Frequently Asked Questions |ROHM Semiconductor

What is the difference between CMOS and bipolar opamps?
- Key advantages of CMOS opamps include extremely small input bias current (on the order of pA) and low power consumption. However, the CMOS process features low withstand voltage, making them suitable for low supply voltage applications. Although bipolar opamps provide higher input bias current and current consumption, they offer higher withstand voltage, low noise, low offset, and wide bandwidth.

Where are the ground sense features of the opamp listed in the datasheet?
- Ground sense opamps can operate up to the ground level of the input signal. The minimum value listed in the parameter for the common mode input voltage range is 0V (=Ground Level=VEE)

Is it a problem to Pullup the SCL and SDA lines of the I²C interface to 3.3V if DVDD=1.8V?
- 3.3V as the pull up source is acceptable even if DVDD is 1.8V. But NVCC_I2C of the I²C domain in SoC should be 3.3V (the same voltage as the pull up source for PMIC) and DVDD in PMIC always needs to be 1.8V.