The resistor improves the circuit’s phase margin by iso-

lating the load capacitor from the op amp’s output.

Power-Up and Shutdown Modes

The MAX4231/MAX4233 have a shutdown option.

When the shutdown pin (SHDN) is pulled low, supply

amplifiers are disabled, and their outputs are driven to

shutdown, any pullup resistor on the output causes a

current drain from the supply. Pulling SHDN high

enables the amplifier. In the dual MAX4233, the two

amplifiers shut down independently. Figure 10 shows

the MAX4231’s output voltage to a shutdown pulse. The

MAX4231–MAX4234 typically settle within 5µs after

plus and voltage power-up cycle.

When exiting shutdown, there is a 6µs delay before the

amplifier’s output becomes active (Figure 10).

High-Output-Drive, 10MHz, 10V/µs,

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

12

______________________________________________________________________________________

Figure 9. Capacitive-Load-Driving Circuit

100

µs/div

SHDN

2V/div

1mA/div

OUT

2V/div

Figure 11. Shutdown Enable/Disable Supply Current

40

µs/div

2V/div

1mA/div

Figure 12. Power-Up/Down Supply Current

4

µs/div

1V/div

1V/div

Figure 10. Shutdown Output Voltage Enable/Disable

Selector Guide

AMPS PER

PACKAGE

SHUTDOWN

MODE

MAX4230

Single

—

MAX4231

Single

Yes

PART

MAX4232

Dual

—

MAX4233

Dual

Yes

MAX4234

Quad

—