MAX6662MSA Maxim Integrated Products, MAX6662MSA Datasheet - Page 8

• Manufacturer Part Number: MAX6662MSA
• Description: Board Mount Temperature Sensors
• Manufacturer: Maxim Integrated Products

Specifications of MAX6662MSA

• Full Temp Accuracy: +/- 2.5 C
• Package / Case: SOIC-8 Narrow
• 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
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

12-Bit + Sign Temperature Sensor with
SPI-Compatible Serial Interface
stored in the Temperature register and is in °C, using a
two’s-complement format with 1LSB corresponding to
0.0625°C (Table 3). The three least-significant bits (LSBs)
are temperature status (flag) bits. The Temperature regis-
ter is read only. Set the command byte to C1h for reading
the Temperature register.
The Configuration register uses only 5 bits, bits 8 to 12.
Table 1 describes its function. Bit 8 is the shutdown bit
and should be set to 1 to shut down the entire
MAX6662 except the serial interface and POR. Bit 12 is
the fault queue bit. When the Fault Queue bit is 1, the
ALERT and OT outputs are asserted if four consecutive
temperature faults occurred. The Configuration register
can be read or written to. Writing to unused bits is
ignored. Set the command byte to C3h for reading from
this register; set the command byte to 83h for writing to
this register.
The High-Temperature (T
(T
temperature limit for triggering the ALERT (Figure 1).
The Maximum-Temperature (T
isters set the temperature threshold for the OT output.
These temperature-limit registers use the 9MSB bits
(8 bits + sign) for setting temperature values in two’s
complement format with 1°C resolution. The 7LSBs are
ignored. These registers can be read or written to.
Table 2 shows the command bytes for reading and
writing to these registers.
Table 3. Output Code vs. Temperature
8
LOW
_______________________________________________________________________________________
TEMPERATURE (°C)
), and the Hysteresis (T
+150.0000
+125.0000
+25.0000
-25.0000
-55.0000
+0.0625
-0.0625
0.0000
Temperature-Limit Registers
HIGH
MAX
Configuration Register
HYST
0100 1011 0000 0xxx
0011 1110 1000 0xxx
0000 1100 1000 0xxx
0000 0000 0000 1xxx
0000 0000 0000 0xxx
1111 1111 1111 1xxx
1111 0011 0111 0xxx
1111 1100 0111 0xxx
), Low-Temperature
) and Hysteresis reg-
BINARY CODE
) registers set the
The MAX6662 supply current is typically 125µA when
the serial interface is active. When driving high-imped-
ance loads, the devices dissipate negligible power;
therefore, the die temperature is essentially the same
as the package temperature. The key to accurate tem-
perature monitoring is good thermal contact between
the MAX6662 package and the monitored device or cir-
cuit. Heat flows in and out of plastic packages primarily
through the leads. Short, wide copper traces leading to
the temperature monitor ensure that heat transfers
quickly and reliably. The rise in die temperature due to
self-heating is given by the following formula:
where P
MAX6662, and θ
The typical thermal resistance is +170°C/W for the
8-pin SO package. To limit the effects of self-heating,
minimize the output currents. For example, if the
MAX6662 sinks 4mA with the maximum ALERT voltage
specification of 0.8V, an additional 3.2mW of power is
dissipated within the IC. This corresponds to a 0.54°C
rise in the die temperature.
TRANSISTOR COUNT: Bipolar: 182
PROCESS: BiCMOS
DISSIPATION
ΔT
Applications Information
JA
J
= P
is the package’s thermal resistance.
is the power dissipated by the
DISSIPATION
MOS: 10177
Chip Information
x θ
JA