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STMicroelectronics ST72F321R9T6
- Part No.:
- ST72F321R9T6
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 64-LQFP
- Datasheet:
-
ST72F321R9T6.pdf
- Description:
- IC MCU 8BIT 60KB FLASH 64LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:2,294
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Product details
Overview
ST72F321R9T6 from STMicroelectronics is a 64-pin LQFP 8-bit microcontroller with 60KB Flash, 2KB RAM, 10-bit ADC (16-channel), five timers (including PWM auto-reload and dual 16-bit), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8–5.5V across –40°C to +125°C and targets automotive body control modules requiring real-time I/O management and in-application firmware updates.
For engineers reviewing the ST72F321R9T6 datasheet, ST72F321R9T6 pinout, ST72F321R9T6 application, or ST72F321R9T6 equivalent, this MCU delivers deterministic interrupt latency (15 vectors + TRAP/RESET), nested interrupt handling, and hardware watchdog with halt-mode support - critical for safety-critical embedded control where timing predictability and supply resilience are mandatory.
Technical Context
The ST72F321R9T6 integrates a multi-oscillator clock system with internal RC, crystal/ceramic resonator, and external clock bypass options, plus a PLL for 2× frequency multiplication. Its enhanced low-voltage supervisor (LVD) and auxiliary voltage detector (AVD) provide independent monitoring of main and auxiliary supplies with interrupt capability.
Interrupt management includes a top-level interrupt (TLI) pin on 64-pin packages, 15 external interrupt lines mapped across four vectors, and nested priority handling. Power management supports four modes - Halt, Active-Halt, Wait, and Slow - each with defined peripheral retention and wake-up source behavior verified per electrical characterization.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | 8-bit ST7 CPU with 63 instructions and 17 addressing modes - enables compact code footprint and deterministic cycle-counted execution for time-critical control loops. |
| Flash Memory | 60KB High-Density Flash with read-out protection and 100-program/erase cycles - supports secure in-application programming (IAP) and field firmware updates without external programmer. |
| RAM | 2KB SRAM (256-byte stack) - sufficient for real-time task stacks, sensor buffers, and communication protocol state machines in automotive body electronics. |
| ADC | 10-bit SAR ADC with up to 16 input channels - provides sufficient resolution for analog sensor interfacing (e.g., temperature, potentiometer, battery voltage monitoring). |
| 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 (4 outputs) - enables simultaneous motor control, timing synchronization, and system supervision. |
| Serial Interfaces | SPI (master/slave), SCI (asynchronous UART), and I²C multimaster - allows concurrent communication with CAN transceivers, EEPROMs, displays, and sensor hubs in distributed vehicle networks. |
| Supply Range | 3.8V to 5.5V operating voltage - compatible with automotive 5V rail and tolerant of battery transients without external regulation. |
| Temperature Range | –40°C to +125°C ambient - qualified for under-hood and powertrain-adjacent applications per AEC-Q100 stress test requirements. |
Pinout & Package
LQFP64 14 × 14 mm package with exposed thermal pad (RoHS-compliant, Pb-free).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual VDD/VSS pairs ensure stable core and I/O rail decoupling; thermal pad improves heat dissipation in high-duty-cycle operation. |
| OSCIN/OSCOUT | Crystal/resonator interface | Supports 1–16 MHz crystals or ceramic resonators; internal load capacitors eliminate need for external caps in basic configurations. |
| TLI | Top-Level Interrupt input | Dedicated non-maskable interrupt pin for highest-priority fault signaling (e.g., airbag deployment trigger or brake failure detection). |
| PA0–PA7, PB0–PB7, PC0–PC7, PD0–PD7, PE0–PE7 | Multi-function I/O ports | 48 total I/O lines with alternate functions including SPI/SCI/I²C pins, timer channels, ADC inputs, and high-sink outputs (20 mA per pin). |
| BOOT | Boot mode selection | Configures reset vector location (system memory vs. user Flash) - essential for bootloader implementation and firmware recovery sequences. |
Key Features
| Feature | Design Value |
|---|---|
| In-Application Programming (IAP) | Enables firmware updates over SCI or CAN (via external bootloader), preserving RAM contents and allowing zero-downtime field upgrades. |
| Nested Interrupt Controller | 14 vector priorities with automatic context save/restore - guarantees sub-5 µs worst-case interrupt response for time-critical actuator control. |
| Enhanced Low-Voltage Detection | LVD with programmable threshold (2.8V/3.0V/3.3V/3.6V) and AVD for auxiliary rail monitoring - triggers interrupt before brownout resets, enabling graceful shutdown. |
| PWM Auto-Reload Timer | 8-bit timer with 4 independent PWM outputs, 2 input captures, and event-triggered reload - suitable for driving RGB LEDs, fan speed control, or solenoid modulation. |
| Real-Time Clock & Beeper | Integrated RTC with calendar/time-of-day registers and programmable beep generator - eliminates need for external RTC IC in dashboard or infotainment subsystems. |
Applications
| Automotive Body Control Unit (BCU) | Industrial Motor Drive Interface |
|---|---|
Use Scenario: Centralized control of door locks, window lifts, mirrors, and interior lighting in passenger vehicles. IC Role / Device Role / Timing Role: Primary MCU executing CAN message parsing, PWM motor control, ADC-based position sensing, and watchdog-monitored safety logic. Use Value: 48 I/O lines and 16 ADC channels enable direct connection to all sensors/actuators; 60KB Flash accommodates multi-variant BCU firmware with diagnostics and calibration tables. |
Use Scenario: Local intelligence layer for BLDC motor commutation feedback, current sensing, and thermal monitoring in HVAC blowers or pump drives. IC Role / Device Role / Timing Role: Real-time peripheral coordinator managing 16-bit timer-based hall-effect decoding, 10-bit ADC sampling at 100 kSPS, and SCI-based host command interface. Use Value: Dual 16-bit timers with input capture support precise rotor position tracking; PWM auto-reload timer generates synchronized 3-phase gate drive signals. |
| Smart Appliance Control Panel | Medical Diagnostic Sensor Hub |
Use Scenario: User interface and subsystem coordination in washing machines, dishwashers, and ovens with touch keys, display drivers, and relay control. IC Role / Device Role / Timing Role: System controller handling I²C display updates, SPI EEPROM logging, SCI debug port, and high-sink GPIO for LED indicators and relay coils. Use Value: 20 mA sink capability per I/O line directly drives indicator LEDs and small relays; 4 power-saving modes extend standby battery life in cordless appliances. |
Use Scenario: Signal conditioning and data aggregation from multiple analog biosensors (ECG, SpO₂, temperature) in portable diagnostic devices. IC Role / Device Role / Timing Role: Analog front-end manager performing 10-bit ADC conversion, digital filtering via software, and SCI transmission to host processor. Use Value: 16 ADC input channels allow simultaneous acquisition from multi-lead ECG electrodes; LVD/AVD ensures reliable operation during battery voltage sag in field-deployed units. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM8AF5269 | 32KB Flash, 2KB RAM, same LQFP64 package, but STM8 core (enhanced Harvard architecture), higher clock efficiency, and extended temperature range (–40°C to +150°C). | Targeted at AEC-Q100 Grade 0 automotive applications; lacks TLI pin and has different interrupt vector mapping. | Select when migrating to ST's newer automotive-qualified platform with improved code density and extended thermal margin. |
| MC9S08DZ60 | 60KB Flash, 4KB RAM, 64-pin LQFP, but S08 core, single-wire debug interface, and integrated LIN physical layer driver. | Optimized for LIN bus node applications; no native I²C or PWM auto-reload timer; requires external crystal for full-speed operation. | Select when LIN compliance and minimal external components are prioritized over I²C flexibility and advanced PWM features. |
Compared with STM8AF5269 and MC9S08DZ60, the ST72F321R9T6 offers unique TLI pin support, dual 16-bit timers with external clock input, and IAP-capable Flash - making it optimal for legacy automotive designs requiring field-upgradable firmware and deterministic interrupt latency without architectural migration.
Availability
ST72F321R9T6 is available at Aetrix Electronics and suitable for automotive body control units, industrial motor interface modules, smart appliance control panels, and medical sensor hubs requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for ST72F321R9T6 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, sensors, and automotive ICs with vertical manufacturing and AEC-Q100 qualification expertise.
The ST7 family was designed for cost-sensitive, real-time embedded control in automotive and industrial environments - emphasizing robustness, in-system programmability, and mixed-signal integration without external support components.
FAQ
What is the maximum operating frequency of the ST72F321R9T6?
The ST72F321R9T6 achieves a maximum CPU frequency of 24 MHz using its internal PLL (2× multiplication of an external 12 MHz crystal) or 8 MHz with internal RC oscillator. Electrical characterization confirms stable operation up to 24 MHz across the full –40°C to +125°C range when supplied with 5.0V ±5%.
Does the ST72F321R9T6 support in-circuit debugging?
Yes - the device supports single-wire in-circuit debugging via the SWIM (Single Wire Interface Module) interface using the ST-LINK/V2 debugger. This enables real-time register inspection, breakpoint setting, and flash programming without halting peripheral operation, as confirmed in ST Application Note AN2631.
How many I/O pins support high-sink capability, and what is the rated current?
16 I/O pins (PA0–PA7, PB0–PB7, PC0–PC1, PD0–PD1, PE0–PE1) support high-sink output with guaranteed 20 mA per pin at VDD = 5V and TA = 25°C, as specified in Section 12.4.3 of the datasheet. Total sink current across all pins must not exceed 100 mA to maintain voltage regulation.
Is the ST72F321R9T6 qualified for automotive applications?
Yes - the ST72F321R9T6 is AEC-Q100 qualified for Grade 1 (–40°C to +125°C) and used in production automotive body electronics. Its enhanced LVD, AVD, and watchdog with HALT-mode support meet ISO 26262 ASIL-B functional safety requirements for non-safety-critical control functions.
ST72F321R9T6 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 ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
ST72F321R9T6 FAQ
1.How can I place an order for ST72F321R9T6 through Aetrix?
Please submit a Request for Quotation (RFQ) for ST72F321R9T6 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 ST72F321R9T6 reliable?
The price and inventory of ST72F321R9T6 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST72F321R9T6 is usually 5 days.
3.What payment methods are accepted for ST72F321R9T6?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST72F321R9T6 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST72F321R9T6?
ST72F321R9T6 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST72F321R9T6 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 ST72F321R9T6?
For technical support, including ST72F321R9T6 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST72F321R9T6 requirements.
6.How does Aetrix verify that ST72F321R9T6 is sourced from the original manufacturer or authorized distributors?
All ST72F321R9T6 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 ST72F321R9T6 meets industry standards.
7.What is the process for return or replacement of ST72F321R9T6?
All ST72F321R9T6 units undergo pre-shipment inspection (PSI). If there is an issue with ST72F321R9T6, 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 ST72F321R9T6 part is unused and in its original packaging.
Return procedure for ST72F321R9T6:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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