- 您现在的位置：买卖IC网 > Sheet目录1194 > ADT7490ZEVB (ON Semiconductor)BOARD EVALUATION FOR ADT7490
ADT7490
PWM MIN
PECI MIN
Theory of Operation
The ADT7490 is a complete thermal monitor and multiple
fan controller for any system requiring thermal monitoring
and cooling. The device communicates with the system via
a serial system management bus. The serial bus controller
has a serial data line for reading and writing addresses and
data (Pin 1), and an input line for the serial clock (Pin 2). All
control and programming functions for the ADT7490 are
performed over the serial bus. In addition, Pin 14 can be
reconfigured as an SMBALERT output to signal
out-of-limit conditions.
Feature Comparisons Between the ADT7490 and
ADT7476A
The ADT7490 is pin and register map compatible with the
ADT7476A. The new or additional features are detailed in
the following sections.
PECI Input
CPU thermal information is provided through the PECI
input. The ADT7490 has PECI master capabilities and can
read the CPU thermal information through the PECI
interface. Each CPU address can have up to two PECI
domains. The ADT7490 has the ability to record four PECI
temperature readings corresponding to the four PECI
addresses of 0x30 to 0x33. The hotter of the two domains at
any given address is stored in the PECI value registers. A
PECI reading is a negative value, in degrees Celsius, which
represents the offset from the thermal control circuit (T CC )
activation temperature. PECI information is not converted
to absolute temperature reading. PECI information is in a
16-bit twos complement value; however, the ADT7490
records the sign bit as well as the bits from 12:6 in the 16-bit
PECI payload. See the Platform Environment Control
Interface (PECI) Specification from Intel ? for more details
on the PECI data format. The PECI format is represented in
Table 6.
Table 6. PECI DATA FORMAT
MSB Upper Nibble MSB Lower Nibble
S x x x x x x x
Sign Bit Integer Value (0 ? C to 127 ? C)
There are associated high and low limits for each PECI
reading that can be programmed. The limit values take the
same format as the PECI reading. Therefore, the
programmed limits are not absolute temperatures but a
relative offset in degrees Celsius from the T CC activation
temperature. An out-of-limit event is recorded as follows:
High Limit > Comparison Performed
Low Limit ? Comparison Performed
An out-of-limit event is recorded in the associated status
register and can be used to assert the SMBALERT pin.
Temperature Data REPLACE Mode
The REPLACE mode is configured by setting Bit 4 of
Register 0x36. In this mode, the data in the existing
Remote 1 registers are replaced by PECI0 data and vice
versa. This is a legacy mode that allows the thermal data
from CPU1 to be stored in the same registers as in the
ADT7476A. This reduces the software changes in systems
transitioning from CPUs with thermal diodes to CPUs with
a PECI interface. See the PECI Temperature Measurement
section for more details.
Fan Control Using PECI Information
The CPU thermal information from PECI can be used in the
existing automatic fan control algorithms. This temperature
reading remains relative to T CC activation temperature and
the associated AFC control parameters are programmed in
relative temperatures as opposed to absolute temperatures,
and are in the same format as detailed in Table 6. PECI MIN ,
T RANGE , and T CONTROL are user defined.
PWM = 100%
PWM MAX
PECI = 0
T RANGE
PWM = 0%
T CONTROL
(T MIN ) (T MAX ) T CC
Figure 17. Overview of Automatic Fan Speed Control
Using PECI Thermal Information
Dynamic T MIN Fan Control Mode
The automatic fan speed control incorporates a feature
called dynamic T MIN control. This intelligent fan control
feature reduces the design effort required to program the
automatic fan speed control loop and improves the system
acoustics.
V TT Input
The V TT voltage is monitored on Pin 8. This voltage is
also used as the reference voltage for the PECI interface. The
V TT voltage must be connected to the ADT7490 in order for
the PECI interface to be operational.
I MON Monitoring
The I MON input on Pin 19 can be used to monitor the I MON
output of ON Semiconductor’s VR10/VR11.1 controllers.
I MON is a voltage representation of the CPU current. Using
http://onsemi.com
10
发布紧急采购，3分钟左右您将得到回复。
相关PDF资料
ADZS-21262-1-EZEXT
BOARD DAUGHTER FOR ADSP-21262
ADZS-BF-EZEXT-1
BOARD DAUGHTER ADSP-BF533/561KIT
ADZS-BFAV-EZEXT
BOARD DAUGHT ADSP-BF533,37,61KIT
ADZS-BFSHUSB-EZEXT
BOARD DAUGHTER EZ EXTENDER
ADZS-BRKOUT-EX3
ADZS-BRKOUT-EX3
ADZS-SHAUDIO-EZEXT
SHARC AUDIO EZ-EXTENDER
ADZS-WVGALCD-EX3
BOARD EXTENDER WVGA/LCD EI3
AGA-3
FUSE 3A 125VAC 1AG FAST
相关代理商/技术参数
ADT75
制造商:AD 制造商全称:Analog Devices 功能描述:+-1∑C Accurate, 12-Bit Digital Temperature Sensor
ADT7516
制造商:AD 制造商全称:Analog Devices 功能描述:SPI/I2C Compatible, Temperature Sensor, Four Channel ADC and Quad Voltage Output DAC
ADT7516_06
制造商:AD 制造商全称:Analog Devices 功能描述:SPI-/I2C-Compatible, Temperature Sensor,4-Channel ADC and Quad Voltage Output
ADT7516ARQ
功能描述:IC TEMP SNSR QUAD DAC 16-QSOP RoHS:否 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:2,500 系列:SilentSense™ 功能:温度监控系统（传感器） 传感器类型:内部和外部 感应温度:-55°C ~ 125°C，外部传感器 精确度:±2°C 本地（最大），±3°C 远程（最大） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:I²C?/SMBus? 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:8-TSSOP，8-MSOP（0.118"，3.00mm 宽） 供应商设备封装:8-MSOP 包装:带卷 (TR) 其它名称:MIC284-2BMMTRMIC284-2BMMTR-ND
ADT7516ARQ-REEL
制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R 制造商:Analog Devices 功能描述:TEMP SENSOR DGTL SERL (4-WIRE, SPI) 16QSOP - Tape and Reel
ADT7516ARQ-REEL7
制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R 制造商:Analog Devices 功能描述:TEMP SENSOR DGTL SERL (4-WIRE, SPI) 16QSOP - Tape and Reel
ADT7516ARQZ
功能描述:IC TEMP SNSR QUAD DAC 16-QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:- 标准包装:3,000 系列:- 功能:温度开关 传感器类型:内部 感应温度:85°C 分界点 精确度:±6°C（最小值） 拓扑:ADC（三角积分型），比较器，寄存器库 输出类型:开路漏极 输出警报:是 输出风扇:是 电源电压:2.7 V ~ 5.5 V 工作温度:-55°C ~ 125°C 安装类型:表面贴装 封装/外壳:SC-74A，SOT-753 供应商设备封装:SOT-23-5 包装:带卷 (TR) 其它名称:ADT6501SRJZP085RL7-ND
ADT7516ARQZ-REEL
制造商:Analog Devices 功能描述:Temp Sensor Digital Serial (4-Wire, SPI, I2C) 16-Pin QSOP T/R