MAX6639F datasheet(13/18 Pages) MAXIM

13 / 18 page

Detailed Description of Hardware

The MAX6639 EV kit is an assembled and tested PCB

used to evaluate the MAX6639 dual-temperature sen-

sor/fan controller. The MAX6639 monitors its own die

temperature and the junction temperature of one exter-

nal diode-connected transistor, or the junction tempera-

tures of two external diode-connected transistors. It

converts the temperature to 8-bit or 11-bit 2-wire serial

data that can be accessed over a 2-wire serial bus.

Slave Address

The slave address can be changed by moving jumper

JU5. See Table 1 for address selection.

3-Wire and 4-Wire Fan Configurations

The MAX6639 EV kit is configured for a 3-wire fan by

default when the shunts are placed in the 1-2 position

of jumpers JU6 and JU7.

For 4-wire fan configuration, the user must move the

shunts to the 2-3 position of jumpers JU6 and JU7.

Replacing Diodes

Jumpers JU11 and JU12 connect the 2N3906 transistor

as the external diodes. To use different diodes, cut the

trace, short the two pins of JU11 and JU12, and con-

nect the diodes (through twisted-pair wire) to the DXP1,

DXN, and DXP2 pads.

User-Supplied I2C Interface

To use the MAX6639 with a user-supplied I2C interface,

first move JU2, JU3, and JU4 to the 2-3 position. Then,

connect SCL, SDA, and

ALERT to the corresponding

pads on the MAX6639 EV kit.

User-Supplied Power Supply

The MAX6639 EV kit is powered completely from the

USB port by default. Move the shunt of JU1 to the 2-3

position and apply a user-supplied 3.0V to 3.6V power

supply at the EXT_VIN and GND pads.

The fan supply is provided by the user and varies

depending on different fans.

MAX6639 Evaluation Kit

______________________________________________________________________________________

MAX6639F Datasheet(PDF) 13 Page - Maxim Integrated Products