Datasheet AD8131 (Analog Devices)

Low Cost, High Speed Differential Driver AD8131 FEATURES FUNCTIONAL BLOCK DIAGRAM High speed 400 MHz, −3 dB full power bandwidth –D 1 8 IN +DIN 750
Ω
750
Ω
2000 V/μs slew rate V 2 7 OCM NC Fixed gain of 2 with no external components V+ 3 6 V– Internal common-mode feedback to improve gain and phase 1.5k
Ω
1.5k
Ω
balance: −60 dB @ 10 MHz +OUT 4 5 –OUT Separate input to set the common-mode output voltage AD8131 Low distortion: 68 dB SFDR @ 5 MHz 200 Ω load NC = NO CONNECT
01072-001
Power supply range +2.7 V to ±5 V
Figure 1.
APPLICATIONS Video line driver Digital line driver Low power differential ADC driver Differential in/out level shifting Single-ended input to differential output driver GENERAL DESCRIPTION
The AD8131 is a differential or single-ended input to
–20
differential output driver requiring no external components for Δ
VOUT, dm = 2V p-p
Δ
V
a fixed gain of 2. The AD8131 is a major advancement over op
OUT, cm/
Δ
VOUT, dm –30
amps for driving signals over long lines or for driving differential input ADCs. The AD8131 has a unique internal
–40
feedback feature that provides output gain and phase matching that are balanced to −60 dB at 10 MHz, reducing radiated EMI
RROR (dB) –50 E
and suppressing harmonics. Manufactured on the Analog
V
Devices, Inc. next generation XFCB bipolar process, the
S = +5V –60 BALANCE
AD8131 has a −3 dB bandwidth of 400 MHz and delivers a differential signal with very low harmonic distortion.
–70 VS =
±
5V
The AD8131 is a differential driver for the transmission of
–80
01072-002 high-speed signals over low-cost twisted pair or coax cables.
1 10 100 1000 FREQUENCY (MHz)
The AD8131 can be used for either analog or digital video Figure 2. Output Balance Error vs. Frequency signals or for other high-speed data transmission. The AD8131 driver is capable of driving either Cat3 or Cat5 twisted pair or The AD8131’s differential output also helps balance the input coax with minimal line attenuation. The AD8131 has for differential ADCs, optimizing the distortion performance of considerable cost and performance improvements over discrete the ADCs. The common-mode level of the differential output is line driver solutions. adjustable by a voltage on the VOCM pin, easily level-shifting the input signals for driving single-supply ADCs with dual supply The AD8131 can replace transformers in a variety of applications, signals. Fast overload recovery preserves sampling accuracy. preserving low frequency and dc information. The AD8131 does not have the susceptibility to magnetic interference and hysteresis The AD8131 is available in both SOIC and MSOP packages for of transformers. It is smaller, easier to work with, and has the high operation over −40°C to +125°C. reliability associated with ICs.
Rev. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. or otherwise under any patent or patent rights of Analog Devices. Trademarks and Tel: 781.329.4700 www.analog.com registered trademarks are the property of their respective owners. Fax: 781.461.3113 ©2005 Analog Devices, Inc. All rights reserved.
Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION SPECIFICATIONS ±DIN TO ±OUT SPECIFICATIONS VOCM TO ±OUT SPECIFICATIONS ±DIN TO ±OUT SPECIFICATIONS VOCM TO ±OUT SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS OPERATIONAL DESCRIPTION THEORY OF OPERATION ANALYZING AN APPLICATION CIRCUIT CLOSED-LOOP GAIN ESTIMATING THE OUTPUT NOISE VOLTAGE CALCULATING THE INPUT IMPEDANCE OF AN APPLICATION CIRCUIT INPUT COMMON-MODE VOLTAGE RANGE IN SINGLE-SUPPLY APPLICATIONS SETTING THE OUTPUT COMMON-MODE VOLTAGE DRIVING A CAPACITIVE LOAD APPLICATIONS TWISTED-PAIR LINE DRIVER 3 V SUPPLY DIFFERENTIAL A-TO-D DRIVER UNITY-GAIN, SINGLE-ENDED-TO-DIFFERENTIAL DRIVER OUTLINE DIMENSIONS ORDERING GUIDE