MCP9801-M/MS Microchip Technology, MCP9801-M/MS Datasheet - Page 24

• Manufacturer Part Number: MCP9801-M/MS
• Description: IC SENSOR THERMAL 2.7V 8MSOP
• Manufacturer: Microchip Technology

Specifications of MCP9801-M/MS

• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Output Type: I²C™/SMBus™
• Function: Temp Monitoring System (Sensor)
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 125°C
• Output Alarm: No
• Output Fan: Yes
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Temperature Threshold: Programmable
• Full Temp Accuracy: 3 C
• Digital Output - Bus Interface: I2C, SMBus
• Digital Output - Number Of Bits: 9 bit to 12 bit
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Description/function: High Accuracy 12-bit Serial Input/Output, Thermal Monitors
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Supply Current: 400 uA
• Ic Output Type: Voltage
• Sensing Accuracy Range: ± 0.5°C
• Temperature Sensing Range: -55°C To +125°C
• Supply Voltage Range: 2.7V To 5.5V
• Resolution (bits): 12bit
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MCP9800/1/2/3
5.3.4.1
The Shutdown mode disables all power-consuming
activities (including temperature sampling operations)
while leaving the serial interface active. The device
consumes 2 µA (maximum) in this mode. It remains in
this mode until the Configuration register is updated to
enable continuous conversion or until power is
recycled.
In Shutdown mode, the CONFIG, T
registers can be read or written to; however, the serial
bus activity will increase the shutdown current.
5.3.4.2
The MCP9800/1/2/3 can also be used in a One-shot
mode that can be selected using bit 7 of the CONFIG
register. The One-shot mode performs a single
temperature measurement and returns to Shutdown
mode. This mode is especially useful for low-power
applications where temperature is measured upon
command from a controller. For example, a 9-bit T
One-shot mode consumes 200 µA (typical) for 30 ms
and 0.1 µA (typical) during shutdown.
To access this feature, the device needs to initially be
in Shutdown mode. This is done by sending a byte to
the CONFIG register with bit 0 set <1> and bit 7 cleared
<0>. Once the device is in Shutdown mode, the
CONFIG register needs to be written to again, with bit
0 and bit 7 set <1>. This begins the single conversion
cycle of t
conversion is completed, T
CONFIG becomes cleared <0> by the MCP9800/1/2/3.
TABLE 5-2:
DS21909D-page 24
Continuous Conversion
Shutdown
Continuous Conversion
(One-shot is ignored)
One-shot
Note 1:
Operational Mode
(Note
CONV
The shutdown command <01> needs to
be programmed before sending a
one-shot command <11>.
Shutdown Mode
One-Shot Mode
, 30ms for 9-bit data. Once the
1)
SHUTDOWN AND ONE-SHOT
MODE DESCRIPTION
A
One-Shot
is updated and bit 7 of
(Bit 7)
0
0
1
1
A
, T
SET
Shutdown
and T
(Bit 0)
0
1
0
1
HYST
A
in
5.3.4.3
The ALERT output can be configured as either a
comparator output or as Interrupt Output mode using
bit 1 of CONFIG. The polarity can also be specified as
an active-high or active-low using bit 2 of CONFIG. The
following sections describe each output mode, while
Figure 5-7
5.3.4.4
In Comparator mode, the ALERT output is asserted
when T
until T
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.
In Comparator mode, if the device enters the Shutdown
mode with asserted ALERT output, the output remains
active during shutdown. The device must be operating
in continuous conversion, with T
ALERT output to be deasserted.
5.3.4.5
In Interrupt mode, the ALERT output is asserted when
T
deasserted when the user performs a read from any
register. This mode is designed for interrupt-driven,
microcontroller-based systems. The microcontroller
receiving the interrupt will have to acknowledge the
interrupt by reading any register from the MCP9800/1/
2/3. This will clear the interrupt and the ALERT pin will
become deasserted. When T
MCP9800/1/2/3 outputs another interrupt and the
controller needs to read a register to deassert the
ALERT output. Shutting down the device will also reset,
or deassert, the ALERT output.
FIGURE 5-7:
ALERT
T
T
ALERT
Comparator mode
Interrupt mode
Register
Read
A
T
SET
A
HYST
Active-low
is greater than T
Active-low
* See
A
A
is lower than T
is greater than T
gives a graphical description.
Section 5.3.4.5 “Interrupt Mode”
ALERT Output Configuration
Comparator Mode
Interrupt Mode
Alert Output.
HYST
SET
 2010 Microchip Technology Inc.
*
SET
. However, the output is
. The Comparator mode is
A
. The pin remains active
drifts below T
A
below T
HYST
HYST
, for the
, the