MAX4322(1999) データシートの表示（PDF） - Maxim Integrated

部品番号

コンポーネント説明

一致するリスト

MAX4322
(Rev.:1999)

Single/Dual/Quad, Low-Cost, SOT23, Low-Power, Rail-to-Rail I/O Op Amps

Maxim Integrated 

Single/Dual/Quad, Low-Cost, SOT23,

Low-Power, Rail-to-Rail I/O Op Amps

with the input capacitance, can create a parasitic pole

that produces an underdamped signal response.

Reducing the input impedance or placing a small (2pF

to 10pF) capacitor across the feedback resistor

improves the response.

The MAX4322/MAX4323/MAX4326/MAX4327/MAX4329’s

inputs are protected from large differential input volt-

ages by 1kΩ series resistors and back-to-back triple

diodes across the inputs (Figure 2). For differential input

voltages less than 1.8V the input resistance is typically

500kΩ. For differential input voltages greater than 1.8V

the input resistance is approximately 2kΩ, and the input

bias current is determined by the following equation:

IBIAS

=

VDIFF - 1.8V

2kΩ

Rail-to-Rail Output Stage

The minimum output voltage will be within millivolts of

ground for single-supply operation where the load is

referenced to ground (VEE). Figure 3 shows the input

voltage range and output voltage swing of a MAX4322

connected as a voltage follower. With a +3V supply

and the load tied to ground, the output swings from

0.00V to 2.90V. The maximum output voltage swing

depends on the load, but will be within 350mV of a +5V

supply, even with the maximum load (500Ω to ground).

Driving a capacitive load can cause instability in most

high-speed op amps, especially those with low quies-

cent current. The MAX4322/MAX4323/MAX4326/

MAX4327/MAX4329 have a high tolerance for capaci-

tive loads. They are stable with capacitive loads up to

500pF. Figure 4 gives the stable operating region for

capacitive loads. Figures 5 and 6 show the response

with capacitive loads and the results of adding an iso-

lation resistor in series with the output (Figure 7). The

resistor improves the circuit’s phase margin by isolat-

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

R3

MAX4322/MAX4323

MAX4326/MAX4327

MAX4329

R1

R2

R3 = R1 R2

Figure 1a. Reducing Offset Error Due to Bias Current

(Noninverting)

1k

R3

MAX4322/MAX4323

MAX4326/MAX4327

MAX4329

R1

R2

R3 = R1 R2

Figure 1b. Reducing Offset Error Due to Bias Current

(Inverting)

1k

Figure 2. Input Protection Circuit

_______________________________________________________________________________________ 9

Share Link: