MA180025 Microchip Technology, MA180025 Datasheet - Page 306

• Manufacturer Part Number: MA180025
• Description: MODULE PLUG-IN PIC18F87J90 PIM
• Manufacturer: Microchip Technology
• Series: PIC®r

Specifications of MA180025

• Accessory Type: Plug-In Module (PIM) - PIC18F87J90
• Product: Microcontroller Modules
• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Silicon Core Number: PIC18F
• Silicon Family Name: PIC18FxxJxx
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PICDEM LCD 2 Demonstration Board (DM163030)
• For Use With: DM163030 - KIT DEV PICDEM LCD2
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18F87J90 FAMILY
FIGURE 23-1:
23.2
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(Figure 23-1) keep CV
ence source rails. The voltage reference is derived
from the reference source; therefore, the CV
changes with fluctuations in that source. The tested
absolute accuracy of the voltage reference can be
found in Section 28.0 “Electrical Characteristics”.
23.3
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
DS39933D-page 306
Voltage Reference Accuracy/Error
Operation During Sleep
CVRR
V
V
CVREN
V
REF
REF
DD
REF
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
+
-
from approaching the refer-
CVRSS =
CVRSS =
0
1
CVRSS =
CVRSS =
16 Steps
REF
output
1
0
8R
R
R
R
R
R
R
R
clearing bit, CVREN (CVRCON<7>). This Reset also
disconnects the reference from the RA2 pin by clearing
23.4
A device Reset disables the voltage reference by
bit, CVROE (CVRCON<6>), and selects the high-voltage
range by clearing bit, CVRR (CVRCON<5>). The CVR
value select bits are also cleared.
23.5
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RF5 pin if the
CVROE bit is set. Enabling the voltage reference out-
put onto RA2 when it is configured as a digital input will
increase current consumption. Connecting RF5 as a
digital output with CVRSS enabled will also increase
current consumption.
The RF5 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to V
Figure 23-2 shows an example buffering technique.
8R
Effects of a Reset
Connection Considerations
CVR<3:0>
 2010 Microchip Technology Inc.
CV
REF
REF
.