by crossing T

Temperature going below T

indefinitely until being reset by a read. Placing the LM75 in

shutdown mode also resets the O.S. Output.

1.2 POWER UP AND POWER DOWN

The LM75 always powers up in a known state. The power up

default conditions are:

1.

Comparator mode

2.

T

3.

T

4.

O.S. active low

5.

Pointer = “00”

If the LM75 is not connected to the I

will act as a stand-alone thermostat with the above tempera-

ture settings.

When the supply voltage is less than about 1.7V, the LM75 is

considered powered down. As the supply voltage rises

above the nominal 1.7V power up threshold, the internal

registers are reset to the power up default values listed

above.

1.3 I

The LM75 operates as a slave on the I

line is an input (no clock is generated by the LM75) and the

SDA line is a bi-directional serial data path. According to I

bus specifications, the LM75 has a 7-bit slave address. The

four most significant bits of the slave address are hard wired

inside the LM75 and are “1001”. The three least significant

bits of the address are assigned to pins A2–A0, and are set

by connecting these pins to ground for a low, (0); or to +V

S

for a high, (1).

Therefore, the complete slave address is:

1

0

0

1

A2

A1

A0

MSB

LSB

01265807

Note 14: These interrupt mode resets of O.S. occur only when LM75 is read or placed in shutdown. Otherwise, O.S. would remain active indefinitely for any event.

FIGURE 4. O.S. Output Temperature Response Diagram

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