19-2032; Rev 1; 7/01
Remote ±1°C Accurate Digital Temperature
Sensors with SPI-Compatible Serial Interface
General Description
The MAX6627/MAX6628 precise digital temperature
sensors report the temperature of a remote sensor. The
remote sensor is a diode-connected transistor, typically
a low-cost, easily mounted 2N3904 NPN type that
replaces conventional thermistors or thermocouples.
The MAX6627/MAX6628 can also measure the die tem-
perature of other ICs, such as microprocessors (µPs) or
microcontrollers (µCs) that contain an on-chip, diode-
connected transistor.
Remote accuracy is ±1°C when the temperature of the
remote diode is between 0°C and +125°C and the tem-
perature of the MAX6627/MAX6628 is +30°C. The tem-
perature is converted to a 12-bit + sign word with
0.0625°C resolution. The architecture of the device is
capable of interpreting data as high as +145°C from
the remote sensor. The MAX6627/MAX6628 tempera-
ture should never exceed +125°C.
These sensors are 3-wire serial interface SPI™ compat-
ible, allowing the MAX6627/MAX6628 to be readily con-
nected to a variety of µCs. The MAX6627/MAX6628 are
read-only devices, simplifying their use in systems
where only temperature data is required.
Two conversion rates are available, one that continu-
ously converts data every 0.5s (MAX6627), and one
that converts data every 8s (MAX6628). The slower ver-
sion provides minimal power consumption under all
operating conditions (30µA, typ). Either device can be
read at any time and provide the data from the last con-
version.
Both devices operate with supply voltages between
+3.0V and +5.5V, are specified between -55°C and
+125°C, and come in the space-saving 8-pin SOT23
package.
Features
o
Accuracy
±1°C (max) from 0°C
≤
T
RJ
≤
+125°C, T
A
= +30°C
±2.4°C (max) from -55°C
≤
T
RJ
≤
+100°C,
0°C
≤
T
A
≤
+70°C
o
12-Bit + Sign, 0.0625°C Resolution
o
Low Power Consumption
30µA (typ) (MAX6628)
200µA (typ) (MAX6627)
o
Operating Temperature Range (-55°C to +125°C)
o
Measurement Temperature Range, Remote
Junction (-55°C to +145°C)
o
0.5s (MAX6627) or 8s (MAX6628) Conversion Rate
o
SPI-Compatible Interface
o
+3.0V to +5.5V Supply Range
o
8-Pin SOT23 Package
MAX6627/MAX6628
Ordering Information
PART
MAX6627MKA-T
MAX6628MKA-T
TEMP. RANGE
-55°C to +125°C
-55°C to +125°C
PIN-
PACKAGE
8 SOT23-8
8 SOT23-8
TOP
MARK
AAEQ
AAER
Typical Operating Circuit
+ 3V TO + 5.5V
0.1µF
Applications
Hard Disk Drive
Smart Battery Packs
Automotive
Industrial Control Systems
Notebooks, PCs
2200pF
V
CC
GND
MAX6627
MAX6628
SDO
DXP
CS
DXN
µC
2200pF
SPI is a trademark of Motorola, Inc.
Pin Configuration appears at end of data sheet.
SCK
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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