MAX944 Maxim, MAX944 Datasheet - Page 8

• Manufacturer Part Number: MAX944
• Description: The MAX941/MAX942/MAX944 are single/dual/quad high-speed comparators optimized for systems powered from a 3V or 5V supply
• Manufacturer: Maxim

The MAX941/MAX942/MAX944 contain a current-driven
output stage as shown in Figure 4. During an output
transition, I
output pin. The output source or sink current is high
during the transition, creating a rapid slew rate. Once
the output voltage reaches V
sink current decreases to a small value, capable of
maintaining the V
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.
High-Speed, Low-Power, 3V/5V, Rail-to-Rail,
Single-Supply Comparators
Figure 2. MAX941 Timing Diagram with Latch Operator
8
_______________________________________________________________________________________
DIFFERENTIAL
SOURCE
VOLTAGE
LATCH
INPUT
OUT
OH
or I
or V
V+
V
V+
V
V+
0V
V+
0V
SINK
2
2
OH
OL
OL
V
OS
Output Stage Circuitry
static condition. This signifi-
is pushed or pulled to the
OH
or V
OL
t
S
, the source or
t
H
t
PD
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:
__________Applications Information
1) Use a printed circuit board with a good, unbro-
2) Place a decoupling capacitor (a 0.1µF ceramic
3) Pay close attention to the decoupling capacitor’s
4) On the inputs and outputs, keep lead lengths
5) Solder the device directly to the printed circuit
ken, low-inductance ground plane.
capacitor is a good choice) as close to V+ as
possible.
bandwidth, keeping leads short.
short to avoid unwanted parasitic feedback
around the comparators.
board instead of using a socket.
t
LPW
Circuit Layout and Bypassing
t
LPD