Signal-Line Circuit Protectors
______________________________________________________________Pin Description
PIN
NAME*
FUNCTION
MAX366
MAX367
1, 2, 3
4
5, 6, 7
8
1, 2, 3
4–8
9
10–14
15, 16, 17
18
IN1, IN2, IN3
IN4–IN8
V-
OUT8–OUT4
OUT3, OUT2,
OUT1
V+
Signal Inputs 1, 2, 3
Signal Inputs 4–8
Negative Supply Voltage Input
Signal Outputs 4–8
Signal Outputs 1, 2, 3
Positive Supply Voltage Input
* Inputs and outputs are names for convenience only; inputs and outputs are identical and interchangeable.
___________Background Information
When a voltage outside the supply range is applied to
most integrated circuits, there is a strong possibility they
will be damaged or “latch up” (that is, fail to operate prop-
erly even after the offending voltage is removed). If an
IC’s input or output pin is supplied with a voltage when the
IC’s power is off, and power is subsequently applied, the
device may act as an SCR and destroy itself and/or other
circuitry. Such “faults” are commonly encountered in
modular control systems where power and signals to inter-
connected modules may be interrupted and re-estab-
lished at random. They can happen during production
testing, maintenance, start-up, or a power “brownout.”
The MAX366/MAX367 are designed to protect delicate
input and output circuitry from overvoltage faults up to
±40V (with or without power applied), in devices such as
op amps, analog-to-digital/digital-to-analog converters,
and voltage references. These circuit protectors automati-
cally limit signal voltages and currents to safe levels with-
out degrading normal signal performance, even in very
high-impedance circuits. They are powered by the power
supply of the protected circuit and inserted into the signal
lines. There are no control lines, programming pins, or
adjustments.
_______________Detailed Description
Internal Construction
Figure 1 shows the simplified internal construction of
each protector inside the MAX366/MAX367. Each circuit
consists of two N-channel FETs and one P-channel FET.
All the FETs are enhancement types; that is, the N chan-
nels must have approximately 1.3V of positive gate volt-
age in order to conduct, and the P channel must have
approximately 2V of negative gate voltage in order to
conduct.
During normal operation, V+ is connected to a positive
potential and V- is connected to a negative potential.
Since their gates are tied to V+, transistors Q1 and Q3
conduct as long as their sources are at least 1.3V below
V+ (the N-channel gate threshold.) Transistor Q2’s gate
is tied to V-, so it conducts as long as its source is 2V or
more above V- (the P-channel gate threshold.)
V-
P
Unlike shunt diode networks, these devices are low-
impedance FETs that become high impedance during a
fault condition, so fault current and power dissipation are
IN
N
Q2
N
OUT
extremely low. Equally important, leakage current during
normal and fault conditions is extremely low. In addition,
Q1
V+
Q3
unlike most discrete networks, these parts protect circuits
both when power is off and during power transitions.
Figure 1. Simplified Internal Structure
_______________________________________________________________________________________
5
相关PDF资料
MAX4080EVKIT+ KIT EVAL FOR MAX4080
MAX4208EVKIT+ KIT EVAL FOR MAX4208
MAX4209EVKIT+ KIT EVAL FOR MAX4209
MAX4210EEVKIT EVAL KIT FOR MAX4210
MAX4273EVKIT EVAL KIT FOR MAX4273
MAX4278EVKIT-SO KIT EVALUATION FOR MAX4178,4278
MAX44265EVKIT# KIT EVAL FOR 44265
MAX4754AEVKIT+ KIT EVAL FOR MAX4754
相关代理商/技术参数
MAX367CWN+ 功能描述:隔离器接口集成电路 Signal Line Circuit Protector RoHS:否 制造商:Texas Instruments 通道数量:2 传播延迟时间: 电源电压-最大:5.5 V 电源电压-最小:3 V 电源电流:3.6 mA 功率耗散: 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:SOIC-8 封装:Tube
MAX367CWN+T 功能描述:隔离器接口集成电路 Signal Line Circuit Protector RoHS:否 制造商:Texas Instruments 通道数量:2 传播延迟时间: 电源电压-最大:5.5 V 电源电压-最小:3 V 电源电流:3.6 mA 功率耗散: 最大工作温度:+ 125 C 安装风格: 封装 / 箱体:SOIC-8 封装:Tube
MAX367CWN-T 功能描述:TVS二极管阵列 RoHS:否 制造商:Littelfuse 极性: 通道:4 Channels 击穿电压: 钳位电压:11.5 V 工作电压:2.5 V 峰值浪涌电流:20 A 安装风格:SMD/SMT 端接类型:SMD/SMT 系列: 最小工作温度:- 40 C 最大工作温度:+ 85 C
MAX367EPN 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube
MAX367EPN+ 功能描述:热插拔功率分布 Signal Line Circuit Protector RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube
MAX367EWN 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube
MAX367EWN+ 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube
MAX367EWN+T 功能描述:热插拔功率分布 RoHS:否 制造商:Texas Instruments 产品:Controllers & Switches 电流限制: 电源电压-最大:7 V 电源电压-最小:- 0.3 V 工作温度范围: 功率耗散: 安装风格:SMD/SMT 封装 / 箱体:MSOP-8 封装:Tube