MAX6639ATE+ Maxim Integrated Products, MAX6639ATE+ Datasheet - Page 7

• Manufacturer Part Number: MAX6639ATE+
• Description: IC TEMP MONITOR 2CH 16-TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX6639ATE+

• Function: Fan Control, Temp Monitor
• Topology: ADC, PWM Generator, Tach Counter
• Sensor Type: External & Internal
• Sensing Temperature: 0°C ~ 150°C, External Sensor
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

From a software perspective, the MAX6639 appears as
a set of byte-wide registers. This device uses a stan-
dard SMBus 2-wire/I
access the internal registers.
The MAX6639 features an address select input (ADD)
that allows the MAX6639 to have three unique addresses
(see Table 1).
The MAX6639 employs four standard SMBus protocols:
write byte, read byte, send byte, and receive byte
(Figures 1, 2, and 3). The shorter receive byte protocol
allows quicker transfers, provided that the correct data
register was previously selected by a read byte instruc-
tion. Use caution with the shorter protocols in multimas-
ter systems, since a second master could overwrite the
command byte without informing the first master.
Table 4 details the register addresses and functions,
whether they can be read or written to, and the power-
Figure 2. SMBus Write Timing Diagram
Figure 3. SMBus Read Timing Diagram
SCL
SDA
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
E = SLAVE PULLS SMBDATA LINE LOW
SCL
SDA
t
SU:STA
A
2-Channel Temperature Monitor with Dual,
t
HD:STA
t
SU:STA
_______________________________________________________________________________________
A
t
t
LOW
HD:STA
2
C-compatible serial interface to
B
Automatic, PWM Fan-Speed Controller
t
HIGH
t
LOW
SMBus Digital Interface
B
t
HIGH
t
SU:DAT
C
t
SU:DAT
C
E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER
I = MASTER PULLS DATA LINE LOW
D
D
E
F
E
F
on reset (POR) state. See Tables 5–9 for all other regis-
ter functions and the Register Descriptions section.
Temperature data can be read from registers 00h and
01h. The temperature data format for these registers is
8 bits, with the LSB representing 1°C (Table 2) and the
MSB representing +128°C. The MSB is transmitted first.
Three additional temperature bits provide resolution
down to 0.125°C and are in the channel 1 extended
temperature (05h) and channel 2 extended temperature
(06h) registers. All values below 0°C clip to 00h.
Table 1. I
V
Floating
GND
ADD INPUT STATE
t
HD:DAT
CC
G
G
2
C Slave Address
I = MASTER PULLS DATA LINE LOW
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
H
H
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
I
2
C SLAVE ADDRESS
I
I
J K
Temperature Reading
J
5Eh
5Ch
58h
K
t
SU:STO
t
SU:STO
L
t
BUF
EQUIVALENT
L
M
0101 111
0101 110
0101 100
BINARY
t
BUF
M
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