Texas Instruments UCC39411DG4

Overview

UCC39411DG4 from Texas Instruments is a low-power synchronous boost converter IC optimized for single/dual alkaline battery operation, delivering 3.3 V at up to 200 mW from inputs as low as 0.8 V start-up and down to 0.5 V in operation. It integrates adaptive current-mode control, dual-output multiplexing (main VOUT + auxiliary VGD), and programmable reset with CT-pin timing. It serves as the core power management IC in ultra-low-voltage portable electronics such as pagers and early cell phones.

For engineers reviewing the UCC39411DG4 datasheet, UCC39411DG4 pinout, UCC39411DG4 application, or UCC39411DG4 equivalent, key selection criteria include its 0.8 V guaranteed start-up voltage, 6 µA shutdown supply current, 0.5 Ω charge switch R_DS(on), 1.2 Ω synchronous rectifier R_DS(on), and dual-output priority arbitration between 3.3 V main output and 7 V gate-drive supply.

Technical Context

The UCC39411DG4 implements a bang-bang (hysteretic) control architecture with automatic transition between discontinuous and continuous conduction modes based on load demand. Its multiplexing logic prioritizes VOUT servicing unless VGD falls below ~6.3 V, at which point VGD gains priority to sustain gate drive integrity.

It features adaptive current-mode modulation where on-time is fixed at t_ON = 5.5 µs/V_IN, off-time is dynamically adjusted, and peak current limiting (up to 715 mA) prevents saturation. The integrated reset generator uses an external capacitor on CT to set delay (e.g., 188 ms with 0.15 µF), with RESB providing active-low open-drain undervoltage detection at 90% of VOUT.

Key Specifications

Pinout & Package

UCC39411DG4 is housed in an 8-pin SOIC (D) package, 3.9 mm × 4.9 mm, 1.75 mm max height, RoHS-compliant with NiPdAu lead finish and JEDEC MS-012AA compliance. Pin 1 identifier is a beveled corner; device marking reads "39411" or "(39411, UCC)".

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-input-voltage boost converter applications.

Compared with TLC59202D and TPS61200DRCR, the UCC39411DG4 uniquely integrates VGD generation, hardware-multiplexed dual outputs, and programmable reset-reducing BOM count by three discrete components while enabling reliable operation down to 0.5 V input without external supervision.

Availability

UCC39411DG4 is available at Aetrix Electronics and suitable for handheld medical monitors, low-power wireless sensor nodes, portable barcode scanners, and industrial handheld terminals requiring stable component supply across extended battery life cycles.

Supply support for UCC39411DG4 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 battery-operated system power solutions.

The UCC39411DG4 belongs to TI's UCCx9411 family of ultra-low-voltage synchronous boost converters, designed specifically for maximizing runtime in single/dual-cell portable electronics where start-up reliability below 1 V is mandatory.

FAQ

What is the guaranteed minimum input voltage for UCC39411DG4 start-up under full load?

The UCC39411DG4 guarantees start-up at ≤1.0 V input voltage with 60 mA load on VOUT, as specified in the Electrical Characteristics table. This ensures reliable boot from nearly depleted alkaline or NiMH cells. Operation continues down to 0.5 V once running. The 1.0 V maximum start-up voltage is ensured by design and applies specifically to the UCC39411DG4 variant per SLUS245E Rev J.

How does the UCC39411DG4 prioritize between VOUT and VGD outputs?

The UCC39411DG4 uses hardware-based priority encoding: VOUT has highest priority as long as VGD remains ≥6.3 V. If VGD falls below this threshold, VGD servicing takes precedence until its voltage recovers. This ensures gate-drive integrity for internal switches during low-battery conditions. The UCC39411DG4 implements this behavior in its internal priority encoder block, independent of external control.

Can the UCC39411DG4 generate a 5 V output?

No - the UCC39411DG4 is the adjustable version (ADJ) of the family, with a 1.25 V internal reference and FB pin for external resistor-divider programming. While it can be configured for 5 V output using appropriate R1/R2 values, the UCC39413DG4 is the factory-trimmed 5 V variant. The UCC39411DG4 datasheet specifies ADJ functionality and lists 1.212–1.288 V reference tolerance, confirming its role as the programmable member of the family.

What is the function of the RESB pin on the UCC39411DG4, and how is its threshold determined?

The RESB pin on the UCC39411DG4 is an active-low, open-drain reset output that asserts when VOUT falls below 90% of its nominal value. Its threshold is internally fixed relative to VOUT and does not require external components. For a 3.3 V output, RESB activates at ~2.97 V. The UCC39411DG4 includes glitch suppression and a user-programmable delay via the CT capacitor to prevent false triggering during transients.

Does the UCC39411DG4 require an external Schottky diode for flyback operation?

No - the UCC39411DG4 integrates synchronous rectification and does not require an external Schottky diode. The SW pin connects directly to the inductor, and internal MOSFETs handle both charging (low-side switch) and discharging (synchronous rectifier) phases. The "VGD flyback diode" referenced in the datasheet is internal; external diodes are unnecessary and would degrade efficiency. This is confirmed by the block diagram showing no external diode path and the 1.2 Ω rectifier R_DS(on) specification.