Texas Instruments MSP430AFE251IPWR

Overview

MSP430AFE251IPWR from Texas Instruments is an ultra-low-power mixed-signal microcontroller featuring a 16-bit RISC CPU, 16 KB flash, 512 B RAM, and one 24-bit sigma-delta ADC with differential PGA inputs. It operates from 1.8 V to 3.6 V, supports up to 12-MHz system clock, and targets precision metrology applications such as single-phase electricity meters.

For engineers reviewing the MSP430AFE251IPWR datasheet, MSP430AFE251IPWR pinout, MSP430AFE251IPWR application, or MSP430AFE251IPWR equivalent, key selection criteria include its single-channel SD24_A ADC configuration, TSSOP-24 package with 11 I/O pins, ultra-low active current (220 µA at 1 MHz/2.2 V), and integrated hardware multiplier for real-time energy computation.

Technical Context

The MSP430AFE251IPWR implements a digitally controlled oscillator (DCO) enabling sub-1-µs wake-up from LPM3/LPM4, paired with a dedicated SD24_A module supporting 24-bit resolution, programmable gain, and built-in voltage reference. Its clock system integrates HF crystal support (up to 16 MHz), internal VLO, and DCO calibration across temperature.

It features a single USART0 configurable as UART or SPI, Timer_A3 with three capture/compare registers, brownout detection, supply voltage supervisor with programmable threshold, and Spy-Bi-Wire debug interface - all optimized for battery-powered, high-accuracy analog sensing in constrained environments.

Key Specifications

Pinout & Package

The MSP430AFE251IPWR is housed in a 24-pin TSSOP (PW) package measuring 7.8 mm × 4.4 mm, with thermal resistance R_θJA = 76.4 °C/W under still-air conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430AFE252IPW, the MSP430AFE251IPWR offers identical processing capability and memory but trades one ADC channel for lower power and cost in single-input metering systems; versus MSP430AFE231IPW, it provides double flash capacity for future firmware expansion or advanced tariff algorithms without changing PCB layout.

Availability

MSP430AFE251IPWR is available at Aetrix Electronics and suitable for single-phase electricity meters, digital power monitors, and precision sensor nodes requiring stable component supply across multi-year production cycles.

Supply support for MSP430AFE251IPWR 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 company specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer applications.

The MSP430AFE2xx product line is designed specifically for ultra-low-power, high-accuracy analog sensing in utility metering and industrial monitoring systems - integrating precision sigma-delta ADCs with low-power MCUs on a single die.

FAQ

What is the maximum system clock frequency supported by the MSP430AFE251IPWR?

The MSP430AFE251IPWR supports a maximum system clock (MCLK) frequency of 12 MHz when supplied at ≥3.3 V. At 2.7 V, the maximum is 9 MHz, and at 1.8 V, it is 4.15 MHz. This frequency scaling ensures stable operation across the full 1.8–3.6 V supply range while maintaining timing integrity for metrology calculations in the MSP430AFE251IPWR.

Does the MSP430AFE251IPWR include an internal voltage reference for the ADC?

Yes, the MSP430AFE251IPWR includes an internal 1.2-V bandgap voltage reference accessible via the VREF pin. It can be used directly as the SD24_A reference source or buffered for external use. The reference exhibits low drift over temperature and supports high-accuracy metrology without requiring external components - a key feature of the MSP430AFE251IPWR design.

How many I/O pins does the MSP430AFE251IPWR provide, and what are their key functions?

The MSP430AFE251IPWR provides 11 configurable I/O pins across Ports P1 and P2. These support UART/SPI communication (UTXD0/URXD0/SIMO0/SOMI0/UCLK0), timer capture/compare (TA0–TA2), crystal oscillation (XT2IN/XT2OUT), and general-purpose GPIO with Schmitt-trigger inputs and programmable pullup/pulldown resistors - all essential for compact metering hardware built around the MSP430AFE251IPWR.

Can the MSP430AFE251IPWR operate without an external crystal?

Yes, the MSP430AFE251IPWR can operate without an external crystal using its internal digitally controlled oscillator (DCO), which is factory-calibrated to ±1% accuracy across voltage and temperature. This allows fully integrated, low-cost meter designs where crystal placement, layout sensitivity, and bill-of-materials count must be minimized - a validated capability of the MSP430AFE251IPWR.

What low-power modes are available on the MSP430AFE251IPWR, and what is the lowest current consumption?

The MSP430AFE251IPWR supports five low-power modes (LPM0–LPM4). In LPM4 (RAM retention only), it draws just 0.1 µA at 2.2 V and 25°C - enabling decade-long battery life in intermittent-read metering applications. Wake-up from LPM4 to active mode occurs in less than 1 µs, allowing rapid response to events like tamper detection or urgent data upload in the MSP430AFE251IPWR.