AD8336 Datasheet, PDF (1/28 Pages) Analog Devices – General-Purpose, −55 to +125, Wide Bandwidth, DC-Coupled VGA

General-Purpose, −55°C to +125°C,
Wide Bandwidth, DC-Coupled VGA
AD8336
FEATURES
Low noise
Voltage noise: 3 nV/√Hz
Current noise: 3 pA/√Hz
Small signal BW: 115 MHz
Large signal BW: 2 V p-p = 80 MHz
Slew rate: 550 V/µs, 2 V p-p
Gain ranges (specified)
−14 dB to +46 dB,
0 dB to 60 dB
Gain scaling: 50 dB/V
DC-coupled
Single-ended input and output
Supplies: ±3 V to ±12 V
Temperature Range: −55°C to +125°C
Power
150 mW @ ±3 V, −55°C < T < +125°C
84 mW @ ±3 V, PWRA = 3 V
APPLICATIONS
Industrial process controls
High performance AGC systems
I/Q signal processing
Video
Industrial and medical ultrasound
Radar receivers
GENERAL DESCRIPTION
The AD8336 is a low noise, single-ended, linear-in-dB, general-
purpose variable gain amplifier, usable over a large range of
supply voltages. It features an uncommitted preamplifier
(preamp) with a usable gain range of 6 dB to 26 dB established
by external resistors in the classical manner. The VGA gain
range is 0 dB to 60 dB, and its absolute gain limits are −26 dB to
+34 dB. When the preamplifier gain is adjusted for 12 dB, the
combined 3 dB bandwidth of the preamp and VGA is 100 MHz,
and the amplifier is fully usable to 80 MHz. With ±5 V supplies,
the maximum output swing is 2 V p-p.
Thanks to its X-Amp® architecture, excellent bandwidth
uniformity is maintained across the entire gain range of the
VGA. Intended for a broad spectrum of applications, the
differential gain control interface provides precise linear-in-dB
gain scaling of 50 dB/V over the temperature span of −55°C to
+125 °C. The differential gain control is easy to interface with a
variety of external circuits within the common-mode voltage
limits of the AD8336.
FUNCTIONAL BLOCK DIAGRAM
PRAO VGAI
8
9
AD8336
INPP 4
INPN 5
+
PrA
–
ATTENUATOR
–60dB TO 0dB
34dB
1 VOUT
PWRA 2
BIAS
GAIN CONTROL
INTERFACE
10
VNEG
13
VPOS
3
VCOM
Figure 1.
11
GPOS
12
GNEG
The large supply voltage range makes the AD8336 particularly
suited for industrial medical applications and for video circuits.
Dual-supply operation enables bipolar input signals, such as
those generated by photodiodes or photomultiplier tubes.
The fully independent voltage feedback preamp allows both
inverting and noninverting gain topologies, making it a fully
bipolar VGA. The AD8336 can be used within the specified
gain range of −14 dB to +60 dB by selecting a preamp gain
between 6 dB and 26 dB and choosing appropriate feedback
resistors. For the nominal preamp gain of 4×, the overall gain
range is −14 dB to +46 dB.
In critical applications, the quiescent power can be reduced by
about half by using the power adjust pin, PWRA. This is
especially useful when operating with high supply voltages of
up to ±12 V, or at high temperatures.
The operating temperature range is −55°C to +125°C. The
AD8336 is available in a 16-lead LFCSP (4 mm × 4 mm).
Rev. 0
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 or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
©2006 Analog Devices, Inc. All rights reserved.