Texas Instruments MSP430G2121IRSA16R

Overview

MSP430G2121IRSA16R from Texas Instruments is an ultra-low-power 16-bit RISC microcontroller with 1 kB flash, 128 B RAM, 16-MHz DCO clock, Timer_A2 with two capture/compare registers, and 10 I/O pins. It operates from 1.8 V to 3.6 V and supports SPI/I²C via USI, targeting battery-powered sensor nodes and portable instrumentation.

For engineers reviewing the MSP430G2121IRSA16R datasheet, MSP430G2121IRSA16R pinout, MSP430G2121IRSA16R application, or MSP430G2121IRSA16R equivalent, key selection criteria include its QFN-16 package, absence of ADC10 (distinguishing it from G2x31 variants), brownout detection, five low-power modes, and Spy-Bi-Wire debug interface compatibility.

Technical Context

The MSP430G2121IRSA16R implements a 16-bit CPU with seven addressing modes and 51 instructions, executing register-to-register operations in one MCLK cycle. Its basic clock module integrates a digitally controlled oscillator (DCO), internal low-frequency oscillator (VLO), and external crystal support (32 kHz) for flexible system timing.

It features a single 8-bit port (P1) with individually configurable pull-up/down resistors and edge-selectable interrupts on all bits, plus two P2 I/O pins. The USI module provides hardware-level SPI and I²C protocol support without CPU overhead, while Timer_A2 enables PWM generation, input capture, and interval timing with dual compare registers.

Key Specifications

Pinout & Package

Package: 16-pin QFN (RSA), 3 mm × 3 mm, 0.5 mm pitch, exposed thermal pad connected to DVSS.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430G2121IRSA16R, MSP430G2221IRSA16 offers headroom for feature-rich firmware, while MSP430FR2111IPW14 trades flash endurance for FRAM's write speed and cycle count - both require PCB layout changes due to different pin counts or packages.

Availability

MSP430G2121IRSA16R is available at Aetrix Electronics and suitable for smart sensor nodes, portable data loggers, and industrial control panels requiring stable component supply across long-lifecycle designs.

Supply support for MSP430G2121IRSA16R 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 focused on analog and embedded processing technologies, with decades of expertise in ultra-low-power design.

The MSP430G2xx family targets cost-sensitive, battery-operated applications demanding sub-µA sleep currents and rapid wake-up - designed specifically for sensor interfaces, metering, and portable instrumentation.

FAQ

What is the maximum operating frequency of the MSP430G2121IRSA16R?

The MSP430G2121IRSA16R supports a maximum MCLK frequency of 16 MHz at VCC ≥ 2.2 V, enabled by its factory-calibrated digitally controlled oscillator (DCO). This allows real-time signal processing and responsive I/O handling while maintaining ultra-low active current - critical for time-sensitive sensor fusion tasks within the MSP430G2121IRSA16R's power budget.

Does the MSP430G2121IRSA16R include an analog-to-digital converter (ADC)?

No, the MSP430G2121IRSA16R does not include an ADC10 module. It belongs to the G2x21 series, which omits the 10-bit ADC present in G2x31 variants like MSP430G2231IRSA16. Designers requiring analog sensing must add an external ADC or select a G2x31-family part - this distinction is confirmed in Table 1 of the SLAS694J datasheet for MSP430G2121IRSA16R.

What debug interface does the MSP430G2121IRSA16R support?

The MSP430G2121IRSA16R supports Spy-Bi-Wire (SBW), a 2-wire variant of JTAG implemented on pins RST/NMI/SBWTDIO (Pin 9) and TEST/SBWTCK (Pin 10). This interface enables full in-system programming, real-time debugging, and flash security fuse configuration - all without requiring a 4-pin JTAG header, reducing board space and connector cost for the MSP430G2121IRSA16R.

What are the low-power mode current specifications for the MSP430G2121IRSA16R?

The MSP430G2121IRSA16R achieves 0.1 µA in LPM4 (RAM retention only), 0.5 µA in LPM3 with internal VLO clock, and 22 µA in LPM2 - verified at 2.2 V and 25°C. These values enable multi-year operation in intermittently active applications, such as environmental sensors that wake every minute to sample and transmit - a core design strength of the MSP430G2121IRSA16R.

Is the MSP430G2121IRSA16R pin-compatible with other devices in the MSP430G2xx family?

The MSP430G2121IRSA16R shares the 16-pin QFN (RSA) package and identical pin mapping with MSP430G2221IRSA16 and MSP430G2131IRSA16, but functional differences exist: G2221 adds 1 kB flash, G2131 adds ADC10. Pin compatibility allows shared PCB footprints, though firmware and peripheral initialization must match the specific variant's capabilities for the MSP430G2121IRSA16R.