
2009 Microchip Technology Inc.
DS80302F-page 13
PIC16F88X
Data Sheet Clarifications
The
following
typographical
corrections
and
clarifications are to be noted for the latest version of the
device data sheet (DS41291F):
1.
Module: ADC (Block Diagram)
Figure
9-1:
ADC
Block
Diagram
changes
references from AVSS to VSS and AVDD to VDD.
2.
Module: ADC
Acquisition Time Example calculation correction.
EQUATION 9-1:
ACQUISITION TIME EXAMPLE
Note:
Corrections are shown in bold. Where
possible, the original bold text formatting
has been removed for clarity.
TACQ
Amplifier Settling Time
Hold Capacitor Charging Time
Temperature Coefficient
++
=
TAMP
TC
TCOFF
++
=
2s
TC
Temperature - 25°C
() 0.05s/°C
()
[]
++
=
TC
CHOLD RIC
RSS
RS
++
() ln(1/2047)
–
=
10pF 1k
Ω 7kΩ 10kΩ
++
()
–
ln(0.0004885)
=
1.37
=
s
TACQ
2s
1.37s
50°C- 25°C
() 0.05s/°C
()
[]
++
=
4.67s
=
VAPPLIED 1e
Tc
–
RC
---------
–
VAPPLIED 1
1
2
n1
+
() 1
–
--------------------------
–
=
VAPPLIED 1
1
2
n1
+
() 1
–
--------------------------
–
VCHOLD
=
VAPPLIED 1e
TC
–
RC
----------
–
VCHOLD
=
;[1] VCHOLD charged to within 1/2 lsb
;[2] VCHOLD charge response to VAPPLIED
;combining [1] and [2]
The value for TC can be approximated with the following equations:
Solving for TC:
Therefore:
Temperature
50°C and external impedance of 10k
Ω 5.0V VDD
=
Assumptions: