Texas Instruments MSP430AFE251IPW

Overview

MSP430AFE251IPW from Texas Instruments is an ultra-low-power 16-bit mixed-signal microcontroller featuring one 24-bit sigma-delta ADC, 16 KB flash, 512 B RAM, and integrated analog front-end for precision metrology. It operates from 1.8 V to 3.6 V, achieves 220 µA active current at 1 MHz/2.2 V, and supports single-phase electricity metering with differential PGA inputs and programmable voltage reference.

For engineers reviewing the MSP430AFE251IPW datasheet, MSP430AFE251IPW pinout, MSP430AFE251IPW application, or MSP430AFE251IPW equivalent, this device delivers verified metrology-grade ADC performance, sub-1-µs wake-up from LPM3/LPM4, and TSSOP-24 packaging optimized for compact energy measurement designs requiring high accuracy and long battery life.

Technical Context

The MSP430AFE251IPW implements a 16-bit RISC CPU with constant generators and digitally controlled oscillator (DCO), enabling efficient code execution and sub-microsecond transition from standby to active mode. Its SD24_A module provides 24-bit resolution with differential input pairs, internal reference buffer, and temperature sensor support - all operating within 2.5 V–3.6 V analog supply range.

It integrates Timer_A3 with three capture/compare registers, USART0 configurable as UART or SPI, hardware multiplier, brownout detector, and supply voltage supervisor. Clock system includes HF crystal support up to 16 MHz, internal VLO, and DCO calibration at two frequencies - all managed via dedicated control registers without external components.

Key Specifications

Pinout & Package

Package: 24-pin TSSOP (PW), body size 7.8 mm × 4.4 mm, JEDEC MO-153 compliant. Thermal resistance R_θJA = 76.4 °C/W (still air).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar mixed-signal microcontroller applications.

Compared with MSP430AFE252IPW and MSP430AFE231IPW, the MSP430AFE251IPW balances memory headroom and single-channel metrology capability - ideal for Class 1.0 meters needing robust firmware validation space without over-provisioning ADC resources.

Availability

MSP430AFE251IPW is available at Aetrix Electronics and suitable for single-phase electricity metering, digital power monitoring, and portable energy audit tools requiring stable component supply and long-term industrial lifecycle support.

Supply support for MSP430AFE251IPW 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 90 years of innovation in industrial and energy infrastructure markets.

The MSP430AFE2xx product line targets precision metrology applications, integrating ultra-low-power MCUs with calibrated sigma-delta ADCs and analog front-end features specifically for electricity, gas, and water metering systems.

FAQ

What is the maximum system clock frequency supported by the MSP430AFE251IPW?

The MSP430AFE251IPW supports a maximum MCLK frequency of 12 MHz when VCC ≥ 3.3 V and duty cycle is 50% ±10%. At lower supply voltages, the maximum frequency is reduced: 9 MHz at 2.7 V and 4.15 MHz at 1.8 V. These limits ensure reliable operation of the DCO and flash memory subsystems under all recommended conditions.

Does the MSP430AFE251IPW include an internal voltage reference for the ADC?

Yes, the MSP430AFE251IPW includes an internal 1.2 V bandgap reference that can be buffered and output on the VREF pin. This reference is used by the SD24_A module and supports both internal and external reference configurations - eliminating the need for external precision references in many metering applications.

How many I/O pins does the MSP430AFE251IPW provide, and what are their key functions?

The MSP430AFE251IPW provides 11 general-purpose I/O pins in its 24-pin TSSOP package. Key functions include UART/SPI communication (P1.3–P1.7), Timer_A3 capture/compare (P1.0–P1.2, P1.6–P1.7, P2.0), XT2 crystal interface (P2.6–P2.7), and supply voltage supervision (P1.0, P1.5). All pins support interrupt capability and configurable pullup/pulldown resistors.

What low-power modes are available on the MSP430AFE251IPW, and what is the lowest current draw?

The MSP430AFE251IPW offers five low-power modes (LPM0–LPM4). The lowest current draw is 0.1 µA in LPM4 (RAM retention only), measured at 2.2 V and 25°C. LPM3 draws 0.5 µA under the same conditions, enabling ultra-long battery life in always-on monitoring applications.

Is the MSP430AFE251IPW pin-compatible with other devices in the MSP430AFE2xx family?

Yes, the MSP430AFE251IPW shares the same 24-pin TSSOP (PW) package and pinout with all MSP430AFE2xx variants, including MSP430AFE252IPW and MSP430AFE231IPW. This allows direct substitution in existing designs when memory or ADC channel requirements change, without PCB revision.