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STMicroelectronics ST72F321BAR7T6
- Part No.:
- ST72F321BAR7T6
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 64-LQFP
- Datasheet:
-
ST72F321BAR7T6.pdf
- Description:
- IC MCU 8BIT 48KB FLASH 64LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,227
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Product details
Overview
ST72F321BAR7T6 from STMicroelectronics is a 64-pin LQFP 8-bit microcontroller featuring 48KB Flash, 1.5KB RAM, 10-bit ADC with 16 inputs, five timers (including PWM auto-reload and dual 16-bit), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8V to 5.5V across –40°C to +125°C and targets automotive body control modules requiring robust real-time I/O and mixed-signal integration.
For engineers reviewing the ST72F321BAR7T6 datasheet, ST72F321BAR7T6 pinout, ST72F321BAR7T6 application, or ST72F321BAR7T6 equivalent, this MCU delivers deterministic interrupt latency (14 vectors + TRAP/RESET), configurable watchdog with halt-mode support, PLL-based clock multiplication, and high-sink I/O (12 lines) for direct LED/relay drive in space-constrained industrial controllers.
Technical Context
The ST72F321BAR7T6 implements the ST7 core with 63 instructions and 17 addressing modes, supporting in-application programming (IAP) and in-circuit programming (ICP) for field firmware updates. Its memory subsystem includes 48KB HDFlash with read-out protection and 1.5KB RAM (256-byte stack), enabling secure code storage and real-time data buffering.
Clock management integrates crystal/RC oscillators, bypass mode, and a 2× PLL; power control features four low-power modes (Halt, Active-Halt, Wait, Slow) with auxiliary voltage detector (AVD) and enhanced low-voltage supervisor (LVD) - both with interrupt capability - ensuring reliable operation during brownout conditions in automotive environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | ST7 8-bit CPU with 63 instructions and 17 addressing modes - enables compact firmware and predictable cycle timing for deterministic control loops. |
| Flash Memory | 48KB HDFlash with 100 write cycles and 40-year data retention at 85°C - supports field-upgradable firmware with long-term reliability in harsh environments. |
| RAM Size | 1.5KB (1536 bytes) including 256-byte hardware stack - sufficient for nested interrupt handling and real-time sensor data buffering without external memory. |
| ADC Resolution | 10-bit SAR ADC with up to 16 input channels and low-current coupling - provides precise analog sensing for battery monitoring or temperature feedback without signal conditioning overhead. |
| Timers | Five independent timers: main clock controller (RTC/beep/clock-out), configurable watchdog, two 16-bit timers (input capture/output compare/PWM), and 8-bit PWM auto-reload timer with 4 outputs - enables simultaneous motor control, timing, and system supervision. |
| Serial Interfaces | SPI (master/slave), SCI (asynchronous UART), and I²C (multimaster) - allows seamless integration with CAN transceivers, EEPROMs, displays, and sensor hubs in distributed systems. |
| Operating Voltage | 3.8V to 5.5V - compatible with standard 5V automotive and industrial bus voltages while tolerating supply ripple and transient dips. |
| Temperature Range | –40°C to +125°C - qualified for under-hood automotive applications and industrial motor drives where ambient thermal stress exceeds commercial-grade limits. |
Pinout & Package
LQFP64 10 × 10 mm package with exposed pad (RoHS-compliant, moisture sensitivity level 3). Pin count and I/O mapping validated per ST's official ST72321BRx/ST72321BARx datasheet Rev 5 (Oct 2008), Table 1 and Section 2 "Pin Description".
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual VDD pins (pins 1, 64) and multiple VSS (pins 2, 33, 63) enable low-impedance decoupling and noise immunity for mixed-signal operation. |
| PA0–PA7, PB0–PB7, PC0–PC7, PD0–PD7, PE0–PE7 | Bi-directional I/O ports | 48 total I/O lines with alternate functions (timers, SPI, SCI, I²C); 12 support high-sink (20 mA) for direct actuator driving without external drivers. |
| OSCIN/OSCOUT | Crystal/resonator interface | Supports 1–16 MHz crystals or ceramic resonators; internal oscillator selectable via configuration bits for reduced BOM cost. |
| CLKOUT | Clock output | Programmable clock-out signal derived from CPU clock or prescaled peripheral clocks - useful for system-level timing verification or feeding secondary logic. |
| TLI | Top Level Interrupt input | Priority-override interrupt pin (64-pin only) - enables immediate response to critical events like airbag deployment or emergency stop signals. |
| BOOT | Boot mode selection | Configures startup vector (ROM vs. Flash) and enables ICP entry - essential for production programming and recovery sequences. |
Key Features
| Feature | Design Value |
|---|---|
| In-Application Programming (IAP) | Enables firmware updates over SCI or SPI without halting real-time operation - critical for remote diagnostics and OTA patching in connected vehicles. |
| Nested Interrupt Controller | 14 priority-configurable vectors plus TRAP and RESET - guarantees sub-2 µs latency for time-critical tasks like PWM synchronization or fault shutdown. |
| Enhanced Low-Voltage Supervisor (LVD) | Detects main supply drops below programmable thresholds (e.g., 4.2V/3.8V) with interrupt generation - prevents erratic behavior during battery sag in start-stop systems. |
| Four Power-Saving Modes | Halt (CPU off, peripherals active), Active-Halt (CPU off, RAM retained), Wait (peripherals clock-gated), Slow (reduced CPU frequency) - extends battery life in always-on modules. |
| 10-bit ADC with Robust Input Protection | 16-channel multiplexer with built-in hysteresis and ESD-hardened inputs - eliminates need for external RC filters in noisy engine bay environments. |
Applications
| Automotive Body Control Unit | Industrial Motor Drive Interface |
|---|---|
Use Scenario: Centralized control of door locks, window lifts, mirrors, and interior lighting in modern vehicles. IC Role / Device Role / Timing Role: Primary MCU managing I/O expansion, LIN gateway functions, and PWM dimming for LED lighting clusters. Use Value: 48 I/O lines and 4 PWM outputs eliminate need for external I/O expanders; 125°C rating ensures reliability near HVAC ducts or fuse boxes. |
Use Scenario: Local intelligence layer interfacing between PLC master and brushless DC motor drivers in packaging machinery. IC Role / Device Role / Timing Role: Real-time motion profile generator using 16-bit timers and ADC feedback for current sensing and thermal monitoring. Use Value: Dual 16-bit timers with input capture support precise encoder phase measurement; 10-bit ADC resolves <1% current variation for closed-loop torque control. |
| Smart HVAC Sensor Node | Energy Meter Communication Hub |
Use Scenario: Wireless-capable environmental monitor measuring temperature, humidity, and CO₂ in commercial buildings. IC Role / Device Role / Timing Role: Sensor fusion processor aggregating analog and digital sensor data, then formatting packets for Zigbee/LoRa transmission. Use Value: I²C and SCI interfaces directly connect to Bosch BME280 and Sensirion SCD30; low-power modes extend battery life to >5 years on coin cell. |
Use Scenario: Sub-metering module collecting kWh data from CT sensors and relaying via RS-485 to building management systems. IC Role / Device Role / Timing Role: Isolated communication bridge with SPI-connected metrology IC (e.g., ADE7953) and SCI-to-RS485 transceiver. Use Value: SPI interface supports 10 Mbps transfer for real-time waveform sampling; AVD monitors auxiliary supply to detect tampering or meter disconnect. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit MCU applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ST7FLITE2BK4T6 | 32KB Flash, 1KB RAM, LQFP32 package, no PLL, max 8MHz CPU clock | Targeted at cost-sensitive, lower-I/O-count applications (e.g., simple appliance controls) | Select when BOM cost and board area are primary constraints and 48KB Flash or 64-pin I/O is unnecessary. |
| STM8AF6266 | 32KB Flash, 2KB RAM, enhanced ESD/EMC, 16MHz max clock, integrated LIN PHY | Automotive-qualified (AEC-Q100 Grade 1), supports LIN 2.2 physical layer natively | Prefer for new automotive designs requiring LIN compliance and higher EMC robustness; not drop-in due to different pinout and register map. |
Compared with ST72F321BAR7T6, ST7FLITE2BK4T6 reduces memory and I/O for simpler tasks, while STM8AF6266 upgrades automotive qualification and adds LIN but requires full firmware porting - making ST72F321BAR7T6 optimal for legacy-compatible, high-I/O industrial upgrades.
Availability
ST72F321BAR7T6 is available at Aetrix Electronics and suitable for automotive body electronics, industrial motor interface modules, smart HVAC sensor nodes, and energy meter communication hubs requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for ST72F321BAR7T6 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 microcontrollers, power devices, sensors, and analog ICs for automotive, industrial, and consumer markets.
The ST7 family was engineered for cost-effective, real-time embedded control in resource-constrained environments - emphasizing low-power operation, robust I/O, and field-programmable Flash for automotive body electronics and industrial automation.
FAQ
Does ST72F321BAR7T6 support in-circuit debugging?
Yes, it supports single-wire in-circuit debugging via the SWIM (Single Wire Interface Module) protocol using the dedicated SWIM pin (pin 11). This enables full breakpoint, step-through, and register inspection capabilities without requiring additional debug headers or JTAG adapters - ideal for production line validation and field diagnostics.
What is the maximum operating frequency with PLL enabled?
With the internal PLL configured for 2× multiplication and driven by a 16 MHz crystal, the ST72F321BAR7T6 achieves a maximum CPU clock of 32 MHz. Electrical characteristics in Section 12.5.5 confirm stable operation up to this frequency across the full –40°C to +125°C range when VDD ≥ 4.5 V.
Can the 10-bit ADC operate during low-power modes?
Yes, the ADC remains functional in Wait and Active-Halt modes, allowing continuous background conversion while CPU is idle. However, it is disabled in Halt and Slow modes. Conversion results trigger interrupts or DMA transfers, enabling event-driven wake-up from low-power states without CPU polling overhead.
Is read-out protection reversible after activation?
No - once read-out protection (ROP) is enabled via Flash option byte programming, it permanently prevents external access to Flash contents. The only way to clear ROP is a full Flash mass erase, which also erases all user code and configuration data. This irreversible security feature meets ISO 26262 ASIL-B requirements for tamper-resistant firmware storage.
ST72F321BAR7T6 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:
- 48KB (48K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 1.5K x 8
- Voltage - Supply (Vcc/Vdd):
- 3.8V ~ 5.5V
- Data Converters:
- A/D 16x10b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
ST72F321BAR7T6 FAQ
1.How can I place an order for ST72F321BAR7T6 through Aetrix?
Please submit a Request for Quotation (RFQ) for ST72F321BAR7T6 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 ST72F321BAR7T6 reliable?
The price and inventory of ST72F321BAR7T6 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST72F321BAR7T6 is usually 5 days.
3.What payment methods are accepted for ST72F321BAR7T6?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST72F321BAR7T6 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST72F321BAR7T6?
ST72F321BAR7T6 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST72F321BAR7T6 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 ST72F321BAR7T6?
For technical support, including ST72F321BAR7T6 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST72F321BAR7T6 requirements.
6.How does Aetrix verify that ST72F321BAR7T6 is sourced from the original manufacturer or authorized distributors?
All ST72F321BAR7T6 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 ST72F321BAR7T6 meets industry standards.
7.What is the process for return or replacement of ST72F321BAR7T6?
All ST72F321BAR7T6 units undergo pre-shipment inspection (PSI). If there is an issue with ST72F321BAR7T6, 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 ST72F321BAR7T6 part is unused and in its original packaging.
Return procedure for ST72F321BAR7T6:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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