MAX7504MUA+ Maxim Integrated Products, MAX7504MUA+ Datasheet - Page 8

• Manufacturer Part Number: MAX7504MUA+
• Description: IC TEMP SENSOR DIGIT 8-UMAX
• Manufacturer: Maxim Integrated Products

Specifications of MAX7504MUA+

• Function: Temp Sensor, Watchdog
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 125°C
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Full Temp Accuracy: +/- 3 C
• Digital Output - Bus Interface: Serial (2-Wire, I2C)
• Digital Output - Number Of Bits: 9 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Digital Temperature Sensors and Thermal
Watchdog with Bus Lockup Protection
The MAX7500–MAX7504 have an internal pnp-junction-
based temperature sensor whose analog output is con-
verted to digital form using a 9-bit sigma-delta ADC.
The measured temperature and temperature configura-
tions are controlled by the temperature, configuration,
T
Read the measured temperature through the tempera-
ture register. The temperature data format is 9 bits,
two’s complement, and the register is read out in 2
bytes: an upper byte and a lower byte. Bit D15 is the
sign bit. When bit D15 is 1, the temperature reading is
negative. When bit D15 is zero, the temperature read-
ing is positive. Bits D14–D7 contain the temperature
data, with the LSB representing 0.5°C and the MSB
representing 64°C (see Table 3). The MSB is transmit-
ted first. The last 7 bits of the lower byte, bits D6–D0,
are don’t cares. When reading the temperature register,
Table 2. Register Functions
Table 3. Temperature Register Definition
X = Don’t care.
Table 4. Temperature Data Output
8
Temperature
Configuration
T
T
HYST
TEMPERATURE (°C)
REGISTER NAME
1= Negative
HYST
OS
0 = Positive
_______________________________________________________________________________________
Sign bit
D15
, and T
+125
+0.5
+25
-0.5
-25
-55
0
OS
64°C
MSB
registers. See Table 2.
D14
ADDRESS (HEX)
0111 1101 0xxx xxxx
0001 1001 0xxx xxxx
0000 0000 1xxx xxxx
0000 0000 0xxx xxxx
1111 1111 1xxx xxxx
1110 0111 0xxx xxxx
1100 1001 0xxx xxxx
32°C
D13
Register Descriptions
00
01
02
03
BINARY
UPPER BYTE
DIGITAL OUTPUT
16°C
D12
Temperature Register
D11
8°C
POR STATE (HEX)
D10
4°C
4B0
500
7D0x
C90x
190x
008x
000x
FF8x
E70x
—
00
hex
2°C
D9
1°C
D8
bits D6–D0 must be ignored. When the measured tem-
perature is greater than +127.5°C, the value stored in
the temperature register is clipped to 7F8h. When the
measured temperature is below -64°C, the value in the
temperature register is clipped to BF8h.
During the time of reading the temperature register, any
changes in temperature are ignored until the read is
completed. The temperature register is updated upon
completion of the next conversion.
Table 3 lists the temperature register definition.
The 8-bit configuration register sets the fault queue, OS
polarity, shutdown control, and whether the OS output
functions in comparator or interrupt mode. When writing
to the configuration register, set bits D7, D6, and D5 to
zero. See Table 5.
Bits D4 and D3, the fault queue bits, determine the
number of faults necessary to trigger an OS condition.
See Table 6. The number of faults set in the queue must
occur to trip the OS output. The fault queue prevents
OS false tripping in noisy environments.
Set bit D2, the OS polarity bit, to zero to force the OS
output active low. Set bit D2 to 1 to set the OS output
polarity to active high. OS is an open-drain output
under all conditions and requires a pullup resistor to
output a high voltage. See Figure 4.
Set bit D1, the comparator/interrupt bit to zero to run
the overtemperature shutdown block in comparator
mode. In comparator mode, OS is asserted when the
temperature rises above the T
ed when the temperature drops below the T
POR STATE
0100 1011 0
0101 0000 0
0000 0000
(BINARY)
0.5°C
LSB
D7
—
D6
X
POR STATE (°C)
D5
X
D4
75
80
—
—
X
LOWER BYTE
OS
Configuration Register
D3
X
value. OS is deassert-
D2
X
Read only
WRITE
READ/
HYST
R/W
R/W
R/W
D1
X
value.
D0
X