Triple Differential Driver

for Wideband Video

AD8146/AD8147/AD8148

Rev. 0

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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

FUNCTIONAL BLOCK DIAGRAMS

AD8146

–IN C

+IN C

18

17

16

15

14

–OUT C

13

24

23

22

21

20

19

7

8

9

10

11

12

A

B

C

Figure 1.

AD8147/

AD8148

OPD

1

–IN R

3

+IN R

4

SYNC LEVEL

–IN B

+IN B

18

17

16

15

14

–OUT R

6

–OUT B

13

24

23

22

21

20

19

7

8

9

10

11

12

A

B

C

×2

Figure 2.

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 differential-

to-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

of 700 MHz and fast slew rates. They have an internal common-

mode 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 common-

mode 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.