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STMicroelectronics STISO621TR
- Part No.:
- STISO621TR
- Manufacturer:
- STMicroelectronics
- Category:
- Digital Isolators
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
STISO621TR.pdf
- Description:
- DUAL CHANNEL DIGITAL ISOLATOR
- Quantity:
- Payment:
- Shipping:
Inventory:1,986
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Product details
Overview
STISO621TR from STMicroelectronics is a dual-channel, unidirectional digital isolator with 1–1 channel directionality, 100 Mbps maximum data rate, 3.3 V/5 V level translation capability, and 6 kV galvanic isolation in SO8 narrow-body package. It replaces optocouplers in industrial fieldbus and battery monitoring systems where high CMTI (>50 kV/µs), wide temperature operation (−40°C to 125°C), and low pulse width distortion (<3 ns) are required.
For engineers reviewing the STISO621TR datasheet, STISO621TR pinout, STISO621TR application, or STISO621TR equivalent, this device supports robust noise immunity via Schmitt-trigger inputs, features watchdog-driven safe-state logic (low-level default), and delivers precise timing integrity across isolated domains in motor drive control and isolated ADC interfaces.
Technical Context
The STISO621TR implements two independent galvanically isolated signal paths using ST's thick-oxide silicon dioxide barrier, enabling bidirectional communication across isolation boundaries with strict 1→2 and 2→1 channel mapping. Each channel integrates Schmitt-trigger input receivers for noise rejection and push-pull outputs with 50 Ω nominal impedance and <4 ns rise/fall times.
It incorporates a refresh mechanism (tREFRESH = 1–2 µs) ensuring data persistence during idle periods, and a watchdog timer (tWD = 2–6 µs) forcing RX outputs to logic low upon loss of TX activity-critical for fail-safe operation in motor gate drivers and battery management safety chains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation rating | 3.5 kVRMS withstand voltage (UL 1577), 6 kVPEAK surge rating (IEC 62368-1) - enables direct interface with 600 VRMS mains-connected circuits. |
| Max data rate | 100 Mbps - supports high-speed serial protocols including SPI, RS-485 transceiver control, and isolated CAN FD signaling. |
| CMTI | 50–65 kV/µs - prevents false triggering in noisy motor drive environments with fast-switching IGBTs or SiC FETs. |
| Supply range | 3 V to 5.5 V per side - allows mixed-voltage system integration (e.g., 3.3 V MCU side / 5 V PLC side). |
| Pulse width distortion | <3 ns - ensures deterministic timing for clock forwarding, PWM edge alignment, and time-of-flight measurements. |
| Operating temperature | −40°C to +125°C ambient - qualified for under-hood automotive subsystems and industrial inverters without derating. |
| Propagation delay | 25–42 ns (H→L/L→H) - enables sub-100 ns loop timing in closed-loop current sensing and gate driver feedback paths. |
Pinout & Package
STISO621TR is housed in an SO8 narrow-body (SO8N) package with 1.27 mm pitch, 4 mm creepage/clearance, and UL/IEC-certified isolation barrier. Pin 1 (VDD1) to Pin 4 (GND1) form Side 1; Pin 5 (GND2) to Pin 8 (VDD2) form Side 2 - no shared ground or supply between sides.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 VDD1 | Supply voltage input (Side 1) | Power domain for RX1/TX1 logic; UVLO threshold at 2.8 V ensures clean startup before enabling isolation path. |
| 2 RX1 | Logic output (Side 1) | Receives data from TX2 on Side 2; drives 4 mA load at VOH ≥ VDD1 − 0.3 V for robust CMOS interfacing. |
| 3 TX1 | Logic input (Side 1) | Transmits data to RX2 on Side 2; Schmitt-trigger input (VIHL = 0.8 V, VILH = 2.0 V) rejects sub-500 mV noise spikes. |
| 4 GND1 | Reference ground (Side 1) | Return path for Side 1 signals only; must be isolated from GND2 to maintain galvanic barrier integrity. |
| 5 GND2 | Reference ground (Side 2) | Return path for Side 2 signals only; physically separated by 4 mm clearance from GND1 per IEC 60664-1. |
| 6 RX2 | Logic output (Side 2) | Receives data from TX1 on Side 1; low-power output stage draws ≤20 mA at 100 Mbps, CL = 20 pF. |
| 7 TX2 | Logic input (Side 2) | Transmits data to RX1 on Side 1; identical Schmitt thresholds and hysteresis (0.5 V) as TX1 for matched noise immunity. |
| 8 VDD2 | Supply voltage input (Side 2) | Independent power domain for RX2/TX2; supports asynchronous supply sequencing with tPOWUP = 30 µs. |
Key Features
| Feature | Design Value |
|---|---|
| Dual unidirectional channels | Fixed 1→2 and 2→1 topology eliminates cross-talk risk and simplifies PCB routing versus bidirectional isolators. |
| Watchdog-enabled safe state | Forces RX outputs low within 6 µs of TX inactivity - critical for disabling gate drivers during MCU reset or power fault. |
| Level translation | 3.3 V ↔ 5 V compatibility on either side enables legacy 5 V sensor interfacing with modern 3.3 V microcontrollers. |
| Low-power 100 Mbps operation | 2 mA quiescent current per side and 18–20 mA at full speed - reduces thermal load in dense isolation clusters. |
| Thick-oxide isolation barrier | ST's proprietary SiO₂ dielectric achieves 1500 VPEAK VIORM in SO8W variant and 1200 VPEAK in SO8N - validated per IEC 60747-17. |
Applications
| Industrial Fieldbus Isolation | Battery Management System (BMS) |
|---|---|
|
Use Scenario: Isolating RS-485 transceiver control lines and data lines in PROFIBUS-DP nodes operating in factory-floor EMI environments. IC Role / Device Role / Timing Role: Dual-channel isolator providing separate TX/RX paths between MCU UART and transceiver, with CMTI >50 kV/µs preventing bit errors during nearby contactor switching. Use Value: Eliminates optocoupler latency and aging drift while maintaining <42 ns propagation delay symmetry for deterministic bus arbitration timing. |
Use Scenario: Isolating cell voltage measurement ADC SPI interface and pack current shunt amplifier outputs in EV traction battery packs. IC Role / Device Role / Timing Role: Transmitting digitized cell voltages from isolated analog front-end to main BMS controller, with watchdog ensuring open-circuit detection on broken sensor lines. Use Value: Enables 100 Mbps SPI clock forwarding without jitter accumulation, supporting 16-bit ADC sampling at >1 MSPS across isolation boundary. |
| Motor Drive Gate Driver Interface | Programmable Logic Controller (PLC) Digital I/O |
|
Use Scenario: Isolating PWM signals and fault feedback between FPGA-based motion controller and IGBT/SiC gate driver ICs in servo inverters. IC Role / Device Role / Timing Role: Delivering synchronized gate pulses with <3 ns pulse width distortion to prevent shoot-through, while returning DESAT or overcurrent alerts with sub-50 ns latency. Use Value: Guarantees matched channel delays (tDHL/tDLH ≤ 42 ns) and tight skew control essential for multi-phase bridge timing integrity. |
Use Scenario: Providing channel-isolated digital input conditioning for 24 V DC field sensors and output driving for solenoid valves in modular PLC backplanes. IC Role / Device Role / Timing Role: Replacing discrete optocouplers per I/O point with integrated dual isolator, supporting 3–5.5 V logic on both sides for mixed-voltage I/O modules. Use Value: Reduces board space by 60% vs. dual optocoupler solution while improving long-term reliability and temperature stability over −40°C to 125°C. |
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 |
|---|---|---|---|
| ADUM120N0BRZ | Lower CMTI (35 kV/µs), 25 Mbps max rate, SOIC-8 narrow body, no watchdog timer | Limited to lower-noise industrial controls; unsuitable for motor drive gate drive timing or fast fieldbus. | Select when cost sensitivity outweighs timing precision and fail-safe requirements. |
| SI8621ED-B-IS | Higher VIORM (1750 VPEAK), 150 Mbps rate, but no Schmitt-trigger inputs and higher PWD (5 ns) | Better for high-voltage energy metering; less robust against slow-rising noise in factory automation. | Prefer for ultra-high isolation voltage needs where input noise immunity is secondary to surge rating. |
Compared with ADUM120N0BRZ and SI8621ED-B-IS, STISO621TR uniquely balances 100 Mbps speed, <3 ns PWD, integrated watchdog, and 50+ kV/µs CMTI in a compact SO8N package-making it optimal for timing-critical, fail-safe isolation in motor drives and BMS.
Availability
STISO621TR is available at Aetrix Electronics and suitable for industrial fieldbus isolation, battery management systems, motor drive gate driver interfaces, and PLC digital I/O requiring stable component supply across extended temperature and high-reliability production cycles.
Supply support for STISO621TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and power applications.
The STISO621TR belongs to ST's STISO family of reinforced digital isolators, engineered specifically for high-noise industrial automation and electric vehicle subsystems demanding certified galvanic isolation, precise timing, and functional safety compliance.
FAQ
What is the isolation voltage rating of STISO621TR and which certifications does it hold?
STISO621TR provides 3.5 kVRMS isolation withstand voltage (60 s test) and 6 kVPEAK surge isolation, certified to UL 1577 (E362869) and IEC 60747-17 (5022192-4880-0002/300335) in SO8 narrow-body package. Its VIORM is 1200 VPEAK and VIOSM is ≥5200 VPEAK, meeting reinforced insulation requirements for 600 VRMS mains-connected equipment.
Does STISO621TR support independent supply voltages on each side?
Yes - STISO621TR accepts 3 V to 5.5 V on VDD1 and VDD2 independently, enabling level translation between 3.3 V microcontrollers and 5 V peripherals. Supply sequencing is flexible: if one side powers up first, the watchdog forces the opposite-side RX outputs into a safe low state until both supplies exceed UVLO (2.8 V).
How does the watchdog function operate and what is its timeout window?
The watchdog monitors TX activity on each side and forces the corresponding RX output low if no valid transition occurs for longer than tWD (2–6 µs). This ensures fail-safe behavior during MCU lockup, supply brownout, or broken communication links - critical for gate driver disable and BMS fault containment.
Can STISO621TR replace optocouplers directly in existing designs?
Yes - STISO621TR uses standard SO8 narrow-body footprint and pinout (VDD1/RX1/TX1/GND1/GND2/RX2/TX2/VDD2), matching common optocoupler footprints. Its Schmitt-trigger inputs, 100 Mbps speed, and low propagation delay enable drop-in replacement without layout changes, while improving timing accuracy and long-term reliability.
STISO621TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Technology:
- Magnetic Coupling
- Type:
- General Purpose
- Isolated Power:
- No
- Number of Channels:
- 2
- Inputs - Side 1/Side 2:
- 1/1
- Channel Type:
- Unidirectional
- Voltage - Isolation:
- 4000Vpk
- Common Mode Transient Immunity (Min):
- 50kV/µs
- Data Rate:
- 100Mbps
- Propagation Delay tpLH / tpHL (Max):
- 42ns, 42ns
- Pulse Width Distortion (Max):
- 3ns
- Rise / Fall Time (Typ):
- 2ns, 2ns
- Voltage - Supply:
- 3V ~ 5.5V
- Grade:
- -
- Qualification:
- -
- Operating Temperature:
- -40°C ~ 125°C
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
STISO621TR FAQ
1.How can I place an order for STISO621TR through Aetrix?
Please submit a Request for Quotation (RFQ) for STISO621TR 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 STISO621TR reliable?
The price and inventory of STISO621TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STISO621TR is usually 5 days.
3.What payment methods are accepted for STISO621TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STISO621TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STISO621TR?
STISO621TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STISO621TR 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 STISO621TR?
For technical support, including STISO621TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STISO621TR requirements.
6.How does Aetrix verify that STISO621TR is sourced from the original manufacturer or authorized distributors?
All STISO621TR 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 STISO621TR meets industry standards.
7.What is the process for return or replacement of STISO621TR?
All STISO621TR units undergo pre-shipment inspection (PSI). If there is an issue with STISO621TR, 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 STISO621TR part is unused and in its original packaging.
Return procedure for STISO621TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
STISO621TR Tags
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