FAQ

Are there any differences between the VMON inputs on the POWR1208 and POWR1220?

There are a few differences between the POWR1208 and POWR1220 which may require minor changes to a design when migrating a design (in either direction):

1. The POWR1220 has ground-sense capability on the VMON inputs, and the POWR1208 does not. Ground sensing allows for more accurate voltage measurements, especially in systems handling high levels of electrical current.


2. The recommended input range of the POWR1208 VMONS (0-6V) is slightly wider than that of the POWR1220 (-0.3 to +5.5V). For most designs this should not be an issue.


3. The POWR1220 offers more VMON thresholds with more accuracy (368 steps and 0.2%) than the POWR1208 (192 steps and 1%). The threshold steps for the POWR1220 also cover a slightly larger range than those of the POWR1208, making it easy to migrate a design from the POWR1208 to the POWR1220.


4. The typical VMON input impedance of the POWR1220 (60k ohms) is somewhat lower than that of the POWR1208 (100k ohms). For this reason it may be necessary to use lsomewhat ower value resistors in input divider circuits to maintain accuracy.


5. The POWR1220 VMON inputs have about 1% hysteresis while the POWR1208 inputs have 0.3% hysteresis. This may affect threshold accuracy slightly, but will generally make the POWR1220 inputs more noise resistant .