Texas Instruments UC3836N

Overview

UC3836N from Texas Instruments is an adjustable-output linear regulator controller IC designed to drive external pass transistors in low-dropout, high-current regulation applications. It delivers precise 2.5 A current limiting with foldback, internal current sensing, remote voltage sense capability, and operates across +VIN = –1.0 V to +40 V. It is used in industrial power supplies where stable 2.5–35 V output and robust short-circuit protection are required.

For engineers reviewing the UC3836N datasheet, UC3836N pinout, UC3836N application, or UC3836N equivalent, key selection considerations include its adjustable output range (2.5 V to 35 V), 2.5 A foldback current limit, thermal/UVLO/reverse-voltage protections, and compatibility with discrete NPN/PNP pass devices such as TIP32B or D45H for sub-0.5 V dropout designs.

Technical Context

The UC3836N implements a high-gain error amplifier referenced to a precision 2.5 V bandgap, enabling accurate output regulation via external resistor divider feedback. Its driver stage provides up to 250 mA sink/source capability with 2.8 V saturation voltage at 250 mA, optimized to drive the base of external PNP or NPN pass transistors.

Current limiting uses an internal sense resistor and foldback architecture: peak current drops from 2.5 A at nominal VOUT Sense to 0.4 A at short circuit, reducing thermal stress. Protection features include under-voltage lockout (4.4 V threshold), thermal shutdown (165 °C), and reverse-voltage detection-though reverse-current protection is specified only for UC1835 family, not UC3836N.

Key Specifications

Pinout & Package

UC3836N is housed in an 8-pin plastic dual in-line package (PDIP, P package), with pin numbering matching standard DIL-8 layout. Pin functions are validated per TI's official connection diagrams and electrical characteristics tables.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear regulator controller applications.

Compared with UC3836D, UC3836N offers identical regulation and protection functionality in a through-hole package ideal for prototyping and repair; versus LM317HV, UC3836N enables higher current, lower dropout, and superior fault management-but requires external pass transistor design effort.

Availability

UC3836N is available at Aetrix Electronics and suitable for industrial bench power supplies, programmable lab PSUs, low-noise instrumentation supplies, and legacy system voltage translation requiring stable component supply and long-term obsolescence management.

Supply support for UC3836N 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 headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies.

The UC38xx family was developed by Texas Instruments as a cost-optimized linear controller platform for high-current, low-dropout discrete regulator designs-targeting industrial, test equipment, and legacy-system upgrade applications.

FAQ

What is the maximum output current supported by UC3836N?

The UC3836N itself does not deliver output current-it controls external pass transistors. Its current-limit function is specified at 2.5 A peak with foldback, and its driver stage supports up to 250 mA sink/source to bias the base/gate of external devices like TIP32B or D45H. Actual output current depends on the selected pass element, heatsinking, and thermal design. The UC3836N datasheet confirms this architecture explicitly in the "High Efficiency Regulator Controller" description and typical application schematics.

Does UC3836N support remote voltage sensing?

Yes, UC3836N supports remote voltage sensing via its VOUT Sense input (Pin 12 in SOIC-16), but the PDIP-8 package (UC3836N) does not expose this pin-its pinout omits VOUT Sense, relying instead on local feedback. The datasheet's "CONNECTION DIAGRAMS" section shows VOUT Sense only on SOIC-16 and PLCC-20 packages. Therefore, remote sensing is not available on UC3836N; it must be implemented locally using the output node directly.

What is the purpose of the Compensation/Shutdown pin (Pin 5) on UC3836N?

Pin 5 serves dual functions: it accepts an external RC compensation network to stabilize the control loop, and it acts as an active-low shutdown input-pulling it below 0.45 V disables the driver output. This allows both loop tuning and system-level enable/disable control without additional logic. The UC3836N datasheet specifies 90–260 µA max compensation output current and 140–300 µA pull-up current at Driver Sink when Pin 5 is at 0.45 V, confirming its integrated control role.

Can UC3836N be used with N-channel MOSFETs as the pass device?

No-UC3836N's driver stage is configured for bipolar transistor drive (PNP high-side or NPN low-side), not N-MOSFET gate driving. Its output stage lacks high-side level shifting, bootstrap capability, or sufficient gate-drive voltage swing for enhancement-mode N-MOSFETs. The datasheet's "Typical Configurations" show only PNP/NPN BJTs (e.g., TIP32B, D45H), and electrical specs list driver saturation voltage-not gate drive voltage. For MOSFET-based designs, a dedicated gate driver or different controller (e.g., UC384x-based) is required.

What is the operating temperature range for UC3836N?

The UC3836N is rated for operation from 0 °C to +70 °C, as confirmed in the "PACKAGE OPTION ADDENDUM" table where UC3836N is listed under "Op Temp (°C)" as "0 to 70". This defines its commercial-grade specification tier-distinct from UC2836 (–25 °C to +85 °C) and UC1836 (–55 °C to +125 °C). Thermal shutdown activates at 165 °C junction temperature, providing fault protection within this ambient range.