Texas Instruments TPS62120DCNR

Overview

TPS62120DCNR from Texas Instruments is a highly efficient synchronous step-down DC-DC converter optimized for ultra-low-power applications, supporting 2 V to 15 V input voltage, 1.2 V to 5.5 V adjustable output voltage, up to 75 mA output current, and 96% peak efficiency - deployed in energy harvesting nodes and low-power RF transceivers.

For engineers reviewing the TPS62120DCNR datasheet, TPS62120DCNR pinout, TPS62120DCNR application, or TPS62120DCNR equivalent, key selection criteria include its 11-µA quiescent current in power-save mode, open-drain power-good (PG) and SGND discharge outputs, hysteretic PFM/PWM control architecture, and SOT-23-8 package compatibility with space-constrained battery-powered systems.

Technical Context

The TPS62120DCNR employs a hysteretic control scheme that automatically transitions between pulse frequency modulation (PFM) at light loads and quasi-fixed-frequency PWM at higher loads, enabling stable regulation with minimal external components. Its internal 0.8-V reference and feedback comparator drive switching based on FB voltage deviation, while minimum ON/OFF times (700 ns / 60 ns) ensure robust operation across wide VIN–VOUT differentials.

It integrates dual MOSFET switches (RDS(ON) = 1.75 Ω high-side / 1.2 Ω low-side at VIN = 8 V), thermal shutdown (150°C), undervoltage lockout (2.5 V rising / 1.85 V falling), and soft-start with ~15 mV/µs ramp rate. The PG and SGND pins provide system-level monitoring and controlled output discharge during shutdown - functions absent in the pin-compatible TPS62122.

Key Specifications

Pinout & Package

SOT-23-8 package (2.90 mm × 1.63 mm body size), thermally enhanced with exposed pad not present - requires standard SOT-23 footprint and reflow profile.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck converter applications.

Compared with TPS62122DRVR and TPS62740DSSR, the TPS62120DCNR uniquely delivers both power-good monitoring and controlled output discharge in a compact SOT-23-8 package - making it the only option among the three for systems requiring verified regulation status and deterministic shutdown behavior.

Availability

TPS62120DCNR is available at Aetrix Electronics and suitable for wireless sensor nodes, energy harvesting systems, ultra-low-power MCU platforms, and industrial analog front-ends requiring stable component supply across extended production lifecycles.

Supply support for TPS62120DCNR 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 designing analog ICs, embedded processors, and system solutions for industrial, automotive, and personal electronics markets.

The TPS6212x product line was engineered specifically for ultra-low-power, wide-input-voltage DC-DC conversion in energy-constrained environments - emphasizing minimal quiescent current, small external component count, and robust start-up under marginal supply conditions.

FAQ

What is the minimum input voltage required for TPS62120DCNR to start switching?

The TPS62120DCNR requires VIN to exceed the rising undervoltage lockout (UVLO) threshold of 2.5 V (typical) to initiate switching. Once enabled, it remains operational down to the falling UVLO threshold of 1.85 V. Startup time from EN assertion to first switching pulse is typically 50 µs, and the device supports start-up into a pre-biased output capacitor.

Does TPS62120DCNR support adjustable output voltage, and how is it configured?

Yes, TPS62120DCNR supports adjustable output voltage from 1.2 V to 5.5 V using an external resistor divider on the FB pin. With an internal 0.8-V reference, VOUT = 0.8 V × (1 + R1/R2). TI recommends R2 between 82 kΩ and 360 kΩ and total divider resistance ≤1 MΩ; a 22-pF feedforward capacitor (Cff) is required for optimal loop stability.

How does the power-good (PG) output of TPS62120DCNR behave during startup and fault conditions?

The PG output of TPS62120DCNR is an open-drain signal that goes low when FB voltage falls below 90% of its nominal value (e.g., 1.62 V for 1.8 V output) and high-impedance when above 95%. It asserts after a 2-µs delay once regulation is achieved and pulls low during UVLO or shutdown - enabling reliable system power sequencing and fault detection without additional supervision circuitry.

Can TPS62120DCNR operate with a 1.5-V input supply?

No, TPS62120DCNR cannot operate with a 1.5-V input supply. Its absolute minimum operating input voltage is 2 V, and the rising UVLO threshold is 2.5 V - meaning the device will not enable or switch below that level. For sub-2-V inputs, alternative regulators such as the TPS62740 (1.8 V min) or TPS61291 (0.7 V min) must be considered.

What is the purpose of the SGND pin on TPS62120DCNR, and how should it be connected?

The SGND pin on TPS62120DCNR is an open-drain NMOS output (RDS(ON) ≈ 370 Ω) that connects internally to GND during shutdown or UVLO. When tied to VOUT, it actively discharges the output capacitor to prevent lingering voltage that could interfere with system reset or cause latch-up. Leaving SGND unconnected results in high-impedance state during normal operation and safe discharge during fault conditions.