HA4201 Datasheet, PDF (3/7 Pages) Intersil Corporation – 480MHz, 1 x 1 Video Crosspoint Switch with Tally Output

HA4201
Electrical Specifications V_SUPPLY = ±5V, R_L = 10kΩ, V_EN = 2.0V, Unless Otherwise Specified (Continued)
PARAMETER
TEST CONDITIONS
TEMP.
(^oC)
MIN
TYP
±0.1dB Flat Bandwidth
Input Resistance
R_S = 82Ω, C_L = 10pF
R_S = 43Ω, C_L = 15pF
R_S = 36Ω, C_L = 21pF
25
-
250
25
-
175
25
-
170
Full
200
400
Input Capacitance
Full
-
1.0
Enabled Output Resistance
Full
-
15
Disabled Output Capacitance
Differential Gain
V_EN = 0.8V
4.43MHz, Note 3
Full
-
2.0
25
-
0.01
Differential Phase
4.43MHz, Note 3
25
-
0.01
Off Isolation
Slew Rate
(1.5V_P-P, +SR/-SR)
Total Harmonic Distortion (Note 3)
1V_P-P, 100MHz, V_EN = 0.8V, R_L = 10Ω
Full
R_S = 82Ω, C_L = 10pF
25
R_S = 43Ω, C_L = 15pF
25
R_S = 36Ω, C_L = 21pF
25
Full
-
85
-
1750/1770
-
1460/1360
-
1410/1360
-
0.01
Disabled Output Resistance
Full
-
12
NOTE:
3. This parameter is not tested. The limits are guaranteed based on lab characterization, and reflect lot-to-lot variation.
MAX
-
-
-
-
-
-
-
0.02
0.02
-
-
-
-
0.1
-
UNITS
MHz
MHz
MHz
kΩ
pF
Ω
pF
%
Degrees
dB
V/µs
V/µs
V/µs
%
MΩ
AC Test Circuit
V_IN
75Ω
HA4201
500Ω ^400Ω
510Ω
R_S
-
75Ω
+
HFA1100
C_X 10kΩ
V_OUT
NOTE: C_L = C_X + Test Fixture Capacitance.
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 (10µF) tantalum in parallel with a small value
(0.1µF) 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.
3
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 75Ω 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
output resistor, R_S, to tune the response for the specific load
capacitance, C_L, driven. Bandwidth and slew rate degrade
as C_L increases (as shown in the Electrical Specification
table), so give careful consideration to component
placement to minimize trace length. As an example, -3dB
bandwidth decreases to 160MHz for C_L = 100pF, R_S = 0Ω.
In big matrix configurations where C_L is large, better
frequency response is obtained by cascading two levels of
crosspoints in the case of multiplexed outputs (see Figure 2),
or distributing the load between two drivers if C_L is due to
bussing and subsequent stage input capacitance.