STMicroelectronics ST72F321J7T6TR

Overview

ST72F321J7T6TR from STMicroelectronics is a 44-pin LQFP 8-bit microcontroller featuring 48KB Flash/ROM, 1.5KB RAM, 10-bit ADC with up to 16 channels, 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 +85°C and targets industrial motor control, sensor interface, and embedded automation systems requiring deterministic real-time response.

For engineers reviewing the ST72F321J7T6TR datasheet, ST72F321J7T6TR pinout, ST72F321J7T6TR application, or ST72F321J7T6TR equivalent, this MCU delivers verified in-application programming (IAP), nested interrupt handling with 14 vectors, PLL-based clock multiplication, and low-power modes including Halt and Wait - all critical for resource-constrained embedded firmware development.

Technical Context

This MCU implements an enhanced ST7 core with 63 instructions and 17 addressing modes, supporting 8×8 unsigned multiply. Its clock system integrates crystal/resonator oscillators, internal RC, external clock bypass, and a 2× PLL for flexible timing generation.

The peripheral set includes a configurable watchdog timer, main clock controller with RTC/beeper, two 16-bit timers with input capture/output compare/PWM, and a dedicated 8-bit PWM auto-reload timer with four outputs - enabling precise motor phase control and sensor sampling synchronization.

Key Specifications

Pinout & Package

LQFP44 10 × 10 mm package with exposed pad (RoHS-compliant), 0.8 mm pitch, and thermal performance suitable for convection-cooled industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM8S105K4T6C and EFM8BB52F16G-A-QFP48, the ST72F321J7T6TR uniquely balances 48KB Flash, 5V tolerance, AVD/LVD dual supervision, and TLI fault signaling - making it irreplaceable in safety-aware industrial controls where supply robustness and deterministic interrupt latency are non-negotiable.

Availability

ST72F321J7T6TR is available at Aetrix Electronics and suitable for industrial motor control, sensor data acquisition, embedded power supply monitoring, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ST72F321J7T6TR 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 management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The ST7 family was engineered specifically for cost-sensitive, real-time embedded applications demanding high I/O density, robust analog integration, and field-upgradable firmware - targeting factory automation, appliance control, and energy metering.

FAQ

Does ST72F321J7T6TR support in-circuit programming (ICP) via standard interfaces?

Yes, ST72F321J7T6TR supports ICP through its single-wire SWIM (Serial Wire Interface Module) interface using the ST-LINK/V2 programmer. This allows full Flash memory erase, program, and verify operations without removing the device from the PCB, and is compatible with ST's STVP and STSW-LINK004 software tools.

What is the maximum ADC sampling rate achievable with hardware trigger synchronization?

The 10-bit ADC achieves up to 1 MSPS conversion rate when triggered by the auto-reload timer (ART) or one of the 16-bit timers. Hardware synchronization ensures jitter-free sampling intervals down to 1µs resolution, critical for motor current reconstruction and harmonic analysis.

Can the PLL be disabled to run the CPU directly from the internal RC oscillator?

Yes, the PLL can be disabled via the CLK_CR register, allowing the CPU to run from the internal 8MHz RC oscillator (±1% accuracy at 25°C). This mode reduces power consumption and eliminates crystal-related BOM cost, though it sacrifices timing precision required for synchronous serial communication.

How many external interrupt sources are available on the LQFP44 package?

The LQFP44 variant provides nine external interrupt lines mapped across four vectors (INT0–INT3), with sensitivity configurable per pin for rising/falling/both edges. The TLI pin adds a dedicated non-maskable interrupt source independent of the vector table.