STMicroelectronics ST72F321BJ7T6

Overview

ST72F321BJ7T6 from STMicroelectronics is a 44-pin LQFP 8-bit microcontroller 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), and three serial interfaces (SPI, SCI, I²C). It operates from 3.8 V to 5.5 V across –40°C to +125°C and targets automotive body control modules, industrial sensor nodes, and appliance motor control.

For engineers reviewing the ST72F321BJ7T6 datasheet, ST72F321BJ7T6 pinout, ST72F321BJ7T6 application, or ST72F321BJ7T6 equivalent, this MCU delivers deterministic real-time response via nested interrupt controller (14 vectors), configurable watchdog, PLL-based clock multiplication, and four power-saving modes - critical for battery-backed or thermally constrained embedded systems.

Technical Context

The ST72F321BJ7T6 implements the ST7 core with 63 basic instructions and 17 addressing modes, supporting in-application programming (IAP) and in-circuit programming (ICP) for field firmware updates. Its memory subsystem includes 48 KB HDFlash with read-out protection and 1.5 KB RAM (256-byte stack), enabling secure code storage and real-time data buffering.

Peripheral integration centers on timing precision and interface flexibility: a main clock controller provides RTC, beep, and clock-out functions; two 16-bit timers support input capture, output compare, PWM, and external event counting; and the 10-bit ADC features robust analog input coupling for noisy industrial environments.

Key Specifications

Pinout & Package

LQFP44 (10 × 10 mm, 0.8 mm pitch) package with exposed thermal pad - optimized for thermal dissipation in sealed enclosures and compatible with standard PCB reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM8S105K4T6C and MC9RS08KA8CP, the ST72F321BJ7T6 offers superior analog integration (16-channel ADC), richer timer resources (five independent units), and broader serial connectivity - making it optimal for mixed-signal control tasks where peripheral concurrency and deterministic timing are essential.

Availability

ST72F321BJ7T6 is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor nodes, home appliance motor control, and smart energy metering requiring stable component supply across extended product lifecycles.

Supply support for ST72F321BJ7T6 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, MEMS, and automotive-grade components since 1987.

The ST7 family was engineered specifically for cost-sensitive, real-time embedded control in automotive, industrial, and appliance markets - emphasizing robustness, low-power operation, and seamless integration of analog and digital peripherals.

FAQ

Does ST72F321BJ7T6 support in-circuit debugging?

Yes, the ST72F321BJ7T6 supports single-wire in-circuit debugging via the SWIM (Single Wire Interface Module) interface, compatible with ST's ST-LINK/V2 and third-party debuggers. This enables real-time variable inspection, breakpoint setting, and flash programming without requiring dedicated debug pins - preserving all 44 I/O for application use.

What is the maximum ADC sampling rate for ST72F321BJ7T6?

The ST72F321BJ7T6 achieves a maximum ADC conversion rate of 100 kSPS at 10-bit resolution, with typical acquisition time of 12 µs per sample. Conversion speed is dependent on ADC clock prescaler settings and input source impedance; for optimal accuracy, input impedance must be ≤10 kΩ per channel.

Can ST72F321BJ7T6 operate reliably at 5.5 V supply?

Yes, the ST72F321BJ7T6 is fully specified for continuous operation at 5.5 V across its full temperature range (–40°C to +125°C). Electrical characteristics including I/O drive strength, ADC linearity, and timer accuracy are guaranteed at this upper limit, with absolute maximum rating of 6.5 V on VDD.

Is there hardware support for PWM dead-time generation?

No, the ST72F321BJ7T6 does not include dedicated hardware dead-time insertion. However, its dual 16-bit timers support complementary PWM outputs via software-synchronized compare registers, and the 8-bit ART timer provides four independent PWM channels - enabling dead-time implementation with <1 µs jitter using interrupt-driven update logic.