Specifications
| Attribute | Value |
| Package / Case | Tube |
| Part Status | Active |
| Output Isolation | Non-Isolated |
| Internal Switch(s) | Yes |
| Topology | Full-Bridge, Half-Bridge, Push-Pull |
| Voltage - Start Up | 16.5 V |
| Voltage - Supply (Vcc/Vdd) | 10.5V ~ 22V |
| Frequency - Switching | 10kHz ~ 1MHz |
| Control Features | Soft Start |
| Operating Temperature | 0°C ~ 70°C (TA) |
| Supplier Device Package | 16-SOIC |
Overview
Description
UC3865DW is a PWM control IC for switch‑mode power supplies. It generates the drive signal for an external switching transistor to regulate output voltage via feedback. It supports current‑mode (typical) control, an adjustable oscillator for switching frequency, and built‑in protections.
Key points:
- Drives an external MOSFET/Transistor
- Oscillator to set switching frequency
- Feedback input (for voltage regulation)
- Protections: undervoltage, overcurrent/short‑circuit, thermal shutdown
- Soft‑start to reduce inrush and improve startup behavior
- Package: 8‑pin SOIC (DW denotes RoHS, low‑pin‑count variant)
Typical uses: flyback and other SMPS topologies in AC/DC adapters, power bricks, and similar DC‑DC power supplies. For exact electrical specs and pinout, consult the UC3865DW datasheet.
Key points:
- Drives an external MOSFET/Transistor
- Oscillator to set switching frequency
- Feedback input (for voltage regulation)
- Protections: undervoltage, overcurrent/short‑circuit, thermal shutdown
- Soft‑start to reduce inrush and improve startup behavior
- Package: 8‑pin SOIC (DW denotes RoHS, low‑pin‑count variant)
Typical uses: flyback and other SMPS topologies in AC/DC adapters, power bricks, and similar DC‑DC power supplies. For exact electrical specs and pinout, consult the UC3865DW datasheet.
Features
UC3865DW is a peak-current‑mode PWM controller for switch‑mode power supplies (flyback, buck, forward). Key features:
- 8‑pin DW package and suitable for off‑line/DC‑DC topologies
- Peak‑current‑mode control with cycle‑by‑cycle current limiting
- Two error amplifiers for voltage feedback with opto‑coupler interface
- Internal reference and configurable feedback/compensation
- Adjustable oscillator frequency via single timing resistor (typical tens of kHz)
- Soft‑start to limit inrush and overshoot
- UVLO with hysteresis and thermal shutdown protection
- Gate drive output for external power MOSFET
- Protection: overcurrent/short‑circuit, fault latch options for reliable startup
Note: Always consult the latest datasheet for exact electrical specs and pinout.
- 8‑pin DW package and suitable for off‑line/DC‑DC topologies
- Peak‑current‑mode control with cycle‑by‑cycle current limiting
- Two error amplifiers for voltage feedback with opto‑coupler interface
- Internal reference and configurable feedback/compensation
- Adjustable oscillator frequency via single timing resistor (typical tens of kHz)
- Soft‑start to limit inrush and overshoot
- UVLO with hysteresis and thermal shutdown protection
- Gate drive output for external power MOSFET
- Protection: overcurrent/short‑circuit, fault latch options for reliable startup
Note: Always consult the latest datasheet for exact electrical specs and pinout.
Pinout
- Pin count: 16 pins (DW package, SOIC-16/DIP-16 style).
- Function: A PWM controller for switch-mode power supplies (off-line and DC-DC). It provides current‑mode control with an external MOSFET gate drive, an internal reference (typically 5V), error amplifier and feedback path, compensation and control pins, RT/CT oscillator for frequency, soft‑start, enable/shutdown, undervoltage lockout, and cycle‑by‑cycle current limiting. Used for flyback/buck/boost topologies.
- Function: A PWM controller for switch-mode power supplies (off-line and DC-DC). It provides current‑mode control with an external MOSFET gate drive, an internal reference (typically 5V), error amplifier and feedback path, compensation and control pins, RT/CT oscillator for frequency, soft‑start, enable/shutdown, undervoltage lockout, and cycle‑by‑cycle current limiting. Used for flyback/buck/boost topologies.
Manufacturer
- Manufacturer: Texas Instruments (TI)
- What kind of company: A global semiconductor company that designs and manufactures analog and embedded processing integrated circuits.
- What kind of company: A global semiconductor company that designs and manufactures analog and embedded processing integrated circuits.
Application
UC3865DW is a high‑voltage, current‑mode PWM controller for switch‑mode power supplies. Common application areas include:
- Isolated offline AC‑DC supplies (flyback/forward converters, wall adapters)
- Non‑isolated DC‑DC converters (buck/boost)
- LED constant‑current drivers for lighting
- Battery chargers and associated power adapters (Li‑ion, lead‑acid)
- Telecom and industrial power modules and auxiliary supplies
These cover compact desktop adapters, consumer electronics supplies, and vegetation of small to mid‑power SMPS designs.
- Isolated offline AC‑DC supplies (flyback/forward converters, wall adapters)
- Non‑isolated DC‑DC converters (buck/boost)
- LED constant‑current drivers for lighting
- Battery chargers and associated power adapters (Li‑ion, lead‑acid)
- Telecom and industrial power modules and auxiliary supplies
These cover compact desktop adapters, consumer electronics supplies, and vegetation of small to mid‑power SMPS designs.
Package
UC3865DW uses a 16‑pin wide SOIC (surface‑mount) package.
