TNY178PN

TNY178PN is a high‑voltage integrated switching regulator from Power Integrations’ TinySwitch family. It combines a 700V MOSFET and a PWM control circuit for off‑line flyback power supplies, intended for low‑ to moderate‑power applications (AC‑DC adapters, chargers, etc.). It runs directly from rectified mains and requires only a few external components (transformer, startup/auxiliary parts, feedback path). Features typically include fixed‑frequency operation, current limiting, thermal shutdown, brown‑out/short‑circuit protection, and an output regulation path via an optocoupler (or similar feedback). The PN suffix denotes the package type (8‑pin DIP/SO package). It’s popular for simple, low-cost, energy‑efficient offline supplies with minimal components. For exact specs (VDS, IDS, switching frequency, efficiency, and packaging), consult the datasheet.

Direct equivalents (Power Integrations TinySwitch-II family): TNY177PN and TNY179PN. They share the same pinout and similar specs as TNY178PN. For non-direct substitutes with different pinouts/features, consider LNK304/306 or VIPER series (Power Integrations), but that may require redesign.

Key features of TNY178PN (TinySwitch-II off-line switch IC):
- Integrated 700 V high-voltage MOSFET for off-line flyback topologies
- Fixed-frequency operation with valley switching for low switching losses
- Requires only a minimal number of external components (simplified design)
- High overall efficiency and very low standby power
- Internal current limit, thermal shutdown, and auto-restart protection
- Suitable for small isolated power supplies (roughly 0.5–3 W range)
- Pb-free (RoHS-compliant) packaging; 8-pin devices are typical
- Compact, cost-effective solution for low-power AC-to-DC adapters and supplies

Manufacturer: Power Integrations. It is a semiconductor company that specializes in high-voltage switch-mode power supply (SMPS) ICs for off-line power supplies (e.g., the TinySwitch family).

Primarily for off-line, low-power isolated flyback power supplies. Typical applications:
- Wall-wart AC-DC adapters and USB chargers
- Compact LED drivers
- Standby/auxiliary power for consumer electronics (TVs, set-top boxes, audio gear, printers)
- Other small, cost-sensitive mains-powered supplies using primary-side regulation with a high-voltage MOSFET

TNY178PN is provided in an 8-pin plastic DIP (through-hole) package.