Texas Instruments TPS7A1409PYBKR

Overview

TPS7A1409PYBKR from Texas Instruments is a 1-A ultra-low-dropout linear regulator (LDO) optimized for battery-powered systems requiring sub-1-V input and low-voltage output (0.9 V fixed). It delivers 70 mV max dropout at 1 A, 1% output accuracy over –40°C to +125°C, and supports dual-rail operation with separate IN (0.7–2.2 V) and BIAS (2.2–5.5 V) supplies. It powers core logic in compact portable devices such as camera modules and wireless earbuds.

For engineers reviewing the TPS7A1409PYBKR datasheet, TPS7A1409PYBKR pinout, TPS7A1409PYBKR application, or TPS7A1409PYBKR equivalent, key selection criteria include ultra-low VIN capability, active output discharge, SENSE feedback for remote sensing, thermal shutdown behavior, and compatibility with 0.71 mm × 1.16 mm WCSP packaging.

Technical Context

The TPS7A1409PYBKR uses a dual-supply architecture: the IN pin carries the main power path (as low as 0.7 V), while the BIAS pin (2.2–5.5 V) powers internal reference and control circuitry-enabling stable regulation even when VIN is only 100 mV above VOUT. Its foldback current limit protects against short circuits, and global UVLO ensures both VIN and VBIAS exceed thresholds before enabling.

It features an active pulldown circuit (RPULLDOWN = 36 Ω) for rapid output discharge during disable, and achieves 80 dB PSRR at 1 kHz under 500 mA load. The SENSE pin enables precision regulation at the load by compensating for PCB trace resistance, critical for high-current, low-voltage rails.

Key Specifications

Pinout & Package

TPS7A1409PYBKR is packaged in a 6-bump, 0.71 mm × 1.16 mm WCSP (YBK) with bottom-side solder balls. The package includes an exposed thermal pad electrically connected to GND for enhanced heat dissipation in space-constrained layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-dropout LDO applications.

Compared with TPS7A1409PYBKR, both alternatives lack the dual-rail LILO architecture, SENSE feedback, and 0.9-V fixed output - making them unsuitable for next-generation ultra-low-voltage portable SoC core regulation where headroom, accuracy, and transient fidelity are paramount.

Availability

TPS7A1409PYBKR is available at Aetrix Electronics and suitable for camera modules, wireless earbuds, and smart watches requiring stable component supply across high-mix, low-volume production runs and long-lifecycle consumer programs.

Supply support for TPS7A1409PYBKR 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 LDO innovation for portable and industrial applications.

The TPS7A14 product line was designed specifically for ultra-low-input, ultra-low-output battery-powered systems - enabling efficient core voltage regulation where traditional LDOs fail due to insufficient VIN–VOUT headroom.

FAQ

What is the minimum input voltage required for TPS7A1409PYBKR to regulate 0.9 V output?

The TPS7A1409PYBKR requires VIN ≥ VOUT + 100 mV for full specification compliance, meaning a minimum of 1.0 V on the IN pin. However, it can operate down to 0.7 V on IN when paired with a valid BIAS supply (≥2.2 V or VOUT + 1.4 V), though regulation accuracy and dropout performance degrade below VIN = 1.0 V. The device's global UVLO also mandates VIN > 603 mV (typ) before enabling.

Does TPS7A1409PYBKR support remote sensing, and how is it implemented?

Yes, TPS7A1409PYBKR supports remote sensing via its dedicated SENSE pin (B1). When connected directly to the load's VDD pin, the SENSE input closes the feedback loop at the point-of-load, compensating for voltage drop across PCB traces and connectors. This ensures ±1% output accuracy at the load, even with up to ~50 mΩ of series resistance between OUT and the load.

What is the purpose of the BIAS pin on TPS7A1409PYBKR, and what voltage range must it be supplied with?

The BIAS pin powers the internal reference, error amplifier, and control circuitry independently of the main IN rail. It must be supplied with 2.2 V to 5.5 V - specifically, ≥ greater of 2.2 V or VOUT(NOM) + 1.4 V - to ensure proper operation. This dual-rail architecture allows the IN pin to operate as low as 0.7 V while maintaining regulation integrity, significantly improving efficiency in LILO applications.

How does the active output discharge function work on TPS7A1409PYBKR, and what is its typical resistance?

When TPS7A1409PYBKR is disabled (EN low, UVLO triggered, or thermal shutdown), an internal MOSFET connects a 36-Ω pulldown resistor between OUT and GND. This actively discharges the output capacitance, ensuring rapid, controlled voltage decay. Discharge time depends on COUT and parallel load resistance; for example, with 10 µF COUT and no load, t ≈ 0.35 ms. Reverse current must be limited to <5% of rated output current to avoid damage.

Can TPS7A1409PYBKR be used without connecting the EN pin, and what is the recommended tie-off?

Yes, TPS7A1409PYBKR can operate without external EN control. If always-on functionality is required, the EN pin must be tied to either the IN or BIAS supply rail - both provide valid logic-high voltage (>0.6 V) to enable the regulator. Leaving EN floating is not permitted, as it may cause unpredictable enable/disable behavior due to noise susceptibility.