MCP9804-E/MS Microchip Technology, MCP9804-E/MS Datasheet - Page 30

• Manufacturer Part Number: MCP9804-E/MS
• Description: IC TEMP SENSOR I2C 2.7V 8MSOP
• Manufacturer: Microchip Technology

Specifications of MCP9804-E/MS

• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Function: Temp Monitoring System (Sensor)
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: Internal
• Sensing Temperature: -40°C ~ 125°C
• Output Type: I²C™/SMBus™
• Output Alarm: No
• Output Fan: No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Temperature Threshold: + 150 C
• Full Temp Accuracy: +/- 0.25 %
• Digital Output - Bus Interface: 2-Wire, I2C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 200 uA
• Ic Output Type: Digital
• Sensing Accuracy Range: ± 0.25°C
• Temperature Sensing Range: -40°C To +125°C
• Supply Voltage Range: 2.7V To 5.5V
• Sensor Case Style: MSOP
• No. Of Pins: 8
• Rohs Compliant: Yes
• Supply Voltage Min: 2.7V
• Leaded Process Compatible: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MCP9804
5.2
5.2.1
Shutdown
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 I
until bit 8 is cleared ‘0’ to enable Continuous
Conversion mode, or until power is recycled.
The Shutdown bit (bit 8) cannot be set to ‘1’ while bits
6 and 7 of CONFIG (Lock bits) are set to ‘1’. However,
it can be cleared ‘0’ or returned to Continuous
Conversion 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
A hysteresis of 0°C, 1.5°C, 3°C or 6°C can be selected
for the T
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, bits 6 and 7 of CONFIG, are set to ‘1’.
The T
are described graphically in
5.2.3
The Alert output can be enabled using bit 3 of CONFIG
(Alert output control bit) and can be configured as
either a comparator output or as Interrupt Output mode
using bit 0 of CONFIG (Alert mode). The polarity can
also be specified as an active-high or active-low using
bit 1 of CONFIG (Alert polarity). This is an open drain
output and requires a pull-up resistor.
When the ambient temperature increases above the
critical temperature limit, the Alert output is forced to a
comparator output (regardless of bit 0 of CONFIG).
When the temperature drifts below the critical
temperature limit minus hysteresis, the Alert output
automatically returns to the state specified by bit 0 of
CONFIG.
DS22203B-page 30
UPPER
SENSOR FEATURE DESCRIPTION
UPPER
SHUTDOWN MODE
TEMPERATURE HYSTERESIS
(T
ALERT OUTPUT CONFIGURATION
, T
mode
HYST
LOWER
, T
)
disables
LOWER
and T
SHDN
Figure
. It remains in this mode
CRIT
and T
all
boundary conditions
5-11.
power-consuming
CRIT
temperate
FIGURE 5-10:
Configuration.
The status of the Alert output can be read using bit 4 of
CONFIG (Alert status). This bit can not be set to ‘1’ in
shutdown mode.
Bit 7 and 6 of the CONFIG register can be used to lock
the T
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 (critical
output only). When this feature is selected, the Alert
output becomes a comparator output. In this mode, the
interrupt output configuration (bit 0 of CONFIG) is
ignored.
5.2.3.1
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.
the conditions that toggle the Alert output.
If the device enters Shutdown mode with asserted Alert
output, the output remains asserted during Shutdown.
The device must be operating in Continuous
Conversion mode for t
T
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.
5.2.3.2
In the Interrupt mode, the Alert output is asserted as
active-high or active-low (depending on the polarity
configuration) when T
and T
bit 5 (Interrupt Clear) 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 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 CONFIG register from the MCP9804.
LOWER
UPPER
LOWER
Alert Output
and T
, T
limits. The output is deasserted by setting
Comparator Mode
Interrupt Mode
LOWER
CRIT
V
DD
boundary conditions need to be
R
A
Active-Low Alert Output
and T
PU
© 2009 Microchip Technology Inc.
drifts above or below T
CONV
CRIT
; the T
MCP9804
registers. The bits
Figure 5-11
A
vs. T
UPPER
shows
UPPER
,