Texas Instruments OPA3684 Data Sheet

查询DEM-OPA368XD供应商

OPA3684

OPA3684

SBOS241A – MAY 2002 – REVISED SEPTEMBER 2002

Low-Power, Triple Current-Feedback OPERATIONAL AMPLIFIER With Disable FEATURES APPLICATIONS MINIMAL BANDWIDTH CHANGE VERSUS GAIN RGB LINE DRIVERS

170MHz BANDWIDTH: G = +2 LOW-POWER BROADCAST VIDEO DRIVERS > 120MHz BANDWIDTH TO GAIN > +10 EQUALIZING FILTERS LOW DISTORTION: < –82d Bc at 5MHz MULTICHANNEL SUMMING AMPLIFIERS HIGH OUTPUT CURRENT: 120m A PROFESSIONAL CAMERAS SINGLE +5V TO +12V SUPPLY OPERATION ADC INPUT DRIVERS DUAL ±2.5V TO ±6.0V SUPPLY OPERATION LOW SUPPLY CURRENT: 1.7m A/ch LOW SHUTDOWN CURRENT: 100µA/ch

have greater bandwidth, and low-power line drivers to meet the

DESCRIPTION

demanding requirements of studio cameras and broadcast video.

The OPA3684 provides a new level of performance in low-power,

The output capability of the OPA3684 also sets a new mark in

wideband, current-feedback (CFB) amplifiers. This CFBPLUS am-

performance for low-power current-feedback amplifiers. Delivering

plifier among the first to use an internally closed-loop input buffer

or al iz ed ai (3 d B /d iv a full ±4Vp-p swing on ±5V supplies, the OPA3684 also has the

stage that enhances performance significantly over earlier low-

output current to support > ±3Vp-p into 50Ω. This minimal output

power CFB amplifiers. While retaining the benefits of very low

headroom requirement is complemented by a similar 1.2V input

power operation, this new architecture provides many of the

stage headroom giving exceptional capability for single +5V opera-

benefits of a more ideal CFB amplifier. The closed-loop input stage

tion.

buffer gives a very low and linearized impedance path at the

The OPA3684’s low 1.7m A/ch supply current is precisely trimmed

inverting input to sense the feedback error current. This improved

at 25°C. This trim, along with low shift over temperature and supply

inverting input impedance retains exceptional bandwidth to much

voltage, gives a very robust design over a wide range of operating

higher gains and improves harmonic distortion over earlier solu-

conditions. System power may be further reduced by using the

tions limited by inverting input linearity. Beyond simple high-gain

optional disable control pin. Leaving this disable pin open, or holding

applications, the OPA3684 CFBPLUS amplifier permits the gain

it HIGH, gives normal operation. If pulled LOW, the OPA3684 supply

setting element to be set with considerable freedom from amplifier

current drops to less than 100µA/ch while the I/O pins go to a high

bandwidth interaction. This allows frequency response peaking

impedance state.

elements to be added, multiple input inverting summing circuits to

BW (MHz) vs GAIN

1 of 3 Channels

VO G = 5

V– Z(S) IERR

IERR G = 20

RF G = 50

–21 RF = 800Ω G = 100 –24

RG Low-Power Amplifier MHz

Patent Pending

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 © 2002, Texas Instruments Incorporated Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

www.ti.com