Datasheet
Fan-Speed Regulators and Monitors
with SMBus/I
2
C-Compatible Interface
MAX6650/MAX6651
4 Maxim Integrated
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
240
245
255
250
260
265
3.0 4.03.5 4.5 5.0 5.5
INTERNAL OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6650/51-01
SUPPLY VOLTAGE (V)
FREQUENCY (kHz)
200
220
260
240
280
300
INTERNAL OSCILLATOR FREQUENCY
vs. TEMPERATURE
MAX6650/51-02
TEMPERATURE (°C)
FREQUENCY (kHz)
-50
050
100
V
CC
= 5.5V
V
CC
= 3.0V
2.0
2.1
2.3
2.2
2.4
2.5
FEEDBACK VOLTAGE
vs. TEMPERATURE
MAX6650/51-03
TEMPERATURE (°C)
FEEDBACK VOLTAGE (V)
-50
050
100
1.9
1.8
V
CC
= 5.5V,
V
FAN
= 5.5V, V
FAN
= 12.0V
V
FAN
= 12.0V, V
FAN
= 5.5V
V
CC
= 3.0V
1.80
1.85
1.90
1.95
2.00
2.05
2.10
2.15
2.20
3.0
3.5
4.0 4.5 5.0 5.5
FEEDBACK VOLTAGE vs. SUPPLY
VOLTAGE (DAC SET TO 35)
MAX6650/51-04
SUPPLY VOLTAGE (V)
FEEDBACK VOLTAGE (V)
V
FAN
= 5.5V
V
FAN
= 12.0V
2.0
2.4
2.2
2.8
2.6
3.0
3.2
3.6
3.4
3.8
3.0
3.4
3.8 4.2 4.63.2 3.6 4.0 4.4 4.8 5.0
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6650/51-05
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
1.5
2.0
3.0
2.5
3.5
4.0
-40 0-20 20 40 60 80 100
SUPPLY CURRENT vs. TEMPERATURE
MAX6650/51-06
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
V
CC
= 5.5V
V
CC
= 3V
TIMING CHARACTERISTICS (continued)
(V
CC
= 3.0V to 5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C and V
CC
= 5V.)
Note 1: For proper measurement of V
FB
, connect OUT and FB as shown in the
Typical Operating Circuit
.
Note 2: GPIO2, GPIO3, and GPIO4 only in the MAX6651.
Note 3: Guaranteed by design and not 100% production tested.
Note 4: For R
ADD
component test purposes only.
Note 5: Note that the transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SCL’s
falling edge.
Note 6: C
B
is the total capacitance of one bus line in pF. Tested with C
B
= 400pF. Rise and fall times are measured between 0.3 x
V
CC
and 0.7 x V
CC
.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
µs
ns050
0.6
t
SPIKE
t
SU:STO
Setup Time for Stop Condition
Pulse Width of Spike Suppressed