Datasheet

6-Channel Intelligent Fan Controller
MAX31785
10
Pin Description
Pin Configuration
PIN NAME FUNCTION
1 RS-4 Ground Reference for Thermal Diode or Remote Voltage ADC4 Measurement
2, 21, 36 V
SS
Digital-Supply Return Node (Ground)
3 RS+4 Thermal Diode or Remote Voltage ADC Input, Measurement Relative to RS-4
4 RS-3 Ground Reference for Thermal Diode or Remote Voltage ADC3 Measurement
5 RS+3 Thermal Diode or Remote Voltage ADC Input, Measurement Relative to RS-3
6 RS+0 Thermal Diode or Remote Voltage ADC Input, Measurement Relative to RS-0
7 RS-0 Ground Reference for Thermal Diode or Remote Voltage ADC0 Measurement
8 RS+1 Thermal Diode or Remote Voltage ADC Input, Measurement Relative to RS-1
9 V
DD
Supply Voltage. Bypass V
DD
to V
SS
with a 0.1FF capacitor.
10 RS-1 Ground Reference for Thermal Diode or Remote Voltage ADC1 Measurement
11 RS+2 Thermal Diode or Remote Voltage ADC Input, Measurement Relative to RS-2
12 RS-2 Ground Reference for Thermal Diode or Remote Voltage ADC2 Measurement
13 RST Reset Active-Low Input
14 MSDA Master I
2
C Data Input/Output. Open-drain output.
15 MSCL Master I
2
C Clock Input/Output. Open-drain output.
16 PWM5
Fan PWM Output #5. CMOS push-pull output. Low when the fan is disabled. A 100% duty cycle
implies this pin is continuously high.
17 TACH5 Fan Tachometer Input
18 PWM4
Fan PWM Output #4. CMOS push-pull output. Low when the fan is disabled. A 100% duty cycle
implies this pin is continuously high.
19 TACH4 Fan Tachometer Input
TOP VIEW
35
36
34
33
12
11
13
V
SS
RS-3
RS+3 RS+0
RS-0
14
RS-4
TACH1 TACH2 PWM2 PWM0 REG25 TACH0 TACH3 REG18
12 4567
27282930 26 24 23 22
CONTROL
V
SS
PWM4
TACH5
PWM5
MSCL
RS+4
PWM1
3
25
37
A1/TACHSEL
MSDA
38
39
40
RS-5
RS+5
RS-2
RS+2
EP
A0
32
15
TACH4
SCL
31
16
17
18
19
20
PWM3
RS+1
V
DD
RS-1
V
SS
8910
21
SDA
FAULT
ALERT
RST
+
TQFN
(6mm × 6mm × 0.75mm)
MAX31785