Information

© 2008 Microchip Technology Inc. DS80209H-page 5
PIC18F2420/2520/4420/4520
16. Module: A/D
The A/D offset is greater than the specified limit in
Table 26-24 of the Device Data Sheet. The addi-
tional Parameter A06A and updated conditions
and limits are shown in bold text in Table 2.
Work around
Three work arounds exist.
1. Configure the A/D to use the V
REF+ and VREF-
pins for the voltage references. This is done by
setting the VCFG<1:0> bits (ADCON1<5:4>).
2. Perform a conversion on a known voltage
reference voltage and adjust the A/D result in
software.
3. Increase system clock speed to 40 MHz and
adjust A/D settings accordingly. Higher system
clock frequencies decrease offset error.
TABLE 2: A/D CONVERTER CHARACTERISTICS: PIC18FX42X/X52X (INDUSTRIAL, EXTENDED)
PIC18LFX42X/X52X (INDUSTRIAL)
Date Codes that pertain to this issue:
All engineering and production devices.
17. Module: BOD
The BOD module may reset below the minimum
operating voltage of the device when configured
for BORV1:BORV0 = 11. The updated Reset
voltage specifications are shown in bold in
Table 3.
TABLE 3: BROWN-OUT RESET VOLTAGE
Work around
Use the next higher BOD voltage setting to ensure
a low V
DD is detected above 2.0V.
Date Codes that pertain to this issue:
All engineering and production devices.
18. Module: EUSART
When performing back-to-back transmission in
9-bit mode (TX9D bit in the TXSTA register is
set), an ongoing transmission’s timing can be
corrupted if the TX9D bit (for the next
transmission) is not written immediately follow-
ing the setting of TXIF. This is because any
write to the TXSTA register results in a reset of
the baud rate timer which will effect any ongoing
transmission.
Work around
Load TX9D just after TXIF is set, either by polling
TXIF or by writing TX9D at the beginning of the
Interrupt Service Routine, or only write to TX9D
when a transmission is not in progress
(TRMT = 1).
Date Codes that pertain to this issue:
All engineering and production devices.
Param
No.
Symbol Characteristic Min Typ Max Units Conditions
A06A E
OFF Offset Error — — <±1.5 LSb VREF = VREF+ and VREF-
A06 EOFF Offset Error — — <±3.5 LSb VREF = VSS and VDD
Param
No.
Sym Characteristic Min Typ Max Unit
D005 V
BOR Brown-out Reset Voltage
PIC18LF2420/2520/4420/4520
BORV1:BORV0 = 11 N/A 2.05 N/A V