Texas Instruments UCC39002DGK

Overview

UCC39002 from Texas Instruments is an advanced 8-pin BiCMOS load-share controller for paralleling DC-DC modules and power supplies in N+1 redundant systems. It delivers <1% current-share error at full load, supports high-side or low-side current sensing via ultra-low-offset amplifier (±100 µV), and complies with Intel® SSI load-share specification. It operates in server, telecom, and workstation distributed power systems requiring precise current balancing.

For engineers reviewing the UCC39002 datasheet, UCC39002 pinout, UCC39002 application, or UCC39002 equivalent, key selection criteria include its single-wire load-share bus architecture, ±100 µV current-sense offset, 75–90 dB CMRR, 2 MHz gain-bandwidth product, and VSSOP-8 package compatibility with space-constrained board layouts.

Technical Context

The UCC39002 implements automatic leader/follower architecture using a post-package-trimmed current-sense amplifier with 0 V to VDD common-mode range, enabling shunt placement in either GND-return or positive output rail. Its transconductance error amplifier (gM = 14 mS) compares follower VCSO against leader VLS to drive ADJ sink current for voltage adjustment.

It features integrated LS bus protection with window comparator monitoring (VLS < 2/3×VCSO or VLS > VVDD − 0.7 V triggers fault shutdown), start-up mode forcing 3 V on ADJ noninverting input until VCSO > 0.8×VLS, and bias-OK hysteresis (4.175 V turn-on / 4.0 V turn-off) ensuring stable operation only above minimum VDD threshold.

Key Specifications

Pinout & Package

UCC39002 is housed in an 8-pin VSSOP package (3.00 mm × 4.90 mm), optimized for compact PCB area and thermal performance in high-density power modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar load-share controller applications.

Compared with UCC29002, the UCC39002 trades extended temperature rating for lower-cost qualification and simplified logistics in commercial-server applications; compared with UC3907, it adds precision sensing, bus protection, and intelligent start-up-enabling robust, standards-compliant N+1 systems.

Availability

UCC39002 is available at Aetrix Electronics and suitable for server power supplies, telecom distributed power systems, and workstation VRMs requiring stable component supply, consistent parametric performance, and long-lifecycle availability.

Supply support for UCC39002 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 over 90 years of innovation in high-reliability electronics.

The UCC39002 belongs to TI's advanced load-share controller product line, designed specifically for high-accuracy current balancing in N+1 redundant power architectures used in datacenter, telecom, and high-performance computing systems.

FAQ

What is the operating temperature range for UCC39002?

The UCC39002 is specified for operation from 0 °C to +70 °C ambient temperature. This differs from the UCC29002, which supports –40 °C to +105 °C. The UCC39002's narrower range reflects its qualification for commercial-server applications where thermal management is tightly controlled. All electrical characteristics in the datasheet are guaranteed within this 0–70 °C range.

How does UCC39002 achieve <1% current-share accuracy?

The UCC39002 achieves <1% current-share accuracy through a combination of ultra-low-offset current-sense amplifier (±100 µV), high CMRR (75–90 dB), and precision transconductance error amplifier (gM = 14 mS). Its post-package-trimmed CSA minimizes initial error, while the negative-feedback loop continuously corrects imbalances by adjusting each module's output voltage via the ADJ pin sink current. This closed-loop method ensures accuracy across load and temperature.

Can UCC39002 be used with high-side current sensing?

Yes, UCC39002 supports high-side current sensing because its current-sense amplifier has a 0 V to VDD input common-mode range. When placing RSHUNT in the positive output rail, ensure CS− does not exceed VDD + 0.3 V. For disable functionality in high-side configuration, pull CS+ at least 0.5 V below CS− instead of raising CS−-this avoids violating absolute maximum ratings while maintaining ENABLE logic integrity.

What happens to UCC39002 during a load-share bus short circuit?

When the LS bus shorts to GND or VDD, UCC39002 detects the fault via its internal window comparator (triggered if VLS < 2/3×VCSO or VLS > VVDD − 0.7 V). The FAULT signal disables the LS bus driver, disconnects the controller from the bus, and forces ADJ sink current to zero-halting output voltage adjustment. This prevents erroneous regulation and protects downstream power stages during bus faults.

Is UCC39002 pin-compatible with UCC29002?

Yes, UCC39002 is fully pin-compatible and functionally identical to UCC29002 in all aspects except operating temperature range and orderable part numbering. Both share identical VSSOP-8 and SOIC-8 footprints, identical pin functions, identical electrical characteristics (within their respective temperature ranges), and identical application schematics. No PCB redesign is required when substituting UCC39002 for UCC29002 in commercial-temperature applications.