Rainbow Electronics MAX6628 User Manual
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 temperature of other ICs, such as microprocessors (µPs) or
microcontrollers (µCs) that contain an on-chip, diodeconnected transistor.
Remote accuracy is ±1°C when the temperature of the
remote diode is between 0°C and +125°C and the temperature of the MAX6627/MAX6628 is +30°C. The temperature 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 temperature should never exceed +125°C.
These sensors are 3-wire serial interface SPI™ compatible, allowing the MAX6627/MAX6628 to be readily connected 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 continuously converts data every 0.5s (MAX6627), and one
that converts data every 8s (MAX6628). The slower version 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 conversion.
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.
Applications
Hard Disk Drive
Smart Battery Packs
Automotive
Industrial Control Systems
Notebooks, PCs
Features
♦ Accuracy
±1°C (max) from 0°C ≤ T
RJ
≤ +125°C, TA= +30°C
±2.4°C (max) from -55°C ≤ TRJ≤ +100°C,
0°C ≤ T
A
≤ +70°C
♦ 12-Bit + Sign, 0.0625°C Resolution
♦ Low Power Consumption
30µA (typ) (MAX6628)
200µA (typ) (MAX6627)
♦ Operating Temperature Range (-55°C to +125°C)
♦ Measurement Temperature Range, Remote
Junction (-55°C to +145°C)
♦ 0.5s (MAX6627) or 8s (MAX6628) Conversion Rate
♦ SPI-Compatible Interface
♦ +3.0V to +5.5V Supply Range
♦ 8-Pin SOT23 Package
MAX6627/MAX6628
Remote ±1°C Accurate Digital Temperature
Sensors with SPI-Compatible Serial Interface
________________________________________________________________ Maxim Integrated Products 1
19-2032; Rev 1; 7/01
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.
Ordering Information
SPI is a trademark of Motorola, Inc.
Pin Configuration appears at end of data sheet.
SDO
GND
SCK
µC
+ 3V TO + 5.5V
MAX6627
MAX6628
CS
DXP
DXN
2200pF
2200pF
0.1µF
VCC
Typical Operating Circuit
PART TEMP. RANGE
MAX6627MKA-T -55°C to +125°C 8 SOT23-8 AAEQ
MAX6628MKA-T -55°C to +125°C 8 SOT23-8 AAER
PINPACKAGE
TOP
MARK
MAX6627/MAX6628
Remote ±1°C Accurate Digital Temperature
Sensors with SPI-Compatible Serial Interface
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
All Voltages Referenced to GND
V
CC
...........................................................................-0.3V to +6V
SO, SCK, DXP, CS ........................................-0.3V to V
CC
+ 0.3V
DXN .......................................................................-0.3V to +0.8V
SO Pin Current Range.........................................-1mA to +50mA
Current Into All Other Pins ..................................................10mA
ESD Protection (Human Body Model)................................2000V
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SOT23 (derate 9.7mW/°C above +70°C)...........777mW
Operating Temperature Range .........................-55°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) ...................................Note 1
ELECTRICAL CHARACTERISTICS
(3.0V ≤ VCC≤ 5.5V, -55°C ≤ TA≤ +125°C, unless otherwise noted. Typical values are at TA= +25°C, VCC= +3.3V, unless otherwise
noted.)
Note 1: This device is constructed using a unique set of packaging techniques that impose a limit on the thermal profile the device
can be exposed to during board-level solder attach and rework. This limit permits only the use of the solder profiles
recommended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and Convection
Reflow. Preheating is required. Hand or wave soldering is not allowed.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
TEMPERATURE
Accuracy
Power-Supply Sensitivity 0.25 0.7 °C/V
Resolution 0.0625 °C
Ti m e Betw een C onver si on S tar ts t
Conversion Time t
POWER SUPPLY
Supply Voltage Range V
Supply Current, SCK Idle
Average Operating Current I
Power-On Reset (POR)
Threshold
Current Sourcing for Diode
SAMPLE
CONV
CC
I
SD
I
IDLE
I
CONV
CC
0°C ≤ TRJ ≤ +125°C, TA = +30°C,
V
= +3.3V
CC
-55°C ≤ TRJ ≤ +100°C, 0°C ≤ TA ≤ +70°C,
V
= +3.3V
CC
-55°C ≤ TRJ ≤ +145°C, 0°C ≤ TA ≤ +70°C,
V
= +3.3V
CC
-55°C ≤ T
V
CC
MAX6627 0.5
MAX6628 8
Shutdown, VCC = +0.8V 5
ADC idle, CS = low 20
ADC converting 360 600
MAX6627 200 400
MAX6628 30 50
V
CC
High level 80 100 120
Low level 8 10 12
≤ +125°C, -55°C ≤ TA ≤ +125°C,
RJ
= +3.3V
, falling edge 1.6 V
-1.0 ±0.5 ±1
-2.4 +2.4
-4.5 +4.5
-5.5 +5.5
180 250 320 ms
3.0 5.5 V
°C
s
µA
µA
µA
MAX6627/MAX6628
Remote ±1°C Accurate Digital Temperature
Sensors with SPI-Compatible Serial Interface
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(3.0V ≤ VCC≤ 5.5V, -55°C ≤ TA≤ +125°C, unless otherwise noted. Typical values are at TA= +25°C, VCC= +3.3V, unless otherwise
noted.)
Note 2: TRJis the temperature of the remote junction.
Note 3: Temperature error specification applies for a 0°C to +70°C temperature range for the MAX6627/MAX6628 package.
Note 4: Serial timing characteristics guaranteed by design.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LOGIC INPUTS (CS, SCK)
Logic Input Low Voltage V
Logic Input High Voltage V
Input Leakage Current I
LOGIC OUTPUTS (SO)
Output Low Voltage V
Output High Voltage V
TIMING CHARACTERISTICS (Note 4, Figure 2)
Serial Clock Frequency f
SCK Pulse Width High t
SCK Pulse Width Low t
CS Fall to SCK Rise t
CS Fall to Output Enable t
CS Rise to Output Disable t
SCK Fall to Output Data Valid t
IL
IH
LEAK
OL
OH
SCL
CH
CL
CSS
DV
TR
DO
0.7 x
V
CC
VCS = V
I
SINK
I
SOURCE
C
LOAD
C
LOAD
C
LOAD
C
LOAD
= GND or V
SCK
= 1.6mA 0.4
= 1.6mA
= 10pF 80 ns
= 10pF 80 ns
= 10pF 50 ns
= 10pF 80 ns
CC
V
-
CC
0.4
100 ns
100 ns
0.3 x
V
CC
1 µA
5 MHz
V
V
V
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