SMBus DIGITAL SWITCHING CHARACTERISTICS
Unless otherwise noted, these specifications apply for VCC=+3.0 Vdc to +3.6 Vdc, CL (load capacitance) on output lines = 80
pF. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25˚C, unless otherwise noted.
The switching characteristics of the LM91 fully meet or exceed the published specifications of the SMBus or I2C bus. The fol-
lowing parameters are the timing relationships between SMBCLK and SMBData signals related to the LM91. They are not nec-
essarily the I2C or SMBus bus specifications.
Symbol
Parameter
Conditions
Typical
Limits
(Note 7)
1.3
Units
(Limit)
µs (min)
(Note 6)
tBUF
SMBus Free Time
SMBus Communication
20034304
SMBus TIMEOUT
20034313
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.
<
>
V
Note 2: When the input voltage (V ) at any pin exceeds the power supplies (V
GND or V
), the current at that pin should be limited to 5 mA. The 20 mA
CC
I
I
I
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.
Parasitics and or ESD protection circuitry are shown in the figure below for the LM91’s pins. The nominal breakdown voltage of the zener D3 is 6.5V. Care should
be taken not to forward bias the parasitic diode, D1, present on pins: NC pins 1,5 and 9, D+, ADD1 and ADD0. Doing so by more than 50 mV may corrupt a
temperature or voltage measurement.
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