AD8264 Quad, 235 MHz, DC-Coupled VGA and Differential Output Amplifier

The AD8264 is a quad, linear-in-dB, general-purpose variable gain amplifier (VGA) with a preamplifier (preamp), and a flexible differential output buffer. DC coupling, combined with wide bandwidth, makes this amplifier a very good pulse processor. Each channel includes a single-ended input preamp/VGA section to preserve the wide bandwidth and fast slew rate for low distortion pulse applications. A 6 dB differential output buffer with common-mode and offset adjustments enable direct coupling to most modern high speed analog-to-digital converters (ADCs), using the converter reference output for perfect dc matching levels.

The −3 dB bandwidth of the preamp/VGA is dc to 235 MHz, and the bandwidth of the differential driver is 80 MHz. The floating gain control interface provides a precise linear-in-dB scale of 20 dB/V and is easy to interface to a variety of external circuits. The gain of each channel is adjusted independently, and all channels are referenced to a single pin, GNLO. Combined with a multioutput, digital-to-analog converter (DAC), each section of the AD8264 can be used for active calibration or as a trim amplifier.

Operation from a bipolar power supply enables amplification of negative voltage pulses generated by current-sinking pulses into a grounded load, such as is typical of photodiodes or photomultiplier tubes (PMT). Delay-free processing of wideband video signals is also possible.

Applications

Features and Benefits

Low noise

Voltage noise: 2.3 nV/√Hz

Current noise: 2 pA/√Hz

Wide bandwidth

Small signal: 235 MHz (VGAx); 80 MHz (output amplifier)

Large signal: 80 MHz
(1 V p-p)

Gain range

0 to 24 dB (input to VGA output)

6 to 30 dB (input to differential output)

Gain scaling: 20 dB/V

DC-coupled

Single-ended input and differential output

Supplies: ±2.5 V to ±5 V

Low power: 140 mW per channel at ±3.3 V

Amplifiers

Data Sheets

Document	note
AD8264: Quad, 235 MHz, DC Coupled VGA and Differential Output Amplifier Data Sheet (Rev. B)	PDF 1.11 M

Frequently Asked Questions

Document	note

Order Information

Part Number	Package	Packing Qty	Temp Range	Price 100-499	Price 1000+	RoHS
AD8264ACPZ Production	40 ld LFCSP (6x6mm w/4.10mm pad)	OTH 490	-40 to 85C	14.54	11.95	Y
AD8264ACPZ-R7 Production	40 ld LFCSP (6x6mm w/4.1mm pad)	REEL 750	-40 to 85C	14.54	11.95	Y
AD8264ACPZ-RL Production	40 ld LFCSP (6x6mm w/4.1mm pad)	REEL 2500	-40 to 85C	0	11.95	Y

Evaluation Boards

Part Number	Description	Price	RoHS
AD8264-EVALZ	Evaluation Board	172.41	Y

AD8264: Quad, 235 MHz, DC Coupled VGA and Differential Output Amplifier Data Sheet (Rev. B) ad8264