Texas Instruments TPS61222DCKT

Overview

TPS61222DCKT from Texas Instruments is a fixed-output 5.0 V synchronous boost converter optimized for ultra-low-input-voltage battery-powered systems. It operates from 0.7 V to 5.5 V input, delivers up to 126 mA output current at 2.4 V input, achieves ≥90% efficiency at 50 mA load (V_IN = 2.4 V), and features 5.5 μA quiescent current. It is used in single-cell Li-ion or multi-cell alkaline/NiMH portable devices requiring regulated 5 V rail.

For engineers reviewing the TPS61222DCKT datasheet, TPS61222DCKT pinout, TPS61222DCKT application, or TPS61222DCKT equivalent, key selection criteria include startup capability at 0.7 V, fixed 5.0 V output with no external feedback resistors, SC-70 package thermal performance, and hysteretic current-mode control behavior under light-load discontinuous conduction mode.

Technical Context

The TPS61222DCKT implements a self-oscillating hysteretic current-mode controller that maintains constant 200 mA inductor ripple current and adjusts average inductor current offset based on load demand. Its synchronous rectification uses two integrated low-R_DS(on) MOSFETs - main switch (550 mΩ typical at V_OUT = 5 V) and rectifying switch (700 mΩ) - enabling high efficiency without external diodes.

Startup begins via internal oscillator when V_IN < 1.8 V, limiting switch current until V_OUT reaches ~1.8 V; then it transitions to normal hysteretic operation. During shutdown (EN = low), the device disables switching but allows passive pass-through via the rectifying MOSFET's body diode, maintaining V_OUT ≈ V_IN under light load.

Key Specifications

Pinout & Package

TPS61222DCKT is housed in a 6-pin SC-70 (DCK) package measuring 2.00 mm × 1.25 mm with 0.65 mm pitch, optimized for space-constrained portable PCBs. Thermal resistance R_θJA is 231.2°C/W; R_θJB is 78.8°C/W, indicating effective heat transfer to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61221DCKT, TPS61222DCKT provides higher output voltage for USB-compatible peripherals but trades off slightly lower max output current at low input voltages; versus MAX17222ETA+, it offers proven SC-70 manufacturability and TI's broad support ecosystem at the cost of marginally higher IQ and startup voltage.

Availability

TPS61222DCKT is available at Aetrix Electronics and suitable for wearable health monitors, smart remote controls, portable medical diagnostics, USB-C accessories, and low-power industrial sensors requiring stable component supply across long production cycles.

Supply support for TPS61222DCKT 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 for battery-powered systems.

The TPS6122x product line was designed specifically for ultra-low-input-voltage boost applications in space- and energy-constrained portable electronics, emphasizing minimal quiescent current, robust startup, and integrated protection.

FAQ

What is the minimum input voltage required for TPS61222DCKT to start up and regulate 5 V output?

The TPS61222DCKT starts up and regulates its 5.0 V output from a minimum input voltage of 0.7 V, as specified in the datasheet's Recommended Operating Conditions and confirmed in Figure 20 (startup waveform at VIN = 0.7 V). This enables reliable operation even with deeply discharged alkaline or NiMH cells. The device uses an internal oscillator during initial startup to build output voltage before transitioning to normal hysteretic control.

Does TPS61222DCKT require external feedback resistors to set its output voltage?

No, the TPS61222DCKT does not require external feedback resistors. It is a fixed-output variant with an internal resistor divider that sets VOUT to 5.00 V. Per the datasheet Pin Functions table and Figure 26, the FB pin must be directly connected to VOUT - no external components are needed. This simplifies layout and improves accuracy versus adjustable versions like TPS61220.

What happens to the output voltage of TPS61222DCKT when the EN pin is driven low?

When EN is driven low, the TPS61222DCKT enters shutdown mode: switching stops, internal control circuitry powers down, and quiescent current drops to 0.2–0.5 μA. However, the output remains connected to the input through the body diode of the internal rectifying MOSFET, so VOUT ≈ VIN minus diode drop (typically 0.2–0.4 V) under light load. This pass-through behavior avoids need for external OR-ing diodes.

Can TPS61222DCKT drive a 100 mA load continuously at 2.0 V input?

At VIN = 2.0 V, the TPS61222DCKT can deliver approximately 85–95 mA continuously while maintaining regulation and ≥85% efficiency, based on interpolation of Figure 4 (Maximum Output Current vs Input Voltage) and Figure 7 (Efficiency curves). Sustained 100 mA requires VIN ≥ 2.2 V to avoid thermal derating or output droop; layout, inductor DCR, and ambient temperature also affect practical current capability.

How does the TPS61222DCKT protect against overvoltage conditions?

The TPS61222DCKT includes internal overvoltage protection (OVP) that triggers when the output voltage exceeds 6.0 V (typical threshold). Upon detection, the voltage error amplifier limits further switching to clamp VOUT at ~6.0 V, preventing damage to downstream 5 V components. This protection operates independently of the FB pin and remains active even if the feedback path is open or shorted - a critical safeguard for LED drivers or systems with intermittent loads.