AD9546SLASHPCBZ datasheet(168/205 Pages) AD

168 / 205 page

AD9546

Data Sheet

Rev. 0 | Page 168 of 205

Temperature Alarm Feature

The temperature sensor routes to a threshold detector. The

threshold detector detects when temperature readings are

outside the range specified by a high temperature threshold and

a low temperature threshold. The high temperature threshold

resides in Bits[15:0] of Register 0x2905 to Register 0x2906. The

low temperature threshold resides in Bits[15:0] of Register

0x2903 to Register 0x2904. The high and low temperature

thresholds use the temperature format shown in Figure 113.

If the output value of the temperature sensor falls outside the

specified limits, status Bit 0 of Register 0x3002 assumes a Logic

1 state (otherwise, it is Logic 0). Status Bit 0 allows the user to

check the status of the threshold detector in real time.

Status Bit 0 of Register 0x3002 is the source for Status Bit 4 of

notification of a temperature threshold detection event via the

IRQ mechanism (see the Interrupt Request (IRQ) section).

EXTERNAL TEMPERATURE SOURCE

The external temperature source constitutes a temperature

value programmed into Bits[15:0] of Register 0x2900 to

properly scales temperature values for use by the internal

temperature compensation functional blocks automatically, the

user must scale the external temperature values properly.

The external temperature bit field represents temperature in

units of °C × 2−7 (see Figure 113). This format yields a

temperature range of ±256°C with 0.0078°C resolution.

For example, to program an external temperature value of

95°C,

External Temperature = 95/2−7

= 12,160

= 0x2F80 (hexadecimal)

AD9546/PCBZ Datasheet(PDF) 168 Page - Analog Devices