Datasheet MAX9140, MAX9141, MAX9142, MAX9144 (Maxim) - 8

link to page 9 MAX9140/MAX9141/ 40ns, Low-Power, 3V/5V, Rail-to-Rail MAX9142/MAX9144 Single-Supply Comparators tS tH VOD DIFFERENTIAL VOS INPUT VOLTAGE tLPW VCC VCC LE 2 0 tPD tLPD VOH VCC OUT 2 VOL Figure 2. MAX9141 Timing Diagram with Latch Operator
Output Stage Circuitry
The MAX9140/MAX9141/MAX9142/MAX9144 contain a current-driven output stage as shown in Figure 4. During an output transition, ISOURCE or ISINK is pushed or pulled
MAX9140
to the output pin. The output source or sink current is high
MAX9141
during the transition, creating a rapid slew rate. Once the 4.1kΩ
MAX9142
output voltage reaches V IN+ TO INTERNAL
MAX9144
OH or VOL, the source or sink CIRCUITRY current decreases to a small value, capable of maintaining the VOH or VOL static condition. This significant decrease in current conserves power after an output transition has occurred. One consequence of a current-driven output stage is a TO INTERNAL linear dependence between the slew rate and the load IN– CIRCUITRY capacitance. A heavy capacitive load will slow down a voltage 4.1kΩ output transition. This can be useful in noisesensitive applications where fast edges may cause interference.
Applications Information Circuit Layout and Bypassing
The high-gain bandwidth of the MAX9140/MAX9141/ Figure 3. Input Stage Circuitry MAX9142/MAX9144 requires design precautions to real- ize the full high-speed capabilities of these comparators. 3) Pay close attention to the decoupling capacitor’s bandwidth, The recommended precautions are: keeping leads short. 1) Use a PCB with a good, unbroken, low-inductance 4) On the inputs and outputs, keep lead lengths short to avoid ground plane. unwanted parasitic feedback around the comparators. 2) Place a decoupling capacitor (a 0.1μF ceramic capacitor 5) Solder the device directly to the PCB instead of using is a good choice) as close to V a socket. CC as possible. www.maximintegrated.com Maxim Integrated │ 8