Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Note 1:
Human Body Model, 100pF discharged through a 1.5kω resistor.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Recommended Operating Conditions
(T
A
= -40°C to +125°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER
Operating Supply Voltage
Input High Voltage
Input Low Voltage
SYMBOL
V
CC
V
IH
V
IL
CONDITIONS
MIN
3.0
V
CC
x
0.7
V
CC
x
0.3
TYP
3.3
MAX
5.5
UNITS
V
V
V
Electrical Characteristics
(T
A
= -40°C to +125°C, typical values are V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.) (Notes 2, 3)
PARAMETER
Quiescent Supply Current
(Note 4)
POR Threshold
Watchdog Timer Accuracy
Output Low Voltage (SDA,
FAN_
FAIL,
PWMOUTn, CLKOUT)
Output High Voltage (CLKOUT)
XTAL1 Input Threshold
Input Leakage
Input Capacitance
I
L
(Note 6)
All digital inputs
-1
5
SYMBOL
I
CC
V
POR
f
TOSC
= 32.768kHz (Note 5)
I
OL
= 3mA
I
OH
= 1mA, V
CC
= 3.0V
2.7
0.85
+1
-0.5
CONDITIONS
3.0V < V
CC
< 3.6V
4.5V < V
CC
< 5.5V
MIN
TYP
1.5
2.5
2
+0.5
0.4
MAX
3
8
UNITS
mA
V
s
V
V
V
FA
pF
www.maximintegrated.com
Maxim Integrated
│
2
MAX31790
6-Channel PWM-Output Fan RPM Controller
Fan Control Characteristics
(T
A
= -40°C to +125°C, typical values are V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.) (Note 3)
PARAMETER
PWM Resolution
PWM Frequency Accuracy
TACH Count Resolution
TACH Count Oscillator and
CLKOUT Clock
f
TOSC
(Note 7)
Using internal oscillator:
T
A
= +25°C, V
CC
= 3.3V
Using internal oscillator:
0°C < T
A
< +70°C, 3.0V < V
CC
< 3.6V
f
ERR:TOSC
Using internal oscillator:
-40°C < T
A
< +125°C, 3.0V < V
CC
< 3.6V
Using internal oscillator:
-40°C < T
A
< +125°C, 3.0V < V
CC
< 5.5V
Using external crystal
TACH Minimum Input Pulse
Width
t
TACHMIN
Pulse width must be greater than this value
to be detected
-0.5
-2.5
-4.0
-7.0
-0.1
25
SYMBOL
CONDITIONS
MIN
9
-6
11
32.768
+0.5
+2.5
+4.0
+7.0
+0.1
75
Fs
%
TYP
MAX
9
+6
11
UNITS
Bits
%
Bits
kHz
TACH Count Oscillator and
CLKOUT Accuracy (Note 7)
I
2
C AC Electrical Characteristics
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +125°C, timing referenced to V
IL(MAX)
and V
IH(MIN)
, unless otherwise noted.) (Notes 3, 8)
(Figure
1)
PARAMETER
Serial Clock Frequency
Bus Free Time Between STOP
and START Conditions
START Condition Hold Time
STOP Condition Setup Time
Clock Low Period
Clock High Period
START Condition Setup Time
Data Setup Time
Data In Hold Time
Maximum Receive SCL/SDA Rise
Time
Minimum Receive SCL/SDA Rise
Time
SYMBOL
f
SCL
t
BUF
t
HD:STA
t
SU:STO
t
LOW
t
HIGH
t
SU:STA
t
SU:DAT
t
HD:DAT
t
R
t
R
90% of SCL to 90% of SDA
10% of SDA to 10% of SCL
10% of SCL to 10% of SDA (Note 9)
(Note 10)
(Note 10)
90% of SCL to 10% of SDA
CONDITIONS
MIN
DC
1.3
0.6
600
1.3
0.6
100
100
0
300
20 + 0.1 x C
B
0.9
TYP
MAX
400
UNITS
kHz
Fs
Fs
ns
Fs
Fs
ns
ns
Fs
ns
ns
www.maximintegrated.com
Maxim Integrated
│
3
MAX31790
6-Channel PWM-Output Fan RPM Controller
I
2
C AC Electrical Characteristics (continued)
(V
CC
= +3.0V to +5.5V, T
A
= -40°C to +125°C, timing referenced to V
IL(MAX)
and V
IH(MIN)
, unless otherwise noted.) (Notes 3, 8)
(Figure
1)
PARAMETER
Maximum Receive SCL/SDA Fall
Time
Minimum Receive SCL/SDA Fall
Time
Transmit SDA Fall Time
Pulse Width of Suppressed Spike
SDA Time Low for Reset of Serial
Interface
SYMBOL
t
F
t
F
t
F
t
SP
t
TIMEOUT
(Note 11)
25
(Note 10)
(Note 10)
CONDITIONS
MIN
TYP
300
20 + 0.1 x C
B
20 +
0.1 x
C
B
35
45
250
MAX
UNITS
ns
ns
10pF
P
C
B
P
400pF (Note 10)
ns
ns
ms
Note 2:
All voltages referenced to ground. Currents entering the IC are specified as positive.
Note 3:
Limits are 100% production tested at T
A
= +25°C and/or T
A
= +85°C. Limits over the operating temperature range and
relevant supply voltage range are guaranteed by design and characterization. Typical values are not guaranteed.
Note 4:
SDA = SCL = V
CC
, PWM active with PWM_FREQUENCY = 25kHz.
Note 5:
The watchdog timer is derived from f
TOSC
and the watchdog timer accuracy specifications do not include the oscillator’s
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