MAX6662MSA+ Maxim Integrated Products, MAX6662MSA+ Datasheet - Page 6

• Manufacturer Part Number: MAX6662MSA+
• Description: IC TEMP SENSOR SPI 8-SOIC
• Manufacturer: Maxim Integrated Products

Specifications of MAX6662MSA+

• Function: Temp Sensor, Watchdog
• Topology: ADC, Register Bank
• Sensor Type: Internal
• Sensing Temperature: -55°C ~ 150°C
• Output Type: SPI™
• Output Alarm: Yes
• Output Fan: No
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -55°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Full Temp Accuracy: +/- 2.5 C
• Digital Output - Bus Interface: Serial (3-Wire, SPI)
• Digital Output - Number Of Bits: 12 bit + Sign
• Maximum Operating Temperature: + 150 C
• Minimum Operating Temperature: - 55 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
The activation of ALERT and OT is subject to the depth
of the fault queue. If the Fault Queue bit in the
Configuration register is enabled, ALERT or OT does
not assert until four consecutive temperature conver-
sions are at fault.
For example: If T
20°C, ALERT is set to interrupt mode, and fault queue
is enabled, ALERT does not assert until four consecu-
tive conversions exceed 100°C. If the temperature is
then read through the serial interface, ALERT
deasserts. ALERT asserts again when four consecutive
conversions are less than 80°C.
The MAX6662 features a programmable shutdown
mode. Set the Shutdown bit in the Configuration register
to 1 to shut down. In the shutdown mode, everything is
disabled except the power-on reset (POR) and the seri-
al interface. In the shutdown mode, information stored
in all registers is retained. The Temperature register
retains the temperature from the last conversion result.
Table 1. Bit Descriptions of the Configuration Register
6
Figure 3. MAX6662 Serial Interface Operation
SCLK
SIO
CS
15 to 13
_______________________________________________________________________________________
7 to 0
BIT
12
11
10
9
8
1
COMMAND BYTE (8 BITS)
2
3
HIGH
POR
4
0
0
0
0
0
0
0
5
Temperature Fault Queue
is set to 100°C, T
6
7
Reserved. Writing to these bits is ignored.
Fault Queue bit. Set to 1 to enable queue.
ALERT polarity bit. Set to 1 for active-high ALERT output. Default is 0 for the ALERT output active-low.
OT polarity bit. Set to 1 for active-high OT output. Default is 0 for the OT output active-low.
Interrupt Mode bit. Set to 1 to enable the interrupt mode. Default is 0 for the comparator mode.
Shutdown bit. Set to 1 to shut down the MAX6662.
Reserved. Writing to these bits is ignored.
8
9 10
Shutdown Mode
DATA WORD (16 BITS)
HYST
23 24
is set to
The serial interface consists of three signal lines: chip
select (CS), bidirectional data line (SIO), and serial
clock (SCLK). Only the master (external) drives CS and
SCLK. Both the master and the MAX6662 drive SIO.
When CS is high, the MAX6662 does not respond to any
activity on clock and data lines. When CS goes low, a
transaction begins. A valid transaction has 24 clock
cycles provided from SCLK after CS goes low—no more
and no fewer. Any communication with more or fewer
than exactly 24 clocks is ignored. Data is clocked in to
the MAX6662 at the rising edge of SCLK when the mas-
ter is writing. Data is clocked out at the falling edge of
SCLK when the master is reading. Both the command
byte and data word are clocked in (or out) with the
most-significant bit (MSB) bit first. The first eight clock
cycles are dedicated to the command byte (1 bit per
cycle). This command byte is input to the MAX6662
through the SIO. Sixteen cycles of data follow. The 16
cycles of data are either driven by the master or by the
MAX6662, depending on the command byte. If the
MAX6662 is driving the SIO, it starts driving at the
falling edge of the eighth clock up until the rising edge
of CS. Data is available on the falling edge of the eighth
clock cycle. Figure 3 depicts a valid serial interface
transaction and Figure 4 is the serial interface timing
diagram.
Figure 4. Detailed Serial Interface Timing Diagram
SCLK
SIO
CS
DESCRIPTION
t
CSS
t
DS
t
CH
Serial Interface Protocol
t
DO
t
CL
t
CSH
t
DH
t
TR
t
CSW
t
F