Texas Instruments TPS62125DSGR

Overview

TPS62125 from Texas Instruments is a synchronous step-down DC-DC converter optimized for low-power and ultralow-power applications, delivering up to 300 mA output current with 3 V to 17 V input range, 1.2 V to 10 V adjustable output voltage, and DCS-Control™ topology enabling seamless PFM/PWM transition. It serves as a primary power rail in battery-powered embedded systems requiring precise enable supervision and power-good signaling.

For engineers reviewing the TPS62125 datasheet, TPS62125 pinout, TPS62125 application, or TPS62125 equivalent, key selection considerations include its 13-µA quiescent current, adjustable enable threshold (1.2 V typical) with hysteresis, open-drain power-good output, 2-mm × 2-mm WSON-8 package, and integrated output discharge function - all critical for energy-constrained and supply-supervised designs.

Technical Context

The TPS62125 implements TI's DCS-Control™ architecture, combining fast AC loop response via VOS-sensed output ripple with a stable DC feedback loop through the FB pin and 0.808-V internal reference. Its dual-loop structure enables <2% output voltage ripple in PFM mode and sub-2-µs load transient recovery.

Functional modes include quasi-fixed-frequency PWM (up to 1 MHz) at medium-to-heavy loads, automatic transition to variable-frequency PFM at light loads, 100% duty-cycle low-dropout operation near V_IN ≈ V_OUT, and thermal shutdown at 150°C with 20°C hysteresis - all managed without external mode control pins.

Key Specifications

Pinout & Package

TPS62125 is housed in a thermally enhanced 2.00 mm × 2.00 mm, 8-pin WSON package with exposed thermal pad (DSG). The package supports high-density PCB layouts and efficient heat dissipation via bottom-side GND connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down converter applications.

Compared with TPS62160DSGR and TPS62840DLCR, the TPS62125 uniquely balances wide input range (3–17 V), adjustable enable supervision, power-good signaling, and 300-mA capability - making it the only option among the three for 4-cell alkaline, multi-rail industrial sensors, or energy-harvesting systems requiring robust supply monitoring.

Availability

TPS62125 is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, energy-harvesting IoT edge devices, and 4-cell alkaline-powered remote controllers requiring stable component supply across long product lifecycles.

Supply support for TPS62125 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 power management technologies, with decades of expertise in high-efficiency DC-DC conversion.

The TPS62125 belongs to TI's DCS-Control™ synchronous buck converter family, designed specifically for ultralow-power, supply-supervised applications in battery-powered and energy-harvesting systems where precision enable control and power-good signaling are essential.

FAQ

What is the minimum input voltage required for TPS62125 to regulate a 3.3-V output at 200 mA?

The minimum input voltage depends on load current, output voltage, and MOSFET R_DS(ON). For TPS62125 delivering 3.3 V at 200 mA, with typical high-side R_DS(ON) of 1.5 Ω at 12 V and inductor DCR of ~0.1 Ω, V_IN(min) ≈ 3.3 V + 200 mA × (1.5 Ω + 0.1 Ω) = 3.62 V. At lower VIN, the device enters 100% duty cycle mode until UVLO (2.8 V) triggers shutdown.

Can TPS62125 start up into a pre-biased output capacitor?

Yes, the TPS62125 supports pre-biased start-up. When enabled, it detects the existing VOUT voltage and begins switching only after the output has discharged (via leakage or external load) to near the target regulation level. This prevents reverse current flow and ensures monotonic ramp-up without damaging downstream circuitry.

How does the EN_hys pin affect the enable threshold hysteresis of TPS62125?

The EN_hys pin is an open-drain output that pulls low when the EN pin voltage falls below V_{TH_EN_OFF} (~1.15 V). Connecting an external resistor from EN_hys to a voltage source (e.g., VOUT) increases the effective hysteresis beyond the internal 50 mV. The exact value depends on resistor ratio and is detailed in Section 8.1.2 of the TPS62125 datasheet.

What is the maximum recommended inductor value for TPS62125 when operating at 300 mA output current?

TI recommends 15 µH for standard 300-mA operation (e.g., V_IN = 12 V, V_OUT = 3.3 V), as validated in the typical application schematic. Larger inductors (e.g., 22 µH) may be used to reduce ripple and improve light-load efficiency but require re-evaluation of minimum ON-time (500 ns) and PFM-to-PWM transition point to avoid instability or excessive soft-start time.

Does TPS62125 provide overvoltage protection on its output?

No, the TPS62125 does not include active overvoltage protection (OVP). Its regulation relies on feedback loop stability and internal reference accuracy (±2.5% on V_{REF_FB}). External OVP must be implemented separately if required - for example, using a dedicated supervisor IC or Zener clamp on the FB node. The PG output indicates regulation status but does not detect overvoltage faults.