STMicroelectronics ST72F324K4B6

Overview

ST72F324K4B6 from STMicroelectronics is an 8-bit microcontroller featuring 8 KB Flash memory, 384 bytes RAM, 10-bit ADC with up to 12 input channels, dual 16-bit timers (Timer A and Timer B), SPI and SCI serial interfaces, and four power-saving modes. It operates across 3.8 V to 5.5 V and supports industrial temperature range (−40°C to +125°C), targeting embedded control in motor drives and sensor interface modules.

For engineers reviewing the ST72F324K4B6 datasheet, ST72F324K4B6 pinout, ST72F324K4B6 application, or ST72F324K4B6 equivalent, this MCU delivers deterministic real-time control with nested interrupts, programmable low-voltage detection, PLL-based clock multiplication, and in-application programming capability for field firmware updates.

Technical Context

This MCU implements a Harvard architecture with 63 basic instructions and 17 addressing modes, including 8×8 unsigned multiply. Its interrupt system supports 10 vectors plus TRAP and RESET, with 9 external interrupt lines mapped across 4 vectors and configurable sensitivity per port pin.

The clock system integrates crystal/ceramic resonator oscillators, internal RC oscillator, clock security system, and a 2× PLL multiplier. Power management includes Halt, Active-Halt, Wait, and Slow modes - each preserving different register states and peripheral clocks while reducing current draw.

Key Specifications

Pinout & Package

TQFP32 (7 × 7 mm, 0.8 mm pitch) package with 32-pin layout optimized for compact industrial control PCBs. All I/O pins support multifunctional configuration including alternate functions for peripherals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST72F324K4B6, the J4 variant offers through-hole mounting at the expense of thermal performance and board density, while the K6 variant doubles Flash and RAM without altering timing or I/O behavior - enabling seamless migration within the same hardware design.

Availability

ST72F324K4B6 is available at Aetrix Electronics and suitable for motor control interface, sensor data acquisition, industrial PLC I/O modules, and legacy bus interface adapters requiring stable component supply across extended product lifecycles.

Supply support for ST72F324K4B6 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 automotive-grade components since 1987.

The ST7 family was engineered for cost-sensitive, real-time embedded control in industrial and automotive environments - emphasizing robustness, low-power operation, and integrated analog/mixed-signal peripherals.

FAQ

Is ST72F324K4B6 still recommended for new designs?

No - the datasheet explicitly marks this device as "NOT FOR NEW DESIGN." STMicroelectronics recommends migrating to the ST72324B series (e.g., ST72324BK4B6) for new projects, which offer enhanced ESD tolerance, updated qualification, and continued long-term supply assurance.

What debug interfaces does ST72F324K4B6 support?

It supports In-Circuit Programming (ICP) via the ICC interface using the dedicated ICCSEL/VPP pin, and In-Application Programming (IAP) through user firmware. No JTAG or SWD is available; debugging relies on ROM monitor routines or external emulators compatible with ST7's proprietary protocol.

Can the 10-bit ADC operate during low-power modes?

Yes - the ADC can perform conversions in Wait mode with CPU halted, provided the ADC clock source remains active. However, it is disabled in Halt and Active-Halt modes unless explicitly enabled via peripheral clock gating registers before entering those states.

What is the maximum frequency achievable with the PLL?

The PLL provides 2× frequency multiplication of the input clock. With a maximum external crystal frequency of 8 MHz, the PLL output reaches 16 MHz - the maximum CPU clock rate supported by this device across its full operating voltage and temperature range.