Rainbow Electronics MAX6616 - Manual

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.
Applications
Desktop Computers
Servers
Power Supplies
Networking Equipment
Workstations
Features
♦ Two Thermistor Inputs
♦ Two Open-Drain PWM Outputs for Fan-Speed
Control
♦ Local Temperature Sensor
♦ Six GPIOs (MAX6616)
♦ Programmable Fan-Control Characteristics
♦ Controlled PWM Rate-of-Change Ensures
Unobtrusive Fan-Speed Adjustments
♦ Fail-Safe System Protection
♦ OT Output for Throttling or Shutdown
♦ Nine Different Pin-Programmable SMBus
Addresses
♦ 16-Pin and 24-Pin QSOP Packages
MAX6615/MAX6616
Dual-Channel Temperature Monitors and
Fan-Speed Controllers with Thermistor Inputs
________________________________________________________________ Maxim Integrated Products 1
19-3713; Rev 1; 7/05
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX6615AEE -40°C to +125°C 16 QSOP
MAX6616AEG -40°C to +125°C 24 QSOP
SMBus is a trademark of Intel Corp.
Typical Application Circuits and Pin Configurations appear at
end of data sheet.
THERMISTORS
AND LOCAL
TEMP SENSOR
PWM
GENERATOR
AND TACH
COUNTER
SMBus
INTERFACE
AND
REGISTERS
LOGIC
ADD0 ADD1
*MAX6616 ONLY
FAN_FAIL
MAX6615
MAX6616
GND
V CC
SDA
SCL
REF
TH1
TH2
PWM1
PWM2
TACH1
TACH2
OT
GPIO0*
GPIO5*
PRESET*
Functional Diagram