TNY284DG

TNY284DG is a TinySwitch off-line switcher IC from Power Integrations. It combines a high-voltage MOSFET and a PWM/controller chip for simple, low‑power offline flyback power supplies.
Key features
- Integrated high-voltage (≈700 V) MOSFET with current-mode control
- Fixed switching frequency with built-in protection: overcurrent, thermal shutdown, startup control
- Primary-side regulation (PSR) options to reduce or omit opto-coupler feedback in many designs
- Tiny footprint and low component count suitable for universal-input adapters
Typical applications
- Low-power offline power supplies and chargers (0.5–6 W class), such as wall warts, USB adapters, LED drivers
Design notes
- Uses a flyback topology; requires transformer, output rectifier, and input/output filtering
- Often enables simplified regulation with PSR, reducing BOM and EMI
Packaging/usage
- DG suffix denotes a specific RoHS-compliant package variant; check the exact datasheet for pinout and package details
For exact electrical specs, pinout, and application circuits, refer to the TNY284DG datasheet from Power Integrations.

TNY284DG features (concise):
- Integrated 700V-class high‑voltage MOSFET for off-line flyback
- Built‑in startup current source and low standby power
- Primary‑side regulation (PSR) with optional optocoupler feedback
- Fixed-frequency operation with valley/low‑loss switching
- Internal current limit and thermal shutdown protection
- Overload protection with auto‑restart (hiccup) on fault
- Very few external components; suitable for compact low‑power isolated supplies
- Universal input (approx. 85–265 VAC) applications
- 8‑pin DG package (DIP/SO-style) for easy PCB layout
Note: Designed for small off‑line flyback converters, typically a few watts.

TNY284DG uses an 8-pin package (DIP-8/SO-8 style), a surface-mount, gull-wing lead package. RoHS lead-free.

- Pin count: 8 pins
- Function: TNY284DG is an 8‑pin TinySwitch‑III device with an integrated high‑voltage MOSFET and PWM controller for off‑line flyback power supplies. It provides primary‑side regulation, startup, current limiting, undervoltage lockout, and protection. In a typical circuit, Drain connects to rectified mains feeding the primary winding, Source to the return, and the remaining pins handle Vcc/startup, feedback, and compensation for regulation.

- Manufacturer: Power Integrations, Inc.
- What kind of company: A semiconductor company that designs and markets high-voltage switching ICs and other power-management components for switch-mode power supplies.

TNY284DG is used in low‑power off‑line isolated switched‑mode power supplies (flyback). Typical applications include:
- Wall‑wart adapters and USB/phone/tablet chargers
- Standby/auxiliary power rails for consumer electronics (TVs, set‑top boxes, routers, modems, audio gear)
- Compact, high‑efficiency SMPS sections inside appliances and peripherals requiring a small footprint and few external components

TNY284DG is a Power Integrations TinySwitch-II device. Close equivalents (same family/footprint) include other TinySwitch-II parts with similar power ratings, such as:
- TNY281
- TNY283
- TNY285
- TNY286
DG-pack variants
For a cross-reference outside TinySwitch-II, you can consider LinkSwitch-TN parts (e.g., LNK304/LNK306), but verify pinout, voltage/current specs, and feedback features before substituting.