参数资料
型号: ADT7476AARQZ
厂商: ON Semiconductor
文件页数: 12/66页
文件大小: 945K
描述: IC REMOTE THERM CTRLR 5V 24QSOP
产品变化通告: MFG CHG Notification ADI to ON Semi
QSOP 24ld Pkg (MSL) Change 17/Jun/2010
Product Discontinuation 30/Sept/2011
标准包装: 56
系列: dBCool®
功能: 风扇控制,温度监控器
传感器类型: 内部和外部
感应温度: -40°C ~ 125°C
精确度: ±2.5%
拓扑: ADC,比较器,风扇速度计数器,多路复用器,寄存器库
输出类型: SMBus?
输出警报:
输出风扇:
电源电压: 3 V ~ 3.6 V
工作温度: -40°C ~ 125°C
安装类型: 表面贴装
封装/外壳: 24-SSOP(0.154",3.90mm 宽)
供应商设备封装: 24-QSOP
包装: 管件
产品目录页面: 1118 (CN2011-ZH PDF)
ADT7476A
http://onsemi.com
12
connected to a common SMBALERT
 line connected to the
master. If a devices SMBALERT
  line goes low, the
following procedure occurs:
1. SMBALERT
 is pulled low.
2. The master initiates a read operation and sends the
alert response address (ARA = 0001 100). This is
a general call address that must not be used as a
specific device address.
3. The device whose SMBALERT
 output is low
responds to the alert response address, and the
master reads its device address. The address of this
device is now known and can be interrogated per
usual.
4. If more than one devices SMBALERT
 output is
low, the one with the lowest device address has
priority in accordance with normal SMBus
arbitration.
5. Once the ADT7476A responds to the alert
response address, the master must read the status
registers, and SMBALERT
 is cleared only if the
error condition goes away.
SMBus Timeout
The ADT7476A includes an SMBus timeout feature. If
there is no SMBus activity for 35 ms, the ADT7476A
assumes the bus is locked and releases the bus. This prevents
the device from locking or holding the SMBus expecting
data. Some SMBus controllers cannot handle the SMBus
timeout feature, so if necessary, it can be disabled.
Table 6. CONFIGURATION REGISTER 1 (REG. 0x40)
Bit
Description
[6] TODIS
0: SMBus Timeout Enabled (Default)
1: SMBus Timeout Disabled
Virus Protection
To prevent rogue programs or viruses from accessing
critical ADT7476A register settings, the lock bit can be set.
Setting Bit 1 of Configuration Register 1 (0x40) sets the
lock bit and locks critical registers. In this mode, certain
registers can no longer be written to until the ADT7476A is
powered down and powered up again. For more information
on which registers are locked see Table 49.
Voltage Measurement Input
The ADT7476A has four external voltage measurement
channels. It can also measure its own supply voltage, V
CC
.
Pin 20 to Pin 23 can measure 5.0 V, 12 V, and 2.5 V
supplies, and the processor core voltage V
CCP
 (0 V to 3 V
input). The V
CC
 supply voltage measurement is carried out
through the V
CC
 pin (Pin 4). The 2.5 V input can be used to
monitor a chipset supply voltage in computer systems.
Analog-to-Digital Converter
All analog inputs are multiplexed into the on-chip,
successive-approximation,   analog-to-digital   converter,
which has a resolution of 10 bits. The basic input range is 0 V
to 2.25 V, but the inputs have built-in attenuators to allow
measurement of 2.5 V, 3.3 V, 5.0 V, 12 V, and the processor
core voltage V
CCP
 without any external components. To
allow the tolerance of these supply voltages, the ADC
produces an output of 3/4 full scale (768 dec or 300 hex) for
the nominal input voltage, giving it adequate headroom to
cope with overvoltages.
Input Circuitry
The internal structure for the analog inputs is shown in
Figure 24 The input circuit consists of an input protection
diode, an attenuator, plus a capacitor to form a first-order
low-pass filter that gives input immunity to high frequency
noise.
Figure 24. Structure of Analog Inputs
17.5 kW
52.5 kW
V
CCP
35 pF
45 kW
94 kW
+2.5V
IN
30 pF
68 kW
71 kW
V
CC
30 pF
93 kW
47 kW
+5V
IN
30 pF
183.6 kW
30 kW
+12V
IN
30 pF
MUX
Table 7. VOLTAGE MEASUREMENT REGISTERS
Register
Description
Default
0x20
2.5 V Reading
0x00
0x21
V
CCP
 Reading
0x00
0x22
V
CC
 Reading
0x00
0x23
5.0 V Reading
0x00
0x24
12 V Reading
0x00
Voltage Limit Registers
Associated with each voltage measurement channel is a
high and low limit register. Exceeding the programmed high
or low limit causes the appropriate status bit to be set.
Exceeding either limit can also generate SMBALERT
interrupts.
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ADT7476AARQZ-R 功能描述:板上安装温度传感器 MONITORS 5V/4 FANS RoHS:否 制造商:Omron Electronics 输出类型:Digital 配置: 准确性:+/- 1.5 C, +/- 3 C 温度阈值: 数字输出 - 总线接口:2-Wire, I2C, SMBus 电源电压-最大:5.5 V 电源电压-最小:4.5 V 最大工作温度:+ 50 C 最小工作温度:0 C 关闭: 安装风格: 封装 / 箱体: 设备功能:Temperature and Humidity Sensor
ADT7476AARQZ-REEL 功能描述:IC REMOTE THERMAL CTRLR 24-QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:dBCool® 标准包装:1 系列:- 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:-40°C ~ 125°C,外部传感器 精确度:±2.5°C 本地(最大值),±5°C 远程(最大值) 拓扑:ADC,比较器,寄存器库 输出类型:2 线 SMBus? 输出警报:无 输出风扇:无 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:SOT-23-8 供应商设备封装:SOT-23-8 包装:Digi-Reel® 其它名称:296-22675-6
ADT7476AARQZ-REEL7 功能描述:IC REMOTE THERMAL CTRLR 24-QSOP RoHS:是 类别:集成电路 (IC) >> PMIC - 热管理 系列:dBCool® 标准包装:1 系列:- 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:-40°C ~ 125°C,外部传感器 精确度:±2.5°C 本地(最大值),±5°C 远程(最大值) 拓扑:ADC,比较器,寄存器库 输出类型:2 线 SMBus? 输出警报:无 输出风扇:无 电源电压:2.7 V ~ 5.5 V 工作温度:-40°C ~ 125°C 安装类型:表面贴装 封装/外壳:SOT-23-8 供应商设备封装:SOT-23-8 包装:Digi-Reel® 其它名称:296-22675-6
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