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STMicroelectronics ISO808AQTR
- Part No.:
- ISO808AQTR
- Manufacturer:
- STMicroelectronics
- Package:
- 36-PowerBSSOP (0.433", 11.00mm Width)
- Datasheet:
-
ISO808AQTR.pdf
- Description:
- LINEAR IC'S
- Quantity:
- Payment:
- Shipping:
Inventory:746
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Product details
Overview
ISO808AQTR from STMicroelectronics is a galvanically isolated octal high-side power solid-state relay with SPI interface, designed for driving inductive loads in industrial control systems. It features 8 independent high-side outputs, 0.125 Ω typical RDS(on) per channel, VCC operating range of 9.2–36 V, and integrated per-channel over-temperature protection with thermal independence. Used in PLC I/O modules for solenoid and valve actuation.
For engineers reviewing the ISO808AQTR datasheet, ISO808AQTR pinout, ISO808AQTR application, or ISO808AQTR equivalent, this device supports daisy-chained SPI configuration, provides open-drain FAULT/PGOOD diagnostics, delivers fast demagnetization (VDEMAG = VCC − 54 V), and meets IEC 61000-4-2/4/5/8 and UL1577 safety standards - critical for robust industrial field I/O design.
Technical Context
The ISO808AQTR integrates two galvanically isolated voltage domains: VCC/GNDCC (process stage, up to 36 V) and VDD/GNDDD (logic stage, 2.75–5.5 V), communicating via ST's proprietary isolation protocol. Each of its eight high-side channels includes independent junction over-temperature shutdown (TJSD = 150–200 °C) and case over-temperature protection (TCSD = 125–135 °C).
It implements an 8-bit SPI interface (up to 20 MHz) with daisy-chain capability, where SDI carries output status commands and SDO returns fault status (all-0 = no fault, all-1 = at least one fault). The watchdog timeout (tWD = 272–400 μs) ensures safe output disable upon logic-stage failure, while OUT_EN enables hardware-level global output disable with 150 ns pulse width requirement.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 9.2 V to 36 V - supports standard 24 V industrial supply with ±10% tolerance and brown-out immunity. |
| RDS(on) (Typ) | 0.125 Ω @ 25 °C - enables <0.3 W conduction loss per channel at 0.5 A, reducing thermal stress in dense I/O modules. |
| IOUT Limit | 0.7 A min (ISO808AQ) - hard current limiting protects against short-circuit faults without external fusing. |
| VDEMAG | VCC − 54 V (typ) - accelerates energy dissipation during inductive turn-off, suppressing voltage spikes >1 kV in relay/solenoid drivers. |
| Isolation Rating | 1500 VPEAK (IEC 60747-17) - certified reinforced insulation barrier enabling safe separation between MCU and 24 V field side. |
| CM Transient Immunity | ±25 V/ns - maintains reliable operation in electrically noisy PLC cabinets with fast-switching motor drives nearby. |
| SPI Speed | 20 MHz max - allows full 8-bit output update in ≤400 ns, supporting real-time deterministic I/O scanning. |
Pinout & Package
ISO808AQTR is packaged in TFQFPN32 (5 mm × 5 mm, 0.5 mm pitch), with exposed thermal pad connected internally to GNDCC. Pin 19 (TAB/GNDCC) must be soldered to a dedicated ground plane for thermal and functional integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OUT1–OUT8 | High-side power output | Eight independent 0.7 A-rated NMOS outputs referenced to GNDCC; each drives one side of load (other side grounded). |
| VCC | Process stage supply | Positive supply for power stage (9.2–36 V); internal clamp at 47–57 V prevents overvoltage damage. |
| GNDCC | Process stage ground | Power ground return; connects to exposed thermal tab - must be low-impedance PCB copper pour. |
| VDD | Logic stage supply | 3.3 V or 5 V digital supply; UVLO thresholds (2.45–2.75 V) prevent erratic SPI behavior during rail droop. |
| GNDDD | Logic stage ground | Digital ground reference; galvanically isolated from GNDCC - no shared ground connection allowed. |
| SS, CLK, SDI, SDO | SPI interface | Standard 4-wire SPI (CPOL=0, CPHA=0); SDO tri-states when SS high, enabling daisy chaining. |
| OUT_EN | Global output enable | Active-low hardware reset: forces all outputs OFF and clears internal register; requires ≥150 ns pulse width. |
| FAULT / PGOOD | Open-drain diagnostics | Active-low fault indicators: FAULT signals OVT/OVC/internal comms error; PGOOD asserts if VCC < 14.5 V. |
Key Features
| Feature | Design Value |
|---|---|
| Galvanic isolation | Reinforced insulation barrier (1500 VPEAK) separating logic and process domains per IEC 60747-17. |
| Per-channel thermal protection | Independent junction shutdown (TJSD = 150–200 °C) and restart (TJR = 160 °C) - non-latching, preserves system uptime. |
| Fast inductive demagnetization | VDEMAG = VCC − 54 V typ - suppresses flyback voltage spikes during turn-off of 100+ mH solenoids. |
| Integrated watchdog & refresh | tWD = 272–400 μs timeout + periodic refresh - ensures fail-safe output disable if MCU freezes or SPI stalls. |
| Loss-of-ground detection | Monitors GNDCC disconnection; limits output current to 500 μA if ground opens - prevents uncontrolled load energization. |
Applications
| PLC Digital Output Module | Industrial PC Peripheral I/O |
|---|---|
Use Scenario: 24 V DC output card in modular PLC rack driving solenoid valves and indicator lamps. IC Role / Device Role / Timing Role: High-side switch IC providing isolated, current-limited, thermally protected drive for 8 discrete field devices. Use Value: Eliminates need for external flyback diodes and thermal sensors; SPI status reporting enables predictive maintenance via FAULT/PGOOD monitoring. |
Use Scenario: Expansion I/O board for industrial PC controlling conveyor belt actuators and position sensors. IC Role / Device Role / Timing Role: Galvanically isolated octal driver interfacing PC's 3.3 V SPI bus to 24 V field wiring. Use Value: Enables deterministic 20 MHz SPI updates for synchronized multi-axis motion control, with per-channel fault isolation preventing cascade failures. |
| Numerical Control Machine I/O | Inductive Load Driver Board |
Use Scenario: CNC machine tool I/O subsystem managing coolant pumps, spindle brakes, and tool changers. IC Role / Device Role / Timing Role: Process-stage high-side driver with fast demag (VDEMAG = VCC − 54 V) for inductive brake coils. Use Value: Prevents contact arcing and coil insulation breakdown by clamping turn-off transients below 50 V, extending actuator life. |
Use Scenario: Standalone driver board for HVAC damper actuators, irrigation solenoids, and lighting ballasts. IC Role / Device Role / Timing Role: Single-chip solution replacing discrete opto-MOS + protection circuitry for resistive/capacitive/inductive loads. Use Value: Reduces BOM count by >12 components per channel while meeting UL1577 and IEC 61000-4-5 surge immunity requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar galvanically isolated high-side driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ISO808A-1TR | Same functionality but in PowerSO-36 package; higher Rth(j-case) (0.8 °C/W vs. 1.0 °C/W) and 1 A current limit (vs. 0.7 A). | Better thermal performance in high-power-density designs; suited for continuous 0.8 A loads where ISO808AQTR's 0.7 A limit may trigger OVL. | Select ISO808A-1TR when board space allows larger package and higher sustained current is required. |
| TPL7407LPWR | Non-isolated 7-channel NPN sink driver; no galvanic barrier, no SPI, no thermal shutdown per channel. | Limited to low-voltage logic-level loads; requires external isolation and protection for industrial 24 V field use. | Only viable for cost-sensitive, non-safety-critical 5 V embedded applications - not a drop-in replacement. |
Compared with ISO808AQTR, ISO808A-1TR offers higher current capability and better thermal dissipation in a larger package, while TPL7407LPWR lacks isolation, diagnostics, and protection - making it unsuitable for industrial field I/O where safety and reliability are mandatory.
Availability
ISO808AQTR is available at Aetrix Electronics and suitable for programmable logic control, industrial PC peripheral I/O, and numerical control machine applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial automation OEMs.
Supply support for ISO808AQTR 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, specializing in automotive, industrial, and power management solutions with broad IP and manufacturing scale.
The ISO808A/Q series belongs to ST's industrial isolated drivers product line, engineered specifically for high-reliability, safety-certified digital output modules in harsh electromagnetic environments - targeting PLC, CNC, and factory automation systems.
FAQ
What is the maximum continuous output current per channel for ISO808AQTR?
The ISO808AQTR specifies a minimum short-circuit current limit (ILIM(MIN)) of 0.7 A per channel under all conditions. Its typical RDS(on) of 0.125 Ω yields ~44 mW conduction loss at 0.6 A, enabling continuous operation up to 0.7 A with proper PCB thermal design. Exceeding this triggers per-channel over-current protection.
Does ISO808AQTR require external flyback diodes for inductive loads?
No. The ISO808AQTR integrates active demagnetization that pulls the output voltage to VDEMAG = VCC − 54 V (typical) during turn-off, effectively clamping flyback energy without external diodes. This feature is validated for inductive loads ≥1 mH and eliminates PCB space and BOM cost associated with discrete snubbers.
How does the FAULT pin behave during SPI communication errors?
The FAULT pin asserts low on three confirmed conditions: (1) any channel junction temperature exceeds TJSD (150–200 °C), (2) case temperature exceeds TCSD (125–135 °C), or (3) internal isolation communication error - including non-multiple-of-8 bit transfers on SDI. The pin remains latched low until the fault clears and SS is cycled.
Can ISO808AQTR operate with a 3.3 V logic supply and 24 V process supply simultaneously?
Yes. ISO808AQTR is explicitly rated for VDD = 2.75–5.5 V (including 3.3 V TTL/CMOS) and VCC = 9.2–36 V (including 24 V). Its input thresholds (VIL = 0.3×VDD, VIH = 0.7×VDD) and isolation barrier ensure robust interoperability between 3.3 V microcontrollers and 24 V field-side loads.
ISO808AQTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 36-PowerBSSOP (0.433", 11.00mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Switch Type:
- Relay, Solenoid Driver
- Number of Outputs:
- 8
- Ratio - Input:Output:
- 1:8
- Output Configuration:
- High Side
- Output Type:
- N-Channel
- Interface:
- On/Off, SPI
- Voltage - Load:
- 9.2V ~ 36V
- Voltage - Supply (Vcc/Vdd):
- 9.2V ~ 36V
- Current - Output (Max):
- 2.3A
- Rds On (Typ):
- 125mOhm
- Input Type:
- Non-Inverting
- Features:
- Auto Restart, Power Good, Status Flag
- Fault Protection:
- Current Limiting (Fixed), Over Load, Over Temperature, Over Voltage, Reverse Current, UVLO
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- PowerSO-36, Bottom Pad
ISO808AQTR FAQ
1.How can I place an order for ISO808AQTR through Aetrix?
Please submit a Request for Quotation (RFQ) for ISO808AQTR 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 ISO808AQTR reliable?
The price and inventory of ISO808AQTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ISO808AQTR is usually 5 days.
3.What payment methods are accepted for ISO808AQTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ISO808AQTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ISO808AQTR?
ISO808AQTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ISO808AQTR 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 ISO808AQTR?
For technical support, including ISO808AQTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ISO808AQTR requirements.
6.How does Aetrix verify that ISO808AQTR is sourced from the original manufacturer or authorized distributors?
All ISO808AQTR 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 ISO808AQTR meets industry standards.
7.What is the process for return or replacement of ISO808AQTR?
All ISO808AQTR units undergo pre-shipment inspection (PSI). If there is an issue with ISO808AQTR, 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 ISO808AQTR part is unused and in its original packaging.
Return procedure for ISO808AQTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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