FINTEK F75385M

F75385M
±1oC Accuracy Temperature Sensor IC Datasheet
Release Date: July, 2006
Revision: V0.21P
F75385
F75385 Datasheet Revision History
Version
Date
Page
0.20P
March, 2006
-
0.21P
July, 2006
10
Revision History
Original Release Version
Modify VT1/VT2 High Limit and VT1 THERM Limit Default Value.
Original (64h) Æ New (55h)
Please note that all data and specifications are subject to change without notice. All the trade marks of products and
companies mentioned in this data sheet belong to their respective owners.
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Fintek for any damages resulting from
such improper use or sales.
F75385
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July, 2006
F75385
Table of Contents
General Description................................................................................................................. 1
Features .................................................................................................................................. 1
Key Specifications ................................................................................................................... 2
Pin Configuration..................................................................................................................... 2
Pin Descriptions ...................................................................................................................... 2
Functional Description............................................................................................................. 3
6.1 General Description.......................................................................................................... 3
6.2 The warning message ...................................................................................................... 3
6.3 Access Interface............................................................................................................... 3
6.4 Temperature Monitoring ..................................................................................................... 4
6.5 Alert#................................................................................................................................ 5
6.5 THERM# ............................................................................................................................ 5
6.6 ADC Conversion Sequence ............................................................................................... 6
6.7 Thermal Mass and Self Heating......................................................................................... 6
6.8 ADC Noise Filtering ........................................................................................................... 6
6.9 PCB Layout Guide ............................................................................................................. 6
7. Registers Description .............................................................................................................. 8
1.
2.
3.
4.
5.
6.
7.1 Configuration Register  Index 03h(Read), 09h(Write)................................................... 8
7.2 Status Register  Index 02h .............................................................................................. 8
7.3 Conversion Rate Register  Index 04h(Read), 0Ah(Write)................................................ 8
7.4 One-Shot Register  Index 0Fh......................................................................................... 9
7.5 Alert Queue & Timeout Register  Index 22h .................................................................... 9
7.6 Status-with-ARA Control Register  Index 24h ............................................................... 9
7.7 Chip ID I Register  Index 5Ah........................................................................................ 10
7.8 Chip ID II Register  Index 5Bh....................................................................................... 10
7.9 Vendor ID I (Manufacturer ID) Register  Index 5Dh....................................................... 10
7.10 Vendor ID I (Manufacturer ID) Register  Index 5Eh ..................................................... 10
7.11 Vendor ID II (Manufacturer ID) Register  Index FEh .................................................... 10
7.12 Value RAM  Index 10h- 2Fh ........................................................................................ 10
8. Electrical characteristic.......................................................................................................... 12
8.1 Absolute Maximum Ratings .............................................................................................. 12
8.2 DC Characteristics ............................................................................................................ 12
8.3 AC Characteristics ............................................................................................................ 13
9. Ordering Information ............................................................................................................. 13
10. Package Dimensions (8 MSOP)............................................................................................ 14
F75385
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July, 2006
1.
General Description
The F75385 is a temperature sensor IC with alert signal which is specific designed for notebook, graphic
cards etc. An 11-bit analog-to-digital converter (ADC) was built inside F75385. The F75385 can monitor two set
of temperature which is very important for the system to work stably and properly. This chip provides 1 remote
temperature sensor and 1 local temperature sensor. The remote temperature sensor can be performed by
CPU thermal diode or transistor 2N3906. The users can set up the upper and lower limits (alarm thresholds) of
all monitored parameters and this chip can also issue warning messages for system protection when there is
something wrong with monitored items.
Through the BIOS or application software, the users can read all the monitored parameters of system all
the time. And a pop-up warning can be also activated when the monitored item was out of the
proper/pre-setting range. The application software could be Fintek's application utility, or other management
application software. The F75385 is in the package of 8-pin MSOP and powered by 3.3V.
2.
Features
‹
Provide 1 on-chip local and 1 remote temperature sensing
‹
±1 oC accuarcy on remote channel and ±3 oC accuarcy on local channel
„
±1 oC (+60 oC to +100 oC, remote)
„
±3 oC (+60 oC to +100 oC, local)
‹
ALERT# output for SMBus alert
‹
THERM# output for over temperature alert or for system shut down
‹
Programmable THERM# limits and THERM# hysteresis
‹
Programmable alert queue
‹
Programmable limited and setting points(alert threshold) for all monitored items
‹
2 wire SMBus interface
‹
3VCC operation and in 8-MSOP package
‹
The SMBus slave address:
F75385
A6
A5
A4
A3
A2
A1
A0
1
0
0
1
1
0
0
--Patented: TW 235231--
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3.
Key Specifications
4.
‹
Supply Voltage
3.0~3.6V
‹
Supply Current
180 uA (typ)
‹
Measured Range
0 ~ 145 oC
‹
Remote Diode Temperature Accuracy
±1oC from +60oC to +100oC
‹
Local Temperature Accuracy
±3oC from +60oC to +100oC
Pin Configuration
5.
VCC
1
D+
2
D-
3
THERM#
4
F75382
F75385M
8
SCL
7
SDA
6
ALERT#
5
GND
Pin Descriptions
OD12
- Open-drain output pin with 12 mA sink capability
PWR
- Power pin
INts
- TTL level input pin and schmitt trigger
AIN
- Input pin(Analog)
PIN NO
PIN NAME
TYPE
PWR
DESCRIPTION
PWR
3VCC
Power Pin
1
VCC
2
D+
AIN
3VCC
Positive connection to remote temperature sensor (ex: thermal diode anode)
3
D-
AIN
3VCC
Negative connection to remote temperature sensor(ex: thermal diode
cathode)
4
THERM#
OD12
3VCC
Active LOW output. This pin will be logic low when the temperature exceeds
o
its limit. (Default 108 C enable)
5
GND
PWR
3VCC
Ground
6
ALERT#
OD12
3VCC
Active LOW output. Used as SMBus alert or Interrupt
7
SDA
INts/OD12
3VCC
Serial bus data
8
SCL
INt s
3VCC
Serial bus clock
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6. Functional Description
6.1
General Description
The F75385 is a simple temperature sensor with warning signal output. It includes a local and a remote
temperature sensor. Both measured temperature are compared with its high, low and THERM limits which are stored
in the registers. When one or more out-of-limit events occur, the flags in Status Register will be set and that may
cause ALERT output to low. Also, measured temperature exceeding THERM limit may cause THERM output to low.
6.2
The warning message
Pin4 and pin6 act as warning message when the temperature exceeds it threshold point.
6.3
Access Interface
The F75385 can be connected to a compatible 2-wire serial system management bus as a slave device under the
control of the master device, using two device terminals SCL and SDA. The F75385 supports SMBus protocol of,
“Write Byte”, “Read Byte”, both with or without Packet Error checking(PEC) which is calculated using CRC-8. For
detail information about PEC, please check SMBus 1.1 specification. F75385 supports 25ms timeout for no activity on
the SMBus. This timeout function is programmed at 22h bit7 and default is disabled. F75385 also supports Alert
Response Address (ARA) protocol.
The operation of the protocol is described with details in the following sections.
(a) SMBus write to internal address register followed by the data byte
0
7
8
0
7
8
SCL
SDA
1
Start By
Master
0
0
1
1
0
0
R/W
D7
Ack
by
382
Frame 1
Serial Bus Address Byte
D6
D5
D4
D3
D2
D1
D0
Ack
by
382
Frame 2
Internal Index Register Byte
0
7
8
SCL (Continued)
SDA (Continued)
D7
D6
D5
D4
D3
D2
D1
D0
Stop
by
Master
Frame 3
Data Byte
Figure 1. Serial Bus Write to Internal Address Register followed by the Data Byte
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(b) Serial bus write to internal address register only
0
7
8
0
7
8
SCL
SDA
1
0
0
Start By
Master
1
1
0
0
R/W
D7
D6
Ack
by
382
Frame 1
Serial Bus Address Byte
D5
D4
D3
D2
D1
D0
Ack
by
382
Frame 2
Internal Index Register Byte
Stop by
Master
0
Figure 2. Serial Bus Write to Internal Address Register Only
(c) Serial bus read from a register with the internal address register prefer to desired location
0
7
8
0
7
8
SCL
1
SDA
0
Start By
Master
0
1
1
0
0
R/W
D7
D6
Ack
by
382
Frame 1
Serial Bus Address Byte
D5
D4
D3
D2
D1
D0
Ack
by
Master
Frame 2
Internal Index Register Byte
Stop by
Master
0
Figure 3. Serial Bus Read from Internal Address Register
(d) Alert Response Address
0
7
8
0
7
8
SCL
0
SDA
Start By
Master
0
0
1
1
0
0
R/W
0
1
0
Ack
by
382
Frame 1
Alert Response Address
0
1
Frame 2
Device Address
1
0
0
Ack
by
Master
Stop by
Master
0
Figure 4. Alert Response Address
6.4 Temperature Monitoring
The F75385 monitors a local and a remote temperature sensor. Both can be measured from 0°C to 145°C.
The temperature format is as the following table:
Temperature ( High Byte )
Digital Output
Temperature ( Low Byte )
Digital Output
0°C
0000 0000
0°C
000 0 0000
1°C
0000 0001
0.125°C
001 0 0000
25°C
0001 1001
0.250°C
010 0 0000
50°C
0011 0010
0.375°C
011 0 0000
75°C
0100 1011
0.500°C
100 0 0000
90°C
0101 1010
0.625°C
101 0 0000
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100°C
0110 0100
0.750°C
110 0 0000
145°C
1001 0001
0.875°C
111 0 0000
Remote-sensor transistor manufacturers
Manufacturer
Model Number
Panasonic
2SB0709 2N3906
Philips
PMBT3906
6.5 Alert#
Five events can trigger ALERT# to low:
(1). VT1(Local) temperature exceeds High Limit
(2). VT1(Local) temperature goes below Low Limit
(3). VT2(Remote) temperature exceeds High Limit
(4). VT2(Remote) temperature goes below Low Limit
(5). VT2(Remote) temperature is Open-circuit.
These five events are wired-NOR together. This means that when one of out-of-limit event occurs, the ALERT#
output goes low if the MASK control is disabled. ALERT# signal can be used as an IRQ-like interrupt or as an
SMBALERT. When ALERT# acts as an IRQ-like interrupt, the ALERT# will be de-asserted until the following 2
conditions are matched:
(1). The abnormal condition is gone
(2). Reading the Status register to clear the status
When ALERT# acts as a SMBALERT, the ALERT# will be de-asserted until the following 3 conditions are
matched:
(1). The abnormal condition is gone
(2). Reading the Status register to clear the status
(3). The ALERT# has been serviced by the SMBus master reading the device address.
For more information about SMBALERT, please see SMBus 1.1 specification.
6.6 THERM#
Either VT1(Local) or VT2(Remote) temperature exceeds the corresponding THERM limit, the THERM# output
will assert low. The asserted output will be de-asserted until the temperature goes below (THERM Limit – Hysteresis).
The hysteresis default value is 10°C and it can be programmed. Both VT1 and VT2 have their own THERM limits and
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Hysteresis values.
6.7 ADC Conversion Sequence
If a START command is written, both channels are converted and the results of both measurements are available
after the end of conversion. A BUSY status bit in the status byte shows that the device is actually performing a new
conversion; however, even if the ADC is busy, the results of the previous conversion are always available.
6.8 Thermal Mass and Self Heating
Thermal mass effect can seriously degrade effective accuracy of the F75385. The thermal time constant of the
SOP package is about 140 in still air. For the F75385 junction temperature to settle to within +1°C after a sudden
+100°C change requires about five time constants or 12 minutes. The use of smaller packages for remote sensors
such as SOT23, improves the situation. Take care to account for thermal gradients between the heat source and the
sensor package do not interfere with measurement accuracy. Sel-heating does not significantly affect measurement
accuracy. Remote sensor self-heating due to the diode current source is negligible. For the local diode, the worst case
error occurs when auto-converting at the fastest rate and simultaneously sinking maximum current at the ALERT#
output. For instance, at an 64Hz rate and ALERT# sink around 0.7mA when pull up resistor 4.7K ohm to 3.3VCC, the
typical power dissipation is VCC x 220 uA plus 0.4V x 0.7mA. Package θJA is about 120 °C/W, so with VCC = 3.3V
and no copper PC board heat-sinking, the resulting temperature rise is:
dT =
1.01mW x 120 °C/W = 0.12 °C
Even with these contrived circumstances, it is difficult to introduce significant self-heating errors.
6.9 ADC Noise Filtering
The ADC is integrating type with inherently good noise rejection. Micro-power operation places constraints on
high-frequency noise rejection; therefore, careful PCB board layout and suitable external filtering are required for
high-accuracy remote measurement in electronically noisy environment. High frequency EMI is best filtered at D+ and
D- with an external 2200pF capacitor. Too high capacitance may introduce errors due to the rise time of the switched
current source. Nearly all noise sources tested cause the ADC measurement to be higher than the actual temperature,
depending on the frequency and amplitude.
6.10 PCB Layout Guide
PCB can be electrically noisy environments, and the F75385 is measuring very small voltage from the remote
sensor, so care must be taken to minimize noise which is occurred at the sensor inputs. The following guideline
should be taken to reduce the measurement error of the temperature sensors:
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1.
Place the F75385 as close as practical to the remote sensing diode. In noisy environments, such as a computer
main-board, the distance can be 4 to 8 inches. (typ). This length can be increased if the worst noise sources are
avoided. Noise sources generally include clock generators, power control circuit, CRTs, memory buses and
PCI/ISA bus etc.
2.
Route the D+ and D- tracks close together, in parallel, with grounded guard tracks on each side. Provide a ground
plane under the tracks if possible. Do not route D+ & D- lines next to the deflection coil of the CRT. And also don’t
route the trace across fast digital signals which can easily induce bigger error.
GND
10MILS
DXP
10MILS
DXN
10MILS
MINIMUM
10MILS
GND
3.
Use wide tracks to minimize inductance and reduce noise pickup. 10 mil track minimum width and spacing is
recommended.
4.
Try to minimize the number of copper/solder joints, which can cause thermocouple effects. Where copper/solder
joints are used, make sure that they are in both the D+ and D- path and at the same temperature. Thermocouple
effects should not be a major problem as 1℃ corresponds to about 200µV. It means that a copper-solder
thermocouple exhibits 3µV/℃, and takes about 200µV of the voltage error at D+ & D- to cause a 1℃
measurement error. Adding a few thermocouples causes a negligible error.
5.
Place a 0.1µF bypass capacitor close to the VDD pin. In very noisy environments, place an external 2200pF input
filter capacitors across D+, D- close to the F75385.
6.
If the distance to the remote sensor is more than 8 inches, the use of twisted pair cable is recommended. It will
work up to around 6 to 12 feet.
7.
Because the measurement technique uses switched current sources, excessive cable and/or filter capacitance
will affect the measurement accuracy. When using long cables, the filter capacitor may be reduced or removed.
Cable resistance can also induce errors. 1 Ω series resistance introduces about 0.5℃ error.
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7.
Registers Description
7.1 Configuration Register  Index 03h(Read),
09h(Write)
Power on default <7:0> = 00h
Bit
Name
Attribute
Description
7
ALERT_MASK
R/W
Set to 1, mask ALERT# signal output.
6
RUN_STOP
R/W
Set to 0, monitor.
5-0
Reserved
Set to 1, stop to monitor(software power down).
7.2 Status Register  Index 02h
Power on default <7:0> = 00h
Bit
Name
Attribute
Description
7
ADC_BUSY
RO
Set to 1, ADC is converting.
6
VT1HIGH
RO
Set to 1, VT1 temperature exceeds high limit.
Set to 0, VT1 temperature does not exceed high limit.
5
VT1LOW
RO
Set to 1, VT1 temperature goes below low limit.
Set to 0, VT1 temperature does not goes below low limit.
4
VT2HIGH
RO
Set to 1, VT2 temperature exceeds high limit.
Set to 0, VT2 temperature does not exceed high limit.
3
VT2LOW
RO
Set to 1, VT2 temperature goes below low limit.
Set to 0, VT2 temperature does not goes below low limit.
2
OPEN
RO
Set to 1, VT2 is open-circuit.
1
VT2THERM
RO
Set to 1, VT2 temperature exceeds its THERM limit.
0
VT1THERM
RO
Set to 1, VT1 temperature exceeds its THERM limit.
VT1(Local) ; VT2(Remote)
7.3 Conversion Rate Register  Index 04h(Read), 0Ah(Write)
Power on default <7:0> = 08h
Bit
Name
Attribute
7-0
CONV_RATE
R/W
Description
Set conversion times per second.
Value
Conversion/Sec
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Value
Conversion/Sec
July 2006
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00h
0.0625
06h
4
01h
0.125
07h
8
02h
0.25
08h
16
03h
0.5
09h
32
04h
1
0Ah
64
05h
2
0Bh ~ FFh
Reserved
7.4 One-Shot Register  Index 0Fh
Power on default <7:0> = xxh
Bit
7-0
Name
ONE-SHOT
Attribute
Description
WO
When F75385 is at standby mode, writing any value to this register will
initiate a single conversion and comparison cycle. After the single cycle,
F75385 will returns to standby mode.
7.5 Alert Queue & Timeout Register  Index 22h
Power on default <7:0> = 01h
Bit
Name
Attribute
7
EN_I2CTMOUT
R/W
Description
Set to 1, enable serial interface timeout function. (Timeout time = 25ms)
Set to 0, disable.
6-4
Reserved
3-1
ALERT_QUEUE
R/W
This number determines how many abnormal measurements must occur before
ALERT signal is generated.
000 : Once
001 : Twice
011 : 3 times
111 : 4 times
0
Reserved
RO
Always read 1.
7.6 Status-with-ARA Control Register  Index 24h
Power on default <7:0> = 01h
Bit
Name
7-6
Reserved
Attribute
Description
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0
EN_ARA_STS
R/W
Set to 1, ALERT de-asserted condition is related with ARA.
Set to 0, ALERT de-asserted condition is not related with ARA(Alert Response
Address).
7.7 Chip ID I Register  Index 5Ah
Power on default: 03h.
7.8 Chip ID II Register  Index 5Bh
Power on default: 03h.
7.9 Vendor ID I (Manufacturer ID) Register  Index 5Dh
Power on default: 19h.
7.10 Vendor ID I (Manufacturer ID) Register  Index 5Eh
Power on default: 34h.
7.11 Vendor ID II (Manufacturer ID) Register  Index FEh
Power on default: 23h. (programmable)
7.12 Value RAM  Index 10h- 2Fh
VT1 : Local Temperature
VT2 : Remote Temperature
The value in quota is its power-on default value.
Description
Attribute
Read Address
Read Address
Write Address
Write Address
(High Byte)
(Low Byte)
(High Byte)
(Low Byte)
VT1 reading
RO
00h
1Ah
VT2 reading
RO
01h
10h
VT1 High Limit
R/W
05h (55h)
1Bh (00h)
0Bh
1Bh
VT1 Low Limit
R/W
06h (00h)
1Ch (00h)
0Ch
1Ch
VT2 High Limit
R/W
07h (55h)
13h (00h)
0Dh
13h
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VT2 Low Limit
R/W
08h (00h)
14h (00h)
VT1 THERM Limit
R/W
20h (55h)
20h
VT1 THERM Hysteresis
R/W
21h (0Ah)
21h
VT2 THERM Limit
R/W
19h (6Ch)
19h
VT2 THERM Hysteresis
R/W
23h (0Ah)
23h
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0Eh
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8. Electrical characteristic
8.1 Absolute Maximum Ratings
PARAMETER
RATING
UNIT
-0.5 to 3.3
V
-0.5 to VDD+0.5
V
Operating Temperature
0 to +140
°C
Storage Temperature
-55 to 150
°C
Power Supply Voltage
Input Voltage
Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability of
the device
8.2 DC Characteristics
(TA = 0° C to 70° C, VDD = 3.3V ± 10%, VSS = 0V )
Parameter
Temperature Error, Remote Diode
Conditions
o
MIN
TYP
o
±1
60 C < TD < 100 C, VCC = 3.0V to 3.6V
o
o
o
o
0 C < TA < 100 C, VCC = 3.0V to 3.6V
Supply Voltage range
Average operating supply current
3.0
16 Conversions / Sec Rate
0.0625 Conversions / Sec Rate
Standby supply current
±3
3.3
3.6
o
C
VDD input, Disables ADC , Rising Edge
o
C
V
180
uA
90
uA
uA
o
0.125
C
2.55
Power on reset threshold
Diode source current
±1
10
Resolution
Under-voltage lockout threshold
Unit
±3
0 C <TD < 60 C
Temperature Error, Local Diode
MAX
2.2
V
2.4
V
High Level
95
uA
Low Level
10
uA
(TA = 0° C to 70° C, VDD = 3.3V ± 10%, VSS = 0V)
PARAMETER
SYM.
MIN.
TYP.
MAX.
UNIT
CONDITIONS
mA
VOL = 0.4V
OD12 - Open-drain output pin with sink capability of 16 mA
Output Low Current
INts
-
IOL
9
12
TTL level Schmitt-triggered input pin
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Input Low Threshold Voltage
Vt-
0.5
0.8
1.1
V
VDD = 3.3V
Input High Threshold Voltage
Vt+
1.6
2.0
2.4
V
VDD = 3.3V
Input High Leakage
ILIH
+1
µA
VIN = VDD
Input Low Leakage
ILIL
µA
VIN = 0 V
-1
8.3 AC Characteristics
t SCL
tR
tR
SCL
t HD;SDA
t SU;STO
t SU;DAT
SDA IN
VALID DATA
t HD;DAT
SDA OUT
Serial Bus Timing Diagram
Serial Bus Timing
PARAMETER
SYMBOL
MIN.
t-SCL
10
uS
Start condition hold time
tHD;SDA
4.7
uS
Stop condition setup-up time
tSU;STO
4.7
uS
DATA to SCL setup time
tSU;DAT
120
nS
DATA to SCL hold time
tHD;DAT
5
nS
SCL and SDA rise time
tR
1.0
uS
SCL and SDA fall time
tF
300
nS
SCL clock period
MAX.
UNIT
9. Ordering Information
Part Number
Package Type
Production Flow
F75385M
8 pin MSOP (Green Package)
Commercial, 0°C to +70°C
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10. Package Dimensions (8 MSOP)
Feature Integration Technology Inc.
Headquaters
Taipei Office
7F, No 31, Shintai Rd.,
Bldg. K4, 7F, No.700, Jungjeng Rd., Junghe
Jubei City, Hsinchu 302, Taiwan, R.O.C.
City, Taipei, Taiwan 235, R.O.C.
TEL : 886-3-6562727
TEL : 886-2-8227-8027
FAX : 886-3-6560537
FAX : 886-2-8227-8037
www: http://www.fintek.com.tw
Please note that all datasheet and specifications are subject to change without notice. All the trade
marks of products and companies mentioned in this datasheet belong to their respective owner
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July 2006
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