Analog Devices AD8260 Evaluation Board AD8260-EVALZ AD8260-EVALZ 数据表
产品代码
AD8260-EVALZ
High Current Driver Amplifier and
Digital VGA/Preamplifier with 3 dB Steps
AD8260
Rev. A
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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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.
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Tel: 781.329.4700
Tel: 781.329.4700
Fax: 781.461.3113 ©2008–2011 Analog Devices, Inc. All rights reserved.
FEATURES
High current driver
Differential input—direct drive from DAC
Preset gain: 1.5×
−3 dB bandwidth: 195 MHz
Large output drive: >±300 mA
Preset gain: 1.5×
−3 dB bandwidth: 195 MHz
Large output drive: >±300 mA
VGA/preamplifier
Low noise
Voltage noise: 2.4 nV/√Hz
Current noise: 5 pA/√Hz
Current noise: 5 pA/√Hz
−3 dB bandwidth: 230 MHz
Gain range: 30 dB in 3 dB steps
Gain range: 30 dB in 3 dB steps
−6 dB to +24 dB (for preamplifier gain of 6 dB)
Single-ended preamplifier input and differential VGA
output
Supplies: 3.3 V to 10 V (with VMID enabled)
±3.3 V to ±5 V (with VMID disabled)
Power: 93 mW with 3.3 V supplies
Power-down for VGA, driver amplifier, and system
APPLICATIONS
Digital AGC systems
Tx/Rx signal processing
Power line transceivers
Tx/Rx signal processing
Power line transceivers
FUNCTIONAL BLOCK DIAGRAM
32
2
3
6
31
30
1.5k
Ω 1kΩ
29
28
27
26
25
1k
Ω 1.5kΩ
GM
HIGH CURRENT DRIVER
9
24
23
22
21
VMID
4
1
AD8260
VMDO
TXEN
VMDI
VNCM
VPSB
ENBL
VGAP
VGAN
VNGR VPSR GNS3 GNS2 GNS1 GNS0 PRAO VNGR
VOCM INPP INRP INRN INPN TXFB VNEG
VNEG
TXOP
TXOP
VPOS
VPOS
VPSR
VMDO
PRAI
FDBK
07192-
001
5
7
8
10
11
12
13
14
16
15
17
18
19
20
BIAS
VGA/PREAMPLIFIER
ATTENUATOR
GM STAGES
LOGIC
×1
+
–
Figure 1. Functional Block Diagram
GENERAL DESCRIPTION
The AD8260 includes a high current driver, usable as a
transmitter, and a low noise digitally programmable variable
gain amplifier (DGA), useable as a receiver.
The receiver section consists of a single-ended input preampli-
fier, and linear-in-dB, differential-output DGA. The receiver has
a small signal –3 dB bandwidth of 230 MHz; the driver small
signal bandwidth is 195 MHz. The driver delivers ±300 mA,
well suited for driving low impedance loads, even when
connected to a 3.3 V supply.
The AD8260 DGA is ideal for trim applications and has a gain
span of 30 dB, in 3 dB steps. Excellent bandwidth uniformity is
maintained across the entire frequency range. The low output-
referred noise of the DGA is advantageous in driving high
speed ADCs. The differential output facilitates the interface to
modern low voltage high speed ADCs.
Single-supply and dual-supply operation makes the part versatile
and enables gain control of negative-going pulses, such as those
generated by photodiodes or photo-multiplier tubes, as well as
processing band-pass signals on a single supply. For maximum
transmitter, and a low noise digitally programmable variable
gain amplifier (DGA), useable as a receiver.
The receiver section consists of a single-ended input preampli-
fier, and linear-in-dB, differential-output DGA. The receiver has
a small signal –3 dB bandwidth of 230 MHz; the driver small
signal bandwidth is 195 MHz. The driver delivers ±300 mA,
well suited for driving low impedance loads, even when
connected to a 3.3 V supply.
The AD8260 DGA is ideal for trim applications and has a gain
span of 30 dB, in 3 dB steps. Excellent bandwidth uniformity is
maintained across the entire frequency range. The low output-
referred noise of the DGA is advantageous in driving high
speed ADCs. The differential output facilitates the interface to
modern low voltage high speed ADCs.
Single-supply and dual-supply operation makes the part versatile
and enables gain control of negative-going pulses, such as those
generated by photodiodes or photo-multiplier tubes, as well as
processing band-pass signals on a single supply. For maximum
dynamic range, it is essential that the part be ac-coupled when
operating on a single supply.
The AD8260 preamplifier (PrA) is configured with external
resistors for gains greater than 6 dB and can be inverting or
noninverting. The DGA is characterized with a noninverting
preamplifier gain of 2×. The attenuator has a range of 30 dB and
the output amplifier has a gain of 8× (18.06 dB). The lowest
noninverting gain range is −6 dB to +24 dB and shifts up with
increased preamplifier gain. The gain is controlled via a parallel
port (Pin GNS0 to Pin GNS3) with 10 gain steps of 3 dB per
code. The preamplifier and DGA are disabled for any code that
is not assigned a gain step.
The AD8260 can operate with single or dual supplies from 3.3 V
to ±5 V. An internal buffer normally provides a split supply
reference for single-supply operation; an external reference
can also be used when the VMID buffer is shut down.
The operating temperature range is −40°C to +105°C. The
AD8260 is available in a 5 mm × 5 mm, 32-lead LFCSP.
operating on a single supply.
The AD8260 preamplifier (PrA) is configured with external
resistors for gains greater than 6 dB and can be inverting or
noninverting. The DGA is characterized with a noninverting
preamplifier gain of 2×. The attenuator has a range of 30 dB and
the output amplifier has a gain of 8× (18.06 dB). The lowest
noninverting gain range is −6 dB to +24 dB and shifts up with
increased preamplifier gain. The gain is controlled via a parallel
port (Pin GNS0 to Pin GNS3) with 10 gain steps of 3 dB per
code. The preamplifier and DGA are disabled for any code that
is not assigned a gain step.
The AD8260 can operate with single or dual supplies from 3.3 V
to ±5 V. An internal buffer normally provides a split supply
reference for single-supply operation; an external reference
can also be used when the VMID buffer is shut down.
The operating temperature range is −40°C to +105°C. The
AD8260 is available in a 5 mm × 5 mm, 32-lead LFCSP.