LNK353/354 LinkSwitch-HF Family Enhanced, Energy Efcient, Low Power Off-Line Switcher IC Product Highlights Features Optimized for Lowest System Cost + DC Output Fully integrated auto-restart for short-circuit and open loop protection Self-biased supply saves transformer auxiliary winding and associated bias supply components Wide Range D HV DC Input FB Tight tolerances and negligible temperature variation on BP key parameters eases design and lowers cost LinkSwitch-HF High maximum switching frequency allows very low S ux density transformer designs, practically eliminating audible noise PI-3855-022704 Frequency jittering greatly reduces EMI Figure 1. Typical Standby Application. Packages with large creepage to high voltage pin Lowest component count switcher solution OUTPUT POWER TABLE Much Better Performance over Linear/RCC Lower system cost than RCC, discrete PWM and other 230 VAC 15% 85-265 VAC (3) integrated solutions PRODUCT Open Open (1) (1) Adapter Adapter (2) (2) Universal input range allows worldwide operation Frame Frame Simple ON/OFF control no loop compensation needed (4) LNK353 P or G 3 W 4 W 2.5 W 3 W No bias winding simpler, lower cost transformer (4) LNK354 P or G 3.5 W 5 W 3 W 4.5 W High frequency switching smaller and lower cost transformer Table 1. Notes: 1. Typical continuous power in a non-ventilated Very low component count higher reliability and single enclosed adapter measured at 50 C ambient. 2. Maximum practical side printed circuit board continuous power in an open frame design with adequate heat sinking, measured at 50 C ambient. 3. Packages: P: DIP-8B, High bandwidth provides fast turn on with no overshoot G: SMD-8B. For lead-free package options, see Part Ordering and excellent transient load response Information. 4. For designs without a Y capacitor, the available power Current limit operation rejects line frequency ripple may be lower (see Key Applications Considerations). Built-in current limit and hysteretic thermal shutdown protection source, frequency jittering, cycle-by-cycle current limit, and thermal shutdown circuitry onto a monolithic IC. The start-up EcoSmart Extremely Energy Efcient and operating power are derived directly from the DRAIN pin, No-load consumption <300 mW without bias winding at eliminating the need for a bias winding and associated circuitry. 265 VAC input The 200 kHz maximum switching frequency allows very Meets California Energy Commission (CEC), Energy low ux transformer designs, practically eliminating audible Star, and EU requirements noise with the simple ON/OFF control scheme using standard varnished transformer construction. Efcient operation at this Applications high switching frequency is achieved due to the optimized Chargers for cell/cordless phones, PDAs, digital cameras, switching characteristics and small capacitances of the integrated MP3/portable audio devices, shavers etc. power MOSFET. The fully integrated auto-restart circuit safely Standby and auxiliary supplies limits output power during fault conditions such as output short circuit or open loop, reducing component count and secondary Description feedback circuitry cost. The internal oscillator frequency is LinkSwitch-HF integrates a 700 V power MOSFET, oscillator, jittered to signicantly reduce both the quasi-peak and average simple ON/OFF control scheme, a high voltage switched current EMI, minimizing ltering cost. February 2005 +LNK353/354 BYPASS DRAIN (BP) (D) REGULATOR 5.8 V FAULT PRESENT AUTO- RESTART BYPASS PIN COUNTER UNDER-VOLTAGE + CLOCK 5.8 V - RESET 4.85 V CURRENT LIMIT 6.3 V COMPARATOR V I LIMIT JITTER CLOCK DC MAX THERMAL SHUTDOWN OSCILLATOR FEEDBACK 1.65 V -V T (FB) S Q R Q LEADING EDGE BLANKING SOURCE (S) PI-2367-021105 Figure 2. Functional Block Diagram. Pin Functional Description P Package (DIP-8B) DRAIN (D) Pin: G Package (SMD-8B) Power MOSFET drain connection. Provides internal operating current for both start-up and steady-state operation. S 1 8 S BYPASS (BP) Pin: Connection point for a 0.1 F external bypass capacitor for the S 2 7 S internally generated 5.8 V supply. BP 3 FEEDBACK (FB) Pin: FB 4 5 D During normal operation, switching of the power MOSFET is controlled by this pin. MOSFET switching is terminated when a current greater than 49 A is delivered into this pin. PI-3491-111903 SOURCE (S) Pin: Figure 3. Pin Conguration. This pin is the power MOSFET source connection. It is also the ground reference for the BYPASS and FEEDBACK pins. F 2 2/05 - +