Key Selection Information
| Selection Parameter | Confirmed Information |
|---|---|
| Control | Peak current-mode PWM |
| Frequency | Up to 1 MHz |
| Startup Current | 50 µA typical / 100 µA maximum stated |
| Operating Current | 2.3 mA stated at 52 kHz family condition |
| Gate Drive | ±1 A peak, rail-to-rail |
| Current Limit | 35 ns stated cycle-by-cycle response |
| UVLO / Duty | 8.4 V / 7.6 V UVLO class; 100% duty-cycle variant |
| Exact Package / Packing | SOIC (D), 8 pins; 2500-piece large reel; −40°C to +125°C; marking 28C43 |
Product Overview
UCC28C43DR is a modern BiCMOS implementation of the classic UCx84x current-mode controller concept. It retains the familiar single-ended PWM architecture while reducing startup/operating current and extending switching frequency to 1 MHz.
The C43 variant permits essentially 100% maximum duty cycle. That makes it appropriate for topologies where the switch may need to remain on for most of an oscillator period, unlike the C45 variant’s 50% limit.
Fast current limiting and a ±1-A gate output support compact off-line or DC-DC stages, but the controller still relies on the external MOSFET, transformer/inductor and compensation network to define power capability.
For related devices, see HKEQGOO’s AC-DC Controllers category.
Technical Specifications
| Parameter | Verified Information |
|---|---|
| Manufacturer | Texas Instruments |
| Exact MPN | UCC28C43DR |
| Control | Peak current-mode PWM |
| Frequency | Up to 1 MHz |
| Startup Current | 50 µA typical / 100 µA maximum stated |
| Operating Current | 2.3 mA stated at 52 kHz family condition |
| Gate Drive | ±1 A peak, rail-to-rail |
| Current Limit | 35 ns stated cycle-by-cycle response |
| UVLO / Duty | 8.4 V / 7.6 V UVLO class; 100% duty-cycle variant |
| Exact Package / Packing | SOIC (D), 8 pins; 2500-piece large reel; −40°C to +125°C; marking 28C43 |
| Manufacturer Status | Active / Production |
| Part Marking | 28C43 |
Functional Highlights
100% duty capability is the key C43/C45 differentiator
The variant choice changes allowable topology/timing, not just the part number suffix.
Low startup current reduces high-voltage bias loss
Offline supplies can use higher-value startup networks while maintaining lower standby dissipation.
Design Considerations
- Use the exact C43 duty-cycle and UVLO behavior in transformer/inductor reset calculations.
- Filter current sense carefully without delaying real overcurrent protection excessively.
- Check oscillator/compensation design at high switching frequencies where layout parasitics matter.
Product Status and Exact Order Code
Texas Instruments/source evidence identifies UCC28C43DR as Active / Production; SOIC (D), 8 pins; 2500-piece large tape and reel; −40°C to +125°C; marking 28C43.
Related Engineering Resources
Quality & Verification Support
Third-party inspection or testing can be arranged according to customer requirements. Testing fees are borne by the buyer. Additional verification requirements can be discussed before shipment. After an order is placed, physical product, label, packaging, and Date Code photos may be provided where appropriate.
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