Triple Differential Driver

With Sync-On-Common-Mode

AD8134

Rev. A

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FEATURES

Triple high speed differential driver

225 MHz, −3 dB large signal bandwidth

450 MHz, −3 dB small signal bandwidth

Easily drives 1.4 V p-p video signal into doubly terminated

100 Ω UTP cable

1600 V/μs slew rate

Fixed internal gain of 2

Internal common-mode feedback network

Output balance error −60 dB @ 50 MHz

On-chip sync-on-common-mode circuitry

Output pull-down feature for line isolation

Differential input and output

Differential-to-differential or single-ended-to-differential

operation

High isolation between amplifiers: 80 dB @ 10 MHz

Low distortion: 64 dB SFDR @ 10 MHz on 5 V supply,

Low offset: 3 mV typical output-referred on 5 V supply

Low power: 26.5 mA @ 5 V for three drivers and sync circuitry

Wide supply voltage range: +5 V to ±5 V

Available in space-saving packaging: 4 mm × 4 mm LFCSP

APPLICATIONS

Keyboard-video-mouse (KVM) networking

GENERAL DESCRIPTION

The AD8134 is a major advancement beyond using discrete

op amps for driving differential RGB signals over twisted pair

cable. The AD8134 is a triple, low cost differential or single-

ended input to differential output driver, and each amplifier has

a fixed gain of 2 to compensate for the attenuation of the line

termination resistors. The AD8134 is specifically designed for

RGB signals but can be used for any type of analog signals or

high speed data transmission. The AD8134 is capable of driving

either Category 5 (Cat-5) unshielded twisted pair (UTP) cable

or differential printed circuit board transmission lines with

minimal signal degradation.

A unique feature that allows the user to transmit balanced

horizontal and vertical video sync signals over the three

common-mode channels with minimal electromagnetic

interference (EMI) radiation is included on-chip.

The outputs of the AD8134 can be set to a low voltage state that

allows easy differential multiplexing of multiple drivers on the

same twisted pair cable, when used with external series diodes.

FUNCTIONAL BLOCK DIAGRAM

AD8134

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

×2

R

G

B

Figure 1.

FREQUENCY (MHz)

0

–20

–10

–40

–30

–60

–50

–80

–70

–100

–90

1

10

100

500

ΔV

ΔV

Figure 2. Output Balance vs. Frequency

The AD8134 driver is a natural complement to the AD8143,

AD8129, and AD8130 differential receivers.

Manufactured on the Analog Devices next generation XFCB

bipolar process, the AD8134 has a large signal bandwidth of

225 MHz and a slew rate of 1600 V/μs. The AD8134 has an

internal common-mode feedback feature that provides output

gain and phase matching that is balanced to −60 dB at 50 MHz,

suppressing harmonics and reducing radiated EMI.

The AD8134 is available in a 24-lead LFCSP and can operate

over the −40°C to +85°C extended industrial temperature range.