Intersil HA4905
The HA4905 comparator has inputs that can work from the 15V supplies, thus the input voltage swing is matched to the op amp’s output voltage swing. The trip point should be set first, then the window can be set to the desired width. Even though the input section of the HA4905 is connected to 15V, the output section can be connected from +5V to ground, thus offering a TTL compatible output voltage.| Part No. | HA4905 |
|---|---|
| Datasheet | HA4905 Download |
| Manufacturer |  Intersil |
| Description | Window Comparator With Independent Adjustments |
| Buy | Stock & Price |
Window Comparator With Independent Adjustments (HA2841, HA4905) Application Note April 1998 AN9802 Introduction Window comparators, or limit comparators as they are sometimes called, determine when the input voltage is within a pre-selected range. The output voltage usually goes to a TTL high when the input voltage is within the pre-selected range. A typical window comparator circuit normally consists of two comparators with two reference adjustments: one for the low trip level, and one for the high trip level. If the reference voltages are derived from the same resistor divider string, hystersis can not be added without having the trip levels interact. If the reference voltages are independently derived they can drift in different directions causing the window to widen or possibly disappear. The window comparator shown in Figure 1 circumvents these problems with independent trip and window adjustments. The HA2841 op amp (selected because it has high speed and low input currents) adds the input signal to the trip voltage developed by RT.
