SERIAL BUS DIGITAL SWITCHING CHARACTERISTICS Unless otherwise noted, these specifications apply for +V

output lines = 80 pF unless otherwise specified. Boldface limits apply for T

+25˚C, unless otherwise noted.

The switching characteristics of the LM77 fully meet or exceed the published specifications of the I

rameters are the timing relationship between SCL and SDA signal related to the LM77. They are not the I

Symbol

Parameter

Conditions

Typical

(Note 8)

Limits

(Note 9)

Units

(Limit)

t

1

SCL (Clock) Period

2.5

µs(min)

t

2

Data in Set-Up Time to SCL High

100

ns(min)

t

3

Data Out Stable after SCL Low

0

ns(min)

t

4

SDA Low Set-Up Time to SCL Low (Start Condition)

100

ns(min)

t

5

SDA High Hold Time after SCL High (Stop Condition)

100

ns(min)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not apply when operating

the device beyond its rated operating conditions.

maximum package input current rating limits the number of pins that can safely exceed the power supplies with an input current of 5 mA to four.

Note 3: See AN-450 “Surface Mounting Methods and Their Effect on Product Reliability” or the section titled “Surface Mount” found in a current National

Semiconductor Linear Data Book for other methods of soldering surface mount devices.

Note 4: Human body model, 100 pF discharged through a 1.5 k

Ω resistor. Machine model, 200 pF discharged directly into each pin.

Note 5: LM77

250˚C/W for the MSOP-8 (MUA08A) package.

Note 6: While the LM77 has a full-scale-range in excess of 128˚C, prolonged operation at temperatures above 125˚C is not recommended.

Note 9: Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).

Note 10: 9 bits + sign, two’s complement

Note 11: This specification is provided only to indicate how often temperature data is updated. The LM77 can be read at any time without regard to conversion state

(and will yield last conversion result). If a conversion is in process it will be interrupted and restarted after the end of the read.

Note 12: For best accuracy, minimize output loading. Higher sink currents can affect sensor accuracy with internal heating. This can cause an error of 0.64˚C at full

rated sink current and saturation voltage based on junction-to-ambient thermal resistance.

discussion of the function of hysteresis refer to

Note 14: Default values set at power up.

DS100136-4

www.national.com

6