onsemi MOC70P1

Overview

MOC70P1 from Fairchild Semiconductor is a phototransistor-based optical interrupter switch with transistor output, 5 mm sensing gap, 0.040" aperture, and PCB mount package. It delivers 0.15 mA minimum on-state collector current at 5 mA LED drive, 30 V V_CEO, and 20 µs typical turn-on time for non-contact position detection in industrial encoders and printer paper-path sensors.

For engineers reviewing the MOC70P1 datasheet, pinout, applications, or equivalent options, key selection criteria include guaranteed low saturation voltage (≤0.40 V), wide operating temperature range (–55°C to +100°C), and validated switching performance under 5 V/2.5 kΩ load conditions.

Technical Context

The MOC70P1 integrates an infrared LED optically coupled to an NPN silicon phototransistor in a single molded housing. Its design enables non-contact sensing across a fixed 5 mm air gap with mechanical shielding against ambient light interference.

Electrical isolation is achieved via internal optical coupling, with no galvanic connection between emitter and sensor sides. The device operates with forward LED current up to 50 mA and supports collector currents up to 20 mA while maintaining V_CEO = 30 V and V_Eco = 4.5 V ratings.

Key Specifications

Pinout & Package

Package: 4-pin DIP-style through-hole plastic housing with 0.100" (2.54 mm) lead pitch, low-profile design optimized for PCB-mounted optical interrupters.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar optical interrupter applications.

Compared with TCST1103 and OPB701, the MOC70P1 offers balanced performance for mid-range gap and sensitivity requirements, with verified 5 mm gap operation, guaranteed 0.15 mA output, and industry-standard DIP-4 footprint - making it optimal for cost-sensitive industrial and office equipment designs requiring proven reliability.

Availability

MOC70P1 is available at Aetrix Electronics and suitable for printer paper-path sensing, industrial encoder slot detection, home appliance door interlocks, and office equipment cover switches requiring stable component supply and long-term production continuity.

Supply support for MOC70P1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Fairchild Semiconductor was a U.S.-based semiconductor manufacturer specializing in power management, analog, and optoelectronic components before its acquisition by ON Semiconductor in 2016.

The MOC70P1 belongs to Fairchild's legacy photointerrupter product line, designed specifically for robust, low-cost, non-contact position and motion sensing in industrial and consumer electromechanical systems.

FAQ

What is the minimum guaranteed on-state collector current for MOC70P1?

The MOC70P1 guarantees a minimum on-state collector current (I_C(ON)) of 0.15 mA when driven with 5 mA LED forward current and 10 V collector-emitter voltage. This value is confirmed in the Optical Switch Selection Guide section of the official datasheet and defines the lowest usable output level for logic interface design. Engineers must verify that their load resistor and supply voltage maintain sufficient margin above this threshold across temperature and aging.

Does MOC70P1 support direct connection to 3.3 V microcontroller GPIOs?

Yes, MOC70P1 supports direct connection to 3.3 V microcontroller GPIOs for both LED drive and phototransistor output. Its LED forward voltage is ≤1.8 V at 50 mA, allowing safe drive with a series resistor; its phototransistor output saturates to ≤0.40 V, ensuring valid logic-low levels. However, a pull-up resistor is required on the collector to establish logic-high, and current limiting must be applied to PIN 1 to avoid exceeding 50 mA absolute maximum.

What is the sensing gap specification for MOC70P1?

The MOC70P1 is specified for a 5 mm nominal sensing gap - the distance between emitter and detector across which optical interruption is reliably detected. This value is explicitly stated in the FEATURES section of the datasheet and confirmed by mechanical drawings showing housing geometry optimized for that spacing. It is not adjustable or field-tunable; mechanical mounting must maintain this gap within tolerance for consistent switching behavior.

Can MOC70P1 replace MOC70P2 or MOC70P3 in existing designs?

No, MOC70P1 cannot directly replace MOC70P2 or MOC70P3 without circuit review. While all three share identical pinout and package, their on-state collector currents differ significantly: MOC70P1 = 0.15 mA min, MOC70P2 = 0.30 mA min, and MOC70P3 = 0.60 mA min at IF = 5 mA. Substituting MOC70P1 into a design relying on higher output current may cause marginal logic-level recognition or increased susceptibility to noise.

What is the maximum allowable soldering temperature for MOC70P1?

The maximum allowable soldering temperature for MOC70P1 is 240°C for 5 seconds using an iron, or 260°C for 10 seconds using flow soldering - per Absolute Maximum Ratings table. Exceeding these limits risks internal bond wire damage or LED degradation. The datasheet also specifies a 1/16" (1.6 mm) minimum distance between soldering iron tip and housing to prevent thermal stress cracking of the plastic package.