Datasheet

PIC16F785/HV785

11.0 OPERATIONAL AMPLIFIER

(OPA) MODULE

The OPA module has the following features:

• Two independent Operational Amplifiers

• External connections to all ports

• 3 MHz Gain Bandwidth Product (GBWP)

11.1 Control Registers

The OPA1CON register, shown in Register 11-1,

controls OPA1. OPA2CON, shown in Register 11-2,

controls OPA2.

11.2 OPAxCON Register

The OPA module is enabled by setting the OPAON bit

of the OPAxCON Register. When enabled, OPAON

forces the output driver of RC3/AN7/C12IN3-/OP1 for

OPA1, and RC2/AN6/C12IN2-/OP2 for OPA2, into

tristate to prevent contention between the driver and

the OPA output. The ADC and comparator inputs which

share the op amp pins operate normally when the op

amp is enabled.

FIGURE 11-1: OPA MODULE BLOCK DIAGRAM

Note: When OPA1 or OPA2 is enabled, the

RC3/AN7/C12IN3-/OP1 pin, or

RC2/AN6/C12IN2-/OP2 pin, respectively,

is driven by the op amp output, not by the

PORTC driver. Refer to Table 19-11 for the

electrical specifications for the op amp

output drive capability.

OPA1

OPA1CON<OPAON>

TO ADC and Comparator MUXs

RC7/AN9/OP1+

RC6/AN8/OP1-

RC3/AN7/C12IN3-/OP1

OPA2

OPA2CON<OPAON>

TO ADC and Comparator MUXs

RB5/AN11/OP2+

RB4/AN10/OP2-

RC2/AN6/C12IN2-/OP2