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STMicroelectronics ST72F321BK6T6
- Part No.:
- ST72F321BK6T6
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 32-LQFP
- Datasheet:
-
ST72F321BK6T6.pdf
- Description:
- IC MCU 8BIT 32KB FLASH 32LQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,487
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Product details
Overview
ST72F321BK6T6 from STMicroelectronics is a 44-pin LQFP 8-bit microcontroller featuring 32KB Flash/ROM, 1KB RAM, 10-bit ADC with up to 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 industrial motor control, sensor interface modules, and embedded HMI panels requiring deterministic real-time response.
For engineers reviewing the ST72F321BK6T6 datasheet, ST72F321BK6T6 pinout, ST72F321BK6T6 application, or ST72F321BK6T6 equivalent, key selection criteria include Flash endurance (100 write cycles), 48 I/O port lines with high-sink capability (16/12/10), PLL-based 2× frequency multiplication, and support for four power-saving modes (Halt, Active-Halt, Wait, Slow) in harsh-temperature environments.
Technical Context
This MCU implements an enhanced ST7 core with 63 basic instructions and 17 addressing modes, including 8×8 unsigned multiply. Its clock system integrates crystal/ceramic resonator oscillators, internal RC oscillator, external clock bypass, and a PLL for precise 2× frequency multiplication - enabling stable CPU clock derivation from low-cost crystals.
Interrupt handling uses a nested controller with 14 vectors plus TRAP and RESET, supporting 15 external interrupt lines on 64-pin variants (9 on 44-pin ST72F321BK6T6). The peripheral set includes a configurable watchdog timer, main clock controller with RTC/beeper, and 10-bit ADC with robust input protection - all designed for deterministic latency and fail-safe operation in safety-critical embedded nodes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | ST7 8-bit CISC CPU with 63 instructions and 17 addressing modes |
| Flash Memory | 32KB HDFlash with read-out protection and 100-cycle endurance |
| RAM | 1024 bytes (256-byte stack), sufficient for real-time task context switching |
| ADC Resolution | 10-bit SAR converter with up to 16 input channels and low-current coupling |
| Timers | Five independent timers: 16-bit ×2 (input capture/output compare/PWM), ART (8-bit PWM auto-reload), MCC/RTC, and WDG |
| Serial Interfaces | SPI (master/slave), SCI (asynchronous UART), I²C (multimaster capable) |
| Operating Voltage | 3.8V–5.5V - compatible with industrial 5V logic and legacy bus systems |
| Temperature Range | –40°C to +125°C - qualified for under-hood automotive and factory-floor applications |
Pinout & Package
LQFP44 (10 × 10 mm, 0.8 mm pitch) package with exposed thermal pad - optimized for compact industrial PCB layouts and moderate-power dissipation (max 100 mW at 125°C).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Power supply and ground | Dual-supply pins supporting noise-immune analog/digital partitioning |
| OSCIN, OSCOUT | Crystal/resonator interface | Supports 1–16 MHz external crystals or ceramic resonators for precise timing |
| PA0–PA7 | Port A bidirectional I/O | 8-bit port with alternate functions including SPI, SCI, I²C, and ADC inputs |
| PB0–PB7 | Port B bidirectional I/O | 8-bit port supporting external interrupts, timer inputs, and high-sink outputs (20 mA) |
| PC0–PC7 | Port C bidirectional I/O | 8-bit port with ADC channel mapping and PWM output capability |
| PD0–PD7 | Port D bidirectional I/O | 8-bit port featuring TLI (Top Level Interrupt) input and reset control signals |
| NRST | Active-low reset input | Asynchronous external reset with internal LVD/AVD supervision |
| BOOT | Boot mode select | Configures startup vector location (system memory vs. user Flash) |
Key Features
| Feature | Design Value |
|---|---|
| In-Application Programming (IAP) | Enables field firmware updates without external programmer via dedicated Flash loader |
| Enhanced Low Voltage Detector (LVD) | Monitors main supply and triggers interrupt/reset at programmable thresholds (e.g., 4.0V ±0.1V) |
| Four Power-Saving Modes | Halt (CPU stopped, peripherals active), Active-Halt (peripherals clocked), Wait (all clocks gated), Slow (RC oscillator only) |
| 16 High-Sink I/O Lines | Deliver up to 20 mA per pin - directly drive LEDs, relays, or optocouplers without external drivers |
| Real-Time Clock & Beeper Controller | Integrated RTC with calendar/timekeeping and programmable tone generator for audible alerts |
Applications
| Industrial Motor Control | Sensor Interface Module |
|---|---|
Use Scenario: Closed-loop speed regulation of 3-phase BLDC motors in HVAC blowers and conveyor drives. IC Role / Device Role / Timing Role: Primary controller executing FOC algorithms, sampling current sensors via ADC, generating PWM gate signals, and managing commutation timing. Use Value: 16-bit timers with input capture and PWM outputs enable sub-microsecond phase alignment; 10-bit ADC provides 12-bit effective resolution after oversampling for torque ripple reduction. |
Use Scenario: Multi-sensor data acquisition node aggregating temperature, humidity, and pressure readings for building automation. IC Role / Device Role / Timing Role: Sensor hub coordinating I²C slave devices, performing local calibration, and transmitting fused data over SCI to central gateway. Use Value: Integrated I²C multimaster interface supports hot-plug sensor discovery; 16 ADC inputs allow direct connection of 8+ analog sensors without multiplexers. |
| Embedded HMI Panel | Automotive Body Control Unit |
Use Scenario: Touch-enabled dashboard display with LED backlight dimming and button debounce in medical equipment. IC Role / Device Role / Timing Role: UI processor managing capacitive touch scanning, PWM-controlled LED brightness, and real-time alarm beeping via integrated beeper module. Use Value: ART timer delivers smooth 8-bit PWM dimming; built-in beeper eliminates external audio driver; 125°C rating ensures reliability behind glass displays. |
Use Scenario: Under-dash lighting and mirror control module in passenger vehicles meeting AEC-Q100 Grade 2 requirements. IC Role / Device Role / Timing Role: Local ECU executing LIN-compatible SCI communication, driving high-side switches, and monitoring door latch status via GPIO. Use Value: 48 I/O lines support 12+ discrete loads; extended temperature range and LVD/AVD supervision meet automotive voltage transient immunity standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8-bit microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM8S105K4T6 | 32KB Flash, 2KB RAM, enhanced ADC (10-bit, 10 ch), but no beeper or RTC; newer STM8 core | Lacks integrated beeper and RTC - requires external components for audible alerts or timekeeping | Select when higher RAM headroom and modern toolchain support outweigh need for beeper/RTC |
| PIC16F887-I/PT | 14KB Flash, 368B RAM, 10-bit ADC (12 ch), no PLL or I²C; Harvard architecture | No I²C or PLL - limits multimaster sensor networks and precision clock scaling | Choose for cost-sensitive designs where SPI/SCI-only comms and fixed-frequency operation suffice |
Compared with STM8S105K4T6 and PIC16F887-I/PT, the ST72F321BK6T6 uniquely combines beeper + RTC + I²C + PLL in a single 44-pin LQFP package - reducing BOM count and board space in space-constrained industrial nodes requiring time-aware feedback and multimaster sensor integration.
Availability
ST72F321BK6T6 is available at Aetrix Electronics and suitable for industrial motor control, sensor interface modules, and embedded HMI panels requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for ST72F321BK6T6 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 ICs, sensors, and analog products for industrial, automotive, and consumer markets.
The ST7 family was engineered for cost-effective, deterministic real-time control in resource-constrained embedded systems - emphasizing low-latency interrupt response, integrated peripherals, and robust operation across wide voltage and temperature ranges.
FAQ
What is the maximum operating frequency of the ST72F321BK6T6?
The ST72F321BK6T6 achieves a maximum CPU frequency of 24 MHz using its internal PLL, which multiplies the base oscillator frequency by 2×. This allows stable operation with low-cost 12 MHz crystals while maintaining precise timing for PWM generation and serial communications.
Does the ST72F321BK6T6 support in-circuit programming?
Yes - the ST72F321BK6T6 supports In-Circuit Programming (ICP) via the SCI interface using the standard STVP (ST Visual Programmer) toolset. No external debugger hardware is required; programming occurs through UART pins with bootloader activation via BOOT pin configuration.
How many I/O pins support external interrupts?
The ST72F321BK6T6 provides 9 dedicated external interrupt lines mapped across ports PA–PD, each configurable for rising/falling/both-edge sensitivity. These lines share 4 interrupt vectors and support wake-up from all power-saving modes except Halt with WDGHALT enabled.
Is the Flash memory protected against unauthorized read-out?
Yes - the ST72F321BK6T6 includes hardware-based read-out protection (ROP) that disables Flash memory access during debug or serial programming when enabled. ROP is activated via a dedicated option byte and persists until Flash is erased, preventing firmware reverse engineering in deployed units.
ST72F321BK6T6 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 32-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:
- 24
- Program Memory Size:
- 32KB (32K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 1K 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:
ST72F321BK6T6 FAQ
1.How can I place an order for ST72F321BK6T6 through Aetrix?
Please submit a Request for Quotation (RFQ) for ST72F321BK6T6 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 ST72F321BK6T6 reliable?
The price and inventory of ST72F321BK6T6 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST72F321BK6T6 is usually 5 days.
3.What payment methods are accepted for ST72F321BK6T6?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST72F321BK6T6 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ST72F321BK6T6?
ST72F321BK6T6 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ST72F321BK6T6 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 ST72F321BK6T6?
For technical support, including ST72F321BK6T6 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST72F321BK6T6 requirements.
6.How does Aetrix verify that ST72F321BK6T6 is sourced from the original manufacturer or authorized distributors?
All ST72F321BK6T6 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 ST72F321BK6T6 meets industry standards.
7.What is the process for return or replacement of ST72F321BK6T6?
All ST72F321BK6T6 units undergo pre-shipment inspection (PSI). If there is an issue with ST72F321BK6T6, 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 ST72F321BK6T6 part is unused and in its original packaging.
Return procedure for ST72F321BK6T6:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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