REV. G

–16–

AD7416/AD7417/AD7418

FAN CONTROLLER

Figure 14 shows a simple fan controller that will switch ON a

cooling fan when the temperature exceeds 80

°C and switch it

OFF again when the temperature falls below 75

°C. The AD7416

can be used standalone in this application or with a serial bus

interface if different trip temperatures are required. If the AD7416

is used with a bus interface, the sense of OTI can be set to active

high, Q1 and R1 can be omitted, and OTI can be connected

directly to the gate of Q2 with R2 as the pull-up resistor.

3V TO 5.5V

AD7416

R1

10k

Q1

2N3904

OR SIMILAR

R2

10k

Q2

LOGIC LEVEL

MOSFET RATED

TO SUIT FAN

CURRENT

12V

Figure 14. AD7416 Used as a Fan Controller

THERMOSTAT

Figure 15 shows the AD7416 used as a thermostat. The heater

and switched OFF again when the temperature rises above

output should be programmed active low.

3V TO

5.5V

AD7416

R1

10k

Q1

2N3904

OR SIMILAR

RELAY

D1

1N4001

HEATER

HEATER

SUPPLY

RLA1

Figure 15. AD7416 Used as a Thermostat

SYSTEM WITH MULTIPLE AD7416S

The three LSBs of the AD7416’s serial address can be set by the

user, allowing eight different addresses from 1001000 to 1001111.

Figure 16 shows a system in which eight AD7416s are connected

to a single serial bus, with their OTI outputs wire-ANDed

together to form a common interrupt line. This arrangement

does mean that each device must be read to determine which

one has generated the interrupt, and if a unique interrupt is

required for each device, the OTI outputs can be connected

separately to the I/O chip.

3V TO 5.5V

R1

10k

Figure 16. Multiple Connection of AD7416s to a Single Serial Bus

100ns

40 s

CONVST

Figure 17.

CONVST When Temperature Channel Selected

100ns

15 s

CONVST

Figure 18.

CONVST When V