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 HA4201 is a 1 x 1 crosspoint switch that is ideal for the

matrix element in small, high input-to-output isolation

switchers and routers. It 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 HA4201’s low input

capacitance and high input resistance provide excellent

video terminations when used with an external 75

Ω resistor.

This crosspoint contains no feedback or gain setting

resistors, so the output is a true high impedance load when

the IC is disabled (EN = 0).

Frequency Response

Most applications utilizing the HA4201 require a series

table), so give careful consideration to component

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

frequency response is obtained by cascading two levels of

crosspoints in the case of multiplexed outputs (see Figure 2),

bussing and subsequent stage input capacitance.

±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

4.43MHz, Note 3

25

-

0.01

0.02

%

Differential Phase

4.43MHz, Note 3

25

-

0.01

0.02

Degrees

Off Isolation

Full

-

85

-

dB

Slew Rate

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

TEMP.

MIN

TYP

MAX

UNITS

500

Ω

400

Ω

510

Ω

75

Ω

75

Ω

HA4201

HFA1100

+

-

10k

Ω

HA4201