Power IntegrationsLNK626PG

The Power Integrations LNK626PG is a LinkSwitch-CV AC/DC off-line switcher with primary-side constant-voltage control, an integrated 725V MOSFET and a typical switching frequency of 100kHz. It enables low-component-count flyback supplies without an optocoupler or secondary CV control circuitry.

Technical description

The LNK626PG integrates a high-voltage MOSFET, oscillator, ON/OFF CV state machine, self-bias supply, frequency jitter, cycle-by-cycle current limit, leading-edge blanking, auto-restart/open-loop protection and hysteretic thermal shutdown. Output regulation is sensed from a primary-referenced bias winding, allowing optocoupler-free CV designs when implemented according to the datasheet.

The official application input range is 85-265VAC. Practical output power depends on conditions: at 230VAC ±15% up to 10.5W in an enclosed adapter and 17W open-frame; at 85-265VAC up to 8.5W in an adapter and 10W open-frame. The datasheet table is based on a 5V output and its stated design assumptions.

Switching frequency is 93-106kHz with 100kHz typical and ±7% jitter. LNK626 current limit is 419-482mA with 450mA typical. Maximum DRAIN voltage is 725V and absolute maximum peak DRAIN current is 720mA, or up to 1080mA when DRAIN voltage is simultaneously below 400V. Internal MOSFET maximum RDS(on) is 11 Ohm at 25C and 17 Ohm at 100C. Thermal shutdown is typically 142C with 60C hysteresis.

Typical applications

Adapters, standby and auxiliary supplies, DVD/STB, home appliances, white goods, consumer electronics, industrial controls and low-power flyback converters requiring primary-side CV regulation.

Compatibility note

The LNK626PG is not a generic drop-in replacement for other LinkSwitch families. Verify the primary-side CV architecture, transformer bias winding, feedback divider, current limit, pinout, package and required power envelope. The official package is P package PDIP-8C, while commercial listings often describe it as a 7-pin DIP/PDIP device.

Frequently asked questions

What is the integrated MOSFET voltage rating?
725V.

What is the typical switching frequency?
100kHz, with a 93-106kHz range and ±7% jitter.

Is an optocoupler required for CV regulation?
Not in a correctly designed LinkSwitch-CV primary-side regulated application.

What is the universal-input output power?
Up to 8.5W in an enclosed adapter and 10W open-frame at 85-265VAC, under the datasheet assumptions.