Texas Instruments MSP430F1121IDWR

Overview

MSP430F1121IDWR from Texas Instruments is an ultralow-power 16-bit RISC mixed-signal microcontroller featuring 4KB flash memory, 256B RAM, a 16-bit Timer_A with three capture/compare registers, an on-chip analog comparator, and 14 programmable I/O pins. It operates from 1.8 V to 3.6 V and achieves active-mode current of 160 μA at 1 MHz/2.2 V, enabling battery-powered sensor systems and portable measurement devices.

For engineers reviewing the MSP430F1121IDWR datasheet, MSP430F1121IDWR pinout, MSP430F1121IDWR application, or MSP430F1121IDWR equivalent, key selection criteria include its 20-pin SOIC-W (DW) package, sub-6-μs wake-up from standby, integrated slope A/D capability via I/O pins, and flash-based in-system programmability without external voltage.

Technical Context

The MSP430F1121IDWR implements a 16-bit RISC CPU with constant generators and seven addressing modes, executing register-to-register instructions in one CPU cycle. Its basic clock module supports multiple sources: internal DCO (stabilizes in <6 μs), 32-kHz crystal, high-frequency crystal, resonator, or external clock - enabling flexible low-power timing architectures.

It integrates peripheral modules directly accessible via memory-mapped I/O: Timer_A3 with three independent capture/compare registers, Comparator_A for analog signal comparison or slope ADC, watchdog timer configurable as interval timer, and two 8-bit ports (P1 fully exposed, P2 with six external pins). All peripherals are controlled using standard CPU instructions without dedicated I/O instructions.

Key Specifications

Pinout & Package

Package: 20-pin Plastic Small-Outline Wide Body (SOIC-W), suffix DW, body width 7.5 mm, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MSP430F1101AIDW, the MSP430F1121IDWR provides double flash and RAM for enhanced functionality; compared with MSP430F1132IDWR, it offers optimal cost/performance balance for mid-complexity sensor applications without over-provisioning memory.

Availability

MSP430F1121IDWR is available at Aetrix Electronics and suitable for wireless sensor nodes, portable medical instruments, and industrial data loggers requiring stable component supply across long-lifecycle embedded programs.

Supply support for MSP430F1121IDWR 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 investment in low-power microcontroller innovation.

The MSP430x1xx family, including the MSP430F1121IDWR, was designed specifically for ultralow-power portable measurement and sensing applications where battery life, integration, and system-level energy efficiency are critical.

FAQ

What is the maximum operating frequency of the MSP430F1121IDWR at 3.6 V?

The MSP430F1121IDWR supports a maximum system clock (MCLK) frequency of 8 MHz at 3.6 V, as specified in the recommended operating conditions. This applies when executing code from flash memory. The internal digitally controlled oscillator (DCO) is calibrated to deliver this frequency under nominal supply and temperature conditions, and the device maintains full functionality-including Timer_A, comparator, and I/O-across this range. MSP430F1121IDWR performance remains stable up to this limit without requiring external crystal support.

Does the MSP430F1121IDWR support in-system programming without external hardware?

Yes, the MSP430F1121IDWR supports in-system programming via its built-in bootstrap loader (BSL), which uses UART communication over P1.1 (TX) and P2.2 (RX). No external programmer or JTAG interface is required for field firmware updates. The BSL is protected by a user-configurable password, and entry is triggered by specific pin states at power-up. This capability enables cost-effective production programming and post-deployment firmware upgrades for MSP430F1121IDWR-based devices.

What are the absolute maximum ratings for VCC and I/O voltage on the MSP430F1121IDWR?

The absolute maximum rating for VCC is −0.3 V to 4.1 V relative to VSS. For any I/O pin, voltage must remain between −0.3 V and VCC + 0.3 V. Exceeding these limits risks permanent damage. The MSP430F1121IDWR is not 5-V tolerant; applying 5 V to any pin-even briefly-can degrade or destroy the device. Proper level-shifting circuitry is required when interfacing with 5-V systems. These ratings apply to the MSP430F1121IDWR across its full operating temperature range.

Can the MSP430F1121IDWR perform analog-to-digital conversion without an external ADC?

Yes, the MSP430F1121IDWR can perform analog-to-digital conversion using its on-chip Comparator_A module in slope ADC mode. By charging a capacitor through a resistive sensor and measuring the time required for the comparator output to toggle, the device converts analog resistance values (e.g., thermistors, photoresistors) into digital results using only GPIO pins and Timer_A. This technique eliminates the need for an external ADC in many low-resolution sensing applications and is explicitly supported in the MSP430F1121IDWR's functional description.

Which low-power modes are available on the MSP430F1121IDWR and how do they differ?

The MSP430F1121IDWR supports five software-selectable low-power modes (LPM0–LPM4), each disabling different clock domains to optimize energy use. LPM0/LPM1 halt the CPU but keep SMCLK/ACLK active; LPM2 stops SMCLK while retaining ACLK; LPM3 disables DCO's DC generator; LPM4 shuts down all clocks including ACLK and stops the crystal oscillator. Wake-up from any mode takes less than 6 μs. These modes are fully implemented and documented for the MSP430F1121IDWR in the SLAS241I datasheet.