AD8334 Quad VGA with Ultralow Noise Preamplifier and Programmable RIN

The AD8334 is an ultralow noise, quad channel linear-in-dB variable gain amplifier (VGA). Although optimized for ultrasound systems, it may be used as a low noise variable gain control in any application whose operating frequency is less than 100 MHz.

Included in each channel are an ultralow noise preamp (LNA), an X-AMP® VGA with 48 dB of gain range, and a selectable gain postamp with adjustable output limiting. The LNA gain is 19 dB with a single-ended input and differential outputs. Using a single resistor, the LNA input impedance can be adjusted to match a signal source without compromising noise performance.

The 48 dB gain range of the VGA makes these devices suitable for a variety of applications. Excellent bandwidth uniformity is maintained across the entire range. The gain control interface provides precise linear-in-dB scaling of 50 dB/V for control voltages between 40 mV and 1 V. Factory trim ensures excellent part-to-part and channel-to-channel gain matching. Differential signal paths result in superb second- and third-order distortion performance and low crosstalk.

The AD8334 is a quad version of the single AD8331 and dual AD8332.

For information on specs, see the AD8331/AD8332/AD8334 datasheet.

Applications

Ultrasound and sonar time-gain controls
High performance automatic gain control (AGC) systems
I/Q signal processing
High speed, dual ADC drivers

Features and Benefits

Ultralow noise preamplifier (preamp)

Voltage noise = 0.74 nV/√Hz
Current noise = 2.5 pA/√Hz

Voltage noise = 0.74 nV/√Hz

Current noise = 2.5 pA/√Hz

3 dB bandwidth: 100 MHz

Low power: 145 mW/channel

Wide gain range with programmable postamp

−4.5 dB to +43.5 dB in LO gain mode
7.5 dB to 55.5 dB in HI gain mode

−4.5 dB to +43.5 dB in LO gain mode

7.5 dB to 55.5 dB in HI gain mode

Low output-referred noise: 48 nV/√Hz typical

Active input impedance matching

Optimized for 10-bit/12-bit ADCs

Selectable output clamping level

Single 5 V supply operation

AD8332 and AD8334 available in lead frame chip scale package

Amplifiers

Data Sheets

Document	note
AD8331/AD8332/AD8334: Ultralow Noise VGAs with Preamplifier and Programmable RIN Data Sheet (Rev. I)	PDF 1.91 M

Frequently Asked Questions

Document	note

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
AD8334ACPZ Production	64 ld LFCSP (9x9mm, 4.70mm exposed pad)	OTH 260	-40 to 85C	18.17	14.66	Y
AD8334ACPZ-REEL Production	64 ld LFCSP (9x9mm, 4.70mm exposed pad)	REEL 2500	-40 to 85C	0	14.66	Y
AD8334ACPZ-REEL7 Production	64 ld LFCSP (9x9mm, 4.70mm exposed pad)	REEL 750	-40 to 85C	18.17	14.66	Y