Texas Instruments ISO7420FCCD

Overview

ISO7420FCCD from Texas Instruments is a low-power dual-channel digital isolator using capacitive SiO₂ isolation barrier technology, delivering 2500 V_RMS (1 min UL) and 4242 V_PK (VDE) isolation. It supports up to 50 Mbps signaling at 5-V supplies, features fail-safe low-default outputs, integrated input noise filtering, and operates across 2.7–5.5 V supply ranges on both sides - used in industrial fieldbus interfaces and motor control signal conditioning.

For engineers reviewing the ISO7420FCCD datasheet, ISO7420FCCD pinout, ISO7420FCCD application, or ISO7420FCCD equivalent, key selection criteria include channel-to-channel skew (≤2 ns), CMTI (≥60 kV/μs at 5 V), default-low fail-safe behavior, SOIC-8 narrow-body package compatibility, and dual-supply level translation between 3.3 V and 5 V domains.

Technical Context

The ISO7420FCCD implements a dual-capacitive isolation architecture with separate high-frequency (DC–50 Mbps) and low-frequency (DC–100 kbps) signal paths, using pulse-width modulation for DC/low-frequency inputs and differential transient detection across the SiO₂ barrier. Its decision logic (DCL) automatically switches between channels based on input signal timing.

Each channel includes TTL-compatible input thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2 V), integrated 12 ns glitch suppression filter, and independent VCC1/VCC2 supplies enabling bidirectional level translation. Fail-safe operation forces OUTA/OUTB low when either supply drops below 2.1 V or inputs are unconnected.

Key Specifications

Pinout & Package

Narrow-body SOIC-8 (D package), 4.90 mm × 3.91 mm body size, with creepage/clearance ≥4 mm and CTI >400 V - compliant with IEC 61010-1 and GB4943.1-2011 for industrial equipment mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel digital isolator applications.

Compared with ADUM1200ARZ and SI8620ED-B-IS, the ISO7420FCCD delivers superior noise immunity (60 kV/μs), deterministic fail-safe behavior, and higher speed (50 Mbps), making it optimal for real-time industrial control where signal integrity and safety state assurance are critical.

Availability

ISO7420FCCD is available at Aetrix Electronics and suitable for industrial fieldbus nodes, motor control feedback paths, servo drive interfaces, and isolated power monitoring requiring stable component supply across extended temperature and regulatory-compliant designs.

Supply support for ISO7420FCCD 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and high-reliability components for industrial, automotive, and communications markets.

The ISO7420FCCD belongs to TI's ISO74xx family of capacitive digital isolators, designed specifically for replacing optocouplers in high-noise industrial automation and motor control systems with enhanced speed, reliability, and safety certification.

FAQ

What is the fail-safe behavior of the ISO7420FCCD?

The ISO7420FCCD outputs default to low when either VCC1 or VCC2 drops below 2.1 V (power-down condition) or when inputs are left floating. This behavior is confirmed in Table 2 of the datasheet and ensures predictable state during brownouts or disconnected signals - a critical safety feature in motor control and power supply monitoring applications where undefined outputs could trigger hazardous conditions. The ISO7420FCCD implements this via internal circuitry that overrides output latches upon supply fault detection.

Does the ISO7420FCCD support level translation between 3.3 V and 5 V domains?

Yes, the ISO7420FCCD supports true bidirectional level translation: VCC1 can operate at 3.3 V while VCC2 runs at 5 V (or vice versa), with TTL-compatible inputs accepting 0–5.5 V regardless of supply voltage. This is verified in Section 6.3 (Recommended Operating Conditions) and Figure 3–4 of the datasheet. The ISO7420FCCD requires no external components to translate logic levels - simplifying interface design between mixed-voltage MCUs and peripherals.

What is the maximum data rate supported by the ISO7420FCCD at 3.3 V supply?

The ISO7420FCCD supports up to 40 Mbps at 3.3 V supplies, as specified in Section 6.10 (Switching Characteristics). At 25 Mbps, typical propagation delay is 22 ns and channel skew remains ≤2 ns. Performance degrades gradually above 40 Mbps - the datasheet does not guarantee operation beyond this rate at 3.3 V. For 50 Mbps operation, 5-V supplies are required, confirming the ISO7420FCCD's voltage-dependent bandwidth scaling.

How does the integrated noise filter in the ISO7420FCCD improve system robustness?

The ISO7420FCCD includes a hardware-based input noise filter that suppresses pulses narrower than 12 ns (t_GS), rejecting common-mode transients from IGBT switching, relay bounce, and EFT events. This is measured per Figure 8 and specified in Sections 6.9–6.11. Unlike software-based filtering, it operates at the physical layer - eliminating need for external RC networks or firmware debouncing. In motor control applications, this prevents spurious edge detection that could corrupt encoder counts or current-sense sampling, directly enhancing ISO7420FCCD system-level reliability.

What safety certifications apply to the ISO7420FCCD?

The ISO7420FCCD is certified to UL 1577 (2500 V_RMS, 1 min), VDE V 0884-10 (4242 V_PK), CSA Component Acceptance Notice 5A, and GB4943.1-2011 (CQC). These are listed in Section 8.3.3 and the front-page "Safety and Regulatory Approvals". Each certification covers specific test conditions - e.g., VDE qualification includes partial discharge <5 pC at 1062 V_PK. These approvals validate the ISO7420FCCD for use in end equipment requiring reinforced insulation per IEC 61010-1 and IEC 60950-1 standards.