Electrical characteristics – Rainbow Electronics MAX1669 User Manual
Page 4
Note 1: Guaranteed but not 100% tested.
Note 2: T
R
is the junction temperature of the remote diode. The temperature error specification is optimized to and guaranteed for a
diode-connected 2N3906 transistor with ideality factor = 1.013. Variations in the ideality factor “m” of the actual transistor
used will increase the temperature error by *. See the Temperature Error vs. Remote Diode Temperature graph in the
Typical Operating Characteristics for typical temperature errors using several random 2N3906s. See Remote Diode
Selection for remote diode forward-voltage requirements.
Note 3: The SMBus logic block is a static design that works with clock frequencies down to DC. While slow operation is possible, it
violates the 10kHz minimum clock frequency and SMBus specifications, and may monopolize the bus.
Note 4: Note that a transition must internally provide at least a hold time in order to bridge the undefined region (300ns max) of
SMBCLK’s falling edge.
Note 5: Specifications to -40°C are guaranteed by design and not production tested.
MAX1669
Fan Controller and Remote Temperature Sensor
with SMBus Serial Interface
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
(V
CC
= +3.3V, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 5)
Pin forced to 0.4V
ADD_, I/O1, I/O2, SYNC, SMBCLK, SMBDATA;
V
CC
= 3V to 5.5V
ADD_, I/O1, I/O2, SYNC, SMBCLK, SMBDATA;
V
CC
= 3V to 5.5V
Logic inputs forced to V
CC
or GND
Pin forced to 5.5V
µA
-1
1
Logic Input Current
µA
1
ALERT, OVERT, I/O1, I/O2 Output
High Leakage Current
V
0.2
FAN Output Voltage Low
mA
6
SMBDATA, ALERT, OVERT, I/O1, I/O2
Output Low Sink Current
V
0.8
Logic Input Low Voltage
V
2.1
Logic Input High Voltage
DAC mode, FAN duty factor = 1111b,
I
OUT
= 5mA
DAC mode, any setting, R
L
= 10k
Ω to GND
PWM mode, any setting
PWM mode, V
FAN
forced to 0.4V
PWM mode, V
FAN
forced to 2.9V
Monotonicity guaranteed
Autoconvert mode
From stop bit to conversion complete
T
R
= -55°C to +125°C, diode ideality factor = 1.013
Autoconvert mode, average measured over
1sec, FAN output set to 150Hz mode
CONDITIONS
V
2.94
FAN Output Voltage High
%FS
-5
5
FAN Total Unadjusted Error
%
-25
+25
FAN PWM Frequency Error
mA
-10
FAN Output Sink Current
mA
10
FAN Output Source Current
Hz
1.6
2.4
Conversion Rate
ms
47
Conversion Time
µA
100
Average Operating Supply Current
Bits
8
Temperature Resolution (Note 1)
°C
-5
5
Temperature Error, Remote Diode (Note 2)
UNITS
MIN
MAX
PARAMETER
DAC mode, FAN duty factor = 0000b,
I
OUT
= -5mA
V
3
5.5
Supply Voltage Range
ADC AND POWER SUPPLY
FAN OUTPUT
SMBus INTERFACE
*
.
.
∆T
m
k
T
C
R
=
−
+
(
)
°
( )
1 013
1
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