Introduction to mid400, mid400 pinout, mid400 power ratings, mid400 applications
Hi Everyone! Hope you’re well today. Happy to see you around. In this post today, I’ll walk you through the Introduction to MID400. The MID400 is an 8-pin optically isolated AC line-to-logic Power Line Monitor Optocoupler. The AC line voltage is detected by two back-to-back LEDs that are connected in series with an external resistor. When this device identifies the AC voltage, the output pin goes low and when there is no AC voltage detected, it remains high. This feature of detecting the AC line voltage is widely employed in AC to DC control and relay latching applications. I suggest you buckle up as I’ll walk you through the complete introduction to MID400 covering datasheet, pinout, features, equivalents, and applications. Let’s dive right in.

Introduction to MID400

  • The MID400 is an 8-pin optically isolated AC line-to-logic Power Line Monitor Optocoupler that identifies the AC line voltage using two back to back LEDs that are attached in series with an external resistor.
  • It features high voltage isolation between input and output and comes with an externally adjustable AC voltage sensing level.
  • This device is available with an 8-pin compact DIP package and SMD Package.
Introduction to mid400, mid400 pinout, mid400 power ratings, mid400 applications
  • It is the best pick for AC to DC control applications where remarkable solid-state reliability and excellent optical isolation is needed.
  • It is also applied to the low-frequency operations where small size, low power, and TTL compatibility is required.

MID400 Datasheet

While working with this device, it’s wise to go through the datasheet of the component before installing this device into your project. The datasheet highlights the main characteristics of the component. Click the link below if you want to download the datasheet of MID400.

MID400 Pinout

The following figure represents the pinout diagram of MID400.
Introduction to mid400, mid400 pinout, mid400 power ratings, mid400 applications
The following table demonstrates the pin description of MID400.
Pin Description of MID400
Pin No. Pin Description Pin Name
1 AC Live wire is connected to this Pin AC Live
2 No connection Not used
3 AC Neutral wire is connected to this pin AC Neutral
4 No connection Not used
5 Ground pin of the device Ground
6 Open collector output pin V Output
7 Used to control time delay and AC voltage sensing by adding a capacitor to this pin Auxiliary
8 Device Operating Voltage Vcc
You can see from the table above… out of 8 pins, two pins 2 & 4 are not used for any connection. Pin 5 is the ground and Pin 8 is the voltage supply pin.  

MID400 Features

The following are the main features of MID400.
  • Working Insulation Voltage Max. = 630Vpeak
  • LED on-state input current = ±30mA
  • Power Line Monitor IC
  • Low level Output current = 20mA
  • Low level output voltage = 0.18V
  • LED forward voltage drop = 1.5V
  • Supply Voltage (Vcc) = 7V
  • Turn-on and Turn-off Time = 1ms each
  • Available Packages = 8-pin DIP and SMD Package

MID400 Sample Application Circuit

The following figure shows the sample application circuit of MID400.
Introduction to mid400, mid400 pinout, mid400 power ratings, mid400 applications
  • MID400 is an AC line monitor where the phase wire is connected to the first pin of the device and the neutral wire is connected to the third pin of the device using a resistor of 22-kilo ohm. This resistor is used to control and limit the current flowing through the AC line voltage.
  • Pin 6 is the output pin that remains high when there is no AC voltage and it remains low when AC line voltage is detected.
  • Optocoupling property is used in this device which keeps both output voltage and AC line completely isolated.
  • Pin 6 is the output pin or open collector pin that is attached to the pull-up resistor of 300 ohms which is further connected with the Vcc pin of the device… as shown in the figure above.
  • The capacitor is attached to pin 7 that is mainly used to control the time delay and sensing level of the output.

MID400 Alternative

The following are the alternatives to MID400
  • ACS71020
  • UC1903
While working with the alternatives, double-check the pinout of the alternatives, as the pinout of the alternatives might differ from the pinout of MID400.

MID400 Applications

MID400 is used in the following applications.
  • Employed in AC sensing applications
  • Employed in Latching circuits
  • Incorporated in Isolation switch
  • Used in AC to DC control applications
  • Used in AC to DC converters
  That was all about the Introduction to MID400. If you’re unsure or have any queries, you can pop your question in the section below. I’d love to help you the best way I can. You’re most welcome to share your valuable suggestions and feedback around the content we share, so we keep producing quality content tailored to your exact needs and requirements. Thank you for reading the article.