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ADT7316
(Rev.:RevPrN)

SPI/I2C® Compatible, 10-Bit Digital Temperature Sensor and Quad Voltage Output 12/10/8-Bit DAC

Analog Devices 

PRELIMINARY TECHNICAL DATA

ADT7316/7317/7318

S/W Reset

INT ERR UPT

STA TU S

REGISTER 1

(TEMP and Ext.

Diode Check)

Internal

Temp

External

Tem p

WATCHDOG

LIMIT

COMPA RISONS

IN TER RU PT

ST AT US

REGISTER 2

(VD D)

INT ERRUP T

MASK

RE GI ST ERS

V

DD

Diode

Fault

INTERRUPT

(Latched Output)

Read Reset

CONTROL

CONFIGURATION

REGISTER 1

I NTE RRUPT

ENABLE BIT

Figure 13. ADT7316/17/18 Interrupt Structure

-25 °C

-10 °C

-0.25 °C

0 °C

+0.25 °C

+10 °C

+25 °C

+50 °C

+75 °C

+100 °C

+105 °C

+125 °C

11 1001 1100

11 1101 1000

11 1111 1111

00 0000 0000

00 0000 0001

00 0010 1000

00 0110 0100

00 1100 1000

01 0010 1100

01 1001 0000

01 1010 0100

01 1111 0100

Temperature Conversion Formula:

1. Positive Temperature = ADC Code/4

2. Negative Temperature = (ADC Code* - 512)/4

*DB9 is removed from the ADC Code

INTERRUPTS

The measured results from the inetrnal temperature sen-

sor, external temperature sensor and the VDD pin are com-

pared with the THIGH/VHIGH and TLOW/VLOW limits. These

limits are stored in on-chip registers. Please note that the

limit registers are 8 bits long while the conversion results

are 10 bits long. If the limits are not masked out then any

out of limit comparisons generate flags that are stored in

Interrupt Status 1 Register (address = 00h) and Interrupt

Status 2 Register (address = 01h). One or more out-of

limit results will cause the INTERRUPT output to pull

either high or low depending on the output polarity set-

ting.

Figure 13 shows the interrupt structure for the ADT7316/

17/18. It gives a block diagram representation of how the

various measurement channels affect the INTERRUPT

pin.

THERMAL VOLTAGE OUTPUT

The ADT7316/17/18 has the capability of outputting a

voltage that is proportional to temperature. DAC A output

can be configured to reperesent the temperature of the

internal sensor while DAC B output can be configured to

reperesent the external temperature sensor. Bits 5 and 6 of

Control Configuration 3 register select the temperature

proportional output voltage. Each time a temperature

measurement is taken the DAC output is updated. The

output resolution ADT7318 is 8 bits with 1°C change

corresponding to one LSB change. The output resolution

for the ADT7316 and ADT7317 is capable of 10 bits with

0.25°C change corresponding to one LSB change. The

default output resolution for the ADT7316 and ADT7317

is 8 bits. To increase this to 10 bits, set bit 1=1 of Con-

trol Configuration 3 register. The default output range is

0V-VREF and this can be increased to 0V-2VREF. Increasing

the outout voltage span to 2VREF can be done by setting

D0 = 1 for DAC A (Internal Temperature Sensor) and

D1 = 1 for DAC B (External Temperature Sensor) in

DAC Configuration register (address 1Bh).

The output voltage is capable of tracking a max tempera-

ture range of -128°C to +127°C but the default setting is -

40°C to +127°C. If the output voltage range is 0V-VREF

–18–

REV. PrN

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