Rainbow Electronics DS1857 - Manual (Page 4)

DS1857
Dual Temperature-Controlled Resistors with
External Temperature Input and Monitors
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PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Fast mode (Note 10) 0 400
SCL Clock Frequency f SCL
Standard mode (Note 10) 0 100
kHz
Fast mode (Note 10) 1.3 Bus Free Time Between STOP and
START Condition
t BUF
Standard mode (Note 10) 4.7
µs
Fast mode (Notes 10, 11) 0.6 Hold Time (Repeated)
START Condition
t
HD:STA
Standard mode (Notes 10, 11) 4.0
µs
Fast mode (Note 10) 1.3
Low Period of SCL Clock t LOW
Standard mode (Note 10) 4.7
µs
Fast mode (Note 10) 0.6
High Period of SCL Clock t HIGH
Standard mode (Note 10) 4.0
µs
Fast mode (Notes 10, 12, 13) 0 0.9
Data Hold Time t HD:DAT
Standard mode (Notes 10, 12, 13) 0
µs
Fast mode (Note 10) 100
Data Setup Time t
SU:DAT
Standard mode (Note 10) 250
ns
Fast mode (Note 10) 0.6
Start Setup Time t SU:STA
Standard mode (Note 10) 4.7
µs
Fast mode (Note 13) 20 + 0.1C B 300 Rise Time of Both SDA and SCL
Signals
t F
Standard mode (Note 13) 20 + 0.1C B 1000
ns
Fast mode (Note 13) 20 + 0.1C B 300 Fall Time of Both SDA and SCL
Signals
t R
Standard mode (Note 13) 20 + 0.1C B 300
ns
Fast mode 0.6
Setup Time for STOP Condition t SU:STO
Standard mode 4.0
µs
Capacitive Load for Each Bus Line C
B
(Note 13) 400 pF
EEPROM Write Time t W (Note 14) 10 ms
AC ELECTRICAL CHARACTERISTICS
(V CC = 3.0V to 5.5V, T A = -40°C to +95°C, unless otherwise noted.)
Note 1: All voltages are referenced to ground.
Note 2: I/O pins of fast-mode devices must not obstruct the SDA and SCL lines if V CC is switched off. The address inputs should be
connected to either V CC or GND depending on the desired address setting.
Note 3: SDA and SCL are connected to V
CC
and all other input signals are connected to well-defined logic levels.
Note 4: The maximum voltage the MON inputs will read is approximately 2.5V, even if the voltage on the inputs is greater than 2.5V.
Note 5: This voltage is defining the maximum range of the analog-to-digital converter and not the maximum V CC voltage.
Note 6: Absolute linearity is the difference of measured value from expected value at DAC position. The expected value is a
straight line from measured minimum position to measured maximum position.
Note 7: Relative linearity is the deviation of an LSB DAC setting change vs. the expected LSB change. The expected LSB change
is the slope of the straight line from measured minimum position to measured maximum position.
Note 8: See the Typical Operating Characteristics.
Note 9: The conversion accuracy does not include any error from the LM50.
Note 10: A fast-mode device can be used in a standard-mode system, but the requirement t SU:DAT > 250ns must then be met. This
is automatically the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the
LOW period of the SCL signal, it must output the next data bit to the SDA line t
RMAX + t SU:DAT = 1000ns + 250ns = 1250ns
before the SCL line is released.