STMicroelectronics ST72F324LJ2T5

Overview

ST72F324LJ2T5 from STMicroelectronics is an 8-bit Flash-based microcontroller with 8KB program memory, 384 bytes RAM, 10-bit ADC (12-channel), dual 16-bit timers (Timer A/B), SPI and SCI serial interfaces, and PLL-based clock management - deployed in industrial motor control panels requiring real-time I/O response and low-voltage operation.

For engineers reviewing the ST72F324LJ2T5 datasheet, ST72F324LJ2T5 pinout, ST72F324LJ2T5 application, or ST72F324LJ2T5 equivalent, this MCU delivers deterministic interrupt latency (9 vectors + TRAP/RESET), high-sink I/O (10 lines), and dual power-saving modes (Halt/Wait) critical for battery-backed sensor nodes and embedded HMI controllers.

Technical Context

The ST72F324LJ2T5 implements a Harvard-architecture CPU with 63 instructions and 17 addressing modes, supporting in-application programming (IAP) and in-circuit programming (ICP) via ICC interface. Its PLL multiplies external clock input by 2× to enable up to 8 MHz system frequency from a 4 MHz crystal.

Interrupt handling uses nested vector architecture with 10 dedicated vectors plus TRAP and RESET; external interrupts are routed across 6 pins mapped to 4 vectors. The 10-bit ADC supports single-ended conversion with programmable sampling time and auto-triggering from Timer A overflow.

Key Specifications

Pinout & Package

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

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM8S003F3P6 and EFM8BB10F8G-A-QSOP24, the ST72F324LJ2T5 uniquely combines dual 16-bit timers with full 12-channel ADC and native SCI/SPI - making it irreplaceable for cost-sensitive, real-time embedded systems requiring concurrent analog acquisition and serial communication.

Availability

ST72F324LJ2T5 is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, embedded HMI panels, and PLC I/O modules requiring stable component supply across extended product lifecycles.

Supply support for ST72F324LJ2T5 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, and sensors for industrial, automotive, and consumer markets.

The ST7 family was engineered for cost-effective, low-power 8-bit control in resource-constrained embedded systems - emphasizing robust I/O, integrated peripherals, and field-programmable Flash for rapid prototyping and maintenance.

FAQ

What is the maximum system clock frequency achievable with the ST72F324LJ2T5?

The ST72F324LJ2T5 achieves up to 8 MHz system clock using its internal PLL, which doubles an external 4 MHz crystal input. Without PLL, the maximum clock is limited to the external source frequency (≤8 MHz). The PLL is disabled by default and must be enabled and stabilized before switching clock sources.

Does the ST72F324LJ2T5 support hardware UART autobaud detection?

No, the ST72F324LJ2T5 SCI peripheral does not implement hardware autobaud detection. Baud rate is set via the BRR register using integer division of the APB clock; synchronization relies on start-bit detection and fixed divisor configuration. External firmware routines must handle variable-rate frame alignment.

Can the 10-bit ADC operate during Halt mode?

Yes, the ADC can perform conversions in Halt mode if the ADC clock source remains active and the HALT instruction is executed after enabling ADC startup. However, the CPU core halts - results must be captured via ADC interrupt or polled upon wake-up, as no instructions execute during Halt.

Is the ICCSEL/VPP pin required for normal operation?

No - ICCSEL/VPP is used exclusively during in-circuit programming (ICP) and must be pulled high only during reset to enter programming mode. In normal operation, it should be tied to VDD or left unconnected; floating or low states may cause unintended ICP entry or reset instability.