9-Bit/12-Bit Temperature Sensors with

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Detailed Description

The MAX6625/MAX6626 continuously convert their die

temperatures into digital values using their self-con-

tained delta-sigma ADCs. The resulting data is read-

interface. A dedicated alarm output asserts if the result

exceeds the value in the programmable high-tempera-

ture register. A programmable fault queue sets the

number of faults that must occur before the alarm

asserts, preventing spurious alarms in noisy environ-

ments. The alarm output polarity is selectable and

deasserts based on either of two operating modes,

comparator or interrupt. In comparator mode, the OT

output deasserts if the temperature conversion result

falls below the programmable low-temperature register

value (subject to the fault queue conditions) providing

adjustable hysteresis. In interrupt mode, the OT output

deasserts when any register is read through the serial

interface. Each conversion cycle takes about 130ms. At

power-up, the temperature register is set to 8000H until

the first conversion is completed.

The MAX6625/MAX6626 feature a shutdown mode,

accessible through the serial interface, that saves power

by turning off everything but the power-on reset and the

temperature register is set to 8000H. The device func-

Write Byte, Write Word, Read Byte, and Read Word com-

mands. Four separate addresses can be configured with

the ADD pin, allowing up to four MAX6625/MAX6626

devices to be placed on the same bus. Figure 2 shows

the functional block diagram of the MAX6625/MAX6626.

Serial interface

The MAX6625/MAX6626 are readable and programma-

Figures 3 and 4 show the timing details of the clock

(SCL) and data (SDA) signals. The device functions as

Byte, Write Word, Read Byte, and Read Word com-

mands.

Addressing

Four separate addresses can be configured with the

ADD pin, allowing up to four MAX6625/MAX6626s to be

placed on the same bus. The address is selected by

connecting the ADD pin to either of four places: GND

address for each state.

MAX6625

MAX6626

TEMPERATURE REGISTER

+Vs

OT

GND

SDA

SCL

ADD

SERIAL BUS INTERFACE

SET-POINT

COMPARATOR

ADDRESS

POINTER

REGISTER

BANDGAP

REGISTER

ADC

REFERENCE

TEMP SIGNAL

FAULT

QUEUE

COUNTER

CONFIGURATION REGISTER

MAX665_ R

ONLY

Figure 2. Functional Block Diagram