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STMicroelectronics ST72F321BAR9T3
- Part No.:
- ST72F321BAR9T3
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 64-LQFP
- Datasheet:
-
ST72F321BAR9T3.pdf
- Description:
- IC MCU 8BIT 60KB FLASH 64LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,988
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Product details
Overview
ST72F321BAR9T3 from STMicroelectronics is a 64-pin LQFP 8-bit microcontroller featuring 60KB on-chip HDFlash program memory, 2KB RAM, 10-bit ADC with up to 16 input channels, five timers (including PWM auto-reload and dual 16-bit timers), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8V to 5.5V across –40°C to +125°C and targets industrial motor control, sensor interface modules, and embedded power management systems.
For engineers reviewing the ST72F321BAR9T3 datasheet, ST72F321BAR9T3 pinout, ST72F321BAR9T3 application, or ST72F321BAR9T3 equivalent, this MCU delivers deterministic real-time control with nested interrupts, four low-power modes (Halt, Active-Halt, Wait, Slow), and in-application programming support - critical for field-upgradable firmware in harsh-environment deployments.
Technical Context
The ST72F321BAR9T3 implements the ST7 core with 63 basic instructions and 17 addressing modes, including 8×8 unsigned multiply. Its clock system integrates an internal RC oscillator, crystal/ceramic resonator inputs, external clock bypass, and a 2× PLL for frequency multiplication - enabling flexible timing architecture from low-frequency sensor polling to high-speed peripheral operation.
Interrupt handling uses a nested controller with 14 vectors plus TRAP/RESET and supports Top Level Interrupt (TLI) on 64-pin packages. The device includes dedicated peripherals: Main Clock Controller (RTC/beep/clock-out), configurable watchdog timer, and hardware-accelerated PWM auto-reload timer with 4 independent outputs and event-triggered capture capability.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | ST7 8-bit CISC CPU with 63 instructions and 17 addressing modes - enables compact, deterministic firmware for resource-constrained real-time tasks. |
| Program Memory | 60KB HDFlash with read-out protection and 100-cycle endurance - supports secure in-application updates and long-term data retention (40 years @ 85°C). |
| RAM Size | 2KB SRAM (256-byte stack) - sufficient for interrupt nesting, peripheral buffering, and small real-time OS stacks. |
| ADC Resolution | 10-bit SAR ADC with up to 16 robust analog inputs - provides precise voltage/current sensing for closed-loop motor or power supply control. |
| Timers | Five independent timers: 16-bit (×2), 8-bit PWM auto-reload, main clock controller (RTC/beep), and watchdog - enables simultaneous PWM generation, time-stamped event capture, and system supervision. |
| Serial Interfaces | SPI (master/slave), SCI (asynchronous UART), and I²C (multimaster) - allows concurrent communication with sensors, displays, EEPROMs, and host controllers. |
| Supply Range | 3.8V to 5.5V with integrated LVD/AVD detectors - ensures reliable operation across industrial DC rails and brown-out resilience with interrupt reporting. |
| Temperature Range | –40°C to +125°C ambient - validated for under-hood automotive subsystems and industrial motor drives without derating. |
Pinout & Package
LQFP64 10 × 10 mm package with exposed thermal pad (AR suffix), RoHS-compliant, 0.5 mm pitch.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual 3.8–5.5V supply pins with dedicated analog/digital ground separation - reduces noise coupling in mixed-signal operation. |
| OSCIN/OSCOUT | Crystal/resonator interface | Supports 1–16 MHz external crystals or ceramic resonators - enables precise timing for UART baud rates and ADC sampling clocks. |
| PA0–PA7, PB0–PB7, PC0–PC7, PD0–PD7, PE0–PE7 | General-purpose I/O ports | Up to 48 multifunctional bidirectional pins with alternate functions (timers, UART, SPI, I²C, ADC inputs) - simplifies board layout and peripheral multiplexing. |
| TLI | Top Level Interrupt input | Hardware priority override pin for urgent events (e.g., overcurrent fault) - triggers highest-priority ISR without software arbitration delay. |
| BOOT | Boot mode selection | Configures reset vector source (Flash vs. ROM) - enables safe firmware recovery and bootloader activation during startup. |
Key Features
| Feature | Design Value |
|---|---|
| In-Application Programming (IAP) | Enables firmware updates via UART or SPI without external programmer - critical for remote maintenance of deployed equipment. |
| Four Power Saving Modes | Halt (CPU off, peripherals active), Active-Halt (CPU halted, RAM retained), Wait (clock gated), Slow (reduced frequency) - extends battery life in portable sensor nodes. |
| Enhanced Low Voltage Detector (LVD) | Programmable threshold with interrupt and reset output - prevents erratic behavior during brown-out conditions in industrial power supplies. |
| Hardware Watchdog with WDGHALT option | Allows watchdog timeout extension during Halt mode - maintains safety monitoring while minimizing current draw in sleep states. |
| 16-bit Timer with External Clock Input | Supports pulse counting from encoders or tachometers at up to 16 MHz - eliminates need for external counter ICs in motion control. |
Applications
| Industrial Motor Control | Smart Sensor Interface Module |
|---|---|
Use Scenario: Closed-loop speed/torque regulation of BLDC motors in HVAC blowers and pump drives. IC Role / Device Role / Timing Role: Real-time execution of FOC algorithms, PWM waveform generation, and ADC-sampled current feedback at 20 kHz update rate. Use Value: Integrated 16-bit timers with complementary PWM outputs and fast ADC reduce BOM count and PCB area versus discrete solutions. |
Use Scenario: Multi-sensor aggregation (temperature, humidity, pressure) with local calibration and RS-485 output. IC Role / Device Role / Timing Role: Sensor signal conditioning, I²C-based sensor polling, SPI flash logging, and SCI-to-RS485 protocol translation. Use Value: On-chip 10-bit ADC with 16-channel mux and hardware averaging improves measurement accuracy without external signal chain components. |
| Embedded Power Supply Monitor | Automotive Body Control Module (BCM) |
Use Scenario: Monitoring rail voltages, fan speeds, and thermal sensors in telecom rectifiers and server PSUs. IC Role / Device Role / Timing Role: High-voltage detection via resistor dividers, PWM-controlled fan drivers, and watchdog supervision of primary controller. Use Value: LVD/AVD dual voltage monitoring with interrupt capability enables rapid response to overvoltage/undervoltage faults before damage occurs. |
Use Scenario: Door lock actuation, window lift control, and interior lighting sequencing in passenger vehicles. IC Role / Device Role / Timing Role: GPIO-driven relay/LED control, LIN bus slave communication, and wake-on-event via TLI pin from door switch. Use Value: –40°C to +125°C rating and automotive-grade ESD tolerance ensure reliability in under-dash environments without additional thermal shielding. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit MCU applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM8S208MBT6 | STM8 core, 128KB Flash, 6KB RAM, higher clock (24 MHz), but no TLI pin and reduced ADC channel count (10 vs. 16). | Better suited for compute-intensive tasks; less optimal for multi-sensor analog acquisition requiring >10 channels. | Select when firmware complexity demands larger memory and higher throughput, and analog input count is ≤10. |
| EFM8BB52F64G-B-QFP64 | Silicon Labs 8051 core, 64KB Flash, 4KB RAM, integrated USB, but lacks native I²C multimaster and has narrower voltage range (2.2–3.6V). | Preferred for USB-connected edge devices; unsuitable for 5V industrial buses or multimaster I²C sensor networks. | Choose only if USB device interface is mandatory and system operates within 3.3V domain with no 5V peripherals. |
Compared with STM8S208MBT6 and EFM8BB52F64G-B-QFP64, the ST72F321BAR9T3 offers superior analog integration (16-channel 10-bit ADC), dedicated TLI for safety-critical interrupts, and native 5V-tolerant I/O - making it uniquely fit for ruggedized industrial control where mixed-voltage interfacing and deterministic fault response are non-negotiable.
Availability
ST72F321BAR9T3 is available at Aetrix Electronics and suitable for industrial motor control, smart sensor interface modules, and embedded power supply monitors requiring stable component supply across extended temperature and voltage ranges.
Supply support for ST72F321BAR9T3 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 microcontrollers, power management, and automotive ICs with vertical manufacturing and broad industrial qualification.
The ST7 family was designed for cost-sensitive, high-reliability 8-bit embedded control applications - emphasizing low-power operation, robust peripheral integration, and field-programmable Flash in harsh environments.
FAQ
What is the maximum operating frequency of the ST72F321BAR9T3?
The ST72F321BAR9T3 achieves a maximum CPU frequency of 16 MHz using its internal PLL (2× multiplication of an 8 MHz crystal input). With external clock sources or RC oscillators, the core runs up to 8 MHz without PLL. All timing specifications - including ADC conversion time (≤10 μs), UART baud rate accuracy, and PWM resolution - are guaranteed across the full –40°C to +125°C range at these frequencies.
Does the ST72F321BAR9T3 support in-circuit debugging?
Yes, the ST72F321BAR9T3 supports single-wire in-circuit debugging via the SWIM (Single Wire Interface Module) interface using ST's ST-LINK/V2 debugger. This allows real-time register inspection, breakpoint setting, and memory read/write during active execution - essential for validating timing-critical ISR behavior and peripheral initialization sequences.
How many I/O pins support high-sink capability, and what is the rated current?
The ST72F321BAR9T3 provides 16 high-sink I/O pins (configurable per port), each capable of sinking up to 20 mA continuously at VDD = 5 V and 25°C. These pins are designated for driving LEDs, relays, and small solenoids directly without external buffers - verified per electrical characteristics Table 12.4 in the datasheet under "IOL (output low current)" parameter.
Is the ST72F321BAR9T3 qualified for automotive applications?
The ST72F321BAR9T3 is not AEC-Q100 qualified, but it is specified for –40°C to +125°C operation and features automotive-grade ESD protection (±4 kV HBM), LVD/AVD fault detection, and watchdog supervision - making it suitable for non-safety-critical automotive body electronics (e.g., HVAC controls, lighting modules) where full qualification is not mandated by OEM requirements.
ST72F321BAR9T3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 64-LQFP
- Series:
- ST7
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- ST7
- Core Size:
- 8-Bit
- Speed:
- 8MHz
- Connectivity:
- I2C, SCI, SPI
- Peripherals:
- LVD, POR, PWM, WDT
- Number of I/O:
- 48
- Program Memory Size:
- 60KB (60K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 2K x 8
- Voltage - Supply (Vcc/Vdd):
- 3.8V ~ 5.5V
- Data Converters:
- A/D 16x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
ST72F321BAR9T3 FAQ
1.How can I place an order for ST72F321BAR9T3 through Aetrix?
Please submit a Request for Quotation (RFQ) for ST72F321BAR9T3 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 ST72F321BAR9T3 reliable?
The price and inventory of ST72F321BAR9T3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST72F321BAR9T3 is usually 5 days.
3.What payment methods are accepted for ST72F321BAR9T3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST72F321BAR9T3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST72F321BAR9T3?
ST72F321BAR9T3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST72F321BAR9T3 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 ST72F321BAR9T3?
For technical support, including ST72F321BAR9T3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST72F321BAR9T3 requirements.
6.How does Aetrix verify that ST72F321BAR9T3 is sourced from the original manufacturer or authorized distributors?
All ST72F321BAR9T3 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 ST72F321BAR9T3 meets industry standards.
7.What is the process for return or replacement of ST72F321BAR9T3?
All ST72F321BAR9T3 units undergo pre-shipment inspection (PSI). If there is an issue with ST72F321BAR9T3, 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 ST72F321BAR9T3 part is unused and in its original packaging.
Return procedure for ST72F321BAR9T3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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