5 mA to V_BB.
Leave V_BB open when it is not used.
PIN
D, D
Q
V_CC
V_EE
V_BB
Table 1. Pin Descriptions
FUNCTION
PECL data inputs
TTL output
Positive supply
Negative supply
Reference voltage output
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
SN65ELT21DGK
PART MARKING
ELT21
SIII
PACKAGE
SOIC
SOIC-TSSOP
LEAD FINISH
NiPdAu
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.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2009, Texas Instruments Incorporated