Texas Instruments UCC2803PWTR

Overview

UCC2803PWTR from Texas Instruments is a low-power BiCMOS current-mode PWM controller designed for fixed-frequency DC-to-DC converters and battery-operated power supplies. It features 4 V reference voltage, 4.1 V UVLO turn-on threshold, 100% maximum duty cycle, 1 A totem-pole gate driver output, and internal leading-edge blanking - enabling compact, efficient SMPS designs with minimal external components.

For engineers reviewing the UCC2803PWTR datasheet, UCC2803PWTR pinout, UCC2803PWTR application, or UCC2803PWTR equivalent, this device serves as a drop-in functional upgrade to UC3842/UC3842A in low-voltage, low-quiescent-current systems where reference voltage, UVLO hysteresis, and soft-start behavior must match battery-input constraints.

Technical Context

The UCC2803PWTR implements a current-mode control architecture with dual comparators on the CS pin (PWM + overcurrent), digital leading-edge blanking (50–150 ns), and a true low-impedance 2-MHz error amplifier capable of sourcing/sinking COMP current. Its oscillator uses REF-derived charging current and supports up to 1 MHz operation via RC timing network.

Unlike UC3842, it integrates full-cycle soft start (COMP rise time ~4–10 ms), eliminates need for external soft-start circuitry, and provides 1.5% initial reference accuracy with ±2.5 mV load regulation - critical for stable regulation in portable and automotive PSU applications operating from –40°C to 125°C.

Key Specifications

Pinout & Package

TSSOP-8 package (4.40 mm × 3.00 mm body size), surface-mount compatible with fine-pitch PCB assembly and thermal performance suitable for industrial ambient conditions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UC3842N and UCC2802D, the UCC2803PWTR delivers lower start-up current, integrated soft start, and digital CS blanking - making it uniquely suitable for battery-fed systems where supply headroom is constrained and component count must be minimized.

Availability

UCC2803PWTR is available at Aetrix Electronics and suitable for battery-operated power supplies, automotive infotainment modules, and portable medical devices requiring stable component supply with extended temperature support and low quiescent power consumption.

Supply support for UCC2803PWTR 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 power IC design expertise.

The UCC280x family was developed specifically for high-efficiency, low-component-count current-mode SMPS in battery-powered and automotive environments - emphasizing low I_Q, integrated protection, and seamless UC3842 migration.

FAQ

What is the reference voltage accuracy of the UCC2803PWTR?

The UCC2803PWTR features a 4.0 V nominal reference voltage with ±2.5% initial tolerance (3.94 V to 4.06 V) and total variation of ±0.08 V across load and temperature. This accuracy is specified at TJ = 25°C with 0.2 mA load, and supports stable regulation in low-voltage battery systems where reference drift directly impacts output precision. The UCC2803PWTR reference remains stable under varying VCC and load conditions due to internal trimming and low-noise design.

Does the UCC2803PWTR require an external soft-start circuit?

No, the UCC2803PWTR integrates full-cycle soft start that clamps the COMP voltage during power-up, ramping it to the REF level in 4–10 ms. This eliminates the need for external resistors, capacitors, or transistors typically used in UC3842-based designs. The internal soft start prevents inrush current and ensures controlled output voltage rise - a key advantage confirmed in the UCC2803PWTR datasheet Section 7.3.1.1 and Figure 6-5.

How does the CS pin blanking work on the UCC2803PWTR?

The UCC2803PWTR implements digital leading-edge blanking on the CS pin: for 50–150 ns after each rising edge of the OUT signal, the CS input is disconnected from both the PWM and overcurrent comparators. This hardware-level blanking removes switching noise artifacts without requiring external RC filtering - unlike UC3842 - and reduces effective CS-to-OUT propagation delay. Confirmed in Table 5-1 and Section 7.3.1.3 of the UCC2803PWTR datasheet.

Is the UCC2803PWTR pin-compatible with UC3842?

Yes, the UCC2803PWTR has identical pin configuration and signal mapping to UC3842 and UC3842A in both SOIC-8 and TSSOP-8 packages. However, it is not a direct plug-in replacement due to differences in COMP drive architecture (low-Z op-amp vs open-collector), UVLO thresholds, and integrated features. Layout reuse is possible, but circuit validation - especially around FB compensation and CS filtering - is required per UCC2803PWTR datasheet Section 7.3.

What is the maximum operating frequency of the UCC2803PWTR?

The UCC2803PWTR supports oscillator frequencies up to 1 MHz, with typical operation at 26–36 kHz using standard RC values (RT = 100 kΩ, CT = 330 pF). Frequency scaling follows f ≈ 1/(R × C), where R connects REF to RC and C connects RC to GND. The UCC2803PWTR's BiCMOS process and fast 70 ns CS-to-OUT response enable reliable high-frequency operation - verified in Section 6.5 and Figure 6-4 of its datasheet.