MAX4432 Maxim, MAX4432 Datasheet - Page 9

• Manufacturer Part Number: MAX4432
• Description: The MAX4430/MAX4431 single and MAX4432/MAX4433 dual operational amplifiers feature wide bandwidth, 16-bit settling times in 37ns, and low-noise/low-distortion operation
• Manufacturer: Maxim

The MAX4430–MAX4433 are wide-bandwidth, ultra-low-
distortion, voltage-feedback amplifiers. The MAX4430/
MAX4432 are internally compensated for unity gain.
The MAX4431/MAX4433 are internally compensated for
gains of +2V/V or greater.
These amplifiers have ultra-fast 37ns (MAX4430/
MAX4432) 16-bit settling times, 100dB SFDR at 1MHz,
and 4Vp-p output swing with minimum 110dB open-
loop gain.
The MAX4430–MAX4433 op amps are ideal for driving
high-speed 14- to 16-bit ADCs. In most cases, these
ADCs operate with a charge balance scheme, with
capacitive loads internally switched on and off from the
input. The driver used must withstand these changing
capacitive loads while holding the signal amplitude sta-
bility consistent with the ADC’s resolution and, at the
same time, have a frequency response compatible with
the sampling speed of the ADC (Figure 1).
The circuits typically used for the inverting and non-
inverting configurations of the MAX4430–MAX4433 are
shown in Figures 2a and 2b. The minimum uncondition-
ally stable gain values are 1 for the MAX4430/MAX4432
Figure 1. Typical Application Circuit
Figure 2a. Noninverting Configuration
Inverting and Noninverting Configurations
High-Speed ADC Input Driver Application
V
R
S
IN
_______________________________________________________________________________________
R
F
+V
-V
Detailed Description
Dual-Supply, 180MHz, 16-Bit Accurate,
EE
CC
I
F
A = 1 +
V
OUT
14/16-BIT ADC
HIGH-SPEED
R
R
F
S
=
Ultra-Low Distortion Op Amps
V
V
OUT
IN
and 2 for the MAX4431/MAX4433. Use care in selecting
the value for the resistor marked R
From dynamic stability considerations (based on the
part’s frequency response and the input capacitance of
the MAX4430–MAX4433), the maximum recommended
value for R
yield a higher bandwidth and better dynamic stability,
at the cost of higher power consumption, higher power
dissipation in the IC, and reduced output drive avail-
ability. For a minimum R
that the current indicated as I
stage and must be discounted from the maximum out-
put current to calculate the maximum current available
to the load. I
tion:
If DC thermal stability is an important design concern,
the Thevenin resistance seen by both inputs at DC
must be balanced. This includes the resistance of the
signal source and termination resistors if the amplifier
signal input is fed from a transmission line. The capaci-
tance associated with the feedback resistors must also
be considered as a possible limitation to the available
bandwidth or to the dynamic stability. Only resistors
with small parallel capacitance specifications should
be considered.
The MAX4430–MAX4433 have wide bandwidth and
consequently require careful board layout. To realize
the full AC performance of these high-speed amplifiers,
pay careful attention to power-supply bypassing and
board layout. The PC board should have a large low-
impedance ground plane that is as free of voids as
possible. Do not use commercial breadboards. Keep
signal lines as short and straight as possible. Observe
high-frequency bypassing techniques to maintain the
Figure 2b. Inverting Configuration
V
IN
Layout and Power-Supply Bypassing
S
F
R
is 500Ω. In general, lower R
R
S
B
can be found using the following equa-
Applications Information
I
F
= V
S
R
IN(MAX)
F
value, take into consideration
F
is supplied by the output
/ R
I
F
S
S
in both circuits.
V
A =
OUT
S
- R
R
S
F
values will
=
V
OUT
V
IN
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