Document
SN65ELT20
www.ti.com
SLLS922A – DECEMBER 2008 – REVISED MARCH 2012
5-V TTL-to-Differential PECL Translator
Check for Samples: SN65ELT20
FEATURES
1
• 1.25-ns Maximum Propagation Delay • Operating Range: VCC = 4.2 V to 5.7 V With
GND = 0 V • Flow-Through Pinout Enables Easy Layout • Built-In Temperature Compensation • Drop-In Compatible With MC10ELT20,
MC100ELT20
APPLICATIONS
• Data and Clock Transmission Over Backplane • Signaling Level Conversion for Clock or Data
DESCRIPTION
The SN65ELT20 is a TTL-to-differential PECL translator. It operates on a 5-V supply and ground only. The output is undetermined when the inputs are left floating. The low output skew makes the device an ideal solution for clock or data signal translation.
The SN65ELT20 is housed in an industry-standard SOIC-8 package and is also available in a TSSOP-8 package.
PINOUT ASSIGNMENT
D-8, DGK-8 Package (Top View)
NC 1
TTL Q2
PECL Q3
8 VCC 7D 6 NC
NC 4
5 GND
PIN D Q,Q VCC GND
Table 1. Pin Description
TTL input PECL outputs Positive supply Ground
FUNCTION
P0065-04
PART NUMBER SN65ELT20D
SN65ELT20DGK
ORDERING INFORMATION(1)
PART MARKING
PACKAGE
SN65ELT20
SOIC
SN65ELT20
SOIC-TSSOP
(1) Leaded device options not initially available; contact a sales representative for further details.
LEAD FINISH NiPdAu NiPdAu
1
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 © 2008–2012, Texas Instruments Incorporated
SN65ELT20
SLLS922A – DECEMBER 2008 – REVISED MARCH 2012
www.ti.com
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
ABSOLUTE MAXIMUM RATINGS(1)
PARAMETER Absolute PECL-mode supply voltage VIN input voltage
Output current
Operating temperature range Storage temperature range
CONDITIONS VCC (GND = 0 V) GND = 0 V; VI ≤ VCC Continuous Surge
VALUE 6 6 50
100 –40 to 85 –65 to 150
UNIT V V mA mA °C °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
POWER DISSIPATION RATINGS
PACKAGE
CIRCUIT-BOARD MODEL
POWER RATING
TA < 25°C (mW)
Low-K
719
SOIC
High-K
840
Low-K
469
SOIC-TSSOP
High-K
527
THERMAL RESISTANCE, JUNCTION-TO-AMBIENT,
NO AIRFLOW
139 119 213 189
DERATING FACTOR TA > 25°C (mW/°C)
7
8
5
5
POWER RATING TA = 85°C (mW)
288
336
188
211
THERMAL CHARACTERISTICS
PARAMETER
θJB
Junction-to-board thermal resistance
θJC Junction-to-case thermal resistance
PACKAGE SOIC
SOIC-TSSOP SOIC
SOIC-TSSOP
VALUE 79 120 98 74
UNIT °C/W °C/W
KEY ATTRIBUTES
CHARACTERISTIC
Moisture sensitivity level
Flammability rating (oxygen index: 28 to 34) ESD—human body model ESD—machine model ESD—charged-device model Meets or exceeds JEDEC Spec EIA/JESD78 latchup test
VALUE SO-8: Level 1 TSSOP-8: Level 3 UL 94 V-0 at 0.125 in
>4 kV 200 V 2 kV
2
Copyright © 2008–2012, Texas Instruments Incorporated
SN65ELT20
www.ti.com
SLLS922A – DECEMBER 2008 – REVISED MARCH 2012
PECL DC CHARACTERISTICS(1) (VCC = 5 V; GND = 0 V)(2)
PARAMETER
–40°C MIN TYP MAX
25°C MIN TYP MAX
85°C MIN TYP MAX
UNIT
ICC
Power-supply current
VOH
Output HIGH voltage(3)
VOL
Output LOW voltage (3)
9.6 16
10.1 16
10.7 16 mA
3915 3958 4120 3915 3963 4120 3915 3967 4120 mV
3170 3247 3380 3170 3244 3380 3170 3244 3380 mV
(1) The device meets these specifications after thermal equilibrium has been established when mounted in a test socket or printed-circuit board with maintained transverse airflow greater than 500 lfpm (2.54 m/s). Electrical parameters are assured only over the declared operating temperature range. Functional operation of the device exceeding these conditions is not implied. Device specification limit values are applied individually under normal operating conditions and are not valid simultaneously.
(2) Output parameters vary 1:1 with Vcc. (3) Outputs are terminated through a 50-Ω resistor to VCC – 2 V.
TTL INPUT DC CHARACTERISTICS(1) (VCC = 4.2 V to 5.7 V; TA = –40°C to 85°C)
PARAMETER
TEST CONDITIONS
MIN TYP MAX UNIT
IIH
Input HIGH current
IIH
IIL
Input LOW current
VIK Input clamp diode voltage
VIH Input HIGH voltage
VIL
Input LOW voltage
VIN = 2.7 V VIN =.