DESCRIPCIÓN GENERAL

The AD8065/AD80661 FastFET™ amplifiers are voltage feedback amplifiers with FET inputs offering high performance and ease of use. The AD8065 is a single amplifier, and the AD8066 is a dual amplifier. These amplifiers are developed in the Analog Devices, Inc. proprietary XFCB process and allow exceptionally low noise operation (7.0 nV/√Hz and 0.6 fA/√Hz) as well as very high input impedance. With a wide supply voltage range from 5 V to 24 V, the ability to operate on single supplies, and a bandwidth of 145 MHz, the AD8065/AD8066 are designed to work in a variety of applications. For added versatility, the amplifiers also contain rail-to-rail outputs. Despite the low cost, the amplifiers provide excellent overall performance. The differential gain and phase errors of 0.02% and 0.02°, respectively, along with 0.1 dB flatness out to 7 MHz, make these amplifiers ideal for video applications. Additionally, they offer a high slew rate of 180 V/µs, excellent distortion (SFDR of −88 dBc @ 1 MHz), extremely high common-mode rejection of −100 dB, and a low input offset voltage of 1.5 mV maximum under warmed up conditions. The AD8065/AD8066 operate using only a 6.4 mA/amplifier typical supply current and are capable of delivering up to 30 mA of load current.  The AD8065/AD8066 are high performance, high speed, FET input amplifiers available in small packages: SOIC-8, MSOP-8, and SOT-23-5. They are rated to work over the industrial temperature range of −40°C to +85°C. The AD8065WARTZ-R7 is fully qualified for automotive applications. It is rated to operate over the extended temperature range (−40°C to +105°C), up to a maximum supply voltage range of ±5 V only.

 

CARACTERÍSTICAS

Cualificado para aplicaciones de automoción

FET input amplifier

1 pA input bias current

Low cost

High speed: 145 MHz, −3 dB bandwidth (G = +1)

180 V/µs slew rate (G = +2)

Low noise 7 nV/√Hz (f = 10 kHz) 0.6 fA/√Hz (f = 10 kHz)

Wide supply voltage range: 5 V to 24 V

Single-supply and rail-to-rail output

Low offset voltage 1.5 mV maximum

High common-mode rejection ratio: −100 dB

Excellent distortion specifications

SFDR −88 dBc @ 1 MHz

Low power: 6.4 mA/amplifier typical supply current

Sin inversión de fase

Small packaging: SOIC-8, SOT-23-5, and MSOP-8

 

APLICACIONES

Automotive driver assistance systems

Photodiode preamps

Filtros

Controladores A/D

Level shifting

Buffering

 

TEORÍA DE FUNCIONAMIENTO

The AD8065/AD8066 are voltage feedback operational amplifiers that combine a laser-trimmed JFET input stage with the Analog Devices eXtra Fast Complementary Bipolar (XFCB) process, resulting in an outstanding combination of precision and speed. The supply voltage range is from 5 V to 24 V. The amplifiers feature a patented rail-to-rail output stage capable of driving within 0.5 V of either power supply while sourcing or sinking up to 30 mA. Also featured is a single-supply input stage that handles commonmode signals from below the negative supply to within 3 V of the positive rail. Operation beyond the JFET input range is possible because of an auxiliary bipolar input stage that functions with input voltages up to the positive supply. The amplifiers operate as if they have a rail-to-rail input and exhibit no phase reversal behavior for common-mode voltages within the power supply. With voltage noise of 7 nV/√Hz and −88 dBc distortion for 1 MHz, 2 V p-p signals, the AD8065/AD8066 are a great choice for high resolution data acquisition systems. Their low noise, sub-pA input current, precision offset, and high speed make them superb preamps for fast photodiode applications. The speed and output drive capability of the AD8065/AD8066 also make them useful in video applications.

CLOSED-LOOP FREQUENCY RESPONSE

The AD8065/AD8066 are classic voltage feedback amplifiers with an open-loop frequency response that can be approximated as the integrator response shown in Figure 53. Basic closed-loop frequency response for inverting and noninverting configurations can be derived from the schematics shown.