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ADT7320

±0.25°C Accurate, 16-Bit Digital SPI Temperature Sensor

Analog Devices 

ADT7320

CS

Data Sheet

DIN

DOUT

0x08

0x20

WAIT 240ms MINIMUM

FOR CONVERSION TO FINISH

DATA

SCLK

Figure 12. Typical SPI One-Shot Write to Configuration Register Followed by a Read from the Temperature Value Register

TEMPERATURE

149°C

148°C

147°C

TCRIT

146°C

145°C

144°C

143°C

142°C

TCRIT – THYST

141°C

140°C

CT PIN

POLARITY = ACTIVE LOW

CT PIN

POLARITY = ACTIVE HIGH

TIME

WRITE TO

BIT 5 AND BIT 6 OF

CONFIGURATION

REGISTER.*

WRITE TO

BIT 5 AND BIT 6 OF

CONFIGURATION

REGISTER.*

WRITE TO

BIT 5 AND BIT 6 OF

CONFIGURATION

REGISTER.*

*THERE IS A 240ms DELAY BETWEEN WRITING TO THE CONFIGURATION REGISTER TO START

A STANDARD ONE-SHOT CONVERSION AND THE CT PIN GOING ACTIVE. THIS IS DUE TO THE

CONVERSION TIME. THE DELAY IS 60ms IN THE CASE OF A ONE-SHOT CONVERSION.

Figure 13. One-Shot CT Pin

ONE-SHOT MODE

When one-shot mode is enabled, the ADT7320 immediately

completes a conversion and then goes into shutdown mode. The

one-shot mode is useful when one of the circuit design priorities is

to reduce power consumption.

CT and INT Operation in One-Shot Mode

See Figure 13 for more information on one-shot CT pin

operation for TCRIT overtemperature events when one of the

limits is exceeded. Note that in interrupt mode, a read from

any register resets the INT and CT pins.

To enable one-shot mode, set Bits [6:5] of the configuration

register (Register Address 0x01) to 01.

After writing to the operation mode bits, wait for at least 240 ms

before reading back the temperature from the temperature value

register. This delay ensures that the ADT7320 has adequate time

to power up and complete a conversion.

To obtain an updated temperature conversion, reset Bits[6:5] of the

configuration register (Register Address 0x01) to 01.

For the INT pin in comparator mode, if the temperature drops

below the THIGH − THYST value or goes above the TLOW + THYST value,

a write to the operation mode bits (Bit 5 and Bit 6 of the

configuration register, Register Address 0x01) resets the INT pin.

For the CT pin in comparator mode, if the temperature drops

below the TCRIT − THYST value, a write to the operation mode bits

(Bit 5 and Bit 6 of the configuration register, Register Address 0x01)

resets the CT pin (see Figure 13).

When using one-shot mode, ensure that the refresh rate is

appropriate to the application being used.

Rev. 0 | Page 10 of 24

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