User guide

MAX6678
2-Channel Temperature Monitor with Dual Automatic
PWM Fan-Speed Controller and Five GPIOs
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at V
CC
= +3.3V, T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Clock Low Period t
LOW
10% to 10% 4 µs
Clock High Period t
HIGH
90% to 90% 4.7 µs
Bus Free Time Between Stop and
Start Conditions
t
BUF
4.7 µs
SMBus Start Condition Setup Time t
SU:STA
90% of SMBCLK to 90% of SMBDATA 4.7 µs
Start Condition Hold Time t
HD:STO
10% of SMBDATA to 10% of SMBCLK 4 µs
Stop Condition Setup Time t
SU:STO
90% of SMBCLK to 10% of SMBDATA 4 µs
Data Setup Time t
SU:DAT
10% of SMBDATA to 10% of SMBCLK 250 ns
Data Hold Time t
HD:DAT
10% of SMBCLK to 10% of SMBDATA 300 ns
SMBus Fall Time t
F
300 ns
SMBus Rise Time t
R
1000 ns
SMBus Timeout t
TIMEOUT
29 37 55 ms
Startup Time After POR t
POR
500 ms
Note 1: Deviation from programmed value in Table 6.
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
400
440
520
480
560
600
3.0 4.03.5 4.5 5.0 5.5
OPERATING SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6678 toc02
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
-4
-2
-3
0
-1
1
2
050
75
25
100
125 150
REMOTE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
MAX6678 toc03
TEMPERATURE (
°
C)
TEMPERATURE ERROR (
°
C)
FAIRCHILD 2N3906