Texas Instruments TPS61122PWR

Overview

TPS61122PWR from Texas Instruments is a synchronous boost converter with integrated 3.3-V/3.3-V dual-output power management IC for single-cell Li-ion or multi-cell alkaline/NiMH battery systems. It delivers up to 500 mA from the boost stage and 200 mA from the LDO, operates from 1.8 V to 5.5 V input, features 40-µA quiescent current, and includes power-good, low-battery detection, and thermal protection - used in portable audio, PDAs, and USB-powered instrumentation.

For engineers reviewing the TPS61122PWR datasheet, TPS61122PWR pinout, TPS61122PWR application, or TPS61122PWR equivalent, key selection considerations include fixed 3.6-V boost output + fixed 3.3-V LDO output, TSSOP-16 package with separate PGND/GND pins, 500-kHz PWM operation with power-save mode, and integrated antiringing switch for EMI reduction in space-constrained battery-powered designs.

Technical Context

The TPS61122PWR implements a fixed-frequency (500 kHz) PWM controller with multiple feedforward control - monitoring V_IN, V_OUT, and NMOS switch voltage drop to directly adjust duty cycle without relying solely on error amplifier feedback. Peak switch current is internally limited to 1300 mA (typ), and soft-start limits inrush during startup by restricting initial duty cycle and reducing current limit to 40% of nominal until regulation is achieved.

Its dual-output architecture separates regulation paths: the boost stage uses FB-sensed feedback (for adjustable versions) or internal divider (for fixed 3.6 V), while the LDO employs LDOSENSE-connected feedback (shorted to LDOOUT for fixed 3.3 V). The LDO supports back-bias operation and independent enable via LDOEN, decoupled from EN control of the boost stage.

Key Specifications

Pinout & Package

The TPS61122PWR is housed in a 16-pin TSSOP package (5.00 mm × 4.40 mm) with exposed thermal pad not connected internally; GND and PGND must be joined at a single point near Pin 12 to minimize ground bounce.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-output boost+LDO applications.

Compared with TPS61122PWR, TPS61088RHLR offers higher boost current but adds design complexity with external LDO and missing battery-monitoring features, while MAX8646ETE+ reduces quiescent current and size but sacrifices integrated diagnostics and EMI mitigation - making TPS61122PWR optimal for balanced performance in mid-power portable instrumentation.

Availability

TPS61122PWR is available at Aetrix Electronics and suitable for portable medical monitors, USB-powered test equipment, and industrial handheld scanners requiring stable component supply with guaranteed long-term manufacturability.

Supply support for TPS61122PWR 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 and embedded processing technologies, with decades of expertise in power management IC design and high-volume manufacturing reliability.

The TPS6112x product line was engineered specifically for space-constrained, battery-powered portable electronics needing dual regulated rails from a single low-voltage source - emphasizing efficiency, integration, and robust protection features.

FAQ

What is the fixed output voltage configuration of the TPS61122PWR?

The TPS61122PWR provides a fixed 3.6-V boost output and a fixed 3.3-V LDO output. These values are trimmed internally - no external resistors are needed on FB or LDOSENSE. The LDOSENSE pin must be shorted to LDOOUT to configure the fixed 3.3-V mode, as specified in the device options table for TPS61122PW.

Does the TPS61122PWR support back-bias operation on its LDO stage?

Yes, the TPS61122PWR LDO supports back-bias operation: when an external supply applied to LDOIN is lower than LDOOUT, current will not flow backward into LDOIN due to internal blocking. This allows safe connection of LDOOUT to VOUT or other system rails without risk of reverse current, provided LDOEN is asserted.

How does the TPS61122PWR handle shutdown and load isolation?

When EN is pulled low, the TPS61122PWR disables the boost converter, turns off all internal control circuits including the low-battery comparator, and activates a backgate control circuit that isolates VOUT from VBAT. This prevents battery drain through output capacitors - a key advantage over conventional synchronous rectifiers where body diodes conduct during shutdown.

What is the purpose of the separate PGND and GND pins on the TPS61122PWR?

The TPS61122PWR uses separate PGND (Pin 3) and GND (Pin 12) pins to isolate high-current switching return paths from sensitive signal references. PGND carries pulsed inductor current; GND serves as reference for EN, SKIPEN, LDOEN, and PGOOD. They must be connected at a single point near Pin 12 to prevent ground bounce from corrupting control signals.

Can the TPS61122PWR operate from a 1.8-V input and still deliver rated output current?

Yes - the TPS61122PWR supports 1.8-V minimum input and delivers up to 500 mA boost output when V_IN ≥ 2.4 V. At 1.8 V, maximum output current is reduced (e.g., ~200 mA at 3.6 V) due to duty-cycle limitations, but regulation is maintained across the full 1.8–5.5 V range per datasheet Figure 1 and Table 2.