MAX4158ESA Maxim, MAX4158ESA Datasheet - Page 12

• Manufacturer Part Number: MAX4158ESA
• Description: 350MHz/250MHz / 2-Channel Video Multiplexer-Amplifiers
• Manufacturer: Maxim

Table 2. MAX4258/MAX4259 Bandwidth
and Gain vs. Gain-Setting Resistors
gives:
V
V
The MAX4158/MAX4159/MAX4258/MAX4259 output
offset voltage, V
the following equation:
V
where:
The following equation represents output noise density:
where:
The MAX4158/MAX4159/MAX4258/MAX4259 have a
very low, 2nV/√Hz noise voltage. The current noise at
the input (i
feedback input (i
An example of DC-error calculations, using the
MAX4258 typical data and the typical operating circuit
with R
350MHz/250MHz, 2-Channel
Video Multiplexer-Amplifiers
12
(V/V)
OUT
OUT
OUT
V
1 + R
I
I
R
R
R
i
e
10
B
FB
n
2
5
n
OS
G
F
S
GAIN
______________________________________________________________________________________
e OUT = 1+R /R
= input noise current density (in A/√Hz)
= input noise voltage density (in V/√Hz)
= [1 x 10
= 3.22mV
= V
F
n
F
i
n
= R
I
(dB)
[2 x 10
FB
/ R
14
20
OS
6
x R
n
G
G
x R
) is 2pA/√Hz, and the current noise at the
x [1 + R
= input offset voltage (in volts)
= amplifier closed-loop gain (dimensionless)
= input bias current (in amps)
= feedback input bias current (in amps)
= gain-setting resistor (in ohms)
= feedback resistor (in ohms)
= source resistor (in ohms)
S
= 510Ω (R
F
-3
-6
2
510
OUT
R
(Ω)
45
20
n(FB)
x (1 + 1)] + [2 x 10
x 510]
G
i
F
n FB
(Figure 2) can be calculated with
) is 22pA/√Hz.
F
/ R
510
180
180
(Ω)
F
R
G
G
F
|| R
] + I
x R
x
G
DC Errors and Noise
B
F
= 255Ω) and R
-3dB BW
||
x R
(MHz)
250
195
R
90
G
S
-6
x [1 + R
x 50 x (1 + 1)] +
2
e
0.1dB BW
n
F
(MHz)
S
2
130
92
14
/ R
= 50Ω,
G
] +
Calculating total output noise in a similar manner yields
the following:
With a 200MHz system bandwidth, this calculates to
168µV
sigma calculation).
The MAX4158/MAX4159/MAX4258/MAX4259 are opti-
mized to drive coaxial transmission lines when the
cable is terminated at both ends (Figure 3). Cable fre-
quency response may cause variations in the flatness
of the signal.
Figure 2. Output Offset Voltage
e n OUT = 1 + 1
e n OUT = 1.9nV/ Hz
2
x
RMS
10
R
S
12
1
(approximately 1.01mVp-p, using the six-
R
I
G
FB
I
B
x
50
x
2
IN_
FB
22
x
10
R
F
12
Video Line Driver
MAX4158
MAX4159
MAX4258
MAX4259
x
255
OUT
2
2
V
OUT
x
10
9
2