Dual-Output Remote-Junction
Temperature Switches
Pin Description
PIN
MAX6685 MAX6686
NAME
FUNCTION
1
2
3
1
2
3
V DD
GND
DXP
Power-Supply Input. Bypass to GND with a 0.1μF capacitor.
Ground
This pin connects to the positive (anode) terminal of the external P-N sense junction. It sources
current into the external junction. A 2200pF capacitor should be connected across DXP and DXN.
This pin connects to the negative (cathode) terminal of the external P-N sense junction. It sinks
4
4
DXN
current from the external junction. A 2200pF capacitor should be connected across DXP and
DXN. DXN must be connected to the GND pin with the shortest possible connection.
Open-Drain, Active-Low Output. T HIGH goes low when the temperature exceeds the factory-
5
5
T HIGH
programmed upper temperature threshold, either +120°C or +125°C. Connect a pullup resistor
(typically 10k ? ) between T HIGH and a positive supply up to 5.5V.
6
T LOW
CMOS Push-Pull, Active-High Output. T LOW goes HIGH when the temperature exceeds the pin-
programmed lower temperature threshold.
Open-Drain, Active-Low Output. T LOW goes LOW when the temperature exceeds the pin-
6
T LOW
programmed lower temperature threshold. Connect a pullup resistor (typically 10k ? ) between
T LOW and a positive supply up to 5.5V.
7
8
7
8
S1
S2
Threshold Select Input. Used in conjunction with S2 to set the lower threshold for T LOW (Table 1).
It can be connected to V DD , GND, or left floating.
Threshold Select Input. Used in conjunction with S1 to set the lower threshold for T LOW (Table 1).
It can be connected to V DD , GND, or left floating.
Detailed Description
The MAX6685/MAX6686 dual-output remote-sensing
junction temperature switches incorporate a precision
remote-junction temperature sensor and two compara-
tors. These devices use an external P-N junction as the
temperature-sensing element (see Typical Operating
Circuits ).
The MAX6685/MAX6686 provide noise immunity by
integration and oversampling of the diode voltage, but
good design practice includes routing the DXP and
DXN lines away from noise sources, such as high-
speed digital lines, switching regulators, inductors, and
transformers. The DXP and DXN traces should be
paired together and surrounded by a ground plane
whenever possible.
The 5 ° C hysteresis keeps the outputs from “ chattering ”
when the measured temperature is close to the threshold
temperature. The MAX6685/MAX6686 are available with
preset upper temperature thresholds of +120 ° C or
+125 ° C. The lower temperature thresholds are pin pro-
grammable in 5 ° C increments (Table 1). Two tempera-
ture ranges are available for the lower trip threshold:
+40 ° C to +80 ° C and +75 ° C to +115 ° C. S1 and S2 pins
must be set to the desired trip temperature before power
is applied to the V DD pin. If this is done after the power is
turned on, the lower trip threshold remains set to the
point where S1 and S2 were when power was applied.
Applications Information
Remote-Diode Selection
The MAX6685/MAX6686 are optimized to measure the
die temperature of CPUs and other ICs that have on-chip
temperature-sensing diodes. These on-chip diodes are
substrate PNPs with their collectors grounded. Connect
the base of the PNP to DXN and the emitter to DXP. When
using a discrete, diode-connected NPN or PNP as a
sensing diode, use a good-quality small-signal device.
Examples are listed in Table 2. Tight specifications for for-
ward current gain indicate the manufacturer has good
process controls and that the devices have consistent
V be characteristics. Always use a transistor for the sens-
ing junction; diodes do not work.
4
_______________________________________________________________________________________
相关PDF资料
MAX6688AU40H+ IC SW TEMP REMOTE 8-UMAX
MAX66901-K00# KIT DEV ISO 14443B/15693 RFID
MAX7030HATJ+T IC TRANSCEIVER ASK 32-TQFN
MAX7031MATJ50+T IC TXRX FSK W/PLL 32TQFN-EP
MAX7032EVSYS-433 EVAL KIT MAX7032
MAX7033ETJ+T IC RX 315MHZ/433MHZ ASK 32TQFN
MAX7033EVKIT-315 EVAL KIT FOR MAX7033 315MHZ
MAX7034EVKIT-433+ EVAL KIT MAX7034
相关代理商/技术参数
MAX6687AU40H 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
MAX6687AU40H+ 功能描述:板上安装温度传感器 Local/Remote Temperature Switch 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
MAX6687AU40H+T 功能描述:板上安装温度传感器 Local/Remote Temperature Switch 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
MAX6687AU40H-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
MAX6687AU40L 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
MAX6687AU40L+ 功能描述:板上安装温度传感器 Local/Remote Temperature Switch 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
MAX6687AU40L+T 功能描述:板上安装温度传感器 Local/Remote Temperature Switch 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
MAX6687AU40L-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