STMicroelectronics UC2842BD1013TR

Overview

UC2842BD1013TR from STMicroelectronics is a high-performance current-mode PWM controller IC designed for fixed-frequency off-line and DC-DC power supplies. It features a trimmed oscillator (250 kHz guaranteed), latching PWM for cycle-by-cycle current limiting, 5 V ±1% internal reference, under-voltage lockout (16 V on / 10 V off), and a totem-pole output capable of ±1 A peak drive - enabling direct N-channel MOSFET gate control in flyback, forward, and boost converters.

For engineers reviewing the UC2842BD1013TR datasheet, UC2842BD1013TR pinout, UC2842BD1013TR application, or UC2842BD1013TR equivalent, key selection considerations include UVLO threshold compatibility with bulk capacitor charging profiles, duty cycle range (up to 96%), oscillator programming flexibility (RT/CT), current sense gain (3 V/V), and SO8 thermal performance (R_{th j-amb} = 150 °C/W).

Technical Context

The UC2842BD1013TR implements current-mode control via a high-speed current-sense comparator (150 ns delay) that terminates switch conduction when sensed inductor current reaches the error amplifier's output voltage level. Its oscillator uses an internal constant-current source to charge CT through RT, delivering precise frequency control with <±1% variation over temperature and supply.

Internal circuitry includes a 2.5 V precision error amplifier input reference, automatic feed-forward compensation via the VFB node, and a latch-based PWM logic block ensuring single-pulse-per-cycle operation. The 5 V reference (±10 mV initial accuracy) supplies bias current to RT and supports external timing while maintaining regulation across 1–20 mA load.

Key Specifications

Pinout & Package

UC2842BD1013TR is housed in a standard SO8 (Small Outline 8-pin) package per JEDEC MS-012, with 1.27 mm lead pitch, gull-wing leads, and R_{th j-amb} = 150 °C/W. Pin 5 serves as the common ground for analog and power sections.

Key Features

Applications

Equivalent & Alternatives

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

Compared with UC3842BD1013TR and NCP1200DR2G, UC2842BD1013TR offers broader temperature capability and full feature parity with legacy UC3842 designs while retaining the VREF output and RT/CT flexibility essential for precision timing and system-level biasing.

Availability

UC2842BD1013TR is available at Aetrix Electronics and suitable for AC-DC adapters, isolated flyback SMPS, and industrial DC-DC boost converters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across manufacturing lots.

Supply support for UC2842BD1013TR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power management, analog, microcontrollers, and automotive-grade ICs.

The UC284xB family was developed for cost-effective, high-reliability current-mode switching power supplies - targeting industrial, telecom, and consumer power conversion where robustness, predictable timing, and minimal external components are critical.

FAQ

What is the maximum recommended operating frequency for UC2842BD1013TR?

The UC2842BD1013TR supports oscillator frequencies up to 500 kHz per datasheet specifications, but stable operation at >300 kHz requires careful PCB layout: short RT/CT traces, low-inductance ground return, and local 100 nF ceramic decoupling at VCC and VREF pins. Thermal derating is needed above 250 kHz in SO8 due to 800 mW power limit.

Can UC2842BD1013TR drive a P-channel MOSFET directly?

No - the OUTPUT pin is a totem-pole stage optimized for sinking current into an N-channel MOSFET gate. Driving a P-channel device would require inversion logic and level shifting, as the output does not swing above VCC nor provide high-side sourcing referenced to input rail. External driver ICs or discrete level-shifters are necessary for P-MOSFET use.

How does the UVLO hysteresis affect system behavior during input brown-out?

With 16 V turn-on and 10 V turn-off, the 6 V hysteresis prevents rapid cycling during marginal input conditions. When VCC drops below 10 V, the IC shuts down completely - holding OUTPUT low and disabling all internal circuits - until VCC rises above 16 V, ensuring clean restart without erratic pulses or partial switching events.

Is slope compensation required when using UC2842BD1013TR in DCM flyback?

No - slope compensation is only mandatory in continuous conduction mode (CCM) flyback or boost to prevent subharmonic oscillation. In DCM operation, the inductor current fully resets each cycle, eliminating the instability mechanism; therefore, the UC2842BD1013TR functions stably without added ramp injection in typical low-power DCM designs.