A LinkSwitch™-HP device monolithically integrates a controller and high-voltage power MOSFET into one package. It has a newly developed analogue control scheme, which enables continuous conduction mode (CCM), primary side regulated (PSR) power supplies up to 90 W without the efficiency limitation of DCM or audible noise. It uses an enhanced peak current mode PWM control scheme with multi-mode operation. The multi-mode control engine uses the error amplifier output signal voltage at the COMPENSATION pin to set the operating peak current and switching frequency to maintain the output voltage in regulation as shown in Figure 5. For COMPENSATION pin voltages lower than VC(MCM) (typ. 1.25 V) the device enters multi-cycle modulation (MCM) with a fixed peak current of 25% of the programmed current limit. Several innovative improvements have been added to the peak current mode control to allow primary side regulated CCM operation with no instability. The device meets less than 30 mW input power with no-load at high-line (LNK67xx families).
Features
• Auto-restart limits power delivery to 3% during overload faults
• Output short-circuit protection (SCP)
• Output overload/over-current protection (OPP, OCP)
• Optional extended shutdown delay time
• Output overvoltage protection (OVP), auto-restart or latching
• Line brown-in/out protection (line UV)
• Line overvoltage (OV) shutdown extends line surge withstand
• Accurate thermal shutdown (OTP), hysteretic or latching
Feature
- External current limit selection
- Primary-side sensed output overvoltage protection
- Lost regulation protection during output overload or short-circuit
- Internal current limit over line compensation for constant overload power over line
- High-voltage bus overvoltage sense for extended line surge withstand
- High-voltage bus undervoltage sense for brown-in/out protection
- Accurate over temperature protection
- Output OVP/OCP/OTP shutdown type selection
- Cycle-by-cycle current limit control
- Regulator/shunt voltage clamp
- Hysteretic thermal shutdown
- Safe operating area protection
- Programmable shutdown delay
- Current limit setting
- Multi-mode control maximizes efficiency over full load range
- Eliminates optocoupler and all secondary control circuitry
- Accurate programmable current limit - Compensation over line limits overload power
- Frequency jittering reduces EMI filter
- Output overvoltage protection, auto-restart or latching
- Line brown-in/out protection
(Picture:Pinout / Diagram)
