User guide

MAX6661
Remote Temperature-Controlled Fan-Speed
Regulator with SPI-Compatible Interface
4 _______________________________________________________________________________________
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
1 10 100
TEMPERATURE ERROR
vs. PC BOARD RESISTANCE
MAX6661 toc01
LEAKAGE RESISTANCE (MΩ)
TEMPERATURE ERROR (°C)
20
-30
-25
-20
-15
-10
-5
0
15
10
5
PATH = DXP TO GND
PATH = DXP TO V
CC
(5V)
-5
-2
-3
-4
-1
0
1
2
3
4
5
-50 0 50 100 150
MAX6661 toc02
TEMPERATURE (°C)
TEMPERATURE ERROR (°C)
TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
1 100 10k 1M10 1k 100k 10M 100M
TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
MAX6661 toc03
FREQUENCY (Hz)
TEMPERATURE ERROR (°C)
20
-30
-25
-20
-15
-10
-5
0
15
10
5
V
IN
= 100mV
P-P
V
IN
= SQUARE WAVE APPLIED TO V
CC
WITH NO 0.1µF V
CC
CAPACITOR
V
IN
= 250mV
P-P
4.0
-1.5
-1.0
MAX6661 toc04
FREQUENCY (Hz)
TEMPERATURE ERROR (°C)
-0.5
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
1 10 100M1M 10M100 1k 10k 100k
TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
V
IN
= 50mV
P-P
V
IN
= SQUARE WAVE
AC-COUPLED TO DXN
V
IN
= 100mV
P-P
V
IN
= 25mV
P-P
-8
-6
-7
-4
-5
-3
-2
0
-1
1
0102030405060708090100
MAX6661 toc05
DXP-DXN CAPACITANCE (nF)
TEMPERATURE ERROR (°C)
TEMPERATURE ERROR
vs. DXP-DXN CAPACITANCE
0
1
3
2
4
5
MAX6661 toc06
SUPPLY VOLTAGE (V)
STANDBY SUPPLY CURRENT (µA)
3.0 4.0 4.53.5 5.0 5.5
STANDBY SUPPLY CURRENT
vs. SUPPLY VOLTAGE
CONFIG BIT 6 = 1
3.0 3.9 4.23.3 3.6 4.5 4.8 5.1 5.4
MAX6661 toc07
SUPPLY VOLTAGE (V)
AVERAGE SUPPLY CURRENT (µA)
450
AVERAGE SUPPLY CURRENT
vs. SUPPLY VOLTAGE