- 您现在的位置：买卖IC网 > PDF目录67802 > MAX6698UE38+T (MAXIM INTEGRATED PRODUCTS INC) 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor PDF资料下载
参数资料
| 型号： | MAX6698UE38+T |
| 厂商： | MAXIM INTEGRATED PRODUCTS INC |
| 元件分类： | 温度/湿度传感器 |
| 英文描述： | 7-Channel Precision Remote-Diode, Thermistor, and Local Temperature Monitor |
| 中文描述： | DIGITAL TEMP SENSOR-SERIAL |
| 封装： | 4.40 MM, PLASTIC, MO-153AB, TSSOP-16 |
| 文件页数： | 8/27页 |
| 文件大小： | 489K |
| 代理商： | MAX6698UE38+T |
第1页第2页第3页第4页第5页第6页第7页当前第8页第9页第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页
MAX6698
7-Channel Precision Remote-Diode, Thermistor,
and Local Temperature Monitor
16
______________________________________________________________________________________
VREF supplies a reference voltage (1V nominal) to bias
the thermistor/REXT_ voltage-divider. The voltage
across REXT is measured by the MAX6698’s ADC,
resulting in a voltage that is directly proportional to tem-
perature. The data in the thermistor registers gives the
voltage across REXT as a fraction of the reference volt-
age (1LSB = 0.5% of VREF).
Because thermistors have nonlinear temperature-resis-
tance functions, and because different thermistors have
different functions, it is important to understand the
relationship between temperature, REXT, and the volt-
age across REXT for a given thermistor. Table 13
shows temperature vs. the thermistor channel data for a
Betatherm 10k3A1 thermistor and REXT=1600.
Thermal Mass and Self-Heating
When sensing local temperature, the MAX6698 mea-
sures the temperature of the PC board to which it is sol-
dered. The leads provide a good thermal path between
the PC board traces and the die. As with all IC temper-
ature sensors, thermal conductivity between the die
and the ambient air is poor by comparison, making air
temperature measurements impractical. Because the
thermal mass of the PC board is far greater than that of
the MAX6698, the device follows temperature changes
on the PC board with little or no perceivable delay.
When measuring the temperature of a CPU or other IC
with an on-chip sense junction, thermal mass has virtu-
ally no effect; the measured temperature of the junction
tracks the actual temperature within a conversion cycle.
When measuring temperature with discrete remote tran-
sistors, the best thermal response times are obtained
with transistors in small packages (i.e., SOT23 or
SC70). Take care to account for thermal gradients
between the heat source and the sensor, and ensure
that 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.
ADC Noise Filtering
The integrating ADC has good noise rejection for low-
frequency signals such as power-supply hum. In envi-
ronments with significant high-frequency EMI, connect
an external 2200pF capacitor between DXP_ and
DXN_. Larger capacitor values can be used for added
filtering, but do not exceed 3300pF because it can
introduce errors due to the rise time of the switched
current source. High-frequency noise reduction is
needed for high-accuracy remote measurements.
Noise can be reduced with careful PC board layout as
discussed in the PC Board Layout section.
PC Board Layout
Follow these guidelines to reduce the measurement
error when measuring remote temperature:
1) Place the MAX6698 as close as is practical to the
remote diode. In noisy environments, such as a
computer motherboard, this distance can be 4in to
8in (typ). This length can be increased if the worst
noise sources are avoided. Noise sources include
CRTs, clock generators, memory buses, and PCI
buses.
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. Each parallel pair of
traces should go to a remote diode. Route these
traces away from any higher voltage traces, such as
+12VDC. Leakage currents from PC board contami-
nation must be dealt with carefully since a 20M
leakage path from DXP to ground causes about
+1°C error. If high-voltage traces are unavoidable,
MANUFACTURER
MODEL NO.
Central Semiconductor (USA)
CMPT3904
Rohm Semiconductor (USA)
SST3904
Samsung (Korea)
KST3904-TF
Siemens (Germany)
SMBT3904
Zetex (England)
FMMT3904CT-ND
Table 11. Remote-Sensors Transistor
Manufacturers
Note: Discrete transistors must be diode connected (base
shorted to collector).
PART
SMBus SLAVE ID
PIN-PACKAGE
MAX6698EE34
0011 010
16 QSOP
MAX6698EE38
0011 100
16 QSOP
MAX6698EE99
1001 100
16 QSOP
MAX6698EE9C
1001 110
16 QSOP
MAX6698UE34
0011 010
16 TSSOP
MAX6698UE38
0011 100
16 TSSOP
MAX6698UE99
1001 100
16 TSSOP
MAX6698UE9C
1001 110
16 TSSOP
Table 12. Slave Address
Table 12 lists the MAX6698 slave addresses.
Slave Addresses
相关PDF资料 |
PDF描述 |
|---|---|
| MAX6699EE34+T | 5-Channel Precision Temperature Monitor |
| MAX6699EE99+ | 5-Channel Precision Temperature Monitor |
| MAX6699EE99+T | 5-Channel Precision Temperature Monitor |
| MAX6699UE34+ | 5-Channel Precision Temperature Monitor |
| MAX6699UE38+ | 5-Channel Precision Temperature Monitor |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX6698UE99 | 功能描述:板上安装温度传感器 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 |
| MAX6698UE99+ | 功能描述:板上安装温度传感器 7Ch Precision Remote Diode Thermistor 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 |
| MAX6698UE99+T | 功能描述:板上安装温度传感器 7Ch Precision Remote Diode Thermistor 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 |
| MAX6698UE99-T | 功能描述:板上安装温度传感器 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 |
| MAX6698UE9C | 功能描述:板上安装温度传感器 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 |
发布紧急采购，3分钟左右您将得到回复。