MAX6615_08 Datasheet, PDF (1/20 Pages) Maxim Integrated Products – Dual-Channel Temperature Monitors and Fan-Speed Controllers with Thermistor Inputs

19-3713; Rev 2; 10/08
Dual-Channel Temperature Monitors and
Fan-Speed Controllers with Thermistor Inputs
General Description
The MAX6615/MAX6616 monitor two temperature chan-
nels, either the internal die temperature and the temper-
ature of an external thermistor, or the temperatures of
two external thermistors. The temperature data controls
a PWM output signal to adjust the speed of a cooling
fan, thereby minimizing noise when the system is run-
ning cool, but providing maximum cooling when power
dissipation increases. The fans’ tachometer output sig-
nals are monitored by the MAX6615/MAX6616 to detect
fan failure. If a fan failure is detected, the FAN_FAIL
output is asserted.
The 2-wire serial interface accepts standard system
management bus (SMBus^TM) write byte, read byte,
send byte, and receive byte commands to read the
temperature data and program the alarm thresholds.
The programmable alarm output can be used to gener-
ate interrupts, throttle signals, or overtemperature shut-
down signals.
The MAX6616 features six GPIOs to provide additional
flexibility. All of the GPIOs power-up as inputs, with the
exception of GPIO0, which powers up as either an input
or an output as determined by connecting the PRESET
pin to ground or V_CC.
The MAX6616 is available in a 24-pin QSOP package,
while the MAX6615 is available in a 16-pin QSOP pack-
age. Both devices operate from a single-supply voltage
range of 3.0V to 5.5V, have operating temperature
ranges of -40°C to +125°C, and consume just 500µA of
supply current.
Desktop Computers
Servers
Power Supplies
Networking Equipment
Workstations
Applications
SMBus is a trademark of Intel Corp.
Typical Application Circuits and Pin Configurations appear at
end of data sheet.
Features
o Two Thermistor Inputs
o Two Open-Drain PWM Outputs for Fan-Speed
Control
o Local Temperature Sensor
o Six GPIOs (MAX6616)
o Programmable Fan-Control Characteristics
o Controlled PWM Rate-of-Change Ensures
Unobtrusive Fan-Speed Adjustments
o Fail-Safe System Protection
o OT Output for Throttling or Shutdown
o Nine Different Pin-Programmable SMBus
Addresses
o 16-Pin and 24-Pin QSOP Packages
PART
MAX6615AEE
MAX6616AEG
Ordering Information
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
16 QSOP
24 QSOP
Functional Diagram
FAN_FAIL
V_CC
TH1
REF
TH2
THERMISTORS
AND LOCAL
TEMP SENSOR
PWM
GENERATOR
AND TACH
COUNTER
TACH1
PWM1
TACH2
PWM2
SCL
SMBus
INTERFACE
AND
SDA
REGISTERS
LOGIC
MAX6615
MAX6616
GND
OT
GPIO0*
GPIO5*
PRESET*
ADD0 ADD1
*MAX6616 ONLY
________________________________________________________________ Maxim Integrated Products 1
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