Texas Instruments ISO7520CDW

Overview

ISO7520CDW from Texas Instruments is a dual-channel, unidirectional digital isolator with 5 kVRMS reinforced insulation, 1 Mbps signaling rate, <20 ns propagation delay, and dual 3.3/5-V supply capability (VCCI/VCCO). It provides galvanic isolation for industrial field-bus interfaces, motor control signal conditioning, and isolated power supply feedback loops.

For engineers reviewing the ISO7520CDW datasheet, ISO7520CDW pinout, ISO7520CDW application, or ISO7520CDW equivalent, this device delivers verified 50 kV/µs CMTI, fail-safe output behavior on input power loss, and UL/VDE/IEC 60950-1/61010-1 safety certification - critical for high-noise industrial PLC I/O modules and servo drive gate driver isolation.

Technical Context

The ISO7520CDW implements capacitive isolation using dual internal data paths: a high-frequency channel (100 kbps–1 Mbps) for fast edge transmission and a low-frequency/PWM channel (DC–100 kbps) for steady-state signals. Its silicon dioxide (SiO₂) barrier achieves 6000 VPK transient withstand and 4243 VRMS 1-minute isolation per UL 1577.

Each channel operates independently with separate input (VCCI/GNDI) and output (VCCO/GNDO) supplies, enabling level translation between 3.3-V and 5-V domains. Input TTL thresholds and 5-V-tolerant inputs on 3.3-V operation support mixed-voltage system interfacing without external logic buffers.

Key Specifications

Pinout & Package

ISO7520CDW uses a 16-pin SOIC (DW package) with 10.30 mm × 7.50 mm body size and creepage/clearance ≥8.1 mm. The isolation barrier separates input-side (pins 1,3,4,5,7) and output-side (pins 9,12,13,14,16) terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADUM1200ARZ and SI8620ED-B-IS, ISO7520CDW provides higher safety certification (5 kVRMS reinforced), superior CMTI (50 kV/µs), fail-safe behavior, and 5-V-tolerant inputs - making it the only choice for UL/IEC-certified industrial power supplies and motor drives requiring guaranteed safe states.

Availability

ISO7520CDW is available at Aetrix Electronics and suitable for industrial field-bus interfaces, motor control gate driver isolation, and isolated power supply feedback requiring stable component supply across multi-year production cycles.

Supply support for ISO7520CDW 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 enterprise applications.

The ISO7520C family was designed specifically for high-noise industrial environments requiring certified reinforced isolation, low propagation delay, and robust CMTI - targeting PLC I/O modules, servo drives, and isolated power controllers.

FAQ

What is the maximum signaling rate supported by ISO7520CDW?

The ISO7520CDW supports a maximum signaling rate of 1 Mbps across both channels. This is specified under recommended operating conditions (–40°C to +105°C, VCC = 3.3 V or 5 V) and validated with 15-pF load and square-wave input. While faster pulses may pass due to sub-20 ns propagation delay, reliable operation above 1 Mbps requires external filtering per TI's design note to suppress spurious signals with input pulse duration <20 ns.

Does ISO7520CDW support level translation between 3.3-V and 5-V logic domains?

Yes, ISO7520CDW supports bidirectional level translation: VCCI can be 3.3 V while VCCO is 5 V (or vice versa), enabling interface between 3.3-V MCUs and 5-V peripherals. Inputs are 5-V tolerant when VCCI = 3.3 V, and output VOH/VOL specs are guaranteed for both supply combinations - eliminating need for external level shifters in mixed-voltage designs.

What safety certifications does ISO7520CDW hold?

ISO7520CDW is certified to 5000 VRMS reinforced isolation per IEC 60950-1, IEC 61010-1, and IEC 60601-1 end-equipment standards; 4243 VRMS for 1 minute per UL 1577; and 6000 VPK per DIN V VDE V 0884-10. It also carries CSA, TUV, and CQC marks - qualifying it for use in medical, industrial, and energy infrastructure applications without additional isolation barriers.

How does the fail-safe output behavior of ISO7520CDW operate?

When input-side power (VCCI) is lost, ISO7520CDW holds its last valid output state for 6 µs (tfs), then transitions to a defined high-impedance or default state depending on internal circuitry. This behavior is tested per Figure 5 in the datasheet and ensures predictable shutdown in safety-critical systems like motor drives - preventing undefined gate driver states during controller brownout.

Can ISO7520CDW replace optocouplers in existing designs?

Yes, ISO7520CDW is explicitly positioned as an optocoupler replacement for industrial field-buses, servo controls, and power supplies. It matches or exceeds optocoupler CMTI (>50 kV/µs vs. ~15 kV/µs), offers 10× longer lifetime, eliminates LED aging drift, and provides tighter propagation delay matching (<3.6 ns skew vs. >100 ns). Pin-compatible layout adaptation is feasible using the SOIC-16 footprint.