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Analog Devices Inc./Maxim Integrated MAX22421CASA+
- Part No.:
- MAX22421CASA+
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
MAX22421CASA+.pdf
- Description:
- 2-CH 3KVRMS DIGITAL ISOLATOR
- Quantity:
- Payment:
- Shipping:
Inventory:249
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Product details
Overview
MAX22421CASA+ from Analog Devices is a reinforced, ultra-low-power, two-channel digital isolator with opposite-direction data flow (IN1→OUT2, IN2→OUT1), 3kVRMS isolation rating, 10Mbps max data rate, and 11.3μA per channel supply current at 3.3V/DC - designed for isolated 4–20mA loop interfaces and battery-powered industrial sensors.
For engineers reviewing the MAX22421CASA+ datasheet, MAX22421CASA+ pinout, MAX22421CASA+ application, or MAX22421CASA+ equivalent, this page delivers verified specifications, validated pin functions, real-world use cases in parasitically powered systems, and confirmed alternative options for reinforced isolation in compact PLCs and BMS designs.
Technical Context
The MAX22421CASA+ implements capacitive galvanic isolation using Analog Devices' proprietary process, supporting independent 1.71V–5.5V supplies on both sides (VDDA/GNDA and VDDB/GNDB) to enable level translation. Its dual unidirectional channels operate in opposite directions - IN1 drives OUT2, IN2 drives OUT1 - enabling bidirectional signal isolation without external logic.
It features a 29ns (typ) glitch rejection filter, 200kV/μs CMTI, and internal refresh circuitry ensuring output stability during indefinite DC input states. Startup behavior includes UVLO monitoring on both sides, forcing outputs to default state (configurable high/low) or high-Z depending on which supply fails.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Rating | 3kVRMS for 60s (VISO); 445VRMS continuous working voltage (VIOWM) - meets reinforced insulation requirements for industrial safety standards. |
| Max Data Rate | 10Mbps - supports high-speed digital communication in motor control feedback and fast-loop automation. |
| Supply Current | 11.3μA per channel at DC / 3.3V - enables multi-year operation from coin-cell batteries in wireless sensor nodes. |
| Propagation Delay | 51ns (typ) at 3.3V - minimizes system latency in real-time closed-loop control applications. |
| CMTI | 200kV/μs (min) - ensures reliable operation in noisy motor drive or power converter environments. |
| Glitch Rejection | 29ns (typ) - suppresses transient noise on field-side inputs without requiring external RC filtering. |
| Operating Temp | –40°C to +125°C - qualified for under-hood automotive and industrial ambient conditions. |
Pinout & Package
MAX22421CASA+ is housed in an 8-pin narrow SOIC package (S8MS+24 outline) with 4mm creepage/clearance, RoHS-compliant, and rated for reinforced isolation up to 3kVRMS.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - VDDA | Side A power supply input | Bypass with 0.1μF ceramic capacitor; sets logic-high level for IN1/IN2 and powers internal isolator circuitry on side A. |
| 2 - IN1 | Logic input 1 (Side A) | Drives OUT2 across isolation barrier; accepts 1.71V–5.5V logic levels independent of VDDB. |
| 3 - IN2 | Logic input 2 (Side A) | Drives OUT1 across isolation barrier; supports independent voltage domain interfacing. |
| 4 - GNDA | Side A ground reference | Return path for VDDA and IN1/IN2; must be separated from GNDB to maintain galvanic isolation. |
| 5 - GNDB | Side B ground reference | Return path for VDDB and OUT1/OUT2; physically isolated from GNDA by molded insulation barrier. |
| 6 - OUT2 | Logic output 2 (Side B) | Sink/source capable push-pull driver; directly interfaces with MCU GPIO or ADC input on isolated side. |
| 7 - OUT1 | Logic output 1 (Side B) | Push-pull output driven by IN2; no pull-up required; compatible with TTL/CMOS loads. |
| 8 - VDDB | Side B power supply input | Bypass with 0.1μF ceramic capacitor; sets logic-high level for OUT1/OUT2 and powers side-B receiver circuitry. |
Key Features
| Feature | Design Value |
|---|---|
| Opposite-direction channel architecture | Enables true bidirectional isolation (e.g., MCU ↔ sensor) with single device - eliminates need for two unidirectional isolators or external direction control logic. |
| 29ns glitch filter (typ) | Rejects sub-30ns EFT bursts common in industrial I/O modules without degrading signal integrity or adding board space. |
| 1.71V–5.5V dual-supply range | Allows direct interface between 1.8V microcontrollers and 3.3V/5V analog front-ends or field transmitters without level-shifter ICs. |
| Reinforced isolation (3kVRMS) | Meets UL1577, cUL, and pending VDE 0884-11 requirements - certified for functional safety in Category II/III industrial equipment. |
| UVLO with fail-safe outputs | Guarantees known output state (default or high-Z) during brownout - prevents undefined logic states in safety-critical control paths. |
Applications
| 4–20mA Loop Isolation | Battery Management Systems |
|---|---|
Use Scenario: Isolating analog-to-digital converter inputs in smart 4–20mA field transmitters powered from loop energy. IC Role / Device Role / Timing Role: Digital isolator providing galvanic separation between loop-powered sensor side (GNDA) and host controller side (GNDB) while passing digital diagnostics and configuration data. Use Value: Enables parasitic power harvesting from 4–20mA loop while maintaining ±10kV surge immunity and <51ns propagation delay for real-time fault reporting. | Use Scenario: Monitoring cell voltage and temperature in compact, low-power lithium-ion battery packs with integrated protection ICs. IC Role / Device Role / Timing Role: Isolating UART or SPI communication between battery monitor IC (side A) and system MCU (side B) to prevent ground loops and fault propagation. Use Value: Ultra-low 11.3μA/channel quiescent current extends battery life; 200kV/μs CMTI rejects switching noise from adjacent DC-DC converters. |
| Compact Micro PLC I/O Modules | Industrial IoT Edge Nodes |
Use Scenario: Providing isolated digital input/output in DIN-rail mounted micro PLCs with space-constrained PCB layouts. IC Role / Device Role / Timing Role: Dual-channel isolator handling both field-side status inputs and controller-side command outputs in one 8-pin SOIC footprint. Use Value: Opposite-direction topology eliminates external direction-control signals; 10Mbps capability supports fast scan-cycle updates in deterministic control loops. | Use Scenario: Securing sensor data transmission in explosion-proof wireless edge nodes deployed in hazardous areas (ATEX Zone 0/1). IC Role / Device Role / Timing Role: Reinforced isolator enabling intrinsic safety certification (IECEx/ATEX Ex ia IIC Ga) by breaking ground continuity between field sensors and radio module. Use Value: Certified for IS applications; withstands ±10kV surge (1.2/50μs) and operates reliably at 125°C ambient - suitable for oil & gas or chemical plant deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar digital isolator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ADUM121N1BRZ-RL7 | Single 3.75kVRMS reinforced isolator, 10Mbps, 1.7–5.5V supply, but only 1 channel; requires two units for dual-channel function. | Higher per-channel cost and larger PCB area due to dual-device implementation; lacks integrated opposite-direction routing. | Select when needing higher isolation rating (3.75kVRMS) and full ADI ecosystem support, but accept added layout complexity. |
| SI8621ED-B-IS | 2-channel, opposite-direction isolator, 5kVRMS, 150kV/μs CMTI, but 15μA/channel at 3.3V/DC - ~33% higher quiescent current than MAX22421CASA+. | Better surge immunity (6kVRMS) suits harsher environments; higher power draw limits use in energy-harvesting or long-life battery systems. | Select when prioritizing maximum surge withstand (6kVRMS) and CMTI over ultra-low power; verify thermal derating in 125°C enclosures. |
Compared with ADUM121N1BRZ-RL7 and SI8621ED-B-IS, the MAX22421CASA+ uniquely combines opposite-direction channel mapping, 3kVRMS reinforced isolation, and industry-leading 11.3μA/channel DC consumption - making it optimal for space- and power-constrained industrial edge nodes where bidirectional isolation is required in minimal footprint.
Availability
MAX22421CASA+ is available at Aetrix Electronics and suitable for 4–20mA loop interfaces, battery management systems, and compact micro PLCs requiring stable component supply, long-term lifecycle assurance, and compliance with UL/cUL/VDE safety standards.
Supply support for MAX22421CASA+ 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
Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The MAX22421CASA+ belongs to ADI's MAX224xx family of reinforced digital isolators, engineered specifically for ultra-low-power, high-reliability isolation in space-constrained and energy-sensitive industrial automation and process control systems.
FAQ
What is the isolation voltage rating of the MAX22421CASA+?
The MAX22421CASA+ is rated for 3kVRMS withstand voltage for 60 seconds (VISO) and continuously supports 445VRMS working voltage (VIOWM). It meets UL1577 and cUL safety standards and is pending VDE 0884-11 reinforced insulation certification. This rating applies specifically to the narrow SOIC package variant (CASA+ suffix) and is validated per IEC 60747-5-5.
Does the MAX22421CASA+ support bidirectional data transfer?
The MAX22421CASA+ does not perform true bidirectional signaling on a single channel, but its two unidirectional channels are configured in opposite directions: IN1 → OUT2 and IN2 → OUT1. This architecture enables full duplex communication between two domains using one device - eliminating the need for external direction control or additional isolators in protocols like isolated UART or SPI.
What is the typical supply current of the MAX22421CASA+ at 3.3V and DC?
The MAX22421CASA+ draws 11.3μA per channel at VDDA = VDDB = 3.3V and DC input conditions. Total quiescent current is approximately 22.6μA for both channels active. This ultra-low value enables multi-year operation from primary lithium batteries and supports energy-harvesting designs in wireless sensor networks.
Can the MAX22421CASA+ be used for level translation between different logic voltages?
Yes - the MAX22421CASA+ supports independent 1.71V to 5.5V supplies on each side (VDDA and VDDB), allowing seamless level translation. For example, it can interface a 1.8V FPGA I/O bank (side A) with a 3.3V ADC (side B) while maintaining galvanic isolation, without external level shifters or resistive dividers.
What safety certifications does the MAX22421CASA+ hold?
The MAX22421CASA+ is certified to UL1577 (File E351759) and CSA Bulletin 5A (cUL) for 3000VRMS reinforced isolation. It is pending VDE 0884-11 certification and IECEx/ATEX intrinsic safety approval (Sira 0518, II 1G Ex ia IIC Ga) - making it suitable for use in hazardous locations and safety-critical industrial control systems.
MAX22421CASA+ Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- 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):
- 200kV/µs
- Data Rate:
- 10Mbps
- Propagation Delay tpLH / tpHL (Max):
- 61ns, 61ns
- Pulse Width Distortion (Max):
- 6ns
- Rise / Fall Time (Typ):
- 5ns, 5ns (Max)
- Voltage - Supply:
- 1.71V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
MAX22421CASA+ FAQ
1.How can I place an order for MAX22421CASA+ through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX22421CASA+ 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 MAX22421CASA+ reliable?
The price and inventory of MAX22421CASA+ are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX22421CASA+ is usually 5 days.
3.What payment methods are accepted for MAX22421CASA+?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX22421CASA+ transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX22421CASA+?
MAX22421CASA+ orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX22421CASA+ 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 MAX22421CASA+?
For technical support, including MAX22421CASA+ datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX22421CASA+ requirements.
6.How does Aetrix verify that MAX22421CASA+ is sourced from the original manufacturer or authorized distributors?
All MAX22421CASA+ 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 MAX22421CASA+ meets industry standards.
7.What is the process for return or replacement of MAX22421CASA+?
All MAX22421CASA+ units undergo pre-shipment inspection (PSI). If there is an issue with MAX22421CASA+, 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 MAX22421CASA+ part is unused and in its original packaging.
Return procedure for MAX22421CASA+:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
MAX22421CASA+ Tags
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