SBOS673 September 2017 OPA837
The OPA837 is intended to work in a nominal supply range of 3.0 V to 5 V. Supply-voltage tolerances are supported with the specified operating range of 2.7 V (–10% on a 3-V supply) and 5.4 V (+8% on a 5-V supply). Good power-supply bypassing is required. Minimize the distance (< 0.1 inch) from the power-supply pins to high-frequency, 0.1-µF decoupling capacitors. A larger capacitor (2.2 µF is typical) is used along with a high-frequency, 0.1-µF supply-decoupling capacitor at the device supply pins. For single-supply operation, only the positive supply has these capacitors. When a split supply is used, use these capacitors for each supply to ground. If necessary, place the larger capacitors further from the device and share these capacitors among several devices in the same area of the printed circuit board (PCB). Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. An optional supply decoupling capacitor across the two power supplies (for bipolar operation) reduces second harmonic distortion.
The OPA837 has a positive supply current temperature coefficient; see Figure 57. This coefficient helps improve the input offset voltage drift. Supply current requirements in the system design must account for this effect using the maximum intended ambient and Figure 57 to size the supply required. The very low power dissipation for the OPA837 typically does not require any special thermal design considerations. For the extreme case of 125°C operating ambient, use the approximate maximum 200°C/W for the two packages, and a maximum internal power of 5.4-V supply × 0.8-mA 125°C supply current from Figure 57 gives a maximum internal power of 4.3 mW. This power only gives a 0.86°C rise from ambient to junction temperature, which is well below the maximum 150°C junction temperature. Load power adds to this value, but also increases the junction temperature only slightly over ambient temperature.