ADI 公司的ADM2914是精度为+/-1.5%的四路电源电压监视集成电路,用来监视各种应用的电源电压. ADM2914每路监视有两个专用输入引脚VHx和VLx,为过压(OV)和欠压(UV)条件监视. ADM2914能监视多达2个负电源,可调的UV和OV输入阈值, 阈值精度高达+/-1.5%,具有漏极开路UV和OV重置输出和尖峰免疫功能,消耗电流仅为62uA,可用在服务器电源监视,FPGA/DSP核和I/O电压监视,通信设备和医疗设备.本文介绍了ADM2914的主要特性,功能方框图, 典型应用框图以及监视四种电压的多个应用框图.
The ADM2914 is a quad voltage supervisory IC ideally suited for monitoring multiple rails in a wide range of applications. Each monitored rail has two dedicated input pins, VHx and VLx, which allows each rail to be monitored for both overvoltage (OV) and undervoltage (UV) conditions. A common active low undervoltage (UV) and overvoltage (OV) pin is shared by each of the monitored voltage rails. The ADM2914 includes a 1 V buffered reference output, REF, that acts as an offset when monitoring a negative voltage. The three-state SEL pin determines the polarity of the third and fourth inputs, that is, it configures the device to monitor positive or negative supplies.
The device incorporates an internal shunt regulator that enables the device to be used in higher voltage systems. This feature requires a resistor to be placed between the main supply rail and the VCC pin to limit the current flow into the VCC pin to no greater than 10 mA. The ADM2914 uses the internal shunt regulator to regulate VCC if the supply line exceeds the absolute maximum ratings. The ADM2914 is available in two models. The ADM2914-1 offers a latching overvoltage output that can be cleared by toggling the LATCH input pin. The ADM2914-2 has a disable pin that can override and disable both the OV and UVoutput signals.
The ADM2914 is available in a 16-lead QSOP package. The device operates over the extended temperature range of -40℃ to +125℃.
ADM2914主要特性:
Quad UV/OV positive/negative supervisor
Supervises up to 2 negative rails
Adjustable UV and OV input thresholds
High threshold accuracy over temperature: ±1.5%
1 V buffered reference output
Open-drain UV and OV reset outputs
Adjustable reset timeout with disable option
Outputs guaranteed down to VCC of 1 V
Glitch immunity
62 μA supply current
16-lead QSOP package
ADM2914应用:
Server supply monitoring
FPGA/DSP core and I/O voltage monitoring
Telecommunications equipment
Medical equipment
图1.ADM2914功能方框图
图2.ADM2914典型应用框图
图3.ADM2914正负电源监视案例
图4.ADM2914监视5 V, 3.3 V, 2.5 V和1.8 V典型应用框图
图5.ADM2914监视+12V和-5 V典型应用框图
图6.ADM2914监视+48 V, +16 V, -3.3 V和-48 V典型应用框图
