Texas Instruments UCC39412D

Overview

UCC39412D from Texas Instruments is a low-power synchronous boost converter IC optimized for single/dual alkaline battery operation, delivering 3.3 V / 200 mW output with 0.5 Ω charge switch R_DS(on), 1.2 Ω synchronous rectifier R_DS(on), and programmable reset function via CT pin. It enables full-load startup at 1 V input and operates down to 0.5 V, serving as primary power supply in ultra-low-voltage portable electronics.

For engineers reviewing the UCC39412D datasheet, UCC39412D pinout, UCC39412D application, or UCC39412D equivalent, key selection criteria include its 3.3 V fixed output, dual-output capability (VOUT + 7 V VGD), adaptive current-mode control, shutdown supply current of 6 µA, and SOIC-8 package compatibility with industrial temperature range (0°C to 70°C).

Technical Context

The UCC39412D implements a multiplexed, priority-based dual-output architecture where VOUT (3.3 V) takes precedence over VGD (7 V) unless VGD falls below 6.3 V. Its bang-bang control transitions between discontinuous and continuous conduction modes based on load, enabling high efficiency across 0–60 mA output current.

Startup is ensured at VIN = 1 V under full load using internal bias derived from VOUT/VGD; regulation relies on adaptive peak-current sensing with 50 ns current-limit delay and integrated glitch-filtered reset generation triggered at 90% of nominal VOUT (2.97 V threshold).

Key Specifications

Pinout & Package

UCC39412D is housed in an 8-pin SOIC (D) package per JEDEC MS-012, with 1.27 mm lead pitch, 3.91 mm body width, and 1.75 mm max height. Pin 1 identifier is located at top-left corner with notch or bevel marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UCC29412D and TPS61200DRCT, the UCC39412D uniquely integrates fixed 3.3 V regulation, dedicated 7 V VGD supply, and programmable reset in an SOIC-8 package-making it optimal for cost-sensitive, battery-constrained portable devices where these three functions are simultaneously required.

Availability

UCC39412D is available at Aetrix Electronics and suitable for pager power management, low-voltage IoT sensor nodes, medical glucose meters, handheld barcode scanners, and portable instrumentation requiring stable component supply across industrial temperature ranges.

Supply support for UCC39412D 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for battery-operated systems.

The UCC39412D belongs to the UCCx9411 family of low-input-voltage synchronous boost converters, designed specifically for single/dual-cell alkaline, NiCd, and NiMH battery applications demanding high efficiency across milliwatt-to-hundred-milliwatt loads.

FAQ

What is the guaranteed minimum input voltage for full-load startup of the UCC39412D?

The UCC39412D guarantees full-load startup at 1 V input voltage under all conditions. Once operating, it continues functioning down to 0.5 V input. This specification is validated across the 0°C to 70°C temperature range and ensures reliable operation as alkaline batteries discharge from fresh 1.5 V to end-of-life ~0.8 V. The UCC39412D achieves this via optimized start-up circuitry that draws initial bias from VOUT or VGD after initial charge.

Does the UCC39412D require an external feedback resistor network for output voltage setting?

No, the UCC39412D features a factory-trimmed 3.3 V fixed output and does not require external feedback resistors. Unlike the adjustable UCC39411D or 5 V UCC39413D variants, the UCC39412D uses internal reference circuitry to regulate VOUT directly. The SD/FB pin serves exclusively as an active-low shutdown control input, eliminating layout complexity and component count associated with feedback dividers.

How is the reset delay time programmed on the UCC39412D?

The reset delay time on the UCC39412D is programmed using an external capacitor connected between the CT pin and GND. The relationship is t_RP = C × 1.25 seconds, where C is in farads. For example, a 0.15 µF capacitor yields a nominal reset period of 188 ms. This delay defines the time between VOUT rising above 2.97 V and RESB transitioning high, ensuring stable power-up sequencing for connected microcontrollers. The UCC39412D includes internal glitch filtering to prevent false resets from noise.

What is the purpose of the VGD pin on the UCC39412D, and can it be used externally?

The VGD pin on the UCC39412D provides a coarsely regulated ~7 V auxiliary supply primarily for internal gate-drive circuitry, but it is fully accessible for external use. It can deliver up to 10 mA while maintaining regulation between 6.3 V and 7.7 V. Designers commonly use VGD to power external MOSFET drivers or analog front-end components, eliminating the need for a second regulator. However, loading VGD below 2 V during startup may impair UCC39412D initialization.

What package type and RoHS status does the UCC39412D have?

The UCC39412D is supplied in an 8-pin SOIC (D) package with NIPDAU lead finish, RoHS-compliant, and moisture sensitivity level (MSL) rating of Level-2 (260°C peak reflow, 1 year floor life). It is offered in tube packaging (75 units per tube) and supports standard surface-mount assembly processes. The package dimensions conform to JEDEC MS-012, with 3.91 mm body width and 1.27 mm lead pitch, enabling compatibility with legacy SOIC footprints.