Texas Instruments MSP430AFE221IPWR

Overview

MSP430AFE221IPWR from Texas Instruments is an ultra-low-power 16-bit mixed-signal microcontroller featuring one 24-bit sigma-delta ADC, 4 KB flash, 256 B RAM, 11 I/O pins, and operation from 1.8 V to 3.6 V. It integrates a 16-bit Timer_A with three capture/compare registers, USART (UART/SPI), hardware multiplier, brownout detector, and supply voltage supervisor - optimized for single-phase electricity metering and precision analog sensing.

For engineers reviewing the MSP430AFE221IPWR datasheet, MSP430AFE221IPWR pinout, MSP430AFE221IPWR application, or MSP430AFE221IPWR equivalent, key selection criteria include its single-channel SD24_A ADC configuration, TSSOP-24 package, ultra-low standby current (0.5 µA), and metrology-grade analog front-end integration for energy measurement systems.

Technical Context

The MSP430AFE221IPWR implements a 16-bit RISC CPU with constant generators and digitally controlled oscillator (DCO), enabling sub-1 µs wake-up from LPM3/LPM4. Its analog subsystem centers on a single 24-bit sigma-delta ADC (SD24_A) with differential PGA inputs, internal reference buffer, and programmable gain - supporting high-resolution DC/low-frequency signal acquisition without external signal conditioning.

Digital peripherals include a 16-bit Timer_A3 with three capture/compare registers, asynchronous UART or synchronous SPI via USART0, and Spy-Bi-Wire debug interface. Clocking supports HF crystal (up to 16 MHz), internal DCO (calibrated at 1/8/12 MHz), and VLO (12 kHz), with independent AVCC/DVCC rails and dedicated analog ground (AVSS) for noise-sensitive metrology applications.

Key Specifications

Pinout & Package

The MSP430AFE221IPWR is housed in a 24-pin TSSOP (PW) package with exposed pad thermal design, rated for –40°C to +85°C operation. Pin functions are defined per TI SLAS701B Rev. JUNE 2018, Figure 4-3 and Table 4-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430AFE222IPWR and MSP430F2274IPW, the MSP430AFE221IPWR uniquely balances metrology-specific analog integration, ultra-low power, and minimal BOM - making it optimal for cost-constrained, single-channel energy measurement where 24-bit resolution is mandatory but dual ADCs are unnecessary.

Availability

MSP430AFE221IPWR is available at Aetrix Electronics and suitable for single-phase electricity metering, digital power monitoring, and low-power analog data logging requiring stable component supply across industrial production cycles.

Supply support for MSP430AFE221IPWR 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 decades of expertise in ultra-low-power microcontrollers and precision analog signal chains.

The MSP430AFE2xx product line is designed specifically for metrology and high-accuracy analog sensing applications, integrating sigma-delta ADCs, low-drift references, and power-optimized MCUs to replace discrete analog front-ends in utility and industrial measurement systems.

FAQ

What is the ADC configuration of the MSP430AFE221IPWR?

The MSP430AFE221IPWR integrates exactly one 24-bit sigma-delta ADC (SD24_A) with differential PGA inputs, A0.0+ and A0.0−, as confirmed in TI SLAS701B Section 1.3 and Table 3-1. This single-channel architecture distinguishes it from MSP430AFE2x2 (two ADCs) and MSP430AFE2x3 (three ADCs) variants. The MSP430AFE221IPWR does not support A1.0+/A1.0− or A2.0+/A2.0− inputs.

Does the MSP430AFE221IPWR support crystal oscillator operation?

Yes, the MSP430AFE221IPWR supports high-frequency crystal oscillation up to 16 MHz via pins P2.6/XT2IN and P2.7/XT2OUT, as specified in Section 1.1 and Figure 4-3 of SLAS701B. This crystal can source MCLK, SMCLK, or ACLK, and is fully compatible with the device's clock system including automatic fault detection and fail-safe DCO fallback.

What is the maximum operating frequency of the MSP430AFE221IPWR CPU?

The MSP430AFE221IPWR CPU supports a maximum system clock (MCLK) frequency of 12 MHz when VCC ≥ 3.3 V, 9 MHz at 2.7 V, and 4.15 MHz at 1.8 V, per Figure 5-1 and Section 5.3 of SLAS701B. These limits apply to the DCO-sourced MCLK; external crystal or resonator frequencies may exceed these values but require appropriate clock divider configuration to keep MCLK within spec.

How many GPIO pins does the MSP430AFE221IPWR provide?

The MSP430AFE221IPWR provides 11 configurable GPIO pins: P1.0 through P1.7 (8 pins), P2.0, P2.6, and P2.7 - matching the I/O count stated in Table 3-1 of SLAS701B. All support interrupt capability, programmable pullup/pulldown resistors, and peripheral function multiplexing such as Timer_A, UART, SPI, and crystal interface.

What debug interface does the MSP430AFE221IPWR use?

The MSP430AFE221IPWR uses the Spy-Bi-Wire (SBW) interface, a two-pin variant of JTAG implemented on pins TEST/SBWTCK (Pin 10) and RST/NMI/SBWTDIO (Pin 11), as documented in Section 4.2 and Figure 4-3 of SLAS701B. This interface supports full in-circuit emulation, flash programming, and real-time debugging without requiring a 4-pin JTAG header.