MAX6641AUB96 [MAXIM]
SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller;
| 型号： | MAX6641AUB96 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | SMBus-Compatible Temperature Monitor with Automatic PWM Fan-Speed Controller |
| 文件： | 总17页 (文件大小：474K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-3304; Rev 1; 4/06
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
General Description
Features
The MAX6641 temperature sensor and fan controller
accurately measures the temperature of its own die and
the temperature of a remote pn junction. The device
reports temperature values in digital form using a 2-wire
serial interface. The remote pn junction is typically the
emitter-base junction of a common-collector pnp on a
CPU, FPGA, or ASIC.
♦ Tiny 3mm x 5mm µMAX Package
♦ Thermal Diode Input
♦ Local Temperature Sensor
♦ Open-Drain PWM Output for Fan Drive
♦ Programmable Fan Control Characteristics
♦ Automatic Fan Spin-Up Ensures Fan Start
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 temperature data controls a PWM output signal to
adjust the speed of a cooling fan, thereby minimizing
noise when the system is running cool, but providing
maximum cooling when power dissipation increases.
The device also features an over-temperature alarm
output to generate interrupts, throttle signals, or shut
down signals. The MAX6641 operates from supply volt-
ages in the 3.0V to 5.5V range and typically consumes
500µA of supply current.
♦ ±±1C ꢀemote Temperature Accuracy ꢁ(+61C to
(±451C)
♦ Controlled ꢀate of Change Ensures Unobtrusive
Fan-Speed Adjustments
♦ Temperature Monitoring Begins at Power-On for
Fail-Safe System Protection
♦ OT Output for Throttling or Shutdown
The MAX6641 is available in a slim 10-pin µMAX® pack-
age and is available over the -40°C to +125°C automo-
tive temperature range.
Ordering Information
PIN-
SMBus
PKG
PAꢀT
PACKAGE
ADDꢀESS
CODE
Applications
Desktop Computers
Notebook Computers
Workstations
MAX6641AUB90
MAX6641AUB92
MAX6641AUB94
MAX6641AUB96
10 µMAX
10 µMAX
10 µMAX
10 µMAX
1001 000x
1001 001x
1001 010x
1001 011x
U10-2
U10-2
U10-2
U10-2
Note: All devices are specified over the -40°C to +125°C tem-
perature range.
Servers
Networking Equipment
Industrial
Pin Configuration
TOP VIEW
Typical Application Circuit appears at end of data sheet.
I.C.
DXN
DXP
GND
OT
1
2
3
4
5
10 PWMOUT
9
8
7
6
V
CC
MAX6641
SMBDATA
SMBCLK
I.C.
µMAX
µMAX is a registered trademark of Maxim Integrated Products, Inc.
SMBus is a trademark of Intel Corp.
________________________________________________________________ Maxim Integrated Products
±
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.
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
ABSOLUTE MAXIMUM ꢀATINGS
(All voltages referenced to GND.)
Continuous Power Dissipation (T = +70°C)
A
V
, OT, SMBDATA, SMBCLK, PWMOUT...............-0.3V to +6V
10-Pin µMAX (derate 5.6mW/°C above +70°C).......... 444mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range ............................-65°C to +150°C
Lead Temperature (soldering, 10s) ............................... +300°C
CC
DXP.........................................................…-0.3V to (V
DXN ......................................................................-0.3V to +0.8V
ESD Protection
+ 0.3V)
CC
(all pins, Human Body Model) ......……………………. 2000V
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTꢀICAL CHAꢀACTEꢀISTICS
(V
= +3.0V to +5.5V, T = 0°C to +125°C, unless otherwise noted. Typical values are at V
= 3.3V, T = +25°C.)
CC A
CC
A
PAꢀAMETEꢀ
SYMBOL
CONDITIONS
MIN
TYP
MAX
5.5
1
UNITS
V
Operating Supply Voltage Range
Operating Current
V
3.0
CC
SMBDATA, SMBCLK not switching
0.5
mA
+25°C ≤ T ≤ +125°C,
R
1
3
4
T
A
= +60°C
0°C ≤ T ≤ +145°C,
R
External Temperature Error
V
V
= 3.3V
= 3.3V
°C
CC
CC
+25°C ≤ T = ≤ +100°C
A
0°C ≤ T ≤ +145°C,
R
0°C ≤ T ≤ +125°C
A
+25°C ≤ T ≤ +100°C
-3
-4
+3
+4
A
Internal Temperature Error
Temperature Resolution
°C
0°C ≤ T ≤ +125°C
A
1
°C
Bits
ms
%
8
Conversion Time
200
-20
80
8
250
300
+20
120
12
PWM Frequency Tolerance
High level
Low level
100
10
Remote-Diode Sourcing Current
µA
V
DXN Source Voltage
0.7
I/O
OT, SMBDATA, PWMOUT Output
Low Voltage
V
I
= 6mA
= 5.5V
0.4
1
V
µA
V
OL
OUT
OT, SMBDATA, PWMOUT
Output-High Leakage Current
I
V
V
V
OH
CC
CC
CC
SMBDATA, SMBCLK Logic-Low
Input Voltage
V
= 3V to 5.5V
= 3V to 5.5V
0.8
IL
SMBDATA, SMBCLK Logic-High
Input Voltage
V
2.1
V
IH
SMBDATA, SMBCLK Leakage
Current
1
µA
pF
SMBDATA, SMBCLK Input
Capacitance
C
5
IN
2
_______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
ELECTꢀICAL CHAꢀACTEꢀISTICS ꢁcontinued)
(V
= +3.0V to +5.5V, T = 0°C to +125°C, unless otherwise noted. Typical values are at V
= 3.3V, T = +25°C.)
CC A
CC
A
PAꢀAMETEꢀ
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
SMBus-COMPATIBLE TIMING (Note 1) (See Figures 2, 3)
Serial-Clock Frequency
Clock Low Period
f
t
(Note 2)
100
kHz
µs
SCLK
t
10% to 10%
90% to 90%
4
LOW
Clock High Period
4.7
µs
HIGH
Bus Free Time Between Stop and
Start Condition
t
4.7
4
µs
µs
BUF
Hold Time After (Repeated) Start
Condition
t
HD:STA
SMBus Start Condition Setup Time
Start Condition Hold Time
Stop Condition Setup Time
Data Setup Time
t
90% of SMBCLK to 90% of SMBDATA
10% of SMBDATA to 10% of SMBCLK
90% of SMBCLK to 10% of SMBDATA
10% of SMBDATA to 10% of SMBCLK
4.7
4
µs
µs
µs
ns
SU:STA
t
HD:STO
t
4
SU:STO
SU:DAT
t
250
10% of SMBCLK to 10% of SMBDATA
(Note 3)
Data Hold Time
t
300
29
ns
HD:DAT
SMBus Fall Time
SMBus Rise Time
SMBus Timeout
t
F
300
1000
55
ns
ns
t
R
t
37
ms
ms
TIMEOUT
Startup Time After POR
t
500
POR
Note ±: Timing specifications guaranteed by design.
Note 2: The serial interface resets when SMBCLK is low for more than t
.
TIMEOUT
Note 3: A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SMBCLK’s falling edge.
Typical Operating Characteristics
(V
= 3.3V, T = +25°C, unless otherwise noted.)
CC
A
OPERATING SUPPLY CURRENT
vs. SUPPLY VOLTAGE
LOCAL TEMPERATURE ERROR
vs. DIE TEMPERATURE
REMOTE TEMPERATURE ERROR
vs. REMOTE-DIODE TEMPERATURE
600
550
2
1
2.0
1.5
NO SMBus ACTIVITY
1.0
500
450
400
350
300
0.5
0
0
-0.5
-1.0
-1.5
-2.0
-1
-2
3.0
3.5
4.0
4.5
5.0
5.5
0
25
50
75
100
125
0
25
50
75
100
125
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Typical Operating Characteristics (continued)
(V
= 3.3V, T = +25°C, unless otherwise noted.)
CC
A
LOCAL TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
REMOTE TEMPERATURE ERROR
vs. COMMON-MODE NOISE FREQUENCY
REMOTE TEMPERATURE ERROR
vs. POWER-SUPPLY NOISE FREQUENCY
1.0
0.5
1.0
0.5
0
0
T
= +25°C, 250mV SQUARE WAVE APPLIED
CC
T
= +80°C, 250mV SQUARE WAVE APPLIED
CC
A
T = +80°C, V = 100mV
A IN P-P
SQUARE WAVE APPLIED TO DXP
A
AT V , NO BYPASS CAPACITOR
AT V , NO BYPASS CAPACITOR
-0.25
-0.50
-0.75
-1.00
-1.25
-1.50
0
-0.5
-1.0
-1.5
-2.0
-0.5
-1.0
-1.5
0.1
1
10
100
1000
0.1
1
10
100
1000
0.1
1
10
100
1000
FREQUENCY (kHz)
FREQUENCY (kHz)
FREQUENCY (kHz)
REMOTE TEMPERATURE ERROR
vs. DXP - DXN CAPACITANCE
REMOTE TEMPERATURE ERROR
vs. DIFFERENTIAL-MODE NOISE FREQUENCY
1.5
1.0
0.5
0
3
2
T
= +80°C, V = 10mV
IN P-P
A
SQUARE WAVE APPLIED
TO DXP - DXN
1
0
-1
-2
-3
-4
-5
-0.5
-1.0
T
= +80°C
A
0.1
1
10
100
1000
0.1
1
10
100
FREQUENCY (kHz)
DXP - DXN CAPACITANCE (nF)
PWM FREQUENCY ERROR
vs. DIE TEMPERATURE
PWM FREQUENCY ERROR
vs. SUPPLY VOLTAGE
2
1
2.0
1.5
1.0
0.5
0
0
-1
-2
-3
-0.5
-1.0
T
= +25°C
A
-50 -25
0
25
50
75 100 125
3.0
3.5
4.0
4.5
5.0
5.5
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
4
_______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Pin Description
PIN
NAME
FUNCTION
Internally Connected. Must be connected to GND.
1, 6
I.C.
Combined Remote-Diode Cathode Connection and A/D Negative Input. Connect the cathode of the
remote-diode-connected transistor to DXN.
2
3
DXN
DXP
Combined Remote-Diode Current Source and A/D Positive Input for Remote-Diode Channel. Connect
DXP to the anode of a remote-diode-connected temperature-sensing transistor. DO NOT LEAVE
DXP FLOATING; connect to DXN if no remote diode is used. Place a 2200pF capacitor between DXP
and DXN for noise filtering.
4
5
GND
Ground
Active-Low, Open-Drain, Over-Temperature Output. Use OT as an interrupt, a system shutdown
signal, or to control clock throttling. OT can be pulled up to 5.5V, regardless of the voltage on V
OT
.
CC
OT is high impedance when V
= 0.
CC
SMBus Serial-Clock Input. SMBCLK can be pulled up to 5.5V, regardless of V . Open drain.
CC
7
SMBCLK
SMBCLK is high impedance when V
= 0.
CC
SMBus Serial-Data Input/Output. SMBDATA can be pulled up to 5.5V, regardless of V . Open drain.
CC
8
9
SMBDATA
SMBDATA is high impedance when V
= 0.
CC
V
Positive Supply. Bypass with a 0.1µF capacitor to GND.
CC
PWM Output to Fan Power Transistor. Connect PWMOUT to the gate of a MOSFET or the base of a
bipolar transistor to drive the fan’s power supply with a PWM waveform. Alternatively, the PWM output
can be connected to the PWM input of a fan with direct speed-control capability, or it can be
converted to a DC voltage for driving the fan’s power supply. PWMOUT requires a pullup resistor. The
10
PWMOUT
pullup resistor can be connected to a voltage supply up to 5.5V, regardless of V
.
CC
The MAX6641 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 when using the shorter protocols in
multimaster systems, as a second master could over-
write the command byte without informing the first mas-
ter. The MAX6641 has four different slave addresses
available; therefore, a maximum of four MAX6641
devices can share the same bus.
Detailed Description
The MAX6641 temperature sensor and fan controller
accurately measures the temperature of its own die
and the temperature of a remote pn junction. The
device reports temperature values in digital form using
a 2-wire serial interface. The remote pn junction is typi-
cally the emitter-base junction of a common-collector
pnp on a CPU, FPGA, or ASIC. The MAX6641 operates
from supply voltages of 3.0V to 5.5V and consumes
500µA of supply current. The temperature data controls
a PWM output signal to adjust the speed of a cooling
fan. The device also features an over-temperature
alarm output to generate interrupts, throttle signals, or
shut down signals.
Temperature data within the 0°C to +255°C range can
be read from the read external temperature register
(00h). Temperature data within the 0°C to +125°C range
can be read from the read internal temperature register
(01h). The temperature data format for these registers is
8 bits, with the LSB representing +1°C (Table 1) and the
MSB representing +128°C. The MSB is transmitted first.
All values below 0°C are clipped to 00h.
Table 1 details the register address and function,
whether they can be read or written to, and the power-on
reset (POR) state. See Tables 1–5 for all other register
functions and the Register Descriptions section. Figure 4
is the MAX6641 block diagram.
SMBus Digital Interface
From a software perspective, the MAX6641 appears as
a set of byte-wide registers that contain temperature
data, alarm threshold values, and control bits. A stan-
dard SMBus-compatible 2-wire serial interface is used
to read temperature data and write control bits and
alarm threshold data. These devices respond to the
same SMBus slave address for access to all functions.
_______________________________________________________________________________________
5
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Table ±. ꢀegister Functions
ꢀEAD/ ꢀEGISTEꢀ
WꢀITE ADDꢀESS STATE
POꢀ
FUNCTION/
NAME
D7
D+
D5
D4
D3
D2
D±
D6
Read remote
(external)
temperature
MSB
(+128°C)
LSB
(+1°C)
R
R
00h
01h
0000 0000
0000 0000
(+64°C)
(+32°C)
(+16°C) (+8°C)
(+4°C) (+2°C)
(+4°C) (+2°C)
Read local
(internal)
temperature
MSB
(+128°C)
LSB
(+1°C)
(+64°C)
(+32°C)
(+16°C) (+8°C)
Min duty
cycle:
0 = 0%, Spin-up
1 = fan- disable
start duty
Timeout: 0 =
enabled, 1 = PWM
disabled
Fan
Configuration Reserved Reserved
R/W
02h
0000 00xx
X
X
byte
set to 0
set to 0
invert
cycle
Remote-diode
0110 1110 temperature
MSB
(+128°C)
LSB
(+1°C)
R/W
R/W
03h
04h
(+64°C)
(+64°C)
(+32°C)
(+32°C)
(+16°C) (+8°C)
(+16°C) (+8°C)
(+4°C) (+2°C)
(+4°C) (+2°C)
OT limit
Local-diode
0101 0000 temperature
OT limit
MSB
(+128°C)
LSB
(+1°C)
Remote 1 Local 1 =
= fault fault
R
05h
06h
07h
00xx xxxx
00xx xxxx
OT status
OT mask
X
X
X
X
X
X
X
X
X
X
X
X
X
Remote 1 Local 1 =
= masked masked
R/W
R/W
0110 000x Fan-start duty
(96 = 40%)
MSB
LSB
(2/240)
(64/240)
(128/240)
(32/240)
(16/240) (8/240) (4/240)
(16/240) (8/240) (4/240)
(16/240) (8/240) (4/240)
(16/240) (8/240) (4/240)
cycle
1111 000x
(240 =
100%)
Fan maximum
duty cycle
MSB
LSB
(2/240)
R/W
R/W
R
08h
09h
0Ah
(64/240)
(128/240)
(32/240)
(32/240)
(32/240)
X
X
X
Fan target duty
cycle
MSB
LSB
(2/240)
0000 000x
0000 000x
(64/240)
(128/240)
Fan
instantaneous
duty cycle
MSB
LSB
(2/240)
(64/240)
(128/240)
Remote-diode
fan-start
temperature
MSB
LSB
(+1°C)
R/W
0Bh
0000 0000
(+64°C)
(+128°C)
(+32°C)
(+16°C) (+8°C)
(+4°C) (+2°C)
+
_______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Table ±. ꢀegister Functions ꢁcontinued)
ꢀEAD/ ꢀEGISTEꢀ
WꢀITE ADDꢀESS STATE
POꢀ
FUNCTION/
NAME
D7
D+
D5
D4
D3
D2
D±
D6
Local-diode
fan-start
temperature
MSB
(+128°C)
LSB
(+1°C)
R/W
R/W
0Ch
0Dh
0000 0000
0000 xxxx
(+64°C)
(+32°C)
(+16°C) (+8°C)
(+4°C) (+2°C)
Temp
step: 0 = Fan control:
1°C, 1 =
2°C
Hysteresis:
0 = 5°C,
1 = 10°C
Fan
Fan
configuration
control:
X
X
X
X
1 = remote
1 = local
Duty-cycle
rate of change
R/W
R/W
0Eh
0Fh
101x xxxx
0101 xxxx
MSB
MSB
—
—
LSB
—
X
X
X
X
X
X
X
X
X
Duty-cycle
step size
LSB
PWM
frequency
select
R/W
10h
010x xxxx
Select A Select B
Select C
X
X
X
X
X
Read device
revision
R
R
FDh
FEh
0000 0001
1000 0111
0
1
0
0
0
0
0
0
0
0
0
1
0
1
1
1
Read
device ID
Read
R
FFh
0100 1101 manufacturer
ID
0
1
0
0
1
1
0
1
X = Don’t care. See register descriptions for further details.
_______________________________________________________________________________________
7
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Write Byte Format
S
ADDꢀESS
Wꢀ
ACK
COMMAND
ACK
DATA
ACK
P
7 bits
8 bits
8 bits
1
Slave address: equiva-
lent to chip-select line of
a 3-wire interface
Command byte: selects to
which register you are writing
Data byte: data goes into the register
set by the command byte (to set
thresholds, configuration masks, and
sampling rate)
Read Byte Format
S
ADDꢀESS
Wꢀ
ACK
COMMAND
ACK
S
ADDꢀESS
ꢀD
ACK
DATA
///
P
7 bits
8 bits
7 bits
8 bits
Slave address: equivalent
to chip-select line
Command byte: selects
from which register you
are reading
Slave address: repeated
due to change in data-
flow direction
Data byte: reads from
the register set by the
command byte
Send Byte Format
Receive Byte Format
S
ADDꢀESS
ꢀD
ACK DATA
///
P
S
ADDꢀESS Wꢀ ACK COMMAND ACK
P
7 bits
8 bits
7 bits
8 bits
Data byte: reads data from
the register commanded
by the last read byte or
write byte transmission;
also used for SMBus alert
response return address
Command byte: sends com-
mand with no data, usually
used for one-shot command
S = Start condition
P = Stop condition
Shaded = Slave transmission
/// = Not acknowledged
Figure 1. SMBus Protocols
A
B
C
D
E
F
G
H
I
J
K
L
M
t
t
HIGH
LOW
SMBCLK
SMBDATA
t
t
BUF
SU:STO
t
t
t
SU:DAT
SU:STA HD:STA
A = START CONDITION
E = SLAVE PULLS SMBDATA LINE LOW
I = MASTER PULLS DATA LINE LOW
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
M = NEW START CONDITION
Figure 2. SMBus Write Timing Diagram
8
_______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
A
B
C
D
E
F
G
H
I
J
K
L
M
t
t
HIGH
LOW
SMBCLK
SMBDATA
t
t
t
t
HD:DAT
HD:STA
SU:STA
SU:DAT
t
t
SU:STO
BUF
A = START CONDITION
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
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
M = NEW START CONDITION
E = SLAVE PULLS SMBDATA LINE LOW
Figure 3. SMBus Read Timing Diagram
is +128°C and the value of the LSB is +1°C. The MSB is
transmitted first. The POR state of the temperature reg-
isters is 00h.
V
CC
DXP
DXN
Configuration Byte Register (02h)
The configuration byte register controls the timeout
conditions and various PWMOUT signals. The POR
state of the configuration byte register is 00h. See
Table 2 for configuration byte definitions.
PWM
GENERATOR
BLOCK
PWMOUT
TEMPERATURE
PROCESSING
BLOCK
Remote and Local OT Limits (03h, 04h)
Set the remote (03h) and local (04h) temperature thresh-
olds with these two registers. Once the temperature is
above the threshold, the OT output is asserted low (for
the temperature channels that are not masked). The POR
state of the remote OT limit register is 6Eh and the POR
state of the LOCAL OT limit register is 50h.
LOGIC
OT
SMBus
INTERFACE AND
REGISTERS
SMBDATA
SMBCLK
MAX6641
OT Status (05h)
Read the OT status register to determine which channel
recorded an over-temperature condition. Bit D7 is high if
the fault reading occurred from the remote diode. Bit D6
is high if the fault reading occurred in the local diode.
The OT status register is cleared only by reading its con-
tents. Reading the contents of the register also makes
the OT output high impedance. If the fault is still present
on the next temperature measurement cycle, the corre-
sponding bits and the OT output are set again. After
reading the OT status register, a temperature register
read must be done to correctly clear the appropriate sta-
tus bit. The POR state of the OT status register is 00h.
GND
Figure 4. Block Diagram
Register Descriptions
Temperature Registers (00h, 01h)
These registers contain the 8-bit results of the tempera-
ture measurements. Register 00h contains the tempera-
ture reading of the remote diode. Register 01h contains
the ambient temperature reading. The value of the MSB
_______________________________________________________________________________________
9
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Table 2. Configuration Byte Definition ꢁ62h)
BIT
7
NAME
—
POꢀ STATE
FUNCTION
0
0
Reserved. Set to zero.
Reserved. Set to zero.
6
—
Set TIMEOUT to zero to enable SMBus timeout for
prevention of bus lockup. Set to 1 to disable this function.
5
4
TIMEOUT
0
Set FAN PWM INVERT to zero to force PWMOUT low when
the duty cycle is 100%. Set to 1 to force PWMOUT high
when the duty cycle is 100%.
FAN PWM INVERT
0
Set MIN DUTY CYCLE to zero for a 0% duty cycle when
the measured temperature is below the fan-temperature
threshold in automatic mode. When the temperature
equals the fan-temperature threshold, the duty cycle is the
value in the fan-start duty-cycle register, which increases
with increasing temperature.
Set MIN DUTY CYCLE to 1 to force the PWM duty cycle to
the value in the fan-start duty-cycle register when the
measured temperature is below the fan-temperature
threshold. As the temperature increases above the
temperature threshold, the duty cycle increases as
programmed.
3
2
MIN DUTY CYCLE
SPIN-UP DISABLE
0
0
Set SPIN-UP DISABLE to 1 to disable spin-up. Set to zero
for normal fan spin-up.
1
0
—
—
X
X
Don’t care.
Don’t care.
Fan Maximum Duty Cycle (08h)
The fan maximum duty-cycle register sets the maxi-
mum allowable PWMOUT duty cycle between 2/240
(0.83% duty cycle) and 240/240 (100% duty cycle).
Any values greater than 240 are recognized as 100%
maximum duty cycle. The POR state of the fan maxi-
mum duty-cycle register is F0h, 100%. In manual con-
trol mode, this register is ignored.
OT Mask (06h)
Set bit D7 to 1 in the OT mask register to prevent the
OT output from asserting on faults in the remote-diode
temperature channel. Set bit D6 to 1 to prevent the OT
output from asserting on faults in the local-diode tem-
perature channel. The POR state of the OT mask regis-
ter is 00h.
Fan-Start Duty Cycle (07h)
The fan-start duty-cycle register determines the PWM
duty cycle where the fan starts spinning. Bit D3 in the
configuration byte register (MIN DUTY CYCLE) deter-
mines the starting duty cycle. If the MIN DUTY CYCLE
bit is 1, the duty cycle is the value written to the fan-
start duty-cycle register at all temperatures below the
fan-start temperature. If the MIN DUTY CYCLE bit is
zero, the duty cycle is zero below the fan-start tempera-
ture and has this value when the fan-start temperature
is reached. A value of 240 represents 100% duty cycle.
Writing any value greater than 240 causes the fan
speed to be set to 100%. The POR state of the fan-start
duty-cycle register is 60h, 40%.
Fan-Target Duty Cycle (09h)
In automatic fan-control mode, this register contains the
present value of the target PWM duty cycle, as deter-
mined by the measured temperature and the duty-
cycle step size. The actual duty cycle needs a settling
time before it equals the target duty cycle if the duty-
cycle rate of change register is set to a value other than
zero. The actual duty cycle needs the time to settle as
defined by the value of the duty-cycle rate-of-change
register; therefore, the target duty cycle and the actual
duty cycle are often different. In manual fan-control
mode, write the desired value of the PWM duty cycle
directly into this register. The POR state of the fan-tar-
get duty-cycle register is 00h.
±6 ______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Fan Instantaneous Duty Cycle (0Ah)
Table 3. Duty-Cycle ꢀate-of-Change
ꢀegister ꢁ6Eh)
Read the fan instantaneous duty-cycle register to deter-
mine the duty cycle at PWMOUT at any time. The POR
state of the fan instantaneous duty-cycle register is 00h.
TIME BETWEEN
INCꢀEMENTS ꢁs)
TIME FꢀOM 33%
TO ±66% ꢁs)
D7, D+, D5
Remote- and Local-Diode
Fan-Start Temperature (0Bh, 0Ch)
000
001
010
011
100
101
110
111
0
0
5
0.0625
0.1250
0.2500
0.5000
1.0000
2.0000
4.0000
These registers contain the temperature threshold val-
ues at which fan control begins in automatic mode. See
the Automatic PWM Duty-Cycle Control section for
details on setting the fan-start thresholds. The POR
state of the remote- and local-diode fan-start tempera-
ture registers is 00h.
10
20
40
80
160
320
Fan Configuration (0Dh)
The fan-configuration register controls the hysteresis
level, temperature step size, and whether the remote or
local diode controls the PWMOUT signal; see Table 1.
Set bit D7 of the fan-configuration register to zero to set
the hysteresis value to 5°C. Set bit D7 to 1 to set the
hysteresis value to 10°C. Set bit D6 to zero to set the
fan-control temperature step size to 1°C. Set bit D6 to 1
to set the fan-control temperature step size to 2°C. Set
bit D5 to 1 to control the fan with the remote-diode’s
temperature reading. Set bit D4 to 1 to control the fan
with the local-diode’s temperature reading. If both bits
D5 and D4 are high, the device uses the highest PWM
value. If both bits D5 and D4 are zero, the MAX6641
runs in manual fan-control mode where only the value
written to the fan-target duty-cycle register (09h) con-
trols the PWMOUT duty cycle. In manual fan-control
mode, the value written to the fan-target duty-cycle reg-
ister is not limited by the value in the maximum duty-
cycle register. It is, however, clipped to 240 if a value
above 240 is written. The POR state of the fan-configu-
ration register is 00h.
Table 4. Duty-Cycle Step-Size
ꢀegister ꢁ6Fh)
CHANGE IN DUTY
CYCLE PEꢀ
TEMPEꢀATUꢀE ꢀANGE
FOꢀ FAN CONTꢀOL
D7–D4
TEMPEꢀATUꢀE STEP ꢁ±°C STEP, 33% TO ±66%)
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
0/240
2/240
N/A
80.00
40.00
26.67
20.00
16.00
13.33
11.43
10.00
8.89
4/240
6/240
8/240
10/240
12/240
14/240
16/240
18/240
20/240
22/240
24/240
26/240
28/240
30/240
8.00
Duty-Cycle Rate of Change (0Eh)
Bits D7, D6, and D5 of the duty-cycle rate-of-change
register set the time between increments of the duty
cycle. Each increment is 2/240 of the duty cycle; see
Table 3. This allows the time from 33% to 100% duty
cycle to be adjusted from 5s to 320s. The rate-of-
change control is always active in manual mode. To
make instant changes, set bits D7, D6, D5 = 000. The
POR state of the duty-cycle rate-of-change register is
A0h (1s time between increments).
7.27
6.67
6.15
5.71
5.33
PWM Frequency Select (10h)
Set bits D7, D6, and D5 (select A, select B, and select
C) in the PWM frequency-select register to control the
PWMOUT frequency; see Table 5. The POR state of the
PWM frequency select register is 40h, 33Hz. The lower
frequencies are usually used when driving the fan’s
power-supply pin as in the Typical Application Circuit,
with 33Hz being the most common choice. The 35kHz
Duty-Cycle Step Size (0Fh)
Bits D7–D4 of the duty-cycle step-size register change
the size of the duty-cycle change for each temperature
step. The POR state of the duty-cycle step-size register
is 50h; see Table 4.
______________________________________________________________________________________ ±±
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Table 5. PWM Frequency Select ꢁ±6h)
V
CC
PWM
FꢀEQUENCY
ꢁHz)
5V
SELECT A
SELECT B
SELECT C
0
0
1
1
X
0
1
0
1
X
10kΩ
20
33
0
0
0
0
1
PWMOUT
P
50
100
35k
frequency setting is used for controlling fans that have
logic-level PWM input pins for speed control. Duty-
cycle resolution is decreased from 2/240 to 4/240 at the
35kHz frequency setting.
Figure 5. Driving a P-Channel MOSFET for Top-Side PWM
Fan Drive
PWM Output
The PWMOUT signal is normally used in one of three
ways to control the fan’s speed:
+12V
1) PWMOUT drives the gate of a MOSFET or the base
of a bipolar transistor in series with the fan’s power
supply. The Typical Application Circuit shows the
PWMOUT pin driving an n-channel MOSFET. In this
case, the PWM invert bit (D4 in register 02h) is set to
1. Figure 5 shows PWMOUT driving a p-channel
MOSFET and the PWM invert bit must be set to zero.
2) PWMOUT is converted (using an external circuit)
into a DC voltage that is proportional to duty cycle.
This duty-cycle-controlled voltage becomes the
power supply for the fan. This approach is less effi-
cient than 1), but can result in quieter fan operation.
Figure 6 shows an example of a circuit that con-
verts the PWM signal to a DC voltage. Because this
circuit produces a full-scale output voltage when
PWMOUT = 0V, bit D4 in register 02h should be set
to zero.
500kΩ
P
+3.3V
0.01µF
120kΩ
V
OUT
18kΩ
10kΩ
1µF
TO FAN
PWMOUT
1µF
27kΩ
+3.3V
Figure 6. Driving a Fan with a PWM-to-DC Circuit
3) PWMOUT directly drives the logic-level PWM
speed-control input on a fan that has this type of
input. This approach requires fewer external com-
ponents and combines the efficiency of 1) with the
low noise of 2). An example of PWMOUT driving a
fan with a speed-control input is shown in Figure 7.
Bit D4 in register 02h should be set to 1 when this
configuration is used.
V
CC
5V
4.7kΩ
PWMOUT
Whenever the fan has to start turning from a motionless
state, PWMOUT is forced high for 2s. After this spin-up
period, the PWMOUT duty cycle settles to the predeter-
mined value. If spin-up is disabled (bit 2 in the configu-
ration byte = 1), the duty cycle changes immediately
from zero to the nominal value, ignoring the duty-cycle
rate-of-change setting.
Figure 7. Controlling a PWM Input Fan with the MAX6641’s
PWM Output (Typically, the 35kHz PWM Frequency is Used)
±2 ______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
The frequency-select register controls the frequency of
the PWM signal. When the PWM signal modulates the
power supply of the fan, a low PWM frequency (usually
33Hz) should be used to ensure the circuitry of the
brushless DC motor has enough time to operate. When
DUTY CYCLE
driving a fan with a PWM-to-DC circuit, as in Figure 6,
the highest available frequency (35kHz) should be
used to minimize the size of the filter capacitors. When
using a fan with a PWM control input, the frequency
should normally be high as well, although some fans
have PWM inputs that accept low-frequency drive.
REGISTER 02H,
BIT D3 = 1
DUTY CYCLE
STEP SIZE
FAN START
DUTY CYCLE
TEMP
STEP
REGISTER 02H,
BIT D3 = 0
TEMPERATURE
The duty cycle of the PWM can be controlled in two ways:
FAN START
TEMPERATURE
1) Manual PWM control by setting the duty cycle of
the fan directly through the fan-target duty-cycle
register (09h).
Figure 8. Automatic PWM Duty Control
2) Automatic PWM control by setting the duty cycle
based on temperature.
FSDC = FanStartDutyCycle
T = Temperature
Manual PWM Duty-Cycle Control
Setting bits D5 and D4 to zero in the fan-configuration
register (0Dh) enables manual PWMOUT control. In this
mode, the duty cycle written to the fan-target duty-
cycle register controls the PWMOUT duty cycle. The
value is clipped to a maximum of 240, which corre-
sponds to a 100% duty cycle. Any value above that is
limited to the maximum duty cycle. In manual control
mode, the value of the maximum duty-cycle register is
ignored and does not affect the duty cycle.
FST = FanStartTemperature
DCSS = DutyCycleStepSize
TS = TempStep
Duty cycle is recalculated after each temperature con-
version if temperature is increasing. If the temperature
begins to decrease, the duty cycle is not recalculated
until the temperature drops by 5°C from the last peak
temperature. The duty cycle remains the same until the
temperature drops 5°C from the last peak temperature
or the temperature rises above the last peak tempera-
ture. For example, if temperature goes up to +85°C and
starts decreasing, duty cycle is not recalculated until
the temperature reaches +80°C or the temperature
rises above +85°C. If temperature decreases further,
the duty cycle is not updated until it reaches +75°C.
Automatic PWM Duty-Cycle Control
In the automatic control mode, the duty cycle is con-
trolled by the local or remote temperature, according to
the settings in the control registers. Below the value of
the fan-start temperature threshold (set by registers 03h
and 04h), the duty cycle is equal to the fan-start duty
cycle. Above the fan-start temperature, the duty cycle
increases by one duty-cycle step each time the tempera-
ture increases by one temperature step. Below the fan-
start temperature, the duty cycle is either 0% or it is
equal to the fan-start duty cycle, depending on the value
of bit D3 in the configuration byte register. See Figure 8.
For temperature < fan-start temperature and bit D3 of
the configuration byte register = 0:
DutyCycle = 0
For temperature < fan-start temperature and bit D3 of
the configuration byte register = 1:
The target duty cycle is calculated based on the follow-
ing formula:
Dutycycle = FanStartDutyCycle
Once the temperature crosses the fan-start tempera-
ture threshold, the temperature has to drop below the
fan-start temperature threshold minus the hysteresis
before the duty cycle returns to either 0% or fan-start
duty cycle. The value of the hysteresis is set by D7 of
the fan-configuration register.
For temperature > fan-start temperature:
DCSS
DC = FSDC + (T - FST)×
TS
where:
DC = DutyCycle
______________________________________________________________________________________ ±3
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
The duty cycle is limited to the value in the fan maxi-
mum duty-cycle register. If the duty-cycle value is larg-
er than the maximum fan duty cycle, it can be set to the
maximum fan duty cycle as in the fan maximum duty-
cycle register. The temp step is bit D6 of the fan-config-
uration register (0Dh).
Effect of Ideality Factor
The accuracy of the remote temperature measurements
depends on the ideality factor (n) of the remote diode
(actually a transistor). The MAX6641 is optimized for n =
®
1.008, which is the typical value for the Intel Pentium III
and the AMD Athlon™ MP model 6. If a sense transistor
with a different ideality factor is used, the output data is
different. Fortunately, the difference is predictable.
If duty cycle is an odd number, the MAX6641 automati-
cally rounds down to the nearest even number.
Assume a remote-diode sensor designed for a nominal
Duty-Cycle Rate-of-Change Control
To reduce the audibility of changes in fan speed, the
rate of change of the duty cycle is limited by the values
set in the duty-cycle rate-of-change register. Whenever
the target duty cycle is different from the instantaneous
duty cycle, the duty cycle increases or decreases at
the rate determined by the duty-cycle rate-of-change
byte until it reaches the target duty cycle. By setting the
rate of change to the appropriate value, the thermal
requirements of the system can be balanced against
good acoustic performance. Slower rates of change
are less noticeable to the user, while faster rates of
change can help minimize temperature variations.
Remember that the fan controller is part of a complex
control system. Because several of the parameters are
generally not known, some experimentation may be
necessary to arrive at the best settings.
ideality factor n
is used to measure the tem-
NOMINAL
perature of a diode with a different ideality factor, n .
1
The measured temperature T can be corrected using:
M
n
1
T
= T
ACTUAL
M
n
NOMINAL
where temperature is measured in Kelvin.
As mentioned above, the nominal ideality factor of the
MAX6641 is 1.008. As an example, assume the MAX6641
is configured with a CPU that has an ideality factor of
1.002. If the diode has no series resistance, the mea-
sured data is related to the real temperature as follows:
n
NOMINAL
1.008
1.002
T
= T
= T
= T 1.00599
(
)
ACTUAL
M
M
M
n
1
Power-Up Defaults
At power-up, the MAX6641 has the default settings
indicated in Table 1. Some of these settings are sum-
marized below:
For a real temperature of +85°C (358.15K), the mea-
sured temperature is +82.87°C (356.02K), which is an
error of -2.13°C.
• Temperature conversions are active.
• Remote OT limit = +110°C.
• Local OT limit = +80°C.
• Manual fan mode.
Effect of Series Resistance
Series resistance in a sense diode contributes addition-
al errors. For nominal diode currents of 10µA and
100µA, change in the measured voltage is:
∆V = R (100µA - 10µA) = 90µA x R
M
S
S
• Fan duty cycle = 0.
Since 1°C corresponds to 198.6µV, series resistance
contributes a temperature offset of:
• PWM Invert bit = 0.
• PWMOUT is high.
µV
Ω
90
When using an nMOS or npn transistor, the fan starts at
full speed on power-up.
°C
Ω
= 0.453
µV
C
198.6
Applications Information
Assume that the diode being measured has a series
resistance of 3Ω. The series resistance contributes an
offset of:
Remote-Diode Selection
The MAX6641 can directly measure the die tempera-
ture of CPUs and other ICs that have on-board temper-
ature-sensing diodes (see the Typical Application
Circuit), or they can measure the temperature of a dis-
crete diode-connected transistor.
°C
:
3Ω × 0.453
=+1.36°C
Ω
Pentium is a registered trademark of Intel Corp.
Athlon is a trademark of AMD.
±4 ______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
The effects of the ideality factor and series resistance
Table +. ꢀemote-Sensor Transistor
are additive. If the diode has an ideality factor of 1.002
Manufacturers
and series resistance of 3Ω, the total offset can be cal-
culated by adding error due to series resistance with
error due to ideality factor:
MANUFACTUꢀEꢀ
Central Semiconductor (USA)
Rohm Semiconductor (USA)
Samsung (Korea)
MODEL NO.
CMPT3906
SST3906
1.36°C - 2.13°C = -0.1477°C
for a diode temperature of +85°C.
KST3906-TF
SMBT3906
In this example, the effect of the series resistance and
the ideality factor partially cancel each other.
Siemens (Germany)
For best accuracy, the discrete transistor should be a
small-signal device with its collector connected to GND
and base connected to DXN. Table 6 lists examples of
discrete transistors that are appropriate for use with
the MAX6641.
2) Do not route the DXP-DXN lines next to the deflec-
tion coils of a CRT. Also, do not route the traces
across fast digital signals, which can easily intro-
duce 30°C error, even with good filtering.
3) Route the DXP and DXN traces in parallel and in
close proximity to each other, away from any higher
voltage traces, such as 12VDC. Leakage currents
from PC board contamination must be dealt with
carefully since a 20MΩ leakage path from DXP to
ground causes about 1°C error. If high-voltage traces
are unavoidable, connect guard traces to GND on
either side of the DXP-DXN traces (Figure 9).
The transistor must be a small-signal type with a rela-
tively high forward voltage; otherwise, the A/D input
voltage range can be violated. The forward voltage at
the highest expected temperature must be greater than
0.25V at 10µA, and at the lowest expected tempera-
ture, the forward voltage must be less than 0.95V at
100µA. Large power transistors must not be used. Also,
ensure that the base resistance is less than 100Ω. Tight
specifications for forward-current gain (50 < ß <150, for
example) indicate that the manufacturer has good
process controls and that the devices have consistent
VBE characteristics.
4) Route through as few vias and crossunders as pos-
sible to minimize copper/solder thermocouple
effects.
5) When introducing a thermocouple, make sure that
both the DXP and the DXN paths have matching
thermocouples. A copper-solder thermocouple
exhibits 3µV/°C, and takes about 200µV of voltage
error at DXP-DXN to cause a 1°C measurement
error. Adding a few thermocouples causes a negli-
gible error.
ADC Noise Filtering
The integrating ADC used has good noise rejection for
low-frequency signals such as 60Hz/120Hz power-sup-
ply hum. In noisy environments, high-frequency noise
reduction is needed for high-accuracy remote measure-
ments. The noise can be reduced with careful PC board
layout and proper external noise filtering.
6) Use wide traces. Narrow traces are more inductive
and tend to pick up radiated noise. The 10-mil
widths and spacing recommended in Figure 9 are
not absolutely necessary, as they offer only a minor
improvement in leakage and noise over narrow
traces. Use wider traces when practical.
High-frequency EMI is best filtered at DXP and DXN with
an external 2200pF capacitor. Larger capacitor values
can be used for added filtering, but do not exceed
3300pF because larger values can introduce errors due
to the rise time of the switched current source.
7) Add a 200Ω resistor in series with V
for best
CC
noise filtering (see the Typical Application Circuit).
PC Board Layout
Follow these guidelines to reduce the measurement
error of the temperature sensors:
8) Copper cannot be used as an EMI shield; only fer-
rous materials such as steel work well. Placing a
copper ground plane between the DXP-DXN traces
and traces carrying high-frequency noise signals
does not help reduce EMI.
1) Place the MAX6641 as close as is practical to the
remote diode. In noisy environments, such as a
computer motherboard, this distance can be 4in to
8in typically. This length can be increased if the
worst noise sources are avoided. Noise sources
include CRTs, clock generators, memory buses,
and ISA/PCI buses.
______________________________________________________________________________________ ±5
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Thermal Mass and Self-Heating
When sensing local temperature, these devices are
GND
intended to measure the temperature of the PC board
10 mils
to which they are soldered. The leads provide a good
10 mils
10 mils
DXP
thermal path between the PC board traces and the die.
Thermal conductivity between the die and the ambient
air is poor by comparison, making air temperature mea-
surements impractical. Because the thermal mass of
the PC board is far greater than that of the MAX6641,
the devices follow temperature changes on the PC
board with little or no perceivable delay. When measur-
ing the temperature of a CPU or other IC with an on-
chip sense junction, thermal mass has virtually no
effect. The measured temperature of the junction tracks
the actual temperature within a conversion cycle.
MINIMUM
10 mils
DXN
GND
Figure 9. Recommended DXP-DXN PC Traces
Twisted-Pair and Shielded Cables
Use a twisted-pair cable to connect the remote sensor
for remote-sensor distance longer than 8in or in very
noisy environments. Twisted-pair cable lengths can be
between 6ft and 12ft before noise introduces excessive
errors. For longer distances, the best solution is a shield-
ed twisted pair like that used for audio microphones. For
example, Belden 8451 works well for distances up to
100ft in a noisy environment. At the device, connect the
twisted pair to DXP and DXN and the shield to GND.
Leave the shield unconnected at the remote sensor.
When measuring temperature with discrete remote sen-
sors, smaller packages, such as µMAXes, yield the
best thermal response times. Take care to account for
thermal gradients between the heat source and the
sensor, and ensure stray air currents across the sensor
package do not interfere with measurement accuracy.
Self-heating does not significantly affect measurement
accuracy. Remote-sensor self-heating due to the diode
current source is negligible.
For very long cable runs, the cable’s parasitic capaci-
tance often provides noise filtering, so the 2200pF capac-
itor can often be removed or reduced in value. Cable
resistance also affects remote-sensor accuracy. For every
1Ω of series resistance, the error is approximately 0.5°C.
Chip Information
TRANSISTOR COUNT: 18,769
Typical Application Circuit
V
CC
(3.0V TO 5.5V)
V
FAN
(5V OR 12V)
PROCESS: BiCMOS
5V
0.1µF
10kΩ
PWMOUT
DXP
MAX6641
5V
2200pF
DXN
10kΩ
EACH
SMBCLK
SMBDATA
OT
µP
TO CLOCK
THROTTLE OR
SYSTEM
GND
SHUTDOWN
±+ ______________________________________________________________________________________
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
e
4X S
10
10
INCHES
DIM MIN
MAX
MILLIMETERS
MIN
-
MAX
1.10
0.15
0.95
3.05
3.00
3.05
3.00
5.05
0.70
A
-
0.043
0.006
0.037
0.120
0.118
0.120
0.118
0.199
A1
A2
D1
D2
E1
E2
H
0.002
0.030
0.116
0.114
0.116
0.114
0.187
0.05
0.75
2.95
2.89
2.95
2.89
4.75
0.40
H
Ø0.50 0.1
0.6 0.1
L
0.0157 0.0275
0.037 REF
L1
b
0.940 REF
0.007
0.0106
0.177
0.090
0.270
1
1
e
0.0197 BSC
0.500 BSC
0.6 0.1
c
0.0035 0.0078
0.0196 REF
0.200
BOTTOM VIEW
0.498 REF
S
TOP VIEW
α
0°
6°
0°
6°
D2
E2
GAGE PLANE
A2
c
A
E1
b
L
α
A1
D1
L1
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 10L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0061
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ ±7
© 2006 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products, Inc.
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