Detailed Description

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.

High-Speed ADC Input Driver Application

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).

Inverting and Noninverting Configurations

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

and 2 for the MAX4431/MAX4433. Use care in selecting

From dynamic stability considerations (based on the

part’s frequency response and the input capacitance of

the MAX4430–MAX4433), the maximum recommended

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-

stage and must be discounted from the maximum out-

put current to calculate the maximum current available

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.

Applications Information

Layout and Power-Supply Bypassing

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

Dual-Supply, 180MHz, 16-Bit Accurate,

Ultra-Low Distortion Op Amps

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9

HIGH-SPEED

14/16-BIT ADC

Figure 1. Typical Application Circuit

=

A = 1 +

Figure 2a. Noninverting Configuration

=

A =

Figure 2b. Inverting Configuration