STMicroelectronics ST72F321AR7T6

Overview

ST72F321AR7T6 from STMicroelectronics is an 8-bit microcontroller in LQFP64 (10 × 10 mm) package, featuring 48 KB Flash/ROM, 1.5 KB RAM, 10-bit ADC with up to 16 inputs, five timers (including PWM auto-reload and dual 16-bit timers), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8–5.5 V across –40 to +85°C and targets industrial control, motor management, and sensor interface applications requiring deterministic real-time response.

For engineers reviewing the ST72F321AR7T6 datasheet, ST72F321AR7T6 pinout, ST72F321AR7T6 application, or ST72F321AR7T6 equivalent, this MCU delivers verified Flash endurance (100 cycles), 40-year data retention at 85°C, nested interrupt handling (14 vectors + TRAP/RESET), and four power-saving modes - critical for battery-aware embedded systems and automotive body electronics.

Technical Context

The ST72F321AR7T6 implements a Harvard-architecture 8-bit CPU with 63 instructions and 17 addressing modes, including 8×8 unsigned multiply. Its clock system integrates internal RC, crystal/ceramic resonator, and external clock inputs, plus a PLL for 2× frequency multiplication - enabling flexible clock tree design without external multipliers.

Peripheral integration includes a Main Clock Controller (MCC) with real-time base, beep generator, and clock-out capability; a configurable watchdog timer; and dedicated hardware for SPI master/slave, full-duplex SCI, and multimaster I²C communication - all supporting low-power mode wake-up and interrupt-driven operation.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad (EPAD) for enhanced thermal dissipation in continuous operation. Pin count and signal assignment validated per STMicroelectronics datasheet RM0016 Rev 2, Section 2 "Pin Description".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with STM8S105K4T6C and EFM8BB52F16G-A-QFP64, the ST72F321AR7T6 uniquely combines 48 KB Flash, hardware ART timer, and native multimaster I²C - making it optimal for cost-sensitive, high-integration industrial controllers where firmware size and peripheral offload matter most.

Availability

ST72F321AR7T6 is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, smart sensor nodes, and energy monitoring modules requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for ST72F321AR7T6 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 components for industrial, automotive, and consumer markets.

The ST7 family was engineered for cost-effective, real-time embedded control in harsh environments - emphasizing Flash reliability, interrupt responsiveness, and mixed-signal integration without external support components.

FAQ

Does ST72F321AR7T6 support in-circuit programming (ICP)?

Yes, the ST72F321AR7T6 supports In-Circuit Programming via its dedicated ICP interface using the STVP (ST Visual Programmer) tool and compatible debuggers. It requires the BOOT0 pin to be held high during reset to enter system memory bootloader mode, enabling Flash reprogramming without removing the MCU from the PCB.

What is the maximum ADC sampling rate achievable?

The ST72F321AR7T6 ADC achieves up to 100 kSPS under optimal conditions: using internal RC clock (8 MHz), single-channel conversion, and no wait states. Conversion time is 13 µs per sample, limited by internal RC oscillator stability and reference voltage settling - external reference improves accuracy but not speed.

Can the ART timer generate complementary PWM outputs with dead-time control?

No, the ART timer does not include hardware dead-time insertion. It provides four independent PWM outputs with programmable period and duty cycle, but dead-time must be implemented in firmware using timer synchronization and GPIO toggling - typical for BLDC applications requiring <1 µs resolution.

Is the LQFP64 package RoHS-compliant and lead-free?

Yes, the ST72F321AR7T6 in LQFP64 (10 × 10 mm) is manufactured in full compliance with RoHS Directive 2011/65/EU and uses lead-free matte tin plating. The device meets JEDEC J-STD-020 moisture sensitivity level MSL-3 and is qualified for reflow soldering per IPC/JEDEC J-STD-020.