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Texas Instruments ISO7021DR
- Part No.:
- ISO7021DR
- Manufacturer:
- Texas Instruments
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
ISO7021DR.pdf
- Description:
- DGTL ISO 3000VRMS 2CH GP 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,204
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Product details
Overview
ISO7021DR from Texas Instruments is an ultra-low-power, two-channel capacitive digital isolator with 3000VRMS reinforced isolation, 4Mbps data rate, 4.8μA per-channel quiescent current at 3.3V, and dual supply operation (1.71–1.89V or 2.25–5.5V). It implements forward/reverse channel directionality in an 8-SOIC package and serves as a galvanic barrier for signal integrity in isolated industrial I/O interfaces.
For engineers reviewing the ISO7021DR datasheet, ISO7021DR pinout, ISO7021DR application, or ISO7021DR equivalent, this page delivers verified technical context, real-world use cases, pin-level design meaning, and validated alternative options - all grounded in TI's production-grade SLLSFA0C specification.
Technical Context
The ISO7021DR uses edge-based encoding with ON-OFF keying (OOK) modulation across a double SiO₂ capacitive barrier, enabling <120μA/Mbps dynamic current consumption while maintaining 3000VRMS isolation per UL 1577. Its refresh logic ensures DC state matching via watchdog-triggered retransmission after >100μs of input inactivity.
It supports asymmetric dual-supply operation: side-1 (VCC1/GND1) and side-2 (VCC2/GND2) may operate independently within 1.71–1.89V or 2.25–5.5V ranges, with guaranteed functionality across –55°C to 125°C ambient temperature and ±100kV/μs CMTI performance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data Rate | Up to 4Mbps - supports high-speed UART, GPIO, and sensor interface isolation without timing bottlenecks. |
| Quiescent Current | 4.8μA per channel at 3.3V - enables battery-powered or energy-harvesting field transmitters with multi-year runtime. |
| Isolation Rating | 3000VRMS reinforced - meets safety requirements for industrial PLC I/O modules and hazardous-area intrinsic safety (ATEX/IECEx). |
| CMTI | ±100kV/μs typical - sustains reliable operation in noisy motor drives and switch-mode power supplies. |
| Supply Range | 1.71–1.89V and 2.25–5.5V per side - allows direct interfacing with 1.8V microcontrollers and 3.3V/5V peripherals without level shifters. |
| Default Output | High (non-F suffix) - ensures fail-safe high-state signaling during power loss in analog output circuits. |
| Package | 8-SOIC (4.90mm × 6.00mm) - standard footprint compatible with legacy PCB layouts and automated assembly. |
Pinout & Package
ISO7021DR is housed in an industry-standard narrow-body 8-pin SOIC (SOIC-8, D package), measuring 4.90mm × 6.00mm, with creepage/clearance ≥4mm and reinforced insulation barrier rated to 3000VRMS.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC1 | Power supply, side 1 | Supplies input-side logic (INB, INA); independent voltage domain enables mixed-voltage system partitioning. |
| VCC2 | Power supply, side 2 | Supplies output-side logic (OUTA, OUTB); decoupled from VCC1 to prevent ground-loop coupling. |
| GND1 | Ground, side 1 | Reference for VCC1 and INB/INA; must be isolated from GND2 to maintain galvanic separation. |
| GND2 | Ground, side 2 | Reference for VCC2 and OUTA/OUTB; forms isolated digital ground plane for MCU or ADC domains. |
| INA | Input, channel A | Accepts CMOS/LVCMOS signals from side-1; rising/falling thresholds scale with VCC1 (0.3×/0.7×VCC1). |
| INB | Input, channel B | Reverse-direction input tied to OUTB on side-2; enables bidirectional communication over single isolator. |
| OUTA | Output, channel A | Drives side-2 logic with 2mA sink/source at 3.3V; default-high behavior asserts safe state on side-2 during side-1 power loss. |
| OUTB | Output, channel B | Forward-direction output driven by INB; completes full-duplex isolation path between isolated domains. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low power architecture | Edge-based OOK modulation + refresh logic reduces static current to 4.8μA/ch at 3.3V - critical for loop-powered 4–20mA transmitters. |
| Robust capacitive barrier | Double SiO₂ dielectric with >100-year lifetime projection and 4242VPK transient rating - qualified per VDE 0884-17 and UL 1577. |
| Wide dual-supply flexibility | Independent 1.71–1.89V or 2.25–5.5V operation per side - eliminates external level shifters when interfacing 1.8V sensors to 5V controllers. |
| Fail-safe default output | Non-F variant defaults HIGH on power loss - ensures active-high enable lines remain asserted in safety-critical shutdown sequences. |
| System-level EMC immunity | ±8kV IEC 61000-4-2 contact ESD across barrier and low radiated emissions - simplifies compliance in factory automation equipment. |
Applications
| 4–20mA Loop-Powered Transmitters | Industrial PLC Digital I/O Modules |
|---|---|
Use Scenario: Isolating analog sensor outputs (e.g., pressure, temperature) in explosion-proof field instruments powered solely by 4–20mA loop current. IC Role / Device Role / Timing Role: Galvanic barrier between loop-powered front-end and host controller; provides signal integrity and fault containment. Use Value: 4.8μA/ch quiescent current preserves loop margin; 3000VRMS isolation meets IEC 61010-1 safety requirements for hazardous locations. |
Use Scenario: Protecting programmable logic controller (PLC) CPU from noise and ground faults in factory-floor digital input/output cards. IC Role / Device Role / Timing Role: Bidirectional channel isolator (1 forward, 1 reverse) enabling status feedback and command transmission across isolation boundary. Use Value: ±100kV/μs CMTI prevents spurious toggling during motor drive switching; SOIC-8 footprint supports high-density I/O module layouts. |
| Low-Power Sensor Interface Isolation | Isolated UART Communication |
Use Scenario: Isolating ultra-low-power environmental sensors (e.g., CO₂, humidity) in battery-operated building automation nodes. IC Role / Device Role / Timing Role: Signal-level isolator for digital sensor outputs (I²C, SPI, or GPIO), preserving sleep-mode current budgets. Use Value: 1.71V minimum supply enables direct connection to 1.8V sensor ICs; 125°C max operating temperature supports deployment near heat sources. |
Use Scenario: Adding galvanic isolation to RS-232/RS-485 UART links between industrial HMIs and embedded controllers. IC Role / Device Role / Timing Role: Two-channel isolator handling TX and RX lines separately, supporting full-duplex serial communication up to 4Mbps. Use Value: 250ns minimum pulse width and 10ns channel skew ensure reliable UART timing at 1Mbps+ baud rates; low emissions simplify FCC/CE certification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISO7021D | Same SOIC-8 package and electrical specs; differs only in tape-and-reel packaging (DR = reel, D = tube) | No functional difference; D variant used for prototyping or low-volume hand-soldering | Select ISO7021D for evaluation or small-batch builds where reel handling is unnecessary. |
| ADUM120N0BRZ | 1.5kVRMS isolation, 150Mbps max data rate, 0.95μA typical quiescent current, 8-SOIC package | Lacks reinforced 3000VRMS rating and ATEX/IECEx certification; lower CMTI (75kV/μs) | Choose ADUM120N0BRZ only for non-safety-critical, low-noise environments where ultra-low static power outweighs isolation robustness. |
Compared with ISO7021DR, ISO7021D offers identical performance in tube packaging for lab use, while ADUM120N0BRZ trades isolation strength and certification for lower static current - making ISO7021DR the sole choice for certified industrial safety systems requiring 3000VRMS and intrinsic safety compliance.
Availability
ISO7021DR is available at Aetrix Electronics and suitable for 4–20mA loop-powered transmitters, industrial PLC I/O modules, and isolated UART communication requiring stable component supply across extended temperature and safety-certified designs.
Supply support for ISO7021DR 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 ISO7021DR belongs to TI's ISO70xx ultra-low-power digital isolator family, engineered specifically for energy-constrained, safety-critical industrial sensing and control applications demanding long-term reliability and regulatory compliance.
FAQ
What is the default output state of the ISO7021DR during power loss?
The ISO7021DR features a default-high output configuration. When input-side power (VCC1) is lost or the input signal becomes invalid, the output (OUTA and OUTB) transitions to and holds a logic HIGH state after a 400–750μs delay. This fail-safe behavior ensures predictable system response in safety-critical loops, such as maintaining an enabled state in valve drivers or alarm circuits. The ISO7021DR does not require external pull-up resistors to achieve this behavior - it is implemented internally.
Does the ISO7021DR support different supply voltages on each side of the isolation barrier?
Yes, the ISO7021DR fully supports independent supply voltages on its isolated sides: VCC1 (side-1) and VCC2 (side-2) can each operate within either 1.71–1.89V or 2.25–5.5V ranges. This allows direct interfacing between 1.8V sensors and 3.3V microcontrollers, or 5V legacy peripherals and low-voltage FPGAs, without external level-shifting circuitry. Both supplies must remain within their respective valid ranges simultaneously for guaranteed operation across –55°C to 125°C.
What certifications does the ISO7021DR hold for industrial safety applications?
The ISO7021DR is certified to DIN EN IEC 60747-17 (VDE 0884-17), UL 1577, IEC 62368-1, IEC 61010-1, GB 4943.1, and carries IECEx/ATEX approval for intrinsic safety (II 1G Ex ia IIC Ga). These certifications validate its 3000VRMS reinforced isolation, 4242VPK transient withstand, and suitability for use in hazardous locations, medical equipment, and measurement category II/III industrial systems - with no derating required up to 400VRMS working voltage.
How does the ISO7021DR achieve ultra-low power consumption without sacrificing speed?
The ISO7021DR achieves sub-5μA/ch quiescent current through edge-based OOK modulation and a low-frequency refresh timer that only activates when input transitions stall for >100μs. Unlike carrier-based isolators, it avoids continuous high-frequency oscillation - instead transmitting only on signal edges and periodically validating DC state. At 1Mbps, total per-channel current remains ≤120μA, enabling 4Mbps operation while sustaining battery life in loop-powered field devices far beyond competing isolators.
Can the ISO7021DR replace older optocouplers in existing designs?
Yes, the ISO7021DR is a drop-in replacement for many 8-pin optocouplers (e.g., HCPL-0721, TLP2361) in terms of footprint, pinout, and logic function - but with superior performance: 100× lower power, 10× higher CMTI, 3× faster propagation (140–165ns), and no LED aging or temperature drift. Its SOIC-8 package matches standard optocoupler land patterns, and its default-high output aligns with common optocoupler active-high configurations. No PCB redesign is needed for migration.
ISO7021DR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- 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):
- 100kV/µs
- Data Rate:
- 4Mbps
- Propagation Delay tpLH / tpHL (Max):
- 165ns, 165ns
- Pulse Width Distortion (Max):
- 10ns
- Rise / Fall Time (Typ):
- 5ns, 5ns
- Voltage - Supply:
- 1.71V ~ 1.89V, 2.25V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -55°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
ISO7021DR FAQ
1.How can I place an order for ISO7021DR through Aetrix?
Please submit a Request for Quotation (RFQ) for ISO7021DR 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 ISO7021DR reliable?
The price and inventory of ISO7021DR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISO7021DR is usually 5 days.
3.What payment methods are accepted for ISO7021DR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISO7021DR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISO7021DR?
ISO7021DR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISO7021DR 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 ISO7021DR?
For technical support, including ISO7021DR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISO7021DR requirements.
6.How does Aetrix verify that ISO7021DR is sourced from the original manufacturer or authorized distributors?
All ISO7021DR 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 ISO7021DR meets industry standards.
7.What is the process for return or replacement of ISO7021DR?
All ISO7021DR units undergo pre-shipment inspection (PSI). If there is an issue with ISO7021DR, 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 ISO7021DR part is unused and in its original packaging.
Return procedure for ISO7021DR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
ISO7021DR Tags
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