My Inquiry
My Account
Texas Instruments ISO7321FCD
- Part No.:
- ISO7321FCD
- Manufacturer:
- Texas Instruments
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISO7321FCD.pdf
- Description:
- DGTL ISO 3000VRMS 2CH GP 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:192
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
ISO7321FCD from Texas Instruments is a dual-channel digital isolator with opposite-direction channel configuration (IN→OUT on one side, OUT→IN on the other), 3000 VRMS galvanic isolation, 25 Mbps signaling rate, and fail-safe low-default output behavior. It enables robust signal transmission across isolated domains in industrial motor drives and servo control interfaces where input-side power loss must not cause undefined output states.
For engineers reviewing the ISO7321FCD datasheet, ISO7321FCD pinout, ISO7321FCD application, or ISO7321FCD equivalent, key selection criteria include its 33 ns typical propagation delay at 5 V, integrated noise filtering for harsh EMI environments, 65 kV/μs CMTI, and dual-supply operation supporting 3.3 V/5 V level translation between isolated domains.
Technical Context
The ISO7321FCD implements capacitive isolation using silicon dioxide (SiO₂) barriers, with separate VCCI/GNDI and VCCO/GNDO supplies enabling independent input/output domain biasing. Its architecture combines high-frequency (100 kbps–25 Mbps) and low-frequency (DC–100 kbps) data paths via PWM modulation and LPF reconstruction to maintain DC accuracy while achieving high-speed performance.
Fail-safe operation is hardware-defined: when VCCI drops below ~2.1 V, outputs default to low state-critical for safety-critical motor gate drivers and battery pack monitoring. Input hysteresis (460 mV typ.) and integrated noise filters suppress short-duration transients common in industrial fieldbus nodes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 3000 VRMS per UL 1577 (1 min); 4242 VPK per VDE 0884-10 - meets reinforced insulation requirements for industrial safety standards. |
| Signaling Rate | 25 Mbps - supports high-speed serial interfaces like SPI, RS-485 transceiver control, and real-time encoder feedback links. |
| Propagation Delay | 33 ns typical at 5 V - enables tight timing budgets in closed-loop servo control and PWM gate driver synchronization. |
| CMTI | 65 kV/μs typical at 5 V - ensures reliable operation in noisy motor drive environments with fast-switching IGBTs. |
| Supply Range | 3 V to 5.5 V on both sides - allows interoperability between 3.3 V microcontrollers and 5 V analog/power domains. |
| Default Output State | Low upon VCCI loss - prevents unintended activation of downstream power stages during brownout or supply fault conditions. |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive subsystems and industrial PLC backplanes. |
Pinout & Package
Narrow-body SOIC-8 package (4.90 mm × 3.91 mm), surface-mount, creepage/clearance ≥4 mm, CTI ≥400 V.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCCI | Input-side power supply | Bias voltage for INx inputs and internal logic; decoupling required near pin for EMC robustness. |
| GNDI | Input-side ground reference | Return path for VCCI; must be isolated from GNDO by PCB layout and system grounding scheme. |
| INA | Input A (channel 1) | TTL-compatible input driving isolated output OUTB; directionality defined by ISO7321 topology (input on side-1, output on side-2). |
| INB | Input B (channel 2) | TTL-compatible input driving isolated output OUTA; opposite-direction pairing enables bidirectional data flow across barrier. |
| VCCO | Output-side power supply | Bias voltage for OUTx outputs; enables level-shifting to match downstream 3.3 V or 5 V logic families. |
| GNDO | Output-side ground reference | Return path for VCCO; forms isolated domain with VCCO; no direct connection to GNDI permitted. |
| OUTA | Output A (channel 1) | CMOS output driven by INB; active-low fail-safe default ensures safe state during VCCI dropout. |
| OUTB | Output B (channel 2) | CMOS output driven by INA; complements OUTA to support full-duplex isolated communication links. |
Key Features
| Feature | Design Value |
|---|---|
| Opposite-direction dual channels | Enables true bidirectional isolation without external logic inversion-reduces component count in half-duplex UART or SPI isolator designs. |
| Integrated input noise filter | Rejects sub-40 ns pulses per tui specification-eliminates need for external RC filters in Modbus RTU or Profibus DP node interfaces. |
| Fail-safe low-default output | Guarantees OUTA/OUTB = low when VCCI ≤2.1 V-prevents false triggering of IGBT gate drivers during power sequencing faults. |
| Robust EMC performance | System-level ESD (IEC 61000-4-2), EFT (IEC 61000-4-4), and surge (IEC 61000-4-5) immunity-reduces need for external protection components. |
| Long isolation barrier life | >25 years at rated working voltage-meets lifetime requirements for industrial automation equipment and renewable energy inverters. |
Applications
| Industrial Fieldbus Isolation | Servo Motor Control Interface |
|---|---|
|
Use Scenario: Isolating RS-485 transceiver control lines and status signals in Profibus DP slave nodes operating in electrically noisy factory floors. IC Role / Device Role / Timing Role: ISO7321FCD provides bidirectional signal isolation between MCU UART and RS-485 PHY, with channel directionality matching TX/RX line routing. Use Value: 65 kV/μs CMTI prevents data corruption during nearby contactor switching; fail-safe low output avoids bus lock-up during transient supply dips. |
Use Scenario: Isolating position encoder feedback (A/B/Z quadrature) and PWM enable signals between servo drive controller and power stage. IC Role / Device Role / Timing Role: ISO7321FCD transmits encoder pulses across isolation barrier while enabling synchronous PWM gating with <33 ns skew. Use Value: 25 Mbps capability supports high-resolution multi-turn encoders; opposite-direction channels simplify PCB routing for compact drive modules. |
| Programmable Logic Controller Backplane | Battery Management System Communication |
|
Use Scenario: Isolating digital I/O expansion module data and address lines from main CPU backplane in modular PLC chassis. IC Role / Device Role / Timing Role: ISO7321FCD serves as a dual-channel isolator for parallel bus signals, with VCCI tied to CPU domain and VCCO to module domain. Use Value: Dual 3.3 V/5 V supply support enables mixed-voltage backplane designs; 125°C rating ensures reliability in enclosed control cabinets. |
Use Scenario: Isolating CAN bus interface and cell voltage monitoring ADC control lines in high-voltage EV battery packs (400–800 V DC). IC Role / Device Role / Timing Role: ISO7321FCD isolates microcontroller SPI commands to isolated ADCs and relays, with fail-safe low preventing inadvertent contactor closure. Use Value: 4242 VPK isolation meets IEC 61010-1 reinforced insulation requirements for battery pack safety; 3000 VRMS UL rating satisfies OEM validation protocols. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-channel digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISO7321CD | Same package and pinout; default output is 'high' on VCCI loss instead of 'low'. | Suitable where fail-safe high state is required (e.g., enable signals for safety relays). | Select ISO7321CD only if system architecture requires active-high fail-safe behavior; otherwise ISO7321FCD is preferred for motor control. |
| ADUM1201BRZ | Lower CMTI (25 kV/μs), no integrated noise filter, 100 Mbps max rate, different pinout (SOIC-8 but channel assignment differs). | Used in lower-noise consumer-grade applications; lacks VDE/UL certifications for industrial safety-critical use. | Choose ADUM1201BRZ only for cost-sensitive non-safety applications; ISO7321FCD provides certified robustness for industrial deployment. |
Compared with ISO7321CD and ADUM1201BRZ, the ISO7321FCD delivers superior noise immunity, safety certification coverage, and deterministic fail-safe behavior-making it the optimal choice for industrial motion control and high-reliability battery systems where output state predictability under fault conditions is mandatory.
Availability
ISO7321FCD is available at Aetrix Electronics and suitable for industrial fieldbus nodes, servo motor control interfaces, PLC backplanes, battery management systems, and isolated power supply monitoring requiring stable component supply and long-term lifecycle assurance.
Supply support for ISO7321FCD 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 company specializing in analog and embedded processing technologies, with leadership in precision analog, power management, and high-reliability isolation solutions.
The ISO732x family was designed specifically for industrial automation, motor control, and energy infrastructure applications demanding robust EMC performance, safety-certified isolation, and fail-safe operation under supply fault conditions.
FAQ
What is the fail-safe behavior of the ISO7321FCD when input power is lost?
The ISO7321FCD defaults its outputs to low state when VCCI drops below approximately 2.1 V. This behavior is hardwired and does not require external circuitry. For ISO7321FCD, this ensures that downstream power switches remain de-energized during brownout events, directly supporting functional safety requirements in motor drive applications. The ISO7321FCD maintains this behavior across its full –40°C to +125°C operating range.
Does the ISO7321FCD support level translation between 3.3 V and 5 V domains?
Yes, the ISO7321FCD supports independent 3.3 V or 5 V supplies on both input (VCCI) and output (VCCO) sides. It accepts TTL input thresholds (VIH ≥2 V, VIL ≤0.8 V) and delivers CMOS-compatible outputs (VOH ≥VCCO–0.5 V, VOL ≤0.4 V), enabling seamless bidirectional level shifting. This capability is fully characterized in both ISO7321FCD electrical specifications tables for 3.3 V and 5 V operation.
What safety certifications does the ISO7321FCD hold?
The ISO7321FCD is certified to UL 1577 (3000 VRMS, 1 minute), VDE 0884-10 (4242 VPK, reinforced insulation), CSA Component Acceptance Notice 5A, IEC 60950-1, IEC 61010-1, and CQC GB4943.1-2011. These approvals cover isolation barrier integrity, creepage/clearance compliance (≥4 mm), and system-level safety for industrial and medical auxiliary equipment applications.
How does the ISO7321FCD handle high-frequency noise on input pins?
The ISO7321FCD incorporates an integrated noise filter that rejects input pulses shorter than 40 ns (tui), as specified in its recommended operating conditions. This feature eliminates the need for external RC filters in environments with fast transients-such as those generated by IGBT switching in motor drives. The filter operates transparently and does not affect signal integrity for valid data pulses above the threshold.
What is the maximum data rate supported by the ISO7321FCD?
The ISO7321FCD supports a maximum signaling rate of 25 Mbps under recommended operating conditions (VCCI/VCCO = 3 V to 5.5 V, TA = –40°C to +125°C). This rate is guaranteed with 33 ns typical propagation delay at 5 V and pulse width distortion of ≤4 ns, making it suitable for high-speed SPI clock domains, encoder feedback, and real-time control loops.
ISO7321FCD Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Technology:
- Capacitive Coupling
- Type:
- General Purpose
- Isolated Power:
- No
- Number of Channels:
- 2
- Inputs - Side 1/Side 2:
- 1/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 3000Vrms
- Common Mode Transient Immunity (Min):
- 25kV/µs
- Data Rate:
- 25Mbps
- Propagation Delay tpLH / tpHL (Max):
- 57ns, 57ns
- Pulse Width Distortion (Max):
- 4ns
- Rise / Fall Time (Typ):
- 2.4ns, 2.1ns
- Voltage - Supply:
- 3V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISO7321FCD FAQ
1.How can I place an order for ISO7321FCD through Aetrix?
Please submit a Request for Quotation (RFQ) for ISO7321FCD on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for ISO7321FCD reliable?
The price and inventory of ISO7321FCD are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISO7321FCD is usually 5 days.
3.What payment methods are accepted for ISO7321FCD?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISO7321FCD transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISO7321FCD?
ISO7321FCD orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISO7321FCD order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for ISO7321FCD?
For technical support, including ISO7321FCD datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISO7321FCD requirements.
6.How does Aetrix verify that ISO7321FCD is sourced from the original manufacturer or authorized distributors?
All ISO7321FCD products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ISO7321FCD meets industry standards.
7.What is the process for return or replacement of ISO7321FCD?
All ISO7321FCD units undergo pre-shipment inspection (PSI). If there is an issue with ISO7321FCD, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The ISO7321FCD part is unused and in its original packaging.
Return procedure for ISO7321FCD:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ISO7321FCD Tags
-
ISO1212DBQR
Texas Instruments
-
ISO6721BDR
Texas Instruments
-
SI8710AC-B-ISR
Skyworks Solutions Inc.
-
ISO7720FDR
Texas Instruments
-
ISO7721DR
Texas Instruments
-
ISO7721FDR
Texas Instruments
-
SI8710CC-B-ISR
Skyworks Solutions Inc.
-
ISO6741FQDWRQ1
Texas Instruments
-
ISO7721DWVR
Texas Instruments
-
ISO7762FDBQR
Texas Instruments
-
ISO7741DWR
Texas Instruments
-
ISO7741FDWR
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
