Texas Instruments TPS61097A-33DBVT

Overview

TPS61097A-33 from Texas Instruments is a low-input-voltage synchronous boost converter optimized for single-cell battery-powered systems. It delivers a fixed 3.3-V output from input voltages as low as 0.9 V, supports up to 100 mA output current at 3.3 V with >93% peak efficiency, features <5 μA quiescent current and <5 nA shutdown current, and integrates a bypass switch for battery-to-load continuity during disable - enabling critical backup in MSP430 and medical sensor applications.

For engineers reviewing the TPS61097A-33 datasheet, TPS61097A-33 pinout, TPS61097A-33 application, or TPS61097A-33 equivalent, key selection criteria include ultra-low VIN capability (0.9 V), fixed 3.3-V output regulation, SOT-23-5 package constraints, bypass-switch behavior under EN control, and thermal/overcurrent protection thresholds verified per SLVSCF2A.

Technical Context

The TPS61097A-33 employs a hysteretic current-mode controller that maintains constant inductor ripple current (~200 mA) and adjusts offset based on load, enabling automatic transition between continuous and discontinuous conduction modes. Its dual-MOSFET synchronous rectification architecture uses integrated N-channel main and P-channel bypass switches, with independent control logic ensuring bypass activation only when EN < 0.58 V - unaffected by UVLO or thermal shutdown.

Startup begins via internal oscillator when VIN is insufficient for control circuitry; operation transitions to normal hysteretic mode once VOUT reaches ~1.8 V. Overload causes output voltage collapse below VIN, forward-biasing the rectifier's body diode - limiting current only by parasitic resistance until condition clears and soft-start resumes.

Key Specifications

Pinout & Package

TPS61097A-33 is housed in a 2.8-mm × 2.9-mm 5-pin SOT-23 (DBV) package with exposed pad not electrically connected. Thermal resistance θ_JA = 208.7°C/W reflects standard JEDEC 2-layer board mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61097A-33, TPS610981DSER trades fixed-output simplicity for adjustability and reduced IQ, while MAX17222ETA+T offers lower minimum VIN and higher output current but omits the critical bypass switch - making TPS61097A-33 uniquely suited for battery-backed, space-tolerant, ultra-low-power systems requiring guaranteed load continuity.

Availability

TPS61097A-33 is available at Aetrix Electronics and suitable for wearable health monitors, MSP430-based data loggers, fuel cell-powered gas detectors, and low-power white LED indicators requiring stable component supply across long-lifecycle industrial and medical programs.

Supply support for TPS61097A-33 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and personal electronics markets.

The TPS61097A series targets ultra-low-power, single-cell battery applications - designed specifically to extend runtime in energy-constrained devices like portable medical sensors and wireless sensor nodes through sub-5-μA quiescent operation and 0.9-V startup.

FAQ

What is the minimum input voltage required for TPS61097A-33 to start switching?

The TPS61097A-33 begins switching at input voltages as low as 0.9 V, enabled by an internal startup oscillator that operates before the control circuit achieves sufficient bias. This allows reliable startup from deeply discharged alkaline or NiMH cells. The device transitions to normal hysteretic mode once VOUT reaches approximately 1.8 V. Full regulation to 3.3 V is maintained across the entire 0.9–5.5 V input range.

How does the bypass switch in TPS61097A-33 behave during shutdown?

When EN is pulled low (<0.58 V), the TPS61097A-33 disables the boost converter and activates an integrated P-channel MOSFET bypass switch, creating a low-impedance path from VIN (via the L pin) to VOUT. This bypass remains active regardless of input voltage level - it is unaffected by undervoltage lockout, overvoltage, or thermal shutdown - ensuring uninterrupted power to critical loads such as real-time clocks or SRAM during system sleep.

Can TPS61097A-33 regulate output when input voltage exceeds 3.3 V?

No - the TPS61097A-33 is a boost-only converter with no buck or pass-through regulation. When VIN exceeds 3.3 V, VOUT tracks VIN minus small diode-drop losses from the internal bypass path; regulation is lost. The device is intended strictly for step-up applications where VIN < VOUT. For mixed-step applications, a separate buck-boost or buck converter is required.

What is the maximum continuous output current supported by TPS61097A-33 at 3.3 V output?

The TPS61097A-33 supports up to 100 mA continuous output current at 3.3 V when powered from a 1.2-V input, limited by its 400 mA average input current ceiling and synchronous switch R_DS(on). Output current decreases as input voltage drops (e.g., ~70 mA at 0.9 V VIN) due to increased duty cycle and conduction losses. Derating is required above 85°C ambient per thermal data (θ_JA = 208.7°C/W).

Does TPS61097A-33 require external compensation components?

No - the TPS61097A-33 uses a hysteretic current-mode control architecture that eliminates the need for external compensation networks. Stability is inherent to the control scheme, enabling robust performance across input/output voltage ranges and load transients without loop tuning. Only external passive components - input/output capacitors and inductor - are required for basic operation per the recommended design in SLVSCF2A.