27 Operational Amplifier

Note: Some device variants support only two op amp instances. Refer to dsPIC33CK512MP608 Product Families for availability.

The dsPIC33CK512MP608 family implements three instances of operational amplifiers (op amps). The op amps can be used for a wide variety of purposes, including signal conditioning and filtering. The three op amps are functionally identical. The block diagram for a single amplifier is shown in Figure 27-1.

Figure 27-1. Single Operational Amplifier Block Diagram

The op amps are controlled by two SFR registers: AMPCON1L and AMPCON1H. They remain in a low-power state until the AMPON bit is set. Each op amp can then be enabled independently by setting the corresponding AMPENx bit (x = 1, 2, 3).

The NCHDISx bit provides some flexibility regarding input range versus Integral Nonlinearity (INL). When NCHDISx = 0 (default), the op amps have a wider input voltage range (see Electrical Characteristics). When NCHDISx = 1, the wider input range is traded for improved INL performance (lower INL).