ANALOG DEVICES AD8146 Service Manual

Triple Differential Driver
A
C
R
R

FEATURES

Triple high speed fully differential driver
700 MHz, −3 dB, 2 V p-p bandwidth (AD8146/AD8148) 600 MHz, −3 dB, 2 V p-p bandwidth (AD8147) 200 MHz, 0.1 dB, 2 V p-p bandwidth
3000 V/μs slew rate Fixed gain (AD8146/AD8147: G = 2, AD8148: G = 4) Differential or single-ended input to differential output
Can be used as differential-to-differential receiver Drives one or two 100 Ω UTP cables Adjustable output common-mode voltage (AD8146) Internal common-mode feedback network
Output balance error −50 dB @ 50 MHz On-chip, sync-on common-mode encoding (AD8147/AD8148) Output pull-down feature for line isolation Low power: 57 mA @ 5 V for 3 drivers (AD8146) Wide supply voltage range: +5 V to ±5 V Available in a small 4 mm × 4 mm LFCSP

APPLICATIONS

QXGA or 1080p video transmission KVM networking Video over unshielded twisted pair (UTP) Differential signal multiplexing

GENERAL DESCRIPTION

The AD8146/AD8147/AD8148 are high speed triple, differential or single-ended input to differential output drivers. The AD8146 and AD8147 have a fixed gain of 2, and the AD8148 has a fixed gain of 4. They are all specifically designed for the highest resolution component video signals but can be used for any type of analog signals or high speed data transmission over either Category 5 UTP cable or differential printed circuit board (PCB) transmission lines.
These drivers can be used with the AD8145 triple differential­to-singled-ended receiver, and the AD8117 crosspoint switch to produce a video distribution system capable of supporting UXGA or 1080p signals.
Manufactured on the Analog Devices, Inc. second generation XFCB bipolar process, the drivers have large signal bandwidths
Rev. A
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.
for Wideband Video
AD8146/AD8147/AD8148

FUNCTIONAL BLOCK DIAGRAMS

VS+–IN B
24 23 22 21 20
OPD
1
V
2
S–
3
–IN A +IN A
4
V
5
S–
–OUT A
6
7 8 9 10 11
VS+–IN G
24 23 22 21 20
1
OPD
–IN R
+IN R
OUT
V
S–
V
S–
AD8147/ AD8148
2
3
4
5
6
A
7 8 9 10 11
+OUT
of 700 MHz and fast slew rates. They have an internal common­mode feedback feature that provides output amplitude and phase matching that is balanced to −60 dB at 50 MHz, suppressing even-order harmonics and minimizing radiated electromagnetic interference (EMI).
The common-mode voltage of each AD8146 output can be set to any level, allowing transmission of signals over the common­mode voltages. The AD8147 and AD8148 encode the vertical and horizontal sync signals on the common-mode voltages of the outputs. All outputs can be independently set to low voltage states to be used with series diodes for line isolation, allowing easy differential multiplexing over the same twisted pair cable.
The AD8146/AD8147/AD8148 are available in a 24-lead LFCSP and operate over a temperature range of −40°C to +85°C.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2007–2010 Analog Devices, Inc. All rights reserved.
+IN B
B
A
S+
V
+OUT A
+OUT B
Figure 1.
(SYNC)
S–
+IN G
V
×2
B
S+
V
–OUT G
+OUT G
Figure 2.
OCM
VS–V
AD8146
C
S+
V
–OUT B
SYNC
V
S+
V
B
OCM
V
19
18
V
C
OCM
17
V
S+
16
–IN C
15
+IN C V
14
S–
–OUT C
13
12
+OUT
SYNC
H
19
18
SYNC LEVEL
V
17
S+
16
–IN B
15
+IN B
V
14
13
S–
–OUT B
C
12
+OUT B
09327-001
(SYNC)
09327-002
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