TNY253/254/255 TinySwitch Family Energy Efficient, Low Power Off-line Switchers Product Highlights + + Lowest Cost, Low Power Switcher Solution Lower cost than RCC, discrete PWM and other DC Output integrated/hybrid solutions Cost effective replacement for bulky linear adapters Lowest component count TinySwitch Wide-Range D Simple ON/OFF control no loop compensation devices HV DC Input EN No bias winding simpler, lower cost transformer BP Allows simple RC type EMI filter for up to 2 W from S universal input or 4 W from 115 VAC input Extremely Energy Efficient PI-2178-022699 Consumes only 30/60 mW at 115/230 VAC with no load Figure 1. Typical Standby Application. Meets Blue Angel, Energy Star, Energy 2000 and 200 mW European cell phone requirements for standby Saves 1 to 4 per year in energy costs (at 0.12/kWHr) TinySwitch SELECTION GUIDE compared to bulky linear adapters Recommended Range Ideal for cellular phone chargers, standby power supplies for Lowest System Cost* for PC, TV and VCR, utility meters, and cordless phones. ORDER PART PACKAGE 230 VAC or 85-265 High Performance at Low Cost NUMBER 115 VAC VAC High voltage powered ideal for charger applications w/Doubler Very high loop bandwidth provides excellent transient TNY253P DIP-8 response and fast turn on with practically no overshoot 0-4 W 0-2 W TNY253G SMD-8 Current limit operation rejects line frequency ripple Glitch free output when input is removed TNY254P DIP-8 Built-in current limit and thermal protection 2-5 W 1-4 W TNY254G SMD-8 44 kHz operation (TNY253/4) with snubber clamp reduces EMI and video noise in TVs & VCRs TNY255P DIP-8 4-10 W 3.5-6.5 W Operates with optocoupler or bias winding feedback SMD-8 TNY255G Table 1. *Please refer to the Key Application Considerations section Description for details. The TinySwitch family uses a breakthrough design to provide the lowest cost, high efficiency, off-line switcher solution in the voltage. At the same time, they allow use of low cost EE16 core 0 to 10 W range. These devices integrate a 700 V power transformers to deliver up to 5 W. The TNY253 is identical to MOSFET, oscillator, high voltage switched current source, TNY254 except for its lower current limit, which reduces current limit and thermal shutdown circuitry. They start-up and output short circuit current for applications under 2.5 W. run on power derived from the DRAIN voltage, eliminating the TNY255 uses higher switching rate of 130 kHz to deliver up to need for a transformer bias winding and the associated circuitry. 10 W from the same low cost EE16 core for applications such And yet, they consume only about 80 mW at no load, from as PC standby supply. An EE13 or EF13 core with safety 265 VAC input. A simple ON/OFF control scheme also spaced bobbin can be used for applications under 2.5 W. eliminates the need for loop compensation. Absence of a bias winding eliminates the need for taping/ margins in most applications, when triple insulated wire is used The TNY253 and TNY254 switch at 44 kHz to minimize EMI for the secondary. This simplifies the transformer construction and to allow a simple snubber clamp to limit DRAIN spike and reduces cost. April 2003TNY253/254/255 REGULATOR BYPASS DRAIN 5.8 V UNDER-VOLTAGE + 50 A 5.8 V V - I LIMIT OSCILLATOR 5.1 V CLOCK DC THERMAL MAX SHUTDOWN S Q R Q LEADING 1.5 V + V TH EDGE BLANKING SOURCE ENABLE PI-2197-061898 Figure 2. Functional Block Diagram. 1 8 BYPASS SOURCE Pin Functional Description 2 7 SOURCE SOURCE DRAIN (D) Pin: 3 6 Power MOSFET drain connection. Provides internal operating SOURCE SOURCE current for both start-up and steady-state operation. ENABLE 4 5 DRAIN BYPASS (BP) Pin: P Package (DIP-8) Connection point for an external bypass capacitor for the G Package (SMD-8) internally generated 5.8 V supply. Bypass pin is not intended PI-2199-031501 for sourcing supply current to external circuitry. Figure 3. Pin Configuration. ENABLE (EN) Pin: circuit, Hysteretic Over Temperature Protection, Current Limit The power MOSFET switching can be terminated by pulling circuit, Leading Edge Blanking, and a 700 V power MOSFET. this pin low. The I-V characteristic of this pin is equivalent to Figure 2 shows a functional block diagram with the most a voltage source of approximately 1.5 V with a source current important features. clamp of 50 A. Oscillator SOURCE (S) Pin: The oscillator frequency is internally set at 44 kHz (130 kHz for Power MOSFET source connection. Primary return. the TNY255). The two signals of interest are the Maximum Duty Cycle signal (D ) which runs at typically 67% duty MAX TinySwitch Functional Description cycle and the Clock signal that indicates the beginning of each cycle. When cycles are skipped (see below), the oscillator TinySwitch is intended for low power off-line applications. It frequency doubles (except for TNY255 which remains at combines a high voltage power MOSFET switch with a power 130 kHz). This increases the sampling rate at the ENABLE pin supply controller in one device. Unlike a conventional PWM for faster loop response. (Pulse Width Modulator) controller, the TinySwitch uses a simple ON/OFF control to regulate the output voltage. Enable (Sense and Logic) The ENABLE pin circuit has a source follower input stage set The TinySwitch controller consists of an Oscillator, Enable at 1.5 V. The input current is clamped by a current source set (Sense and Logic) circuit, 5.8 V Regulator, Under-Voltage at 50 A with 10 A hysteresis. The output of the enable sense D 2 4/03 - +