tny256 Power Integrations, Inc., tny256 Datasheet
tny256
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tny256 Summary of contents
Page 1
... The line under- voltage sense threshold can be externally programmed using a line sense resistor. During start-up, this feature keeps the TNY256 off until the input line voltage reaches the under-voltage threshold. When the input line voltage is removed, the line under-voltage circuit prevents auto-restart attempts after the output goes out of regulation ...
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... A is drawn out of this pin. This pin also senses line under-voltage conditions through an external resistor connected to the DC line voltage. If there is no external resistor connected to this pin, TNY256 detects this and disables the line under-voltage function. SOURCE (S) Pin: Power MOSFET source connection ...
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... Unlike conventional PWM (Pulse Width Modulator) controllers, TinySwitch uses a simple ON/OFF control to regulate the output voltage. The TNY256 controller consists of an Oscillator, Enable (Sense and Logic) circuit, 5.8 V Regulator, Bypass pin Under-Voltage circuit, Over Temperature Protection, Current Limit circuit, Leading Edge Blanking and a 700 V power MOSFET ...
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... TNY256 is constant, the power delivered is proportional to the primary inductance of the transformer and is relatively independent of the input voltage. Therefore, the design of the power supply involves calculating the primary inductance of the transformer for the maximum power required. If the TNY256 is appropriately chosen for the V EN CLOCK D ...
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... Time (ms) Figure 9. TNY256 Power-up Without External Resistor Connected to EN/UV Pin. ON/OFF Control The internal clock of the TNY256 runs all the time. At the MAX beginning of each clock cycle, it samples the EN/UV pin to decide whether or not to implement a switch cycle. If the EN/UV pin is high (< 40 A), then a switching cycle takes place ...
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... Y1-capacitor C5 and a shield winding between primary and secondary windings inside transformer T1. Diode D5, capacitor C3 and resistor R3 form an RCD clamp circuit that limits the turn-off voltage spike to a safe value on the TNY256 DRAIN pin. The secondary winding is rectified and filtered by D6, C6 and C7 to provide the 9V output. Additional filtering is provided by L3 and C8 ...
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... If this is the case, replacing them with a capacitor having a different type of dielectric is the simplest solution. Polyester film capacitors and ceramic capacitors with dielectrics such as NPO or X7R are good alternatives. TNY256 ...
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... TNY256 Layout Single Point Grounding Use a single point ground connection at the SOURCE pin for the BYPASS pin capacitor and the Input Filter Capacitor (see Figure 13). Primary Loop Area The area of the primary loop that connects the input filter capacitor, transformer primary and TinySwitch together, should be kept as small as possible ...
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... Not Switching) See Note B EN/UV Open (MOSFET Switching) See Note See Note See Note D, E TNY256 (1) (2) ................ -40 to 150 C (3) ................................................ 260 2oz (610 gm/m ) copper 2 ), 2oz. (610 gm copper clad Min Typ Max ...
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... TNY256 Parameter Symbol CONTROL FUNCTIONS (cont.) BYPASS Pin V Voltage BP BYPASS V Hysteresis BPH EN/UV Pin Line I Under-voltage LUV Threshold CIRCUIT PROTECTION I Current Limit LIMIT Initial Current I Limit INIT Leading Edge t LEB Blanking Time Current Limit t Delay ILD Thermal Shutdown Temperature Thermal Shutdown Hysteresis ...
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... I. Auto-restart on time has the same temperature characteristics as the oscillator (inversely proportional to frequency). Conditions SOURCE = -40 to 125 C J See Figure 14 (Unless Otherwise Specified) See Note See Note I and I when EN/UV pin is shorted to ground (MOSFET not switching) S1 DSS TNY256 Max Units Min Typ 0.5 ms 28.9 32.0 35 ...
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... TNY256 D EN/ NOTE: This test circuit is not applicable for current limit or output characteristic measurements. Figure 14. TinySwitch General Test Circuit 90% DRAIN VOLTAGE 10 Figure 15. TinySwitch Duty Cycle Measurement 7/01 470 5 W 470 150 V 0 MAX ...
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... Junction Temperature ( C) CURRENT LIMIT vs. TEMPERATURE 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -50 - Temperature ( C) BYPASS PIN START-UP WAVEFORM 0.2 0.4 0.6 Time (ms) FREQUENCY vs. TEMPERATURE 75 100 125 0.8 1.0 TNY256 1.2 1.0 0.8 0.6 0.4 0.2 0 -50 - 100 125 Junction Temperature ( C) CURRENT LIMIT vs. di/dt 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 240 480 720 960 di/dt in mA/ s OUTPUT CHARACTERISTIC 600 T =25 C ...
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... TNY256 Typical Performance Characteristics (cont.) C OSS vs. DRAIN VOLTAGE 100 200 400 DRAIN Voltage ( 7/01 DRAIN CAPACITANCE POWER 100 600 0 UNDERVOLTAGE THRESHOLD 80 Power-up* 40 Power-down resistor connected to EN/UV pin. ** Load dependant and determined by the level of the device upon entering auto- restart ...
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... SMD-8 Heat Sink is 2 oz. Copper As Big As Possible .046 .060 .060 .046 Pin 1 .086 .186 -D- .286 Solder Pad Dimensions -F- .004 (.10 TNY256 - - DIM inches mm A 0.370-0.385 9.40-9.78 B 0.245-0.255 6.22-6.48 C 0.125-0.135 3.18-3.43 G 0.004-0.012 0.10-0.30 .420 H 0 ...
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... TNY256 .400 (10.16) .146 (3.71) .415 (10.54) .156 (3.96) + .860 (21.84) .880 (22.35) PIN 1 .050 (1.27) BSC .150 (3.81) BSC .050 (1.27) .050 (1.27) .050 (1.27) .200 (5.08) PIN 1 .150 (3.81) Y07B MOUNTING HOLE PATTERN C 16 7/01 TO-220-7B .108 (2.74) REF .467 (11.86) .487 (12.37) .028 (.71) .010 (.25) M .032 (.81) .015 (.38) .020 (.51) Notes: 1. Controlling dimensions are inches. Millimeter .050 (1.27) 2 ...
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... Notes TNY256 C 17 7/01 ...
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... TNY256 C 18 7/01 Notes ...
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... Notes TNY256 C 19 7/01 ...
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... TNY256 Revision Notes - A 1) TO-220-7B package information added minimum increased to 44 LUV 1) Updated package references Corrected spelling. 3) Added Omega symbol ( pg. 8). 4) Corrected storage temperature and 5) Corrected spacing and font sizes in figures. For the latest updates, visit our Web site: www.powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability ...