ZHCSGM4C August 2017 – October 2023 OPA838
PRODUCTION DATA
The OPA838 device is intended to work in a supply range of 2.7 V to 5.4 V. Good power-supply bypassing is required. Minimize the distance (less than 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 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 PCB. Avoid narrow power and ground traces to minimize inductance between the pins and the decoupling capacitors. An optional 0.1-µF supply decoupling capacitor across the two power supplies (for bipolar operation) reduces second harmonic distortion.
The OPA838 has a positive supply
current temperature coefficient; see Figure 7-57. This helps improve the input offset voltage drift. Supply current requirements
in system design must account for this effect using the maximum intended ambient and
Figure 7-57 to size the supply required. The very low power dissipation for the OPA838
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
three packages, and a maximum internal power of
5.4-V
supply × 1.25-mA 125°C supply current from Figure 7-57 gives a maximum internal power of 6.75 mW. This only gives a 1.35°C rise from
ambient to junction temperature which is well below the maximum 150°C junction
temperature. Load power adds to this, but also increases the junction temperature
only slightly over ambient temperature.