Output Stage Circuitry

The MAX941/MAX942/MAX944 contain a current-driven

output stage as shown in Figure 4. During an output

output pin. The output source or sink current is high

during the transition, creating a rapid slew rate. Once

sink current decreases to a small value, capable of

cant decrease in current conserves power after an out-

put transition has occurred.

One consequence of a current-driven output stage is a

linear dependence between the slew rate and the load

capacitance. A heavy capacitive load will slow down a

voltage output transition. This can be useful in noise-

sensitive applications where fast edges may cause

interference.

__________Applications Information

Circuit Layout and Bypassing

The high gain bandwidth of the MAX941/MAX942/

MAX944 requires design precautions to realize the

comparators’ full high-speed capability. The recom-

mended precautions are:

1) Use a printed circuit board with a good, unbro-

ken, low-inductance ground plane.

2) Place a decoupling capacitor (a 0.1µF ceramic

capacitor is a good choice) as close to V+ as

possible.

3) Pay close attention to the decoupling capacitor’s

bandwidth, keeping leads short.

4) On the inputs and outputs, keep lead lengths

short to avoid unwanted parasitic feedback

around the comparators.

5) Solder the device directly to the printed circuit

board instead of using a socket.

High-Speed, Low-Power, 3V/5V,

Rail-to-Rail Single-Supply Comparators

8

_______________________________________________________________________________________

OUT

V+

0V

V+

0V

V+

2

V+

2

LATCH

DIFFERENTIAL

INPUT

VOLTAGE

Figure 2. MAX941 Timing Diagram with Latch Operator