PIC14000-04I/SS Microchip Technology, PIC14000-04I/SS Datasheet - Page 65
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PIC14000-04I/SS
Manufacturer Part Number
PIC14000-04I/SS
Description
IC, 8BIT MCU, PIC14, 4MHZ, SSOP-28
Manufacturer
Microchip Technology
Datasheet
1.PIC14000-04SO.pdf
(153 pages)
Specifications of PIC14000-04I/SS
Controller Family/series
PIC14
No. Of I/o's
22
Ram Memory Size
192Byte
Cpu Speed
4MHz
No. Of Timers
2
Interface
I2C
Digital Ic Case Style
SSOP
Core Size
8 Bit
Program Memory Size
4096 X 14
Embedded Interface Type
I2C
Rohs Compliant
Yes
Processor Series
PIC14000
Core
PIC
Data Bus Width
8 bit
Program Memory Type
EPROM
Data Ram Size
192 B
Interface Type
SPI, UART
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
22
Number Of Timers
1
Operating Supply Voltage
2.7 V to 6 V
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
Package / Case
SSOP-28
Development Tools By Supplier
ICE2000
Minimum Operating Temperature
- 40 C
On-chip Adc
14 bit
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
9.0
The PIC14000 has additional analog modules for
mixed signal applications. These include:
• bandgap voltage reference
• comparators with programmable references
• internal temperature sensor
• voltage regulator control
9.1
The bandgap reference circuit is used to generate a
1.2V nominal stable voltage reference for the A/D and
the low-voltage detector. The bandgap reference is
channel 4 of the analog mux. The bandgap reference
voltage is stored in the calibration space EPROM
(See Table 4-2). To enable the bandgap reference
REFOFF (SLPCON<5>) must be cleared.
9.2
The RA1/AN1 and RA5/AN5 pins have an internal
level-shift network. A current source and resistor are
used to bias the pin voltage by about +0.5V into a range
usable by the A/D converter. The nominal value of bias
current source is 5 A and the resistor is 100 kohms.
The level-shift function can be turned on by clearing the
LSOFF bit (SLPCON<4>) to '0'.
1996 Microchip Technology Inc.
Note:
OTHER ANALOG MODULES
Bandgap Voltage Reference
Level-Shift Networks
The minimum voltage permissible at the
RA1/AN1 and RA5/AN5 pins is -0.3V. The
input protection diodes will begin to turn
on beyond -0.3V, introducing significant
errors in the A/D readings. Under no con-
ditions should the pin voltage fall below
-0.5V.
This document was created with FrameMaker 4 0 4
Preliminary
9.2.1
The RA1/AN1 and RA5/AN5 inputs also have a
matched pair of pass gates useful for current-measure-
ment applications. One gate is connected between the
pin and the level-shift network. The second pass gate
is connected to ground as shown in Figure 9-1. By set-
ting the ADZERO bit (ADCON0<0>), a zero-current
condition is simulated. Subsequent A/D readings are
calculated relative to this zero count from the A/D. This
zeroing of the current provides very high accuracies at
low current values where it is most needed.
For additional noise filtering or for capturing short dura-
tion periodic pulses, an optional filter capacitor may be
connected from the SUM pin to ground (this feature is
available for RA1/AN1 only). This forms an RC network
with the internal 100 kohm (nominal) bias resistor to act
as a low pass filter. The capacitor size can be adjusted
for the desired time constant.
A switch is included between the output from the
RA1/AN1 level-shift network and the SUM pin. This
switch is closed during A/D sampling periods and is
automatically opened during a zeroing operation (if
ADZERO = '1'). If not required in the system, this pin
should be left floating (not connected).
Setting the LSOFF bit (SLPCON<4>) disables the
level-shift networks, so the RA1/AN1 and RA5/AN5
pins can continue to be used as general-purpose ana-
log inputs.
ZEROING/FILTERING SWITCHES
PIC14000
DS40122B-page 65