The UC1856 UC2856 UC3856 is a high performance version of the popular UC3846 series of current mode controllers, and is intended for both design upgrades and new applications where speed and accuracy are impor- tant.
The UC3856 family is a high‑performance version of the popular UC3846 series, offering reduced input‑to‑output delays, a low‑noise differential current‑sense amplifier, and 1.5 A peak dual totem‑pole outputs for rapid power‑FET switching. Features include a 65 ns typical shutdown‑to‑output delay, 50 ns sync‑to‑output delay, 4 kV ESD protection, and a 1 V shutdown threshold.
The datasheet provides detailed electrical characteristics, absolute‑maximum ratings, and application information such as oscillator design, parallel operation, and pulse‑by‑pulse current limiting. Package dimensions and material specifications are also included for PCB layout and manufacturing.
| Shutdown to output delay (typical) | 65 ns |
|---|---|
| Sync to output delay (typical) | 50 ns |
| Shutdown threshold (typical) | 1 V |
| Peak output current (dual totem pole) | 1.5 A |
| ESD protection (minimum) | 4 kV |
The typical shutdown‑to‑output delay is 65 ns.
Each pin is protected for a minimum of 4 kV ESD.
The dual totem‑pole output drivers can source or sink up to 1.5 A peak.
The controller shuts down at an accurate 1 V threshold.