Hi,
I have made the following design with THS4524 differential amplifier. The primary goal is to amplify by 6 the difference between four input signals (BRIDGE_SHUNT_XXX in the range of [2.2-2.8] Volts, referred to THS4524 ground) and a 2.5 volts reference. Rf resistor is set to 5.9K and Rg resistor is set to 1K for this purpose on each signal path. The amplified output signal is then referenced to an internal ground (plus an 1.5 volts reference) by means of four ina148 high input common range amplifiers.
The problem is that THS4524 is getting burnt after a few seconds of use, and it starts to draw high current (>100mA). All the VOCM pins (that set the output common range of the THS4524) are tied together (as well as the power down PDx inputs) to an external 0.22uF capacitor. Voltage at this junction (Capacitor to ground) is not 2.5 volts and is fluctuating. Could it be that tying all VOCM pins togheter is not a good idea? I have read the datasheet and i am unable to find information about this fact.
Thanking you in advance.
Angel
