PIC12F1840-I/P Microchip Technology, PIC12F1840-I/P Datasheet - Page 125

• Manufacturer Part Number: PIC12F1840-I/P
• Description: 7 KB Flash, 256 Bytes RAM, 32 MHz Int. Osc, 6 I/0, Enhanced Mid Range Core 8 PDI
• Manufacturer: Microchip Technology

Specifications of PIC12F1840-I/P

• Processor Series: PIC12F
• Core: PIC
• Program Memory Type: Flash
• Program Memory Size: 7 KB
• Data Ram Size: 256 B
• Interface Type: MI2C, SPI, EUSART
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• Package / Case: PDIP-8
• Development Tools By Supplier: MPLAB IDE Software
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

15.0
This family of devices is equipped with a temperature
circuit designed to measure the operating temperature
of the silicon die. The circuit's range of operating
temperature falls between -40°C and +85°C. The
output is a voltage that is proportional to the device
temperature. The output of the temperature indicator is
internally connected to the device ADC.
The circuit may be used as a temperature threshold
detector or a more accurate temperature indicator,
depending on the level of calibration performed. A one-
point calibration allows the circuit to indicate a
temperature closely surrounding that point. A two-point
calibration allows the circuit to sense the entire range
of temperature more accurately. Reference Application
Note AN1333, “Use and Calibration of the Internal
Temperature Indicator” (DS01333) for more details
regarding the calibration process.
15.1
Figure 15-1
temperature circuit. The proportional voltage output is
achieved by measuring the forward voltage drop across
multiple silicon junctions.
Equation 15-1
the temperature indicator.
EQUATION 15-1:
The temperature sense circuit is integrated with the
Fixed
Section 14.0 “Fixed Voltage Reference (FVR)”
more information.
The circuit is enabled by setting the TSEN bit of the
FVRCON register. When disabled, the circuit draws no
current.
The circuit operates in either high or low range. The high
range, selected by setting the TSRNG bit of the
FVRCON register, provides a wider output voltage. This
provides more resolution over the temperature range,
but may be less consistent from part to part. This range
requires a higher bias voltage to operate and thus, a
higher V
The low range is selected by clearing the TSRNG bit of
the FVRCON register. The low range generates a lower
voltage drop and thus, a lower bias voltage is needed to
operate the circuit. The low range is provided for low
voltage operation.
 2011 Microchip Technology Inc.
Voltage
DD
High Range: V
Low Range: V
TEMPERATURE INDICATOR
MODULE
Circuit Operation
is needed.
shows a simplified block diagram of the
describes the output characteristics of
Reference
OUT
V
OUT
OUT
= V
= V
RANGES
DD
DD
(FVR)
- 2V
- 4V
T
T
module.
See
Preliminary
for
FIGURE 15-1:
15.2
When the temperature circuit is operated in low range,
the device may be operated at any operating voltage
that is within specifications.
When the temperature circuit is operated in high range,
the device operating voltage, V
enough to ensure that the temperature circuit is cor-
rectly biased.
Table 15-1
range setting.
TABLE 15-1:
15.3
The output of the circuit is measured using the internal
analog to digital converter. Channel 29 is reserved for
the temperature circuit output. Refer to Section 16.0
“Analog-to-Digital Converter (ADC) Module” for
detailed information.
15.3.1
The user must wait at least 200 sec when the ADC
input multiplexer is switched to the temperature indica-
tor output. This wait time is also required between
sequential conversions of the temperature indicator
output voltage.
Min. V
Minimum Operating V
Minimum Sensing Temperature
DD
Temperature Output
shows the recommended minimum V
3.6V
, TSRNG = 1
ACQUISITION TIME
V
PIC12(L)F1840
DD
RECOMMENDED V
RANGE
TEMPERATURE CIRCUIT
DIAGRAM
V
OUT
(ADCON0 register)
TSEN
TSRNG
CHS bits
Min. V
ADC
MUX
n
DD
DS41441B-page 125
DD
, must be high
DD
1.8V
, TSRNG = 0
DD
vs.
ADC
VS.
DD
vs.