ST's offline pulse-width modulator (PWM) controllers portfolio includes standard current-mode PWMs (UC family) and standard voltage-mode PWMs (SG family), as well as advanced PWMs (L6668, L6566 and L6591), covering most common and advanced SMPS applications.
New PWM controllers enable smaller, low-cost power supplies delivering high efficiency from standby to full load, thereby reducing switching losses and minimizing EMI emissions.
Regulations such as the International Energy Authority’s1-watt plan for standby power, the EU’s EuP Directive for energy-using products, and the US Government’s Energy Star program, now call for a minimum |
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operating efficiency of 85% in power supplies for equipment such as PCs, servers, consumer products, and general-purpose AC-DC adapters and chargers. ST’s new PWM controllers offer the headroom to meet these tighter requirements.
Key features
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Universal input mains range |
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Standard and advanced solutions/topologies: flyback, forward, zero-voltage switch half-bridge, single-stage PFC |
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High efficiency (more than 85%) |
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Advanced standby performances |
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Compliance to the main worldwide energy programs (EPA2, Energy Star, etc.) |
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Compliance to the main worldwide EMI regulations |
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Cost-effective solutions |
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PWM controllers |
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Main applications |
Consumer
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LCD, PDP TVs |
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Audio/video systems |
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Set-top boxes |
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Low-power AC-DC adapters/chargers |
Computer
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Desktop PCs (85+ initiative for ATX) |
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Medium- and high-power AC-DC adapters/chargers |
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Entry-level servers |
Industrial
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LED drivers |
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White goods |
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| New Products |
The L6591
is the first integrated controller optimized for zero-voltage switching, asymmetrical half-bridge converters, which enable smaller, lower-cost power supplies delivering high efficiency from standby to full load.
The L6591 IC is an extremely efficient double-ended peak current-mode PWM primary controller specifically designed for soft-switched half-bridge topologies. It provides complementary PWM control, where the high-side switch is driven on for a duty cycle D and the low-side switch for a duty cycle 1-D, with D internally limited at 50% by a T-flip-flop. An externally programmable dead-time inserted between the turn-off of one switch and the turn-on of the other guarantees soft-switching and enables high-frequency operation. The converter operating frequency is fixed by means of an externally programmable oscillator.
Main features and benefits
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Double-ended topology |
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Zero-voltage switching |
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Up to 500 kHz operating frequency |
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Advanced power management |
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Protections |
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Related information |
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