3-3

AC Test Circuit

PC Board Layout

The frequency response of this circuit depends greatly on the

care taken in designing the PC board. The use of low

inductance components such as chip resistors and chip

capacitors is strongly recommended, while a solid ground

plane is a must!

Attention should be given to decoupling the power supplies.

A large value (10

µF) tantalum in parallel with a small value

(0.1

µF) chip capacitor works well in most cases.

Keep input and output traces as short as possible, because

trace inductance and capacitance can easily become the

performance limiting items.

Application Information

General

The HA4600 is a unity gain buffer that is optimized for high

performance video applications. The output disable function

makes it ideal for the matrix element in small, high input-to-

output isolation switchers and routers. This buffer contains no

feedback or gain setting resistors, so the output is a true high

impedance load when the IC is disabled (EN = 0). The HA4600

also excels as an input buffer for routers with a large number of

outputs (i.e. each input must connect to a large number of

outputs) and delivers performance superior to most video

amplifiers at a fraction of the cost. As an input buffer, the

HA4600’s low input capacitance and high input resistance

provide excellent video terminations when used with an

external 75

Ω resistor.

Frequency Response

Most applications utilizing the HA4600 require a series

table), so give careful consideration to component

placement to minimize trace length. As an example, -3dB

±0.1dB Flat Bandwidth

25

-

250

-

MHz

25

-

175

-

MHz

25

-

170

-

MHz

Input Resistance

Full

200

400

-

k

Ω

Input Capacitance

Full

-

1.0

-

pF

Enabled Output Resistance

Full

-

15

-

Ω

Disabled Output Capacitance

Full

-

2.0

-

pF

Differential Gain (Note 3)

4.43MHz

25

-

0.01

0.02

%

Differential Phase (Note 3)

4.43MHz

25

-

0.01

0.02

Degrees

Off Isolation

Full

-

85

-

dB

25

-

1750/1770

-

V/

µs

25

-

1460/1360

-

V/

µs

25

-

1410/1360

-

V/

µs

Total Harmonic Distortion (Note 3)

Full

-

0.01

0.1

%

Disabled Output Resistance

Full

-

12

-

M

Ω

NOTE:

3. This parameter is not tested. The limits are guaranteed based on lab characterization, and reflect lot-to-lot variation.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

500

Ω

400

Ω

510

Ω

75

Ω

75

Ω

HA4600

HFA1100

+

-

10k

Ω

HA4600