MAX4230 Ver la hoja de datos (PDF) - Maxim Integrated

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Fabricante

MAX4230

High-Output-Drive, 10MHz, 10V/µs, Rail-to-Rail I/O Op Amps with Shutdown in SC70

Maxim Integrated 

High-Output-Drive, 10MHz, 10V/µs,

Rail-to-Rail I/O Op Amps with Shutdown in SC70

INVERTING

VIN

R

Cf

Rf

MAX4230

VOUT

R′ = R || Rf

RfCf = RCIN

NONINVERTING

VIN

VOUT

MAX4230

Rf

Cf

2500

2000

UNSTABLE

1500

STABLE

1000

500

VDD = 5.0V

RL TO VDD/2

0

1

10 100 1k 10k 100k

RESISTIVE LOAD (Ω)

Figure 6. Capacitive-Load Stability

20mV/div

R

R′ = R || Rf

RfCf = RCIN

Figure 5. Inverting and Noninverting Amplifiers with Feedback

Compensation

To improve step response when R′ > 2kΩ, connect

small capacitor Cf between the inverting input and out-

put. Choose Cf as follows:

Cf = 8(R / Rf) [pf]

where Rf is the feedback resistor and R is the gain-set-

ting resistor (Figure 5).

Driving Capacitive Loads

The MAX4230–MAX4234 have a high tolerance for

capacitive loads. They are stable with capacitive loads

up to 780pF. Figure 6 is a graph of the stable operating

region for various capacitive loads vs. resistive loads.

Figures 7 and 8 show the transient response with

excessive capacitive loads (1500pF), with and without

the addition of an isolation resistor in series with the

output. Figure 9 shows a typical noninverting capaci-

tive-load-driving circuit in the unity-gain configuration.

20mV/div

VDD = 3.0V, CL = 1500pF

RL = 100kΩ, RISO = 0Ω

1μs/div

Figure 7. Small-Signal Transient Response with Excessive

Capacitive Load

20mV/div

20mV/div

VDD = 3.0V, CL = 1500pF

RL = 100kΩ, RISO = 39Ω

1μs/div

Figure 8. Small-Signal Transient Response with Excessive

Capacitive Load with Isolation Resistor

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