MAX4102/MAX4103
250MHz, Broadcast-Quality, Low-Power
Video Op Amps
8 _______________________________________________________________________________________
_______________Detailed Description
The MAX4102/MAX4103 low-power, high-speed op
amps feature ultra-low differential gain and phase, and
are optimized for the highest quality video applications.
Differential gain and phase errors are 0.002%/0.002°
for the MAX4102 and 0.008%/0.003° for the MAX4103.
The MAX4102 also features a -3dB bandwidth of over
250MHz and 0.1dB gain-flatness of 130MHz. The
MAX4103 features a -3dB bandwidth of 180MHz and a
0.1dB bandwidth of 80MHz.
The MAX4102 is unity-gain stable, and the MAX4103 is
optimized for closed-loop gains of 2V/V (6dB) and higher.
Both devices drive back-terminated 50Ω or 75Ω cables to
±3.1V (min) and deliver an output current of 80mA.
Available in a small 8-pin SO package, the MAX4102/
MAX4103 are ideal for high-definition TV systems (in
RGB, broadcast, or consumer video applications) that
benefit from low power consumption and superior dif-
ferential gain and phase characteristics.
__________Applications Information
Grounding, Bypassing,
and PC Board Layout
In order to achieve the full bandwidth, Microstrip and
Stripline techniques are recommended in most cases.
To ensure your PC board does not degrade the amp’s
performance, it’s wise to design the board for a fre-
quency greater than 1GHz. Even with very short runs,
it’s good practice to use this technique at critical
points, such as inputs and outputs. Whether you use a
constant-impedance board or not, observe the follow-
ing guidelines when designing the board:
• Do not use wire-wrap boards, because they are too
inductive.
• Do not use IC sockets. They increase parasitic
capacitance and inductance.
• In general, surface-mount components have shorter
leads and lower parasitic reactance, and give better
high-frequency performance than through-hole com-
ponents.
• The PC board should have at least two layers, with
one side a signal layer and the other a ground plane.
• Keep signal lines as short and as straight as possi-
ble. Do not make 90° turns; round all corners.
• The ground plane should be as free from voids as
possible.
On Maxim’s evaluation kit, the ground plane has been
removed from areas where keeping the trace capaci-
tance to a minimum is more important than maintaining
ground continuity. For example, the ground plane has
been removed from beneath the IC to minimize pin
capacitance.
The bypass capacitors should include a 0.1µF at each
supply pin and the ground plane, located as close to the
package as possible. Then place a 10µF to 15µF low-
ESR tantalum at the point of entry (to the PC board) of
the power-supply pins. The power-supply trace should
lead directly from the tantalum capacitor to the V
CC
and
V
EE
pins to maintain the low differential gain and phase
of these devices.
Setting Gain
The MAX4102/MAX4103 are voltage-feedback op
amps that can be configured as an inverting or nonin-
verting gain block, as shown in Figures 1a and 1b. The
gain is determined by the ratio of two resistors and
does not affect amplifier frequency compensation.
In the unity-gain configuration (Figure 1c), maximum
bandwidth and stability are achieved with the MAX4102
when a small feedback resistor is included. This resis-
tor suppresses the negative effects of parasitic induc-
tance and capacitance. A value of 24Ω provides the
best combination of wide bandwidth, low peaking, and
fast settling time. In addition, this resistor reduces the
errors from input bias currents.
Choosing Resistor Values
The values of feedback and input resistors used in the
inverting or noninverting gain configurations are not
critical (as is the case with current-feedback ampli-
fiers), but should be kept small and noninductive.
Not internally connectedN.C.8
Positive Power Supply. Connect
to +5V
V
CC
7
Amplifier OutputOUT6
Not internally connectedN.C.5
Negative Power Supply. Connect
to -5V
V
EE
4
Noninverting InputIN+3
Inverting InputIN-2
Not internally connectedN.C.1
FUNCTIONNAMEPIN
_____________________Pin Description
