Rainbow Electronics MAX6616 - Manual (Page 5)

MAX6615/MAX6616
Dual-Channel Temperature Monitors and
Fan-Speed Controllers with Thermistor Inputs
_______________________________________________________________________________________ 5
PIN
MAX6616 MAX6615
NAME FUNCTION
1, 2, 5, 20,
23, 24
—
GPIO0–
GPIO5
Active-Low, Open-Drain GPIOs. Can be pulled up to 5.5V regardless of V CC .
3 1 PWM1
Fan Driver Output 1. The pullup resistor can be connected to a supply voltage as high as
12V, regardless of the supply voltage. See the PWM Output section for configuration.
4 2 TACH1
Fan Tachometer Input. Accepts logic-level signal from fan’s tachometer output. Can be
connected to a supply voltage as high as 12V, regardless of the supply voltage.
6 3 ADD0 SMBus Slave Address Selection
7 4 ADD1 SMBus Slave Address Selection
8 5, 10 GND Ground. Must be connected together for MAX6615.
9 6 TH1
External Thermistor Input 1. Connect a thermistor in series with a fixed resistor between
REF and ground.
10, 15 — N.C. No Connection
11 7 REF
Reference Voltage Output. Provides 1V during measurements. High impedance when not
measuring.
12 8 TH2
External Thermistor Input 2. Connect a thermistor in series with a fixed resistor between
REF and ground.
13 9 FAN_FAIL
Fan-Failure Output. Asserts low when either fan fails. Can be pulled up as high as 5.5V
regardless of V
CC . High impedance when V CC = 0V.
14 — PRESET Connect to GND or V CC to set POR state of the GPIO0.
16 11 OT
Overtemperature Output. Active low, open drain. Typically used for system shutdown or
clock throttling. Can be pulled up as high as 5.5V regardless of V
CC . High impedance
when V CC = 0V.
17 12 V CC Power Supply. 3.3V nominal. Bypass with a 0.1µF capacitor to GND.
18 13 SDA
SMBus Serial-Data Input/Output. Pull up with a 10k Ω resistor. Can be pulled up as high
as 5.5V regardless of V
CC
. High impedance when V
CC
= 0V.
19 14 SCL
SMBus Serial-Clock Input. Pull up with a 10k Ω resistor. Can be pulled up as high as 5.5V
regardless of V CC . High impedance when V CC = 0V.
21 15 TACH2
Fan Tachometer Input. Accepts logic-level signal from fan’s tachometer output. Can be
connected to a supply voltage as high as 12V, regardless of the supply voltage.
22 16 PWM2
Fan Driver Output 2. The pullup resistor can be connected to a supply voltage as high as
12V, regardless of the supply voltage. See the PWM Output section for configuration.
Pin Description