Rainbow Electronics MAX6684 - Manual

General Description
The MAX6684 is an integrated fan-failure detector that
detects when a fan exhibits excessive underspeed or a
locked rotor. This device is especially well suited for criti-
cal systems where no fan control, or simple on/off control
is desired. The MAX6684 detects fan failure by evaluat-
ing fluctuations in current at the low side of the fan; no
tachometer signal is necessary. The output of the device,
FAIL, is an active-low, open-drain alarm. The MAX6684
can also be used to switch the fan on or off, based on
the state of a logic-level input, OFF. This device can be
used with fans rated at up to 24V and 250mA. The
MAX6684 is available in an 8-pin SO package, and is
specified for operation from -40°C to +85°C.
Applications
Desktop PCs
Notebooks
Networking Equipment
Telecommunications
Industrial Applications
Features
♦ Dedicated Fan-Failure Detector
♦ Works with Ordinary 2-Wire Fans
♦ No Fan Tachometer Output Required
♦ No Software Development Required
♦ No Analog Circuit Design Required
♦ Logic-Level Fan Driver Control
♦ Works with Fans Rated Up to 24V/250mA
MAX6684
Fan-Failure Detector with Integrated
Power Switch
________________________________________________________________ Maxim Integrated Products 1
V
CC
FC+ FC-
1
2
8
7
PGND
OFF FAIL
GND
SENSE
SO
TOP VIEW
3
4
6
5
MAX6684
Pin Configuration
Ordering Information
MAX6684
OFF
SENSE
V
CC
12V
PGND GND
FC+
10k Ω
FC-
3.3V
1 µF
0.1 µF
0.1 µF
FAIL
Typical Operating Circuit
19-2306; Rev 0; 1/02
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.
PART TEMP RANGE PIN-PACKAGE
MAX6684ESA -40°C to +85°C 8 SO