MCP9808
±0.5°C Maximum Accuracy Digital Temperature Sensor
Features
Description
• Accuracy:
- ±0.25 (typical) from -40°C to +125°C
- ±0.5°C (maximum) from -20°C to 100°C
- ±1°C (maximum) from -40°C to +125°C
• User-Selectable Measurement Resolution:
- +0.5°C, +0.25°C, +0.125°C, +0.0625°C
• User-Programmable Temperature Limits:
- Temperature Window Limit
- Critical Temperature Limit
• User-Programmable Temperature Alert Output
• Operating Voltage Range: 2.7V to 5.5V
• Operating Current: 200 µA (typical)
• Shutdown Current: 0.1 µA (typical)
• 2-wire Interface: I2C™/SMBus Compatible
• Available Packages: 2x3 DFN-8, MSOP-8
Microchip Technology Inc.’s MCP9808 digital
temperature sensor converts temperatures between
-20°C and +100°C to a digital word with
±0.25°C/±0.5°C (typical/maximum) accuracy.
The MCP9808 comes with user-programmable registers
that provide flexibility for temperature sensing
applications. The registers allow user-selectable
settings such as Shutdown or Low-Power modes and
the specification of temperature Alert window limits and
critical output limits. When the temperature changes
beyond the specified boundary limits, the MCP9808
outputs an Alert signal. The user has the option of setting
the Alert output signal polarity as an active-low or activehigh comparator output for thermostat operation, or as a
temperature Alert interrupt output for microprocessorbased systems. The Alert output can also be configured
as a critical temperature output only.
This sensor has an industry standard 400 kHz, 2-wire,
SMBus/I2C compatible serial interface, allowing up to
eight or sixteen sensors to be controlled with a single
serial bus (see Table 3-2 for available Address codes).
These features make the MCP9808 ideal for
sophisticated, multi-zone, temperature-monitoring
applications.
Typical Applications
•
•
•
•
•
•
•
•
General Purpose
Industrial Applications
Industrial Freezers and Refrigerators
Food Processing
Personal Computers and Servers
PC Peripherals
Consumer Electronics
Handheld/Portable Devices
Package Types
8-Pin 2x3 DFN*
SDA 1
Temperature Accuracy
40%
SCL 2
Alert 3
TA = -20°C, 25°C, 85°C, 100°C
VDD = 3.3V
854 units
GND 4
Occurrences
30%
EP
9
8-Pin MSOP
8 VDD
SDA 1
8 VDD
7 A0
SCL 2
7 A0
6 A1
Alert 3
GND 4
6 A1
5 A2
5 A2
* Includes Exposed Thermal Pad (EP); see Table 3-1.
20%
10%
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
0%
Temperature Accuracy (°C)
© 2011 Microchip Technology Inc.
DS25095A-page 1
MCP9808
Functional Block Diagram
Hysteresis
Shutdown
Critical Trip Lock
Alarm Window Lock
Clear Alert
Alert Status
Output Control
Critical Alert only
Band Gap
Temperature
Sensor
Alert Polarity
Alert Comp./Int.
Configuration
Temperature
ΔΣ ADC
TUPPER Limit
TLOWER Limit
+0.5°C
+0.25°C
+0.125°C
+0.0625°C
TCRITICAL Limit
Manufacturer ID
Device ID/Rev
Resolution
Register
Pointer
SMBus/Standard I2C™
Interface
A0
DS25095A-page 2
A1
A2
Alert
SDA
SCL
VDD
GND
© 2011 Microchip Technology Inc.
MCP9808
1.0
ELECTRICAL
CHARACTERISTICS
†Notice: Stresses above those listed under “Maximum
ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at those or any other conditions above those
indicated in the operational listings of this specification
is not implied. Exposure to maximum rating conditions
for extended periods may affect device reliability.
Absolute Maximum Ratings †
VDD.................................................................................. 6.0V
Voltage at All Input/Output Pins .............. GND – 0.3V to 6.0V
Storage Temperature ....................................-65°C to +150°C
Ambient Temperature with Power Applied ....-40°C to +125°C
Junction Temperature (TJ) .......................................... +150°C
ESD Protection on All Pins (HBM:MM) ................ (4 kV:400V)
Latch-up Current at Each Pin (+25°C) ..................... ±200 mA
TEMPERATURE SENSOR DC CHARACTERISTICS
Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground and
TA = -40°C to +125°C.
Parameters
Sym
Min
Typ
Max
Unit
Conditions
TACY
TACY
-0.5
±0.25
+0.5
°C
VDD = 3.3V
-1.0
±0.25
+1.0
°C
VDD = 3.3V
tCONV
—
30
—
ms
33s/sec (typical)
—
65
—
ms
15s/sec (typical)
Temperature Sensor Accuracy
-20°C < TA ≤ +100°C
-40°C < TA ≤ +125°C
Temperature Conversion Time
0.5°C/bit
0.25°C/bit
0.125°C/bit
—
130
—
ms
7s/sec (typical)
0.0625°C/bit
—
250
—
ms
4s/sec (typical)
Power Supply
VDD
2.7
—
5.5
V
Operating Current
IDD
—
200
400
µA
Shutdown Current
ISHDN
—
0.1
2
µA
Power-on Reset (POR)
VPOR
—
2.2
—
V
Power Supply Rejection
Δ°C/ΔVDD
—
-0.1
—
°C/V
Operating Voltage Range
Threshold for falling VDD
VDD = 2.7V to 5.5V, TA = +25°C
Alert Output (open-drain output, external pull-up resistor required), see Section 5.2.3 “Alert Output Configuration”
High-Level Current (leakage)
Low-Level Voltage
IOH
—
—
1
µA
VOH = VDD (Active-Low, Pull-up Resistor)
VOL
—
—
0.4
V
IOL= 3 mA (Active-Low, Pull-up Resistor)
Time to 63% (+89°C)
Thermal Response, from +25°C (air) to +125°C (oil bath)
8L-DFN
8L-MSOP
© 2011 Microchip Technology Inc.
tRES
—
0.7
—
s
—
1.4
—
s
DS25095A-page 3
MCP9808
DIGITAL INPUT/OUTPUT PIN CHARACTERISTICS
Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground and
TA = -40°C to +125°C.
Parameters
Sym
Min
Typ
Max
Units
V
Conditions
Serial Input/Output (SCL, SDA, A0, A1, A2)
Input
High-Level Voltage
VIH
0.7 VDD
—
VDD
Low-Level Voltage
VIL
GND
—
0.3 VDD
V
Input Current
IIN
—
—
±5
µA
Low-Level Voltage
VOL
—
—
0.4
V
IOL= 3 mA
High-Level Current (leakage)
IOH
—
—
1
µA
VOH = 5.5V
Low-Level Current
IOL
6
—
—
mA
VOL = 0.6V
VHYST
—
0.05 VDD
—
V
Spike Suppression
tSP
—
—
50
ns
Capacitance
CIN
—
5
—
pF
Output (SDA)
SDA and SCL Inputs
Hysteresis
GRAPHICAL SYMBOL DESCRIPTION
Voltage VDD
INPUT
Voltage
OUTPUT
VDD
VIH
VOL
VIL
IOL
Current
Current
IIN
IOH
time
time
TEMPERATURE CHARACTERISTICS
Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V and GND = Ground.
Parameters
Sym
Min
Typ
Max
Units
Specified Temperature Range
TA
-40
—
+125
°C
Operating Temperature Range
TA
-40
—
+125
°C
Storage Temperature Range
TA
-65
—
+150
°C
Thermal Resistance, 8L-DFN
θJA
—
68
—
°C/W
Thermal Resistance, 8L-MSOP
θJA
—
211
—
°C/W
Conditions
Temperature Ranges
(Note 1)
Thermal Package Resistances
Note 1:
Operation in this range must not cause TJ to exceed Maximum Junction Temperature (+150°C).
DS25095A-page 4
© 2011 Microchip Technology Inc.
MCP9808
SENSOR SERIAL INTERFACE TIMING SPECIFICATIONS
Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, TA = -40°C to +125°C, GND = Ground
and CL = 80 pF. (Note 1)
Parameters
Sym
2-Wire SMBus/Standard Mode
I2C™
Min
Max
Units
Conditions
Compatible Interface (Note 1)
(Note 2, 4)
fSC
0
400
kHz
Low Clock
tLOW
1300
—
ns
(Note 2)
High Clock
tHIGH
600
—
ns
(Note 2)
Rise Time
tR
20
300
ns
tF
20
300
ns
tSU-DI
100
—
ns
Serial Port Clock Frequency
Fall Time
Data in Setup Time
(Note 3)
Data In Hold Time
tHD-DI
0
—
ns
(Note 5)
Data Out Hold Time
tHD-DO
200
900
ns
(Note 4)
Start Condition Setup Time
tSU-START
600
—
ns
Start Condition Hold Time
tHD-START
600
—
ns
Stop Condition Setup Time
tSU-STOP
600
—
ns
Bus Free
tB-FREE
1300
—
ns
Time-out
tOUT
25
35
ms
Cb
—
400
pf
Bus Capacitive Load
Note 1:
2:
3:
4:
5:
All values referred to VIL MAX and VIH MIN levels.
If tLOW > tOUT or tHIGH > tOUT, the temperature sensor I2C interface will time-out. A Repeat Start command
is required for communication.
This device can be used in a Standard mode I2C bus system, but the requirement, tSU-DI ≥ 100 ns, must
be met. This device does not stretch the SCL Low time.
As a transmitter, the device provides internal minimum delay time, tHD-DO MIN, to bridge the undefined
region (min. 200 ns) of the falling edge of SCL, tF MAX, to avoid unintended generation of Start or Stop
conditions.
As a receiver, SDA should not be sampled at the falling edge of SCL. SDA can transition tHD-DI 0 ns after
SCL toggles Low.
TIMING DIAGRAM
tHD-START
tSU-START
tHIGH
tLOW
tB-FREE
tSU-STOP
SCL
SDA
tOUT
tR, tF
tSU-DI
START Condition
© 2011 Microchip Technology Inc.
tHD-DI/tHD-DO
Data Transmission
STOP Condition
DS25095A-page 5
MCP9808
NOTES:
DS25095A-page 6
© 2011 Microchip Technology Inc.
MCP9808
2.0
TYPICAL PERFORMANCE CURVES
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
Note: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, SDA/SCL pulled-up to VDD and
TA = -40°C to +125°C.
40%
VDD = 3.3V
854 units at -20°C, 25°C, 85°C, 100°C
240 units at -40°C, 125°C
30%
0.5
Occurrences
0.0
+Std. Dev.
Average
-Std. Dev.
FIGURE 2-1:
FIGURE 2-4:
Histogram.
Temperature Accuracy.
Temperature Accuracy
40%
TA = -20°C
VDD = 3.3V
827 units
TA = 85°C
VDD = 3.3V
859 units
Occurrences
30%
20%
10%
20%
10%
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.5
Temperature Accuracy (°C)
-0.4
0%
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
0%
Temperature Accuracy (°C)
FIGURE 2-2:
Temperature Accuracy
Histogram, TA = -20°C.
FIGURE 2-5:
Temperature Accuracy
Histogram, TA = +85°C.
40%
40%
TA = 25°C
VDD = 3.3V
875 units
30%
Occurrences
20%
10%
TA = 100°C
VDD = 3.3V
856 units
20%
10%
FIGURE 2-3:
Temperature Accuracy
Histogram, TA = +25°C.
© 2011 Microchip Technology Inc.
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
0%
-0.4
Temperature Accuracy (°C)
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
-0.2
-0.3
-0.4
-0.5
0%
-0.5
Occurrences
0.5
Temperature Accuracy (°C)
40%
30%
0.4
120
0.3
100
0.2
80
0.1
40
60
TA (°C)
0.0
20
-0.1
0
-0.2
-20
0%
-0.3
-40
+3 * Std. Dev.
-3 * Std. Dev.
-0.4
-1.0
Occurrences
20%
10%
-0.5
30%
TA = -20°C, 25°C, 85°C, 100°C
VDD = 3.3V
854 units
-0.5
Temperature Accuracy (°C)
1.0
Temperature Accuracy (°C)
FIGURE 2-6:
Temperature Accuracy
Histogram, TA = +100°C.
DS25095A-page 7
MCP9808
Note: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, SDA/SCL pulled-up to VDD and
TA = -40°C to +125°C.
40%
350
IDD (µA)
300
250
200
150
100
0
20
40
60
80
100
1.00
0.50
0.5
0.4
0.00
-0.50
-1.00
120
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
FIGURE 2-11:
Supply Voltage.
Supply Current vs.
Temperature Accuracy vs
1000
3
0.0625°C
tCONV (ms)
2.5
VPOR (V)
0.3
∆°C/∆VDD = 0.1°C/V
VDD = 2.7V
VDD = 3.3V
VDD = 5.5V
Temperature (°C)
FIGURE 2-8:
Temperature.
0.2
FIGURE 2-10:
Temperature Accuracy
Histogram, TA = +125°C.
Temperature Accuracy (°C)
400
-20
0.1
Temperature Accuracy (°C)
Temperature Accuracy (°C)
FIGURE 2-7:
Temperature Accuracy
Histogram, TA = -40°C.
-40
0.0
-0.5
0.5
0.4
0.3
0.2
0.1
0.0
-0.1
0%
-0.2
0%
-0.3
10%
-0.4
10%
-0.1
20%
-0.2
Occurrences
30%
20%
-0.5
Occurrences
30%
TA = 125°C
VDD = 3.3V
240 units
-0.3
TA = -40°C
VDD = 3.3V
240 units
-0.4
40%
2
0.125°C
100
0.25°C
0.5°C
1.5
1
10
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
FIGURE 2-9:
Power-on Reset Threshold
Voltage vs. Temperature.
DS25095A-page 8
-40
-20
0
20
40
60
80
100
120
Temperature (°C)
FIGURE 2-12:
Temperature Conversion
Time vs. Temperature.
© 2011 Microchip Technology Inc.
MCP9808
0.4
35
IOL = 3 mA
SMBus/I2C Bus tOUT (ms)
SDA & Alert Output VOL (V)
Note: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, SDA/SCL pulled-up to VDD and
TA = -40°C to +125°C.
0.3
0.2
Alert VOL
SDA VOL
0.1
0
30
25
20
-40
-20
0
20
40
60
80
100
120
-40
-20
0
Temperature (°C)
FIGURE 2-13:
vs. Temperature.
40
60
80
100
120
SDA and Alert Output VOL
FIGURE 2-16:
Temperature.
SMBus Time-out vs.
2.00
48
VOL = 0.6V
42
1.50
36
ISHDN (µA)
SDA IOL (mA)
20
Temperature (°C)
30
24
18
1.00
0.50
12
6
0.00
-40
-20
0
20
40
60
80
100
120
-40
-20
0
FIGURE 2-14:
SDA IOL vs. Temperature.
100%
80%
60%
MSOP-8
DFN-8
20%
Room to +125°C (Oil bath)
0%
-2
0
FIGURE 2-15:
Response.
2
4
6
8
Time (s)
10
12
Package Thermal
© 2011 Microchip Technology Inc.
14
FIGURE 2-17:
Temperature.
Normalized Temp. Error (°C)
Thermal Response (%)
120%
40%
20
40
60
80
100
120
Temperature (°C )
Temperature (°C)
Shutdown Current vs
1.0
∆°C/∆VDD, VDD = 3.3V + 150 mVPP (AC)
TA = +25°C
25°C
0.5
0.0
-0.5
No decoupling capacitor
-1.0
100
100
16
1,000
1k
1k
10,000
10k
10k
100,000
100k
100k
1M
1M
1,000,000
Frequency (Hz)
FIGURE 2-18:
Frequency.
Power Supply Rejection vs.
DS25095A-page 9
MCP9808
NOTES:
DS25095A-page 10
© 2011 Microchip Technology Inc.
MCP9808
3.0
PIN DESCRIPTION
The descriptions of the pins are listed in Table 3-1.
TABLE 3-1:
3.1
PIN FUNCTION TABLE
DFN
MSOP
Symbol
Pin Function
1
1
SDA
2
2
SCL
Serial Clock Line
3
3
Alert
Temperature Alert Output
4
4
GND
Ground
5
5
A2
Slave Address
6
6
A1
Slave Address
7
7
A0
Slave Address
8
8
VDD
Power Pin
9
—
EP
Exposed Thermal Pad (EP); must be connected to GND
Serial Data Line
Serial Data Line (SDA)
SDA is a bidirectional input/output pin, used to serially
transmit data to/from the host controller. This pin
requires a pull-up resistor. (See Section 4.0 “Serial
Communication”.)
3.2
Serial Clock Line (SCL)
The SCL is a clock input pin. All communication and
timing is relative to the signal on this pin. The clock is
generated by the host or master controller on the bus.
(See Section 4.0 “Serial Communication”.)
3.3
Temperature Alert, Open-Drain
Output (Alert)
The MCP9808 temperature Alert output pin is an
open-drain output. The device outputs a signal when the
ambient temperature goes beyond the user-programmed
temperature limit. (See Section 5.2.3 “Alert Output
Configuration”).
3.4
Ground Pin (GND)
The GND pin is the system ground pin.
3.5
Address Pins (A0, A1, A2)
These pins are device address input pins.
The address pins correspond to the Least Significant
bits (LSbs) of the address bits and the Most Significant
bits (MSbs): A6, A5, A4, A3. This is illustrated in
Table 3-2.
TABLE 3-2:
Device
MCP9808
MCP9808(2)
Note 1:
2:
3.6
MCP9808 ADDRESS BYTE
Address Code
Slave
Address
A6
A5
A4
A3
A2
A1
A0
0
0
1
1
x(1)
x
x
1
0
0
1
x
x
x
User-selectable address is shown by ‘x’.
A2, A1 and A0 must match the
corresponding device pin configuration.
Contact factory for this address code.
Power Pin (VDD)
VDD is the power pin. The operating voltage range, as
specified in the DC electrical specification table, is
applied on this pin.
3.7
Exposed Thermal Pad (EP)
There is an internal electrical connection between the
Exposed Thermal Pad (EP) and the GND pin. The EP
may be connected to the system ground on the Printed
Circuit Board (PCB).
© 2011 Microchip Technology Inc.
DS25095A-page 11
MCP9808
NOTES:
DS25095A-page 12
© 2011 Microchip Technology Inc.
MCP9808
4.0
SERIAL COMMUNICATION
4.1
2-Wire Standard Mode I2C™
Protocol Compatible Interface
The MCP9808 Serial Clock (SCL) input and the
bidirectional Serial Data (SDA) line form a 2-wire
bidirectional, Standard mode, I2C compatible
communication port (refer to the Digital Input/Output
Pin Characteristics and Sensor Serial Interface
Timing Specifications tables).
The following bus protocol has been defined:
TABLE 4-1:
Term
MCP9808 SERIAL BUS
PROTOCOL DESCRIPTIONS
Description
Master
The device that controls the serial bus,
typically a microcontroller.
Slave
The device addressed by the master,
such as the MCP9808.
Transmitter Device sending data to the bus.
Receiver
Device receiving data from the bus.
START
A unique signal from the master to
initiate serial interface with a slave.
STOP
A unique signal from the master to
terminate serial interface from a slave.
Read/Write A read or write to the MCP9808
registers.
ACK
A receiver Acknowledges (ACK) the
reception of each byte by polling the bus.
NAK
A receiver Not-Acknowledges (NAK) or
releases the bus to show End-of-Data
(EOD).
Busy
Communication is not possible
because the bus is in use.
Not Busy
The bus is in the Idle state; both SDA
and SCL remain high.
Data Valid
SDA must remain stable before SCL
becomes high in order for a data bit to
be considered valid. During normal
data transfers, SDA only changes state
while SCL is low.
© 2011 Microchip Technology Inc.
4.1.1
DATA TRANSFER
Data transfers are initiated by a Start condition
(START), followed by a 7-bit device address and a
read/write bit. An Acknowledge (ACK) from the slave
confirms the reception of each byte. Each access must
be terminated by a Stop condition (STOP).
Repeated communication is initiated after tB-FREE.
This device does not support sequential register
read/write. Each register needs to be addressed using
the Register Pointer.
This device supports the receive protocol. The register
can be specified using the pointer for the initial read.
Each repeated read or receive begins with a Start
condition and address byte. The MCP9808 retains the
previously selected register. Therefore, it outputs data
from the previously specified register (repeated pointer
specification is not necessary).
4.1.2
MASTER/SLAVE
The bus is controlled by a master device (typically a
microcontroller) that controls the bus access and
generates the Start and Stop conditions. The MCP9808
is a slave device and does not control other devices in
the bus. Both master and slave devices can operate as
either transmitter or receiver. However, the master
device determines which mode is activated.
4.1.3
START/STOP CONDITION
A high-to-low transition of the SDA line (while SCL is
high) is the Start condition. All data transfers must be
preceded by a Start condition from the master. A
low-to-high transition of the SDA line (while SCL is
high) signifies a Stop condition.
If a Start or Stop condition is introduced during data
transmission, the MCP9808 releases the bus. All data
transfers are ended by a Stop condition from the
master.
DS25095A-page 13
MCP9808
4.1.4
4.1.5
ADDRESS BYTE
Following the Start condition, the host must transmit an
8-bit address byte to the MCP9808. The address for the
MCP9808 temperature sensor is ‘0011,A2,A1,A0’ in
binary, where the A2, A1 and A0 bits are set externally
by connecting the corresponding pins to VDD ‘1’ or GND
‘0’. The 7-bit address, transmitted in the serial bit stream,
must match the selected address for the MCP9808 to
respond with an ACK. Bit 8 in the address byte is a
read/write bit. Setting this bit to ‘1’ commands a read
operation, while ‘0’ commands a write operation (see
Figure 4-1).
Address Byte
SCL
1
2
3
4
5
6
7
SDA
0
0
1 1 A2 A1 A0
8
9
A
C
K
Start
Address
Code
Slave
Address R/W
MCP9808 Response
See Table 3-2.
FIGURE 4-1:
DS25095A-page 14
Device Addressing.
DATA VALID
After the Start condition, each bit of data in the
transmission needs to be settled for a time specified by
tSU-DATA before SCL toggles from low-to-high (see the
Sensor Serial Interface Timing Specifications section).
4.1.6
ACKNOWLEDGE (ACK/NAK)
Each receiving device, when addressed, must
generate an ACK bit after the reception of each byte.
The master device must generate an extra clock pulse
for ACK to be recognized.
The Acknowledging device pulls down the SDA line for
tSU-DATA before the low-to-high transition of SCL from
the master. SDA also needs to remain pulled down for
tH-DATA after a high-to-low transition of SCL.
During read, the master must signal an End-of-Data
(EOD) to the slave, by not generating an ACK bit
(NAK), once the last bit has been clocked out of the
slave. In this case, the slave will leave the data line
released to enable the master to generate the Stop
condition.
4.1.7
TIME-OUT
If the SCL stays low or high for the time specified by
tOUT, the MCP9808 temperature sensor resets the
serial interface. This dictates the minimum clock speed
as outlined in the specification.
© 2011 Microchip Technology Inc.
MCP9808
5.0
FUNCTIONAL DESCRIPTION
The MCP9808 temperature sensors consist of a bandgap-type temperature sensor, a Delta-Sigma Analog-toDigital Converter (ΔΣ ADC), user-programmable
registers and a 2-wire SMBus/I2C protocol compatible
serial interface. Figure 5-1 shows a block diagram of the
register structure.
Hysteresis
Shutdown
Critical Trip Lock
Alarm Win. Lock
Clear Alert
Alert Status
Output Control
Critical Alert Only
Band Gap
Temperature
Sensor
Alert Polarity
Alert Comp/Int
Configuration
Temperature
ΔΣ ADC
TUPPER Limit
TLOWER Limit
+0.5°C
+0.25°C
+0.125°C
+0.0625°C
TCRITICAL Limit
Manufacturer ID
Device ID/Rev
Resolution
Register
Pointer
SMBus/Standard I2C™
Interface
A0
FIGURE 5-1:
A1
A2
Alert
SDA
SCL
VDD
GND
Functional Block Diagram.
© 2011 Microchip Technology Inc.
DS25095A-page 15
MCP9808
5.1
Registers
The MCP9808 has several registers that are
user-accessible. These registers include the Temperature register, Configuration register, Temperature Alert
Upper Boundary and Lower Boundary Limit registers,
Critical Temperature Limit register, Manufacturer
Identification register and Device Identification register.
The Temperature register is read-only, used to access
the ambient temperature data. This register is doublebuffered and it is updated every tCONV. The Temperature
Alert Upper Boundary and Lower Boundary Limit
registers are read/write registers. If the ambient
temperature drifts beyond the user-specified limits, the
MCP9808 outputs a signal using the Alert pin (refer to
REGISTER 5-1:
Section 5.2.3 “Alert Output Configuration”). In
addition, the Critical Temperature Limit register is used
to provide an additional critical temperature limit.
The Configuration register provides access to
configure the MCP9808 device’s various features.
These registers are described in further detail in the
following sections.
The registers are accessed by sending a Register
Pointer to the MCP9808, using the serial interface. This
is an 8-bit write-only pointer. However, the four Least
Significant bits are used as pointers and all unused bits
(Register Pointer<7:4>) need to be cleared or set to ‘0’.
Register 5-1 describes the pointer or the address of
each register.
REGISTER POINTER (WRITE-ONLY)
W-0
W-0
W-0
W-0
—
—
—
—
W-0
W-0
W-0
W-0
Pointer bits
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-4
W: Writable bits
Write ‘0’.
Bits 7-4 must always be cleared or written to ‘0’. This device has additional registers that are reserved
for test and calibration. If these registers are accessed, the device may not perform according to the
specification.
bit 3-0
Pointer bits
0000 = RFU, Reserved for Future Use (Read-Only register)
0001 = Configuration register (CONFIG)
0010 = Alert Temperature Upper Boundary Trip register (TUPPER)
0011 = Alert Temperature Lower Boundary Trip register (TLOWER)
0100 = Critical Temperature Trip register (TCRIT)
0101 = Temperature register (TA)
0110 = Manufacturer ID register
0111 = Device ID/Revision register
1000 = Resolution register
1xxx = Reserved(1)
Note 1:
Some registers contain calibration codes and should not be accessed.
DS25095A-page 16
© 2011 Microchip Technology Inc.
MCP9808
TABLE 5-1:
BIT ASSIGNMENT SUMMARY FOR ALL REGISTERS
(See Section 5.3 “Summary of Power-on Default” for Power-on Defaults)
Register
Pointer
(Hex)
MSB/
LSB
7
6
5
4
3
2
1
0
0x00
MSB
0
0
0
0
0
0
0
0
LSB
0
0
0
1
1
1
0x01
MSB
0
0
0
0
0
LSB
Crt Loc
Win Loc
Int Clr
Alt Stat
Alt Cnt
Alt Sel
Alt Pol
Alt Mod
0x02
MSB
0
0
0
SIGN
27°C
26°C
25°C
24°C
LSB
23°C
22°C
21°C
20°C
2-1°C
2-2°C
0
0
26°C
25°C
24°C
2-2°C
0
0
25°C
24°C
0x03
Bit Assignment
MSB
0
0
0
SIGN
27°C
LSB
23°C
22°C
21°C
20°C
2-1°C
1
SHDN
MSB
0
0
0
SIGN
2 °C
26°C
LSB
23°C
22°C
21°C
20°C
2-1°C
2-2°C
MSB
TA ≥ TCRIT
TA > TUPPER
TA < TLOWER
SIGN
2 °C
2 °C
2 °C
2 °C
LSB
23°C
22°C
21°C
20°C
2-1°C
2-2°C
2-3°C
2-4°C
0x06
MSB
0
0
0
0
0
0
0
0
LSB
0
1
0
1
0
1
0
0
0x07
MSB
0
0
0
0
0
1
0
0
LSB
0
0
0
0
0
0
0
0
LSB
0
0
0
0
0
0
1
1
0x04
0x05
0x08
© 2011 Microchip Technology Inc.
7
1
Hysteresis
7
6
0
0
5
4
DS25095A-page 17
MCP9808
5.1.1
SENSOR CONFIGURATION
REGISTER (CONFIG)
user-specified
temperature
boundary
(see
Section 5.2.2 “Temperature Hysteresis (THYST)”.
The Continuous Conversion or Shutdown mode is
selected using bit 8. In Shutdown mode, the band gap
temperature
sensor
circuit
stops
converting
temperature and the Ambient Temperature register
(TA) holds the previous temperature data (see
Section 5.2.1 “Shutdown Mode”). Bits 7 and 6 are
used to lock the user-specified boundaries TUPPER,
TLOWER and TCRIT to prevent an accidental rewrite.
The Lock bits are cleared by resetting the power. Bits 5
through 0 are used to configure the temperature Alert
output pin. All functions are described in Register 5-2
(see Section 5.2.3 “Alert Output Configuration”).
The MCP9808 has a 16-bit Configuration register
(CONFIG) that allows the user to set various functions for
a robust temperature monitoring system. Bits 10 through
0 are used to select the temperature alert output
hysteresis, device shutdown or Low-Power mode,
temperature boundary and critical temperature lock, and
temperature Alert output enable/disable. In addition, Alert
output condition (output set for TUPPER and TLOWER
temperature boundary or TCRIT only), Alert output status
and Alert output polarity and mode (Comparator Output
or Interrupt Output mode) are user-configurable.
The temperature hysteresis bits 10 and 9 can be used
to prevent output chatter when the ambient
temperature
gradually
changes
beyond
the
REGISTER 5-2:
CONFIG: CONFIGURATION REGISTER (→ ADDRESS ‘0000 0001’b)
U-0
U-0
U-0
U-0
U-0
—
—
—
—
—
R/W-0
R/W-0
THYST
R/W-0
SHDN
bit 15
bit 8
R/W-0
R/W-0
R/W-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
Crit. Lock
Win. Lock
Int. Clear
Alert Stat.
Alert Cnt.
Alert Sel.
Alert Pol.
Alert Mod.
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 15-11
Unimplemented: Read as ‘0’
bit 10-9
THYST: TUPPER and TLOWER Limit Hysteresis bits
00 = 0°C (power-up default)
01 = +1.5°C
10 = +3.0°C
11 = +6.0°C
x = Bit is unknown
(Refer to Section 5.2.3 “Alert Output Configuration”.)
This bit can not be altered when either of the Lock bits are set (bit 6 and bit 7).
This bit can be programmed in Shutdown mode.
bit 8
SHDN: Shutdown Mode bit
0 = Continuous conversion (power-up default)
1 = Shutdown (Low-Power mode)
In shutdown, all power-consuming activities are disabled, though all registers can be written to or read.
This bit cannot be set to ‘1’ when either of the Lock bits is set (bit 6 and bit 7). However, it can be
cleared to ‘0’ for continuous conversion while locked (refer to Section 5.2.1 “Shutdown Mode”).
DS25095A-page 18
© 2011 Microchip Technology Inc.
MCP9808
REGISTER 5-2:
bit 7
CONFIG: CONFIGURATION REGISTER (→ ADDRESS ‘0000 0001’b)
Crit. Lock: TCRIT Lock bit
0 = Unlocked. TCRIT register can be written (power-up default)
1 = Locked. TCRIT register can not be written
When enabled, this bit remains set to ‘1’ or locked until cleared by an internal Reset (Section 5.3
“Summary of Power-on Default”).
This bit can be programmed in Shutdown mode.
bit 6
Win. Lock: TUPPER and TLOWER Window Lock bit
0 = Unlocked; TUPPER and TLOWER registers can be written (power-up default)
1 = Locked; TUPPER and TLOWER registers can not be written
When enabled, this bit remains set to ‘1’ or locked until cleared by a Power-on Reset (Section 5.3
“Summary of Power-on Default”).
This bit can be programmed in Shutdown mode.
bit 5
Int. Clear: Interrupt Clear bit
0 = No effect (power-up default)
1 = Clear interrupt output; when read, this bit returns to ‘0’
This bit can not be set to ‘1’ in Shutdown mode, but it can be cleared after the device enters Shutdown
mode.
bit 4
Alert Stat.: Alert Output Status bit
0 = Alert output is not asserted by the device (power-up default)
1 = Alert output is asserted as a comparator/Interrupt or critical temperature output
This bit can not be set to ‘1’ or cleared to ‘0’ in Shutdown mode. However, if the Alert output is configured as Interrupt mode, and if the host controller clears to ‘0’, the interrupt, using bit 5 while the device
is in Shutdown mode, then this bit will also be cleared ‘0’.
bit 3
Alert Cnt.: Alert Output Control bit
0 = Disabled (power-up default)
1 = Enabled
This bit can not be altered when either of the Lock bits are set (bit 6 and bit 7).
This bit can be programmed in Shutdown mode, but the Alert output will not assert or deassert.
bit 2
Alert Sel.: Alert Output Select bit
0 = Alert output for TUPPER, TLOWER and TCRIT (power-up default)
1 = TA > TCRIT only (TUPPER and TLOWER temperature boundaries are disabled)
When the Alarm Window Lock bit is set, this bit cannot be altered until unlocked (bit 6).
This bit can be programmed in Shutdown mode, but the Alert output will not assert or deassert.
bit 1
Alert Pol.: Alert Output Polarity bit
0 = Active-low (power-up default; pull-up resistor required)
1 = Active-high
This bit cannot be altered when either of the Lock bits are set (bit 6 and bit 7).
This bit can be programmed in Shutdown mode, but the Alert output will not assert or deassert.
bit 0
Alert Mod.: Alert Output Mode bit
0 = Comparator output (power-up default)
1 = Interrupt output
This bit cannot be altered when either of the Lock bits are set (bit 6 and bit 7).
This bit can be programmed in Shutdown mode, but the Alert output will not assert or deassert.
© 2011 Microchip Technology Inc.
DS25095A-page 19
MCP9808
Writing to the CONFIG Register to Enable the Event Output Pin <0000 0000 0000 1000>b:
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
W C
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
1
SCL
SDA
S
A
K
Address Byte
A
C
K
Configuration Pointer
MCP9808
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
0
A
C
K
1
2
3
4
5
6
7
8
0
0
0
0
1
0
0
0
MSB Data
A
C
K
P
LSB Data
MCP9808
MCP9808
Note: This is an example routine (see Appendix A: “Source Code”).
i2c_start();
// send START command
i2c_write(AddressByte & 0xFE);
//WRITE Command (see Section 4.1.4 “Address Byte”)
//also, make sure bit 0 is cleared ‘0’
i2c_write(0x01);
// Write CONFIG Register
i2c_write(0x00);
// Write data
i2c_write(0x08);
// Write data
i2c_stop();
// send STOP command
FIGURE 5-2:
Timing Diagram for Writing to the Configuration Register (see Section 4.0 “Serial
Communication”).
DS25095A-page 20
© 2011 Microchip Technology Inc.
MCP9808
Reading the CONFIG Register:
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Note:
SCL
SDA
0
S
0
1
A
2
1
A
1
A
A
0
W C
K
0
Address Byte
0
0
0
0
0
0
It is not necessary to
select the Register
Pointer if it was set
from the previous
read/write.
A
C
K
1
Configuration Pointer
MCP9808
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
R C
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
0
1
2
3
4
5
6
7
8
0
0
0
0
1
0
0
0
SCL
SDA
S
A
K
Address Byte
A
C
K
MSB Data
MCP9808
N
A
K
P
LSB Data
Master
Master
Note: This is an example routine (see Appendix A: “Source Code”).
i2c_start();
// send START command
i2c_write(AddressByte & 0xFE);
//WRITE Command (see Section 4.1.4 “Address Byte”)
//also, make sure bit 0 is cleared ‘0’
i2c_write(0x01);
// Write CONFIG Register
i2c_start();
// send Repeat START command
i2c_write(AddressByte | 0x01);
//READ Command
UpperByte = i2c_read(ACK);
// READ 8 bits
LowerByte = i2c_read(NAK);
// READ 8 bits
i2c_stop();
// send STOP command
//also, make sure bit 0 is set ‘1’
//and Send ACK bit
//and Send NAK bit
FIGURE 5-3:
Timing Diagram for Reading from the Configuration Register (see Section 4.0 “Serial
Communication”).
© 2011 Microchip Technology Inc.
DS25095A-page 21
MCP9808
5.1.2
UPPER/LOWER/CRITICAL
TEMPERATURE LIMIT REGISTERS
(TUPPER/TLOWER/TCRIT)
The MCP9808 has a 16-bit read/write Alert Output
Temperature Upper Boundary register (TUPPER), a 16-bit
Lower Boundary register (TLOWER) and a 16-bit Critical
Boundary register (TCRIT) that contain 11-bit data in
two’s complement format (0.25°C). This data represents
REGISTER 5-3:
the maximum and minimum temperature boundary or
temperature window that can be used to monitor
ambient temperature. If this feature is enabled
(Section 5.1.1 “Sensor Configuration Register
(CONFIG)”) and the ambient temperature exceeds the
specified boundary or window, the MCP9808 asserts an
Alert output. (Refer to Section 5.2.3 “Alert Output
Configuration”).
TUPPER/TLOWER/TCRIT UPPER/LOWER/CRITICAL TEMPERATURE LIMIT REGISTER
(→ ADDRESS ‘0000 0010’b/‘0000 0011’b/‘0000 0100’b)(1)
U-0
U-0
U-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
—
—
—
Sign
27°C
26°C
25°C
24°C
bit 15
bit 8
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
U-0
U-0
23°C
22°C
21°C
20°C
2-1°C
2-2°C
—
—
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 15-13
Unimplemented: Read as ‘0’
bit 12
Sign: Sign bit
0 = TA ≥ 0°C
1 = TA < 0°C
bit 11-2
TUPPER/TLOWER/TCRIT: Temperature Boundary bits
Temperature boundary trip data in two’s complement format.
bit 1-0
Unimplemented: Read as ‘0’
Note 1:
x = Bit is unknown
This table shows two 16-bit registers for TUPPER, TLOWER and TCRIT, located at ‘0000 0010b’,
‘0000 0011b’ and ‘0000 0100b’, respectively.
DS25095A-page 22
© 2011 Microchip Technology Inc.
MCP9808
Writing +90°C to the TUPPER Register <0000 0101 1010 0000>b:
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
A
W C
0
K
0
0
0
0
0
0
1
0
SCL
SDA
S
Address Byte
A
C
K
TUPPER Pointer
MCP9808
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
1
0
1
A
C
K
1
2
3
4
5
6
7
8
1
0
1
0
0
0
0
0
MSB Data
A
C
K
P
LSB Data
MCP9808
MCP9808
Reading from the TUPPER Register:
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Note:
SCL
SDA
S
0
0
1
1
A
2
A
1
A
0
A
W C
K
0
Address Byte
0
0
0
0
0
1
0
It is not necessary to
select the Register
Pointer if it was set
from the previous
read/write.
A
C
K
TUPPER Pointer
MCP9808
MCP9808
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
R C
1
2
3
4
5
6
7
8
0
0
0
0
0
1
0
1
1
2
3
4
5
6
7
8
1
0
1
0
0
0
0
0
SCL
SDA
S
A
K
Address Byte
A
C
K
MSB Data
MCP9808
N
A
K
P
LSB Data
Master
Master
FIGURE 5-4:
Timing Diagram for Writing and Reading from the TUPPER Register (see Section 4.0
“Serial Communication”).
© 2011 Microchip Technology Inc.
DS25095A-page 23
MCP9808
5.1.3
AMBIENT TEMPERATURE
REGISTER (TA)
In addition, the TA register uses three bits (TA<15:13>)
to reflect the Alert pin state. This allows the user to
identify the cause of the Alert output trigger (see
Section 5.2.3 “Alert Output Configuration”); bit 15 is
set to ‘1’ if TA is greater than or equal to TCRIT, bit 14 is
set to ‘1’ if TA is greater than TUPPER and bit 13 is set to
‘1’ if TA is less than TLOWER.
The MCP9808 uses a band gap temperature sensor
circuit to output analog voltage proportional to absolute
temperature. An internal ΔΣ ADC is used to convert the
analog voltage to a digital word. The digital word is
loaded to a 16-bit read-only Ambient Temperature
register (TA) that contains 13-bit temperature data in
two’s complement format.
The TA register bit assignment and boundary
conditions are described in Register 5-4.
The TA register bits (TA<12:0>) are double-buffered.
Therefore, the user can access the register, while in the
background, the MCP9808 performs an Analog-toDigital conversion. The temperature data from the ΔΣ
ADC is loaded in parallel to the TA register at tCONV
refresh rate.
REGISTER 5-4:
R-0
TA: AMBIENT TEMPERATURE REGISTER (→ ADDRESS ‘0000 0101’b)(1)
R-0
R-0
TA vs. TCRIT(1) TA vs. TUPPER(1) TA vs. TLOWER(1)
R-0
R-0
R-0
R-0
R-0
SIGN
27 °C
26 °C
25 °C
24 °C
bit 15
bit 8
R-0
2
3 °C
R-0
R-0
R-0
R-0
R-0
R-0
R-0
22 °C
21 °C
20 °C
2-1 °C
2-2 °C(2)
2-3 °C(2)
2-4 °C(2)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 15
TA vs. TCRIT bit(1)
0 = TA < TCRIT
1 = TA ≥ TCRIT
bit 14
TA vs. TUPPER bit(1)
0 = TA ≤ TUPPER
1 = TA > TUPPER
bit 13
TA vs. TLOWER bit(1)
0 = TA ≥ TLOWER
1 = TA < TLOWER
bit 12
SIGN bit
0 = TA ≥ 0°C
1 = TA < 0°C
bit 11-0
TA: Ambient Temperature bits(2)
12-bit ambient temperature data in two’s complement format.
Note 1:
2:
x = Bit is unknown
Bits 15, 14 and 13 are not affected by the status of the Alert Output Configuration (CONFIG<5:0> bits,
Register 5-2).
Bits 2, 1 and 0 may remain clear at ‘0’ depending on the status of the Resolution register (Register 5-7).
The power-up default is 0.25°C/bit; bits 1 and 0 remain clear ‘0’.
DS25095A-page 24
© 2011 Microchip Technology Inc.
MCP9808
5.1.3.1
TA Bits to Temperature Conversion
To convert the TA bits to decimal temperature, the
upper three boundary bits (TA<15:13>) must be
masked out. Then, determine the SIGN bit (bit 12) to
check positive or negative temperature, shift the bits
accordingly, and combine the upper and lower bytes of
the 16-bit register. The upper byte contains data for
temperatures greater than +32°C while the lower byte
contains data for temperature less than +32°C, including fractional data. When combining the upper and
lower bytes, the upper byte must be right-shifted by
4 bits (or multiply by 24) and the lower byte must be leftshifted by 4 bits (or multiply by 2-4). Adding the results
of the shifted values provides the temperature data in
decimal format (see Equation 5-1).
instruction code, outlined in Example 5-1, shows the
communication flow; also see Figure 5-5 for the timing
diagram.
EQUATION 5-1:
Temperature TA ≥ 0°C
4
–4
T A = ( UpperByte × 2 + LowerByte × 2 )
Temperature < 0°C
4
–4
T A = 256 – ( UpperByte × 2 + LowerByte × 2 )
Where:
TA = Ambient Temperature (°C)
UpperByte = TA bit 15 to bit 8
The temperature bits are in two’s compliment format,
therefore, positive temperature data and negative temperature data are computed differently. Equation 5-1
shows the temperature computation. The example
EXAMPLE 5-1:
BYTES TO
TEMPERATURE
CONVERSION
LowerByte = TA bit 7 to bit 0
SAMPLE INSTRUCTION CODE
This example routine assumes the variables and I2C™ communication subroutines are predefined
(see Appendix A: “Source Code”):
i2c_start();
// send START command
i2c_write (AddressByte & 0xFE);
//WRITE Command (see Section 4.1.4 “Address Byte”)
i2c_write(0x05);
// Write TA Register Address
//also, make sure bit 0 is cleared ‘0’
i2c_start();
//Repeat START
i2c_write(AddressByte | 0x01);
// READ Command (see Section 4.1.4 “Address Byte”)
UpperByte = i2c_read(ACK);
// READ 8 bits
LowerByte = i2c_read(NAK);
// READ 8 bits
i2c_stop();
// send STOP command
//also, make sure bit 0 is Set ‘1’
//and Send ACK bit
//and Send NAK bit
//Convert the temperature data
//First Check flag bits
if ((UpperByte & 0x80) == 0x80){
//TA ³ TCRIT
}
if ((UpperByte & 0x40) == 0x40){
//TA > TUPPER
}
if ((UpperByte & 0x20) == 0x20){
//TA < TLOWER
}
UpperByte = UpperByte & 0x1F;
//Clear flag bits
if ((UpperByte & 0x10) == 0x10){
//TA < 0°C
UpperByte = UpperByte & 0x0F;
//Clear SIGN
Temperature = 256 - (UpperByte x 16 + LowerByte / 16);
}else
//TA
³ 0°C
Temperature = (UpperByte x 16 + LowerByte / 16);
//Temperature = Ambient Temperature (°C)
© 2011 Microchip Technology Inc.
DS25095A-page 25
MCP9808
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Note:
SCL
SDA
S
0
0
1
1
A
2
A
1
A
0
A
W C
K
0
0
Address Byte
0
0
0
1
0
1
It is not necessary to
select the Register
Pointer if it was set from
the previous read/write.
A
C
K
TA Pointer
MCP9808
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
R C
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
1
1
2
3
4
5
6
7
8
1
0
0
1
0
1
0
0
SCL
SDA
S
A
K
Address Byte
A
C
K
MSB Data
MCP9808
N
A
K
P
LSB Data
Master
Master
FIGURE 5-5:
Timing Diagram for Reading +25.25°C Temperature from the TA Register
(see Section 4.0 “Serial Communication”).
DS25095A-page 26
© 2011 Microchip Technology Inc.
MCP9808
5.1.4
MANUFACTURER ID REGISTER
This register is used to identify the manufacturer of the
device in order to perform manufacturer-specific
operation. The Manufacturer ID for the MCP9808 is
0x0054 (hexadecimal).
REGISTER 5-5:
MANUFACTURER ID REGISTER – READ-ONLY (→ ADDRESS ‘0000 0110’b)
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
Manufacturer ID
bit 15
bit 8
R-0
R-1
R-0
R-1
R-0
R-1
R-0
R-0
Manufacturer ID
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
x = Bit is unknown
Device Manufacturer Identification bits
bit 15-0
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
W C
K
1
2
3
4
5
6
7
8
0
0
0
0
0
1
1
0
Note:
SCL
SDA
S
A
Address Byte
It is not necessary to
select the Register
Pointer if it was set
from the previous
read/write.
A
C
K
Manufacturer ID Pointer
MCP9808
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
R C
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
0
1
2
3
4
5
6
7
8
0
1
0
1
0
1
0
0
SCL
SDA
S
A
K
Address Byte
A
C
K
MSB Data
MCP9808
N
A
K
P
LSB Data
Master
Master
FIGURE 5-6:
Timing Diagram for Reading the Manufacturer ID Register (see Section 4.0 “Serial
Communication”).
© 2011 Microchip Technology Inc.
DS25095A-page 27
MCP9808
5.1.5
DEVICE ID AND REVISION
REGISTER
The upper byte of this register is used to specify the
device identification and the lower byte is used to
specify the device revision. The Device ID for the
MCP9808 is 0x04 (hex).
The revision begins with 0x00 (hex) for the first release,
with the number being incremented as revised versions
are released.
REGISTER 5-6:
DEVICE ID AND DEVICE REVISION – READ-ONLY (→ ADDRESS ‘0000 0111’b)
R-0
R-0
R-0
R-0
R-0
R-1
R-0
R-0
Device ID
bit 15
bit 8
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
Device Revision
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 15-8
Device ID: Bit 15 to bit 8 are used for device ID
bit 7-0
Device Revision: Bit 7 to bit 0 are used for device revision
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
x = Bit is unknown
8
Note:
SCL
SDA
S
0
0
1
1
A
2
A
1
A
0
A
W C
K
0
Address Byte
0
0
0
0
1
1
1
It is not necessary to
select the Register
Pointer if it was set
from the previous
read/write.
A
C
K
Device ID Pointer
MCP9808
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
R C
MCP9808
1
2
3
4
5
6
7
8
0
0
0
0
0
1
0
0
1
2
3
4
5
6
7
8
0
0
0
0
0
0
0
0
SCL
SDA
S
A
K
Address Byte
A
C
K
MSB Data
MCP9808
N
A
K
P
LSB Data
Master
Master
FIGURE 5-7:
Timing Diagram for Reading Device ID and Device Revision Register (see
Section 4.0 “Serial Communication”).
DS25095A-page 28
© 2011 Microchip Technology Inc.
MCP9808
5.1.6
RESOLUTION REGISTER
This register allows the user to change the sensor
resolution
(see
Section 5.2.4
“Temperature
Resolution”). The POR default resolution is
+0.0625°C. The selected resolution is also reflected in
the Capability register (see Register 5-2).
REGISTER 5-7:
RESOLUTION REGISTER (→ ADDRESS ‘0000 1000’b)
U-0
U-0
U-0
U-0
U-0
U-0
—
—
—
—
—
—
R/W-1
R/W-1
Resolution
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
U = Unimplemented bit, read as ‘0’
-n = Value at POR
‘1’ = Bit is set
‘0’ = Bit is cleared
bit 7-2
Unimplemented: Read as ‘0’
bit 1-0
Resolution bits
00 = +0.5°C (tCONV = 30 ms typical)
01 = +0.25°C (tCONV = 65 ms typical)
10 = +0.125°C (tCONV = 130 ms typical)
11 = +0.0625°C (power-up default, tCONV = 250 ms typical)
1
2
3
4
5
6
7
8
0
0
1
1
A
2
A
1
A
0
W C
1
2
3
4
5
6
7
8
0
0
0
0
1
0
0
0
x = Bit is unknown
1
2
3
4
5
6
7
8
0
0
0
0
0
0
1
1
SCL
SDA
S
A
K
Address Byte
A
C
K
Resolution Pointer
MCP9808
A
C
K
P
Data
MCP9808
MCP9808
FIGURE 5-8:
Timing Diagram for Changing TA Resolution to +0.0625°C <0000 0011>b (see
Section 4.0 “Serial Communication”).
© 2011 Microchip Technology Inc.
DS25095A-page 29
MCP9808
5.2
5.2.1
SENSOR FEATURE DESCRIPTION
Shutdown mode disables all power consuming
activities (including temperature sampling operations)
while leaving the serial interface active. This mode is
selected by setting bit 8 of CONFIG to ‘1’. In this mode,
the device consumes ISHDN. It remains in this mode
until bit 8 is cleared to ‘0’ to enable Continuous
Conversion mode or until power is recycled.
The Shutdown bit (bit 8) cannot be set to ‘1’ while the
CONFIG<7:6> bits (Lock bits) are set to ‘1’. However, it
can be cleared to ‘0’ or returned to Continuous
Conversion mode while locked.
In Shutdown mode, all registers can be read or written.
However, the serial bus activity increases the shutdown
current. In addition, if the device is in shutdown while
the Alert pin is asserted, the device will retain the active
state during shutdown. This increases the shutdown
current due to the additional Alert output current.
5.2.2
TEMPERATURE HYSTERESIS
(THYST)
A hysteresis of 0°C, +1.5°C, +3°C or +6°C can be
selected for the TUPPER, TLOWER and TCRIT temperate
boundaries, using bits 10 and 9 of CONFIG. The
hysteresis applies for decreasing temperature only (hot
to cold) or as temperature drifts below the specified
limit.
The Hysteresis bits can not be changed if either of the
Lock bits (CONFIG<7:6) are set to ‘1’.
The TUPPER, TLOWER and TCRIT boundary conditions
are described graphically in Figure 5-10.
5.2.3
VDD
SHUTDOWN MODE
ALERT OUTPUT CONFIGURATION
The Alert output can be enabled by using bit 3 of the
CONFIG register (Alert Output Control bit) and can be
configured as either a comparator output or as an
Interrupt Output mode using bit 0 of CONFIG (Alert
Output Mode bit). The polarity can also be specified as
active-high or active-low using bit 1 of CONFIG (Alert
Polarity bit). This is an open-drain output and requires
a pull-up resistor.
MCP9808
RPU
Alert Output
FIGURE 5-9:
Configuration.
Active-Low Alert Output
The status of the Alert output can be read using
CONFIG<4> (Alert Output Status bit). This bit can not
be set to ‘1’ in Shutdown mode.
Bits 7 and 6 of the CONFIG register can be used to lock
the TUPPER, TLOWER and TCRIT registers. These bits
prevent false triggers at the Alert output due to an
accidental rewrite to these registers.
The Alert output can also be used as a critical temperature output using bit 2 of CONFIG (Alert Output Select
bit). When this feature is selected, the Alert output
becomes a comparator output. In this mode, the
interrupt output configuration (Alert Output Mode bit,
CONFIG<0>) is ignored.
5.2.3.1
Comparator Mode
Comparator mode is selected using bit 0 of CONFIG. In
this mode, the Alert output is asserted as active-high or
active-low, using bit 1 of CONFIG. Figure 5-10 shows
the conditions that toggle the Alert output.
If the device enters Shutdown mode with asserted Alert
output, the output remains asserted during Shutdown
mode. The device must be operating in Continuous
Conversion mode for tCONV. The TA vs. TUPPER,
TLOWER and TCRIT boundary conditions need to be
satisfied in order for the Alert output to deassert.
Comparator mode is useful for thermostat type
applications, such as turning on a cooling fan or
triggering a system shutdown when the temperature
exceeds a safe operating range.
When the ambient temperature increases above the
critical temperature limit, the Alert output is forced to a
comparator output (regardless of CONFIG<0>). When
the temperature drifts below the critical temperature
limit minus hysteresis, the Alert output automatically
returns to the state specified by CONFIG<0> bit.
DS25095A-page 30
© 2011 Microchip Technology Inc.
MCP9808
5.2.3.2
Interrupt Mode
In Interrupt mode, the Alert output is asserted as activehigh or active-low (depending on the polarity
configuration) when TA drifts above or below TUPPER
and TLOWER limits. The output is deasserted by setting
bit 5 (Interrupt Clear bit) of CONFIG. Shutting down the
device will not reset or deassert the Alert output. This
mode can not be selected when the Alert output is used
as a critical temperature output only, using bit 2 of
CONFIG.
This mode is designed for interrupt driven
microcontroller-based systems. The microcontroller
receiving the interrupt will have to Acknowledge the
interrupt by setting bit 5 of the CONFIG register from the
MCP9808.
© 2011 Microchip Technology Inc.
5.2.4
TEMPERATURE RESOLUTION
The MCP9808 is capable of providing temperature
data with +0.5°C to +0.0625°C resolution. The resolution can be selected using the Resolution register
(Register 5-7). It is located at address, ‘00001000’b,
and it provides measurement flexibility. A +0.0625°C
resolution is set as a POR default by the factory.
TABLE 5-2:
TEMPERATURE
CONVERSION TIME
Resolution
tCONV
(ms)
Samples/sec
(typical)
+0.5°C
30
33
+0.25°C
65
15
+0.125°C
130
7
+0.0625°C
(Power-up Default)
250
4
DS25095A-page 31
MCP9808
TCRIT – THYST
TCRIT
TUPPER – THYST
TUPPER
TUPPER – THYST
TA
TLOWER – THYST
TLOWER
TLOWER – THYST
Alert Output
(Active-Low)
Comparator
Interrupt
S/w Int. Clear
Critical Only
Alert Output
(Active-High)
Comparator
Interrupt
S/w Int. Clear
Critical Only
Notes: 1
Alert Output Boundary
Conditions
Notes
1
2
3
4
5
6
7
2
Comparator
1 3
4
3 5 6
Interrupt
Critical
Alert Output (Active-Low/High)
7 4
2
TA Bits
15
14
13
TA ≥ TLOWER
TA < TLOWER – THYST
High/Low
Low/High
High/Low
0
0
0
Low/High
Low/High
High/Low
0
0
1
TA > TUPPER
TA ≤ TUPPER – THYST
Low/High
Low/High
High/Low
0
1
0
High/Low
Low/High
High/Low
0
0
0
TA ≥ TCRIT
Low/High
Low/High
Low/High
1
1
0
When TA ≥ TCRIT, the Alert output is forced to Comparator mode and the CONFIG<0> (Alert Output
Mode bit) is ignored until TA < TCRIT – THYST. In the Interrupt mode, if the interrupt is not cleared
(bit 5 of CONFIG), as shown in the diagram at Note 6, then Alert will remain asserted at Note 7
until the interrupt is cleared by the controller.
TA < TCRIT – THYST
FIGURE 5-10:
DS25095A-page 32
Low/High
High/Low
High/Low
0
1
0
Alert Output Conditions.
© 2011 Microchip Technology Inc.
MCP9808
5.3
Summary of Power-on Default
The MCP9808 has an internal Power-on Reset (POR)
circuit. If the power supply voltage, VDD, glitches below
the VPOR threshold, the device resets the registers to
the power-on default settings.
Table 5-3 shows the power-on default summary for the
Temperature Sensor registers.
TABLE 5-3:
POWER-ON RESET DEFAULTS
Registers
Address
(Hexadecimal)
Register Name
Default Register
Data (Hexadecimal)
Power-Up Default
Register Description
0x01
CONFIG
0x0000
Comparator Mode
Active-Low Output
Alert and Critical Output
Output Disabled
Alert Not Asserted
Interrupt Cleared
Alert Limits Unlocked
Critical Limit Unlocked
Continuous Conversion
0°C Hysteresis
0x02
TUPPER
0x0000
0°C
0x03
TLOWER
0x0000
0°C
0x04
TCRIT
0x0000
0°C
0x05
TA
0x0000
0°C
0x06
Manufacturer ID
0x0054
0x0054 (hex)
0x07
Device ID/Device Revision
0x0400
0x0400 (hex)
0x08
Resolution
© 2011 Microchip Technology Inc.
0x03
0x03 (hex)
DS25095A-page 33
MCP9808
NOTES:
DS25095A-page 34
© 2011 Microchip Technology Inc.
MCP9808
6.0
APPLICATIONS INFORMATION
6.1
Layout Considerations
ature accuracy error of approximately +0.5°C could
result from self-heating if the communication pins
sink/source the maximum current specified.
For example, if the event output is loaded to maximum
IOL, Equation 6-1 can be used to determine the effect
of self-heating.
The MCP9808 does not require any additional
components besides the master controller in order to
measure temperature. However, it is recommended
that a decoupling capacitor of 0.1 µF to 1 µF be used
between the VDD and GND pins. A high-frequency
ceramic capacitor is recommended. It is necessary for
the capacitor to be located as close as possible to the
power and ground pins of the device in order to provide
effective noise protection.
EQUATION 6-1:
T Δ = θ JA ( V DD • I DD + V
•I
+ V OL_SDA • I OL_SDA )
OL_Alert OL_Alert
Where:
TΔ = TJ – TA
In addition, good PCB layout is key for better thermal
conduction from the PCB temperature to the sensor
die. For good temperature sensitivity, add a ground
layer under the device pins, as shown in Figure 6-1.
6.2
EFFECT OF
SELF-HEATING
TJ = Junction Temperature
TA = Ambient Temperature
θJA = Package Thermal Resistance
VOL_Alert, SDA = Alert and SDA Output VOL
(0.4 Vmax)
Thermal Considerations
IOL_Alert, SDA = Alert and SDA Output IOL
(3 mAmax)
A potential for self-heating errors can exist if the
MCP9808 SDA, SCL and Event lines are heavily
loaded with pull-ups (high current). Typically, the
self-heating error is negligible because of the relatively
small current consumption of the MCP9808. A temper-
At room temperature (TA = +25°C) with maximum
IDD = 500 µA and VDD = 3.6V, the self-heating due to
power dissipation TΔ is +0.2°C for the DFN-8 package
and +0.5°C for the TSSOP-8 package.
VDD
SDA
A0
SCL
EP9
FIGURE 6-1:
Alert
A1
GND
A2
DFN Package Layout (Top View).
© 2011 Microchip Technology Inc.
DS25095A-page 35
MCP9808
NOTES:
DS25095A-page 36
© 2011 Microchip Technology Inc.
MCP9808
7.0
PACKAGING INFORMATION
7.1
Package Marking Information
8-Lead DFN (2x3x0.9 mm)
Example
ALP
141
25
8-Lead MSOP (3x3 mm)
Example
9808E
141256
Legend: XX...X
Y
YY
WW
NNN
e3
*
Note:
Customer-specific information
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
Pb-free JEDEC designator for Matte Tin (Sn)
This package is Pb-free. The Pb-free JEDEC designator ( e3 )
can be found on the outer packaging for this package.
In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
© 2011 Microchip Technology Inc.
DS25095A-page 37
MCP9808
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DS25095A-page 38
© 2011 Microchip Technology Inc.
MCP9808
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
© 2011 Microchip Technology Inc.
DS25095A-page 39
MCP9808
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DS25095A-page 40
© 2011 Microchip Technology Inc.
MCP9808
Note:
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
© 2011 Microchip Technology Inc.
DS25095A-page 41
MCP9808
NOTES:
DS25095A-page 42
© 2011 Microchip Technology Inc.
MCP9808
Software License Agreement
The software supplied herewith by Microchip Technology Incorporated (the “Company”) is intended and supplied to you, the
Company’s customer, for use solely and exclusively with products manufactured by the Company.
The software is owned by the Company and/or its supplier, and is protected under applicable copyright laws. All rights are reserved.
Any use in violation of the foregoing restrictions may subject the user to criminal sanctions under applicable laws, as well as to civil
liability for the breach of the terms and conditions of this license.
THIS SOFTWARE IS PROVIDED IN AN “AS IS” CONDITION. NO WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR
SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
APPENDIX A:
SOURCE CODE
/********************************************************************
FileName:
I2C.c
Processor:
PIC18 Microcontrollers
Complier:
Microchip C18 (for PIC18) or C30 (for PIC24)
Company:
Microchip Technology, Inc.
#include <p18cxxx.h> // This code is developed for PIC18F2550
//It can be modified to be used with any PICmicro with MSSP module
/** PRIVATE PROTOTYPES *********************************************/
void i2c_init(void);
void i2c_start(void);
void i2c_repStart(void);
void i2c_stop(void);
unsigned char i2c_write( unsigned char i2cWriteData );
unsigned char i2c_read( unsigned char ack );
/********************************************************************
*
Function Name: i2c_init
*
Return Value:
void
*
Parameters:
Enable SSP
*
Description:
This function sets up the SSP1 module on a
*
PIC18CXXX device for use with a Microchip I2C
********************************************************************/
void i2c_init(void) {
TRISBbits.TRISB0 = 1;
TRISBbits.TRISB1 = 1;
// Digital Output (make it input only when reading data)
// Digital Output
SSPCON1 = 0x28;
SSPCON2 = 0x00;
SSPSTAT = 0x80;
// enable I2C Master mode
// clear control bits
// disable slew rate control; disable SMBus
SSPADD = 19;
// set baud rate to 100 kHz (Fosc = 48 MHz)
PIR1bits.SSPIF = 0;
PIR2bits.BCLIF = 0;
SSPCON2bits.SEN = 0;
// force idle condition
}
© 2011 Microchip Technology Inc.
DS25095A-page 45
MCP9808
/********************************************************************
*
Function Name:
i2c_start
*
Return Value:
void
*
Parameters:
void
*
Description:
Send I2C Start Command
********************************************************************/
void i2c_start(void) {
PIR1bits.SSPIF = 0; //clear flag
while (SSPSTATbits.BF );
// wait for idle condition
SSPCON2bits.SEN = 1;
// initiate START condition
while (!PIR1bits.SSPIF) ;
// wait for a flag to be set
PIR1bits.SSPIF = 0; // clear flag
}
/********************************************************************
*
Function Name:
i2c_repStart
*
Return Value:
void
*
Parameters:
void
*
Description:
Resend I2C Start Command
*
********************************************************************/
void i2c_repStart(void) {
PIR1bits.SSPIF = 0; // clear flag
while ( SSPSTATbits.BF ) ; // wait for idle condition
SSPCON2bits.RSEN = 1;
// initiate Repeated START condition
while (!PIR1bits.SSPIF) ; // wait for a flag to be set
PIR1bits.SSPIF = 0; // clear flag
}
/********************************************************************
*
Function Name:
i2c_stop
*
Return Value:
void
*
Parameters:
void
*
Description:
Send I2C Stop command
*
********************************************************************/
void i2c_stop(void) {
PIR1bits.SSPIF = 0; // clear flag
while ( SSPSTATbits.BF ) ; // wait for idle condition
SSPCON2bits.PEN = 1;
// Initiate STOP condition
while (!PIR1bits.SSPIF) ; // wait for a flag to be set
PIR1bits.SSPIF = 0; // clear flag
}
DS25095A-page 46
© 2011 Microchip Technology Inc.
MCP9808
/********************************************************************
*
Function Name:
i2c_write
*
Return Value:
Status byte for WCOL detection.
*
Parameters:
Single data byte for I2C2 bus.
*
Description:
This routine writes a single byte to the
*
I2C2 bus.
********************************************************************/
unsigned char i2c_write( unsigned char i2cWriteData ) {
PIR1bits.SSPIF = 0; // clear interrupt
while ( SSPSTATbits.BF ) ; // wait for idle condition
SSPBUF = i2cWriteData;
ted)
// Load SSPBUF with i2cWriteData (the value to be transmit-
while (!PIR1bits.SSPIF) ; // wait for a flag to be set
PIR1bits.SSPIF = 0; // clear flag
return ( !SSPCON2bits.ACKSTAT ); // function returns '1' if transmission is acknowledged
}
/********************************************************************
*
Function Name:
i2c_read
*
Return Value:
contents of SSP2BUF register
*
Parameters:
ack = 1 and nak = 0
*
Description:
Read a byte from I2C bus and ACK/NAK device
********************************************************************/
unsigned char i2c_read( unsigned char ack ) {
unsigned char i2cReadData;
PIR1bits.SSPIF = 0;// clear interrupt
while ( SSPSTATbits.BF ) ; // wait for idle condition
SSPCON2bits.RCEN = 1;
// enable receive mode
while (!PIR1bits.SSPIF) ; // wait for a flag to be set
PIR1bits.SSPIF = 0;// clear flag
i2cReadData = SSPBUF;
// Read SSPBUF and put it in i2cReadData
if ( ack ) {
SSPCON2bits.ACKDT = 0;
} else {
SSPCON2bits.ACKDT = 1;
}
// if ack=1
//
then transmit an Acknowledge
SSPCON2bits.ACKEN = 1;
// send acknowledge sequence
//
otherwise transmit a Not Acknowledge
while (!PIR1bits.SSPIF) ; // wait for a flag to be set
PIR1bits.SSPIF = 0;// clear flag
return( i2cReadData );
// return the value read from SSPBUF
}
© 2011 Microchip Technology Inc.
DS25095A-page 47
MCP9808
NOTES:
DS25095A-page 48
© 2011 Microchip Technology Inc.
MCP9808
APPENDIX B:
REVISION HISTORY
Revision A (October 2011)
• Original Release of this Document.
© 2011 Microchip Technology Inc.
DS25095A-page 49
MCP9808
NOTES:
DS25095A-page 50
© 2011 Microchip Technology Inc.
MCP9808
PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
X
Device
Tape and Reel
and/or
Alternate Pinout
-X
/XX
Temperature Package
Range
Examples:
a) MCP9808-E/MC:
b) MCP9808-E/MS:
Device:
MCP9808: Digital Temperature Sensor
MCP9808T: Digital Temperature Sensor (Tape and Reel)
c) MCP9808T-E/MC:
Temperature Range:
E
d) MCP9808T-E/MS:
Package:
MC = Plastic Dual Flat No-Lead (DFN) 2x3, 8-lead
MS = Plastic Micro Small Outline (MSOP), 8-lead
= -40°C to +125°C
© 2011 Microchip Technology Inc.
Extended Temperature
8LD DFN package.
Extended Temperature
8LD MSOP package.
Tape and Reel,
Extended Temperature
8LD DFN package.
Tape and Reel,
Extended Temperature
8LD MSOP package.
DS25095A-page 51
MCP9808
NOTES:
DS25095A-page 52
© 2011 Microchip Technology Inc.
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
•
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
FITNESS FOR PURPOSE. Microchip disclaims all liability
arising from this information and its use. Use of Microchip
devices in life support and/or safety applications is entirely at
the buyer’s risk, and the buyer agrees to defend, indemnify and
hold harmless Microchip from any and all damages, claims,
suits, or expenses resulting from such use. No licenses are
conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, dsPIC,
KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART,
PIC32 logo, rfPIC and UNI/O are registered trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor,
MXDEV, MXLAB, SEEVAL and The Embedded Control
Solutions Company are registered trademarks of Microchip
Technology Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, chipKIT,
chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net,
dsPICworks, dsSPEAK, ECAN, ECONOMONITOR,
FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP,
Mindi, MiWi, MPASM, MPLAB Certified logo, MPLIB,
MPLINK, mTouch, Omniscient Code Generation, PICC,
PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, REAL ICE,
rfLAB, Select Mode, Total Endurance, TSHARC,
UniWinDriver, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2011, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
ISBN: 978-1-61341-739-3
Microchip received ISO/TS-16949:2009 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
© 2011 Microchip Technology Inc.
DS25095A-page 53
Worldwide Sales and Service
AMERICAS
ASIA/PACIFIC
ASIA/PACIFIC
EUROPE
Corporate Office
2355 West Chandler Blvd.
Chandler, AZ 85224-6199
Tel: 480-792-7200
Fax: 480-792-7277
Technical Support:
http://www.microchip.com/
support
Web Address:
www.microchip.com
Asia Pacific Office
Suites 3707-14, 37th Floor
Tower 6, The Gateway
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Hong Kong
Tel: 852-2401-1200
Fax: 852-2401-3431
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Tel: 91-80-3090-4444
Fax: 91-80-3090-4123
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Tel: 91-11-4160-8631
Fax: 91-11-4160-8632
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Tel: 43-7242-2244-39
Fax: 43-7242-2244-393
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Tel: 45-4450-2828
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Tel: 886-2-2500-6610
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Tel: 66-2-694-1351
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Italy - Milan
Tel: 39-0331-742611
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Netherlands - Drunen
Tel: 31-416-690399
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Tel: 34-91-708-08-90
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UK - Wokingham
Tel: 44-118-921-5869
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Tel: 86-29-8833-7252
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Tel: 86-592-2388138
Fax: 86-592-2388130
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Tel: 86-756-3210040
Fax: 86-756-3210049
DS25095A-page 54
Korea - Daegu
Tel: 82-53-744-4301
Fax: 82-53-744-4302
08/02/11
© 2011 Microchip Technology Inc.