PIC16F627-04 Microchip Technology, PIC16F627-04 Datasheet - Page 70

• Manufacturer Part Number: PIC16F627-04
• Description: FLASH-Based 8-Bit CMOS Microcontrollers
• Manufacturer: Microchip Technology

PIC16F62X
EXAMPLE 11-1: VOLTAGE REFERENCE
11.2
The full range of V
the construction of the module. The transistors on the
top and bottom of the resistor ladder network
(Figure 11-2) keep V
The Voltage Reference is V
the V
tested absolute accuracy of the Voltage Reference can
be found in Table 17-2.
11.3
When the device wakes up from sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the VRCON register are not affected. To minimize
current consumption in SLEEP mode, the Voltage
Reference should be disabled.
FIGURE 11-3: VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
TABLE 11-1:
DS40300B-page 70
MOVLW
MOVWF
BSF
MOVLW
MOVWF
MOVLW
MOVWF
BCF
CALL
Address
9Fh
1Fh
85h
Note:
Note 1: R is dependent upon the Voltage Reference Configuration VRCON<3:0> and VRCON<5>.
REF
Voltage Reference Accuracy/Error
Operation During Sleep
output changes with fluctuations in V
Name
VRCON
CMCON C2OUT C1OUT
TRISA
-
0x02
CMCON
STATUS,RP0
0x07
TRISA
0xA6
VRCON
STATUS,RP0
DELAY10
= Unimplemented, read as "0"
REGISTERS ASSOCIATED WITH VOLTAGE REFERENCE
SS
Module
V
CONFIGURATION
REF
TRISA7 TRISA6
REF
VREN
to V
Bit 7
from approaching V
DD
Impedance
Reference
DD
cannot be realized due to
; 4 Inputs Muxed
; to 2 comps.
; go to Bank 1
; RA3-RA0 are
; outputs
; enable V
; low range
; set V
; go to Bank 0
; 10 s delay
Voltage
Output
VROE
Bit 6
derived and therefore,
R
(1)
R
<3:0>=6
C2INV
Bit 5
VRR
—
REF
RA2
SS
DD
or V
TRISA4
C1INV
Bit 4
•
. The
—
Preliminary
DD
.
TRISA3
Bit 3
VR3
CIS
11.4
A device reset disables the Voltage Reference by clear-
ing bit V
the reference from the RA2 pin by clearing bit V
(VRCON<6>) and selects the high voltage range by
clearing bit V
bits, VRCON<3:0>, are also cleared.
11.5
The
independently of the comparator module. The output of
the reference generator may be connected to the RA2
pin if the TRISA<2> bit is set and the V
VRCON<6>, is set. Enabling the Voltage Reference
output onto the RA2 pin with an input signal present will
increase current consumption. Connecting RA2 as a
digital output with V
current consumption.
The RA2 pin can be used as a simple D/A output with
limited drive capability. Due to the limited drive
capability, a buffer must be used in conjunction with the
Voltage Reference output for external connections to
V
technique.
REF
TRISA2
Bit 2
CM2
VR2
. Figure 11-3 shows an example buffering
+
–
REN
Voltage
Effects of a Reset
Connection Considerations
TRISA1
(VRCON<7>). This reset also disconnects
Bit 1
CM1
VR1
RR
•
(VRCON<5>). The V
Reference
V
TRISA0
REF
Bit 0
CM0
REF
VR0
Output
1999 Microchip Technology Inc.
enabled will also increase
000- 0000
0000 0000
11-1 1111
Value On
POR
Module
REF
value select
0000 0000
11-1 1111
000- 0000
Value On
All Other
Resets
operates
ROE
ROE
bit,