Datasheet

PIC16F627A/628A/648A

FIGURE 11-2: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE

TABLE 11-1: REGISTERS ASSOCIATED WITH VOLTAGE REFERENCE

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

Value On

POR

Value On

All Other

Resets

9Fh VRCON VREN VROE VRR

— VR3 VR2 VR1 VR0 000- 0000 000- 0000

1Fh CMCON

C2OUT C1OUT C2INV C1INV CIS CM2 CM1 CM0 0000 0000 0000 0000

85h TRISA

TRISA7 TRISA6 TRISA5 TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 1111 1111 1111 1111

Legend: - = Unimplemented, read as ‘0’.

Note 1: R is dependent upon the voltage reference configuration VRCON<3:0> and VRCON<5>.

VREF

Module

(1)

Voltage

Reference

Output

Impedance

RA2

VREF Output

Op Amp