onsemi HCPL0638R1

Overview

HCPL0638R1 from Fairchild Semiconductor is a dual-channel, high-speed logic gate optocoupler with 10 MBit/s data rate, open-collector output, and CMOS-based detector for reduced power consumption. It provides galvanic isolation between input and output circuits, features strobable enable control per channel, and operates across -40°C to +85°C for industrial digital interface applications.

For engineers reviewing the HCPL0638R1 datasheet, pinout, applications, or equivalent options, key selection criteria include propagation delay (≤75 ns), common-mode transient immunity (5000 V/µs at |VCM| = 50 V), dual-channel open-collector logic output compatibility, and SO-8 package footprint compliance.

Technical Context

The HCPL0638R1 integrates an AlGaAs LED optically coupled to a CMOS-process bipolar detector, enabling lower supply current versus bipolar-only variants. Its dual-channel architecture supports independent signal isolation with shared VCC and GND pins and separate input (VF1/VF2) and output (VO1/VO2) terminals per channel.

Each channel features an enable-controlled logic gate output with wired-OR capability, requiring no external pull-up resistors due to internal biasing. The device achieves 5000 V/µs common-mode rejection at 50 V transient amplitude and guarantees performance over full industrial temperature range without derating.

Key Specifications

Pinout & Package

HCPL0638R1 uses an 8-pin Small Outline (SO-8) package with gull-wing leads, 1.27 mm pitch, and maximum lead coplanarity of 0.10 mm. Pin 1 is marked by a notch or dot; pin numbering follows standard SOIC convention.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar logic gate optocoupler applications.

Compared with ACPL-M61T and 6N137, HCPL0638R1 uniquely delivers dual-channel 10 MBd isolation in one SO-8 package with 5000 V/µs CMTI and CMOS detector efficiency - making it optimal for space-constrained industrial controllers needing coordinated signal isolation.

Availability

HCPL0638R1 is available at Aetrix Electronics and suitable for industrial motor control, isolated data acquisition, switching power supply feedback, and computer peripheral interface applications requiring stable component supply and long-term lifecycle support.

Supply support for HCPL0638R1 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 company specializing in power management, analog, and optoelectronic components before its acquisition by ON Semiconductor in 2016.

The HCPL0638R1 belongs to the HCPL06XX family of high-speed logic gate optocouplers designed specifically for noise-immune digital signal isolation in industrial automation, power conversion, and computing infrastructure.

FAQ

What is the maximum recommended forward input current for HCPL0638R1?

The absolute maximum DC/average forward input current per channel for HCPL0638R1 is 50 mA, but the recommended operating condition specifies 15 mA maximum to ensure long-term reliability and CTR stability. Operating above 15 mA may accelerate LED degradation and reduce isolation lifetime, especially at elevated temperatures.

Does HCPL0638R1 require an external pull-up resistor on its output pins?

No, HCPL0638R1 does not require an external pull-up resistor on VO1 or VO2 because its open-collector outputs are designed to interface directly with standard TTL or CMOS logic inputs using an external pull-up. The device itself contains no internal pull-up; the 0.1 µF bypass capacitor is required between VCC (Pin 8) and GND (Pin 5), not on output lines.

What is the purpose of the enable input in HCPL0638R1?

HCPL0638R1 does not include an enable input - that feature applies only to single-channel variants (HCPL0600/0601/0611). The HCPL0638R1 has no enable pin; its dual-channel operation is always active when powered. Pin 7 is VO2, not an enable terminal - confirmation is found in the dual-channel circuit diagram on page 2 of the datasheet.

Can HCPL0638R1 operate with a 3.3 V supply on the output side?

No, HCPL0638R1 requires a minimum VCC of 4.5 V and maximum of 5.5 V on the detector side (Pin 8); it is not rated for 3.3 V operation. Attempting to power the output stage at 3.3 V violates the Recommended Operating Conditions table (page 3), resulting in undefined logic thresholds, increased VOL, and potential failure to meet 10 MBd timing specs.

What isolation certification does HCPL0638R1 hold?

HCPL0638R1 is UL recognized (File #E90700) and meets IEC60747-5-2 requirements for optocouplers. It achieves 3750 VRMS withstand voltage for 1 minute and provides 10¹² Ω input-to-output resistance at 500 V, confirming compliance with reinforced insulation standards for industrial equipment safety certification.