ADIS16006

Rev. 0 | Page 12 of 16

TEMPERATURE SENSOR SERIAL INTERFACE

Read Operation

Figure 4 shows the timing diagram for a serial read from the

temperature sensor. The TCS line enables the SCLK input.

Ten bits of data and a leading 0 are transferred during a read

operation. Read operations occur during streams of 16 clock

pulses. The serial data can be received into two bytes to

accommodate the entire 10-bit data stream. If only eight bits

of resolution are required, then the data can be received into

a single byte. At the end of the read operation, the DOUT line

remains in the state of the last bit of data clocked out until TCS

goes high, at which time the DOUT line from the temperature

sensor goes three-state.

Write Operation

Figure 4 also shows the timing diagram for the serial write to

the temperature sensor. The write operation takes place at the

same time as the read operation. Data is clocked into the

control register on the rising edge of SCLK. DIN should remain

low for the entire cycle.

Temperature Sensor Control Register

MSB

LSB

ZERO

ZERO

ZERO

ZERO

ZERO

ZERO

ZERO

ZERO

Table 7. Temperature Sensor Control Register Bit Functions

Bit

Mnemonic

Comments

7 to 0

ZERO

All bits should be held low.

ZERO

ZERO is defined as the logic low level.

Output Data format

The output data format for the temperature sensor is twos

complement. Table 8 shows the relationship between the digital

output and the temperature.

Temperature Sensor Conversion Details

The ADIS16006 features a 10-bit digital temperature sensor that

allows accurate measurement of the ambient device temperature.

The conversion clock for the temperature sensor is internally

generated so no external clock is required except when reading

from and writing to the serial port. In normal mode, an internal

clock oscillator runs the automatic conversion sequence. A con-

version is initiated approximately every 350 μs. At this time,

the temperature sensor wakes up and performs a temperature

conversion. This temperature conversion typically takes 25 μs,

at which time the temperature sensor automatically shuts down.

The result of the most recent temperature conversion is avail-

able in the serial output register at any time. Once the conversion is

finished, an internal oscillator starts counting and is designed to

time out every 350 μs. The temperature sensor then powers up

and does a conversion.

Note that if the TCS is brought low every 350 μs (±30%) or less,

the same temperature value is output onto the DOUT line every

time without changing. It is recommended that the TCS line not

be brought low every 350 μs (±30%) or less. The ±30% covers

process variation. The TCS should become active (high to low)

outside this range.

The device is designed to autoconvert every 350 μs. If the

temperature sensor is accessed during the conversion process,

an internal signal is generated to prevent any update of the

temperature value register during the conversion. This prevents

the user from reading back spurious data. The design of this

feature results in this internal lockout signal being reset only at

the start of the next autoconversion. Therefore, if the TCS line

goes active before the internal lockout signal is reset to its

inactive mode, the internal lockout signal is not reset. To ensure

that no lockout signal is set, bring TCS low at a greater time

than 350 μs (±30%). As a result, the temperature sensor is not

interrupted during a conversion process.

In the automatic conversion mode, every time a read or write

operation takes place, the internal clock oscillator is restarted at

the end of the read or write operation. The result of the conversion

is typically available 25 μs later. Reading from the device before

conversion is complete provides the same set of data.

Table 8. Temperature Sensor Data Format

Temperature

Digital Output (DB9 … DB0)

–40°C

11 0110 0000

–25°C

11 1001 1100

–0.25°C

11 1111 1111

0°C

00 0000 0000

+0.25°C

00 0000 0001

+10°C

00 0010 1000

+25°C

00 0110 0100

+50°C

00 1100 1000

+75°C

01 0010 1100

+100°C

01 1001 0000

+125°C

01 1111 0100

POWER SUPPLY DECOUPLING

The ADIS16006 integrates two decoupling capacitors that are

0.047 μF in value. For local operation of the ADIS16006, no

additional power supply decoupling capacitance is required.

However, if the system power supply presents a substantial

amount of noise, additional filtering can be required. If

additional capacitors are required, connect the ground terminal

of each of these capacitors directly to the underlying ground

plane. Finally, note that all analog and digital grounds should be

referenced to the same system ground reference point.