SA56004GD NXP Semiconductors, SA56004GD Datasheet - Page 12

• Manufacturer Part Number: SA56004GD
• Description: Board Mount Temperature Sensors I2C LOC +/- 2OC AND REM +/- 1OC TS
• Manufacturer: NXP Semiconductors

Specifications of SA56004GD

• Full Temp Accuracy: +/- 1 C, +/- 3 C
• Package / Case: SOT-96
• Digital Output - Bus Interface: I2C
• Digital Output - Number Of Bits: 11 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: SA56004GD,112

NXP Semiconductors
SA56004X_5
Product data sheet
7.9.1.1 ALERT output in comparator mode
7.9.1.2 ALERT output in interrupt mode
7.9.1 ALERT output
7.9 Interruption logic and functional description
The ALERT output is used to signal Alert interruptions from the device to the SMBus or
other system interrupt handler and it is active LOW. Because this is an open-drain output,
a pull-up resistor (typically 10 k ) to V
common interrupt line on the same SMBus.
The ALERT function is very versatile and accommodates three separate operating
modes:
The ARA and interrupt modes are different only in how the user interacts with the
SA56004X.
At the end of every temperature reading, digital comparators determine if the readings are
above the HIGH or T_CRIT setpoint or below the LOW setpoint register values. If so, the
corresponding bit in the Status register is set. If the ALERT mask bit 7 of the Configuration
register is not HIGH, then any bit set in the Status register other than the BUSY (D7) and
OPEN (D2) will cause the ALERT output pin to be active LOW. An alert will be triggered
after any conversion cycle that finds the temperature is out of the limits defined by the
setpoint registers. In order to trigger an ALERT in all alert modes, the ALERT mask bit 7 of
the Configuration register must be cleared (not HIGH).
When operating the SA56004X in a system that utilizes an SMBus controller not having
an interrupt, the ALERT output may be operated as a temperature comparator. In this
mode, when the condition that triggered the ALERT to be asserted is no longer present,
the ALERT output is released as it goes HIGH. In order to use the ALERT output as a
temperature comparator, bit D0 (the ALERT configure bit) in the ALERT Mode (AM)
register must be set HIGH. This is not the POR default.
In the interrupt mode, the ALERT output is used to provide an interrupt signal that remains
asserted until the interrupt service routine has elapsed. In the interrupt operating mode, a
read of the Status register will set the ALERT mask bit 7 of the Configuration register if
any of the temperature alarm bits of the Status register is set, with exception of BUSY
(D7) and OPEN (D2). This protocol prevents further ALERT output triggering until the
master device has reset the ALERT mask bit at the end of the interrupt service routine.
The Status register bits are cleared only upon a read of the Status register by the serial
bus master (see
ALERT Configure bit D0 of the ALERT Mode (AM) register must be set LOW (POR
default).
•
•
•
Temperature comparator
System interrupt based on temperature
SMBus Alert Response Address (ARA) response.
Figure
Rev. 05 — 22 May 2008
5). In order for the ALERT output to be used as an interrupt, the
Digital temperature sensor with overtemperature alarms
DD
is required. Several slave devices can share a
SA56004X
© NXP B.V. 2008. All rights reserved.
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