LNK632DG LinkSwitch-II Family ® Energy-Efficient, Accurate CV Switcher With CC Control for Adapters and Chargers Product Highlights Dramatically Simplifies CV Converters • Eliminates optocoupler and all secondary CV/CC control circuitry • Eliminates all control loop compensation circuitry • Enables Clampless™ designs Wide Range HV DC Input Advanced Performance Features • Compensates for cable voltage drop • Compensates for external component temperature variations • Very tight IC parameter tolerances using proprietary trimming technology • Frequency jittering greatly reduces EMI filter cost Advanced Protection/Safety Features • Auto-restart protection reduces power delivered by about 85% for output short circuit and control loop faults (open and shorted components) • Hysteretic thermal shutdown – automatic recovery reduces power supply returns from the field EcoSmart ® – Energy Efficient • Easily meets all global energy efficiency regulations with no added components • No-load consumption down to <30 mW at 230 VAC input with bias winding • ON/OFF control provides constant efficiency down to very light loads – ideal for EISA and ENERGY STAR regulations • No current sense resistors – maximizes efficiency Green Package • Halogen free and RoHS compliant package Applications • Chargers for cell/cordless phones, PDAs, MP3/portable audio devices, adapters, etc. Description The LNK632DG dramatically simplifies low power CV/CC charger designs by eliminating an optocoupler and secondary control circuitry. The device uses an ON/OFF control technique to provide very tight output voltage regulation, in addition to output current control ideal for battery charging applications. The combination of proprietary IC trimming and E-Shield™ transformer construction techniques enables Clampless designs with the LNK632DG when an external bias circuit is used. D LNK632DG FB BP/M S PI-5346-022509 (a) Typical application schematic ±5% VO ±18% PI-5292-120908 (b) Output characteristic Figure 1. IO Typical Application – Not a Simplified Circuit (a) and Output Characteristic Envelope (b). Output Power Table Product3 LNK632DG 85-265 VAC Adapter Open Frame2 3.1 W 3.1 W 1 Table 1. Output Power Table. Notes: 1. Minimum continuous power in a typical non-ventilated enclosed adapter measured at +50 °C ambient. 2. Maximum practical continuous power in an open frame design with adequate heatsinking, measured at 50 °C ambient. 3. Packages: D: SO-8C. The device incorporates a 700 V power MOSFET, a novel ON/OFF control state machine, a high voltage switched current source for self biasing, frequency jittering, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry onto a monolithic IC. www.powerint.com September 2009 LNK632DG REGULATOR 6V BYPASS (BP/M) DRAIN (D) + + FEEDBACK (FB) VTH - D Q FB OUT 6V 5V Reset STATE MACHINE - VILIMIT tSAMPLE-OUT ILIM CABLE DROP COMPENSATION VILIMIT FAULT Auto-Restart Open-Loop FB 6.5 V Drive DCMAX THERMAL SHUTDOWN DCMAX CONSTANT CURRENT CONTROLLER SAMPLE DELAY tSAMPLE-OUT OSCILLATOR SOURCE (S) + SOURCE (S) ILIM VILIMIT - Current Limit Comparator LEADING EDGE BLANKING PI-5293-022309 Figure 2 Functional Block Diagram. Pin Functional Description DRAIN (D) Pin: This pin is the power MOSFET drain connection. It provides internal operating current for both start-up and steady-state operation. BYPASS/MULTI-FUNCTIONAL Programmable (BP/M) Pin: This pin has multiple functions: 1. It is the connection point for an external bypass capacitor for the internally generated 6 V supply. 2. It is a mode selection for the cable drop compensation. FEEDBACK (FB) Pin: During normal operation, switching of the power MOSFET is controlled by this pin. This pin senses the AC voltage on the bias winding. This control input regulates both the output voltage in CV mode and output current in CC mode based on the Flyback voltage of the bias winding. The internal inductance correction circuit uses the forward voltage on the bias winding to sense the bulk capacitor voltage. D Package (SO-8C) FB 1 8 S BP/M 2 7 S D 4 6 S 5 S PI-4907-032808 Figure 3. Pin Configuration. SOURCE (S) Pin: This pin is internally connected to the output MOSFET source for high voltage power and control circuit common returns. 2 Rev. C 09/09 www.powerint.com LNK632DG LNK632DG Functional Description The LNK632DG combines a high voltage power MOSFET switch with a power supply controller in one device. Similar to the LinkSwitch-LP and TinySwitch-III it uses a simple ON/OFF control to regulate the output voltage. In addition, the switching frequency is modulated to regulate the output current to provide a constant current characteristic. The LNK632DG controller consists of an oscillator, feedback (sense and logic) circuit, 6 V regulator, over-temperature protection, frequency jittering, current limit circuit, leading-edge blanking, frequency control for constant current regulation and ON/OFF state machine for CV control. Constant Current Control (CC) Operation As the output voltage and therefore the Flyback voltage across the bias winding ramps up, the feedback pin voltage increases. The switching frequency is adjusted as the feedback pin voltage increases to provide a constant output current regulation. Constant Voltage (CV) Operation As the feedback pin approaches VFBth from the constant current regulation mode, the power supply transitions into CV operation. The switching frequency at this point is at its maximum value, corresponding to the peak power point of the CCCV characteristic. The controller regulates the feedback pin voltage to remain at VFBth using an ON/OFF state-machine. The feedback pin voltage is sampled 2.5 ms after the turn-off of the high voltage switch. At light loads the current limit is also reduced to decrease the transformer flux density. Output Cable Compensation This compensation provides a constant output voltage at the end of the cable over the entire load range in CV mode. As the converter load increases from no-load to the peak power point (transition point between CV and CC) the voltage drop introduced across the output cable is compensated by increasing the feedback pin reference voltage. The controller determines the output load and therefore the correct degree of compensation based on the output of the state machine. Cable drop compensation for a 26 AWG (0.4 W) cable is selected with CBP = 1 mF and for a 28 AWG (0.75 W) cable with CBP = 10 mF. Auto-Restart and Open-Loop Protection In the event of a fault condition such as an output short or an open loop condition the LNK632DG enters into an appropriate protection mode as described below. In the event the feedback pin voltage during the Flyback period falls below 0.7 V before the feedback pin sampling delay (~2.5 ms) for a duration in excess of ~300 ms (auto-restart on- time (t AR-ON) the converter enters into Auto-restart, wherein the power MOSFET is disabled for 1.2 seconds (~20% Auto-Restart duty cycle). The auto-restart alternately enables and disables the switching of the power MOSFET until the fault condition is removed. In addition to the conditions for auto-restart described above, if the sensed feedback pin current during the Forward period of the conduction cycle (switch “on” time) falls below 120 mA, the converter annunciates this as an open-loop condition (top resistor in potential divider is open or missing) and reduces the Auto-restart time from 300 ms to approximately 6 clock cycles (60 ms), whilst keeping the disable period of 1.2 seconds. This effectively reduces the Auto-Restart duty cycle to less than 0.05%. Over-Temperature Protection The thermal shutdown circuitry senses the die temperature. The threshold is set at 142 °C typical with a 60 °C hysteresis. When the die temperature rises above this threshold (142 °C) the power MOSFET is disabled and remains disabled until the die temperature falls by 60 °C, at which point the MOSFET is reenabled. Current Limit The current limit circuit senses the current in the power MOSFET. When this current exceeds the internal threshold (ILIMIT), the power MOSFET is turned off for the remainder of that cycle. The leading edge blanking circuit inhibits the current limit comparator for a short time (tLEB) after the power MOSFET is turned on. This leading edge blanking time has been set so that current spikes caused by capacitance and rectifier reverse recovery time will not cause premature termination of the MOSFET conduction. 6 V Regulator The 6 V regulator charges the bypass capacitor connected to the BYPASS pin to 6 V by drawing a current from the voltage on the DRAIN, whenever the MOSFET is off. The BYPASS pin is the internal supply voltage node. When the MOSFET is on, the device runs off of the energy stored in the bypass capacitor. Extremely low power consumption of the internal circuitry allows the LNK632DG to operate continuously from the current drawn from the DRAIN pin. A bypass capacitor value of either 1 mF or 10 mF is sufficient for both high frequency decoupling and energy storage. Clampless Design Considerations Ensure that worse-case high line, peak drain voltage is below the BVDSS specification of the internal MOSFET and ideally <650 V to allow margin for design variation. 3 www.powerint.com Rev. C 09/09 LNK632DG Absolute Maximum Ratings(1,5) DRAIN Voltage ............................................ ..............-0.3 V to 700 V DRAIN Peak Current: . ..................................... 232 (350) mA(4) Peak Negative Pulsed Drain Current ............................. -100 mA(2) Feedback Voltage ......................................................... -0.3 V to 9 V Feedback Current ................................................................ 100 mA BYPASS Pin Voltage ................................................... -0.3 V to 9 V Storage Temperature ............................................ -65 °C to 150 °C Operating Junction Temperature........................ -40 °C to 150 °C Lead Temperature(4) .................................................................260 °C Notes: 1. All voltages referenced to SOURCE, TA = 25 °C. 2. Duration not to exceed 2 ms. 3. 1/16 in. from case for 5 seconds. 4. The higher peak DRAIN current is allowed while the DRAIN voltage is simultaneously less than 400 V. 5. Maximum ratings specified may be applied, one at a time without causing permanent damage to the product. Exposure to Absolute Maximum ratings for extended periods of time may affect product reliability. Thermal Impedance Thermal Impedance: D Package: (qJA) ..................................100 °C/W(2); 60 °C/W(3) (qJC)(1) .........................................................30 °C/W Parameter Symbol Notes: 1. Measured on pin 8 (SOURCE) close to plastic interface. 2. Soldered to 0.36 sq. in. (232 mm2), 2 oz. (610 g/m2) copper clad. 3. Soldered to 1 sq. in. (645 mm2), 2 oz. (610 g/m2) copper clad. Conditions SOURCE = 0 V; TJ = -40 to 125 °C (Unless Otherwise Specified) Min Typ Max Units 98 105 112 kHz 1.57 1.635 1.7 Control Functions Output Frequency fOSC Frequency Ratio (Constant Current) fRATIO(CC) TJ = 25 °C VFB = VFBth TJ = 25 °C Between VFB = 1.0 V and VFB = 1.6 V Peak-Peak Jitter Compared to Average Frequency, TJ = 25 °C Frequency Jitter Ratio of Output Frequency at Auto-RST fOSC(AR) TJ = 25 °C Relative to fOSC Maximum Duty Cycle DCMAX (Note 2,3) Feedback Pin Voltage VFBth TJ = 25 °C See Figure 10, CBP = 10 mF Feedback Pin Voltage Temperature Coefficient TCVFB Feedback Pin Voltage at Turn-Off Threshold VFB(AR) Cable Compensation Factor υFB ±7 12 16.5 % 21 55 2.015 2.040 % 2.065 -0.01 0.65 See Figure 10 0.72 CBP = 1 mF 1.06 CBP = 10 mF 1.09 % V %/°C 0.79 V 4 Rev. C 09/09 www.powerint.com LNK632DG Symbol Conditions SOURCE = 0 V; TJ = -40 to 125 °C (Unless Otherwise Specified) Minimum Switch ON-Time tON(min) TJ = 25 °C See Note 3 Feedback Pin Sampling Delay tFB TJ = 25 °C See Figure 10 IS1 Parameter Min Typ Max Units Control Functions (cont.) DRAIN Supply Current BYPASS Pin Charge Current 700 2.35 ns 2.55 2.75 FB Voltage > VFBth 260 330 IS2 FB Voltage = VFBTH -0.2, Switch ON-Time = tON (MOSFET Switching at fOSC) 440 520 ICH1 VBP = 0 V -5 -3.4 -1.8 ICH2 VBP = 4 V -4 -2.3 -1 ms mA mA BYPASS Pin Voltage VBP 5.65 6.00 6.25 V BYPASS Pin Voltage Hysteresis VBPH 0.7 1.0 1.2 V BYPASS Pin Shunt Voltage VSHUNT IBP = 10 mA 6.2 6.5 6.8 V ILIMIT di/dt = 36 mA/ms TJ = 25 °C 135 145 155 mA Power Coefficient I2f I2f = I2LIMIT(TYP) x fOSC(TYP) TJ = 25 °C 0.9 x I2f 1.17 x I2f A2Hz Leading Edge Blanking Time tLEB TJ = 25 °C See Note 3 170 215 Thermal Shutdown Temperature TSD 135 142 Thermal Shutdown Hysteresis TSDH Circuit Protection Current Limit 60 ns 150 °C °C 5 www.powerint.com Rev. C 09/09 LNK632DG Parameter Symbol Conditions SOURCE = 0 V; TJ = -40 to 125 °C (Unless Otherwise Specified) Min Typ Max TJ = 25 °C 45 53 TJ = 100 °C 68 79 Units Output ON-State Resistance OFF-State Leakage Breakdown Voltage RDS(ON) ID = 13 mA IDSS1 VDS = 560 V See Figure 11 TJ = 125 °C See Note 1 IDSS2 VDS = 375 V See Figure 11 TJ = 50 °C BVDSS TJ = 25 °C See Figure 11 DRAIN Supply Voltage W 50 mA 15 700 V 50 V Auto-Restart ON-Time tAR-ON VFB = 0 See Note 3 300 Auto-Restart OFF-Time tAR-OFF See Note 3 1.2 IOL See Note 3 -120 mA See Note 3 60 ms Open-Loop FB Pin Current Threshold Open-Loop ON-Time ms 2.0 s NOTES: 1. IDSS1 is the worst case OFF state leakage specification at 80% of BVDSS and maximum operating junction temperature. IDSS2 is a typical specification under worst case application conditions (rectified 265 VAC) for no-load consumption calculations. 2. When the duty-cycle exceeds DCMAX the LNK632DG operates in on-time extension mode. 3. This paramter is derived from characterization. 6 Rev. C 09/09 www.powerint.com LNK632DG 0.8 0.6 0.4 0.2 PI-5034-032108 1.0 1.2 Feedback Pin Voltage (Normalized to 25 °C) PI-5031-032808 Frequency (Normalized to 25 °C) 1.2 1.0 0.8 0.6 0.4 0.2 0 0 -40 -15 10 35 60 85 -40 -15 110 135 10 85 110 135 Figure 5. Feedback Pin Voltage vs. Temperature PI-4164-100505 PI-2213-012301 1.4 1.2 Current Limit (Normalized to 25 °C) Figure 4. Output Frequency vs. Temperature. Breakdown Voltage (Normalized to 25 °C) 60 Temperature (°C) Temperature (°C) 1.1 35 1.0 0.8 1.0 0.6 0.4 0.2 0 0.9 -50 -25 0 25 50 -50 75 100 125 150 0 100 °C 125 100 75 50 25 PI-3928-083104 1000 Drain Capacitance (pF) 25 °C 150 150 Figure 7. Current Limit vs. Temperature. PI-3927-083104 DRAIN Current (mA) 175 100 Temperature (°C) Junction Temperature (°C) Figure 6. Breakdown vs. Temperature. 200 50 100 10 1 0 0 2 4 6 8 10 12 14 16 18 20 DRAIN Voltage (V) Figure 8. Output Characteristics. 0 100 200 300 400 500 600 Drain Voltage (V) Figure 9. COSS vs. Drain Voltage. 7 www.powerint.com Rev. C 09/09 LNK632DG LNK632DG VIN + FB S BP S D S 10 µF + VBP VOUT S 500 Ω + 2V PI-5347-122208 1) Raise VBP voltage from 0 V to 6.2 V, down to 4.5 V, up to 6.2 V 2) Raise VIN until cycle skipping occurs at VOUT to measure VFBth 3) Reduce VIN until cycle skipping stops at VOUT to measure VFBth-. Cable drop compensaion factor is υFB = VFBth / VFBth4) Apply 1.5 V at VIN and measure tFB delay from start of cycle falling edge to the next falling edge Figure 10. Test Set-up for Feedback Pin Meassurements. 5 µF 50 kΩ 10 kΩ 4 kΩ VIN 16 V FB S BP S D S .1 µF S1 S PI-5348-122208 LNK632DG S2 + Curve Tracer To measure BVDSS, IDSS1, and IDSS2 follow these steps: 1) Close S1, open S2 2) Power-up VIN source (16 V) 3) Open S1, close S2 4) Measure I/V characteristics of Drain pin using the curve tracer Figure 11. Test Set-up for Leakage and Breakdown Tests. 8 Rev. C 09/09 www.powerint.com LNK632DG SO-8C 4 B 0.10 (0.004) C A-B 2X 2 DETAIL A 4.90 (0.193) BSC A 4 8 D 5 2 3.90 (0.154) BSC GAUGE PLANE SEATING PLANE 6.00 (0.236) BSC C 0-8 1.04 (0.041) REF 0.10 (0.004) C D 2X 1 Pin 1 ID 4 0.25 (0.010) BSC 0.40 (0.016) 1.27 (0.050) 0.20 (0.008) C 2X 7X 0.31 - 0.51 (0.012 - 0.020) 0.25 (0.010) M C A-B D 1.27 (0.050) BSC 1.25 - 1.65 (0.049 - 0.065) 1.35 (0.053) 1.75 (0.069) o DETAIL A 0.10 (0.004) 0.25 (0.010) 0.10 (0.004) C H 7X SEATING PLANE 0.17 (0.007) 0.25 (0.010) C Reference Solder Pad Dimensions + 2.00 (0.079) + 4.90 (0.193) + + 1.27 (0.050) D07C Notes: 1. JEDEC reference: MS-012. 2. Package outline exclusive of mold flash and metal burr. 3. Package outline inclusive of plating thickness. 4. Datums A and B to be determined at datum plane H. 5. Controlling dimensions are in millimeters. Inch dimensions are shown in parenthesis. Angles in degrees. 0.60 (0.024) PI-4526-040207 Part Ordering Information • LinkSwitch Product Family • II Series Number • Package Identifier D Plastic SO-8 • Package Material G GREEN: Halogen Free and RoHS Compliant • Tape & Reel and Other Options LNK 632 D G - TL Blank Standard Configurations TL Tape & Reel, 2.5 k pcs. 9 www.powerint.com Rev. C 09/09 Revision Notes Date 02/09 A Initial release B Introduced Max current limit when V DRAIN is below 400 V 07/09 C Added Clampless design note on page 3 09/09 ® For the latest updates, visit our website: www.powerint.com Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability. Power Integrations does not assume any liability arising from the use of any device or circuit described herein. POWER INTEGRATIONS MAKES NO WARRANTY HEREIN AND SPECIFICALLY DISCLAIMS ALL WARRANTIES INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT OF THIRD PARTY RIGHTS. Patent Information The products and applications illustrated herein (including transformer construction and circuits external to the products) may be covered by one or more U.S. and foreign patents, or potentially by pending U.S. and foreign patent applications assigned to Power Integrations. A complete list of Power Integrations patents may be found at www.powerint.com. Power Integrations grants its customers a license under certain patent rights as set forth at http://www.powerint.com/ip.htm. Life Support Policy POWER INTEGRATIONS PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF POWER INTEGRATIONS. As used herein: 1. A Life support device or system is one which, (i) is intended for surgical implant into the body, or (ii) supports or sustains life, and (iii) whose failure to perform, when properly used in accordance with instructions for use, can be reasonably expected to result in significant injury or death to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. The PI logo, TOPSwitch, TinySwitch, LinkSwitch, DPA-Switch, PeakSwitch, EcoSmart, Clampless, E-Shield, Filterfuse, StakFET, PI Expert and PI FACTS are trademarks of Power Integrations, Inc. Other trademarks are property of their respective companies. ©2009, Power Integrations, Inc. Power Integrations Worldwide Sales Support Locations World Headquarters 5245 Hellyer Avenue San Jose, CA 95138, USA. Main: +1-408-414-9200 Customer Service: Phone: +1-408-414-9665 Fax: +1-408-414-9765 e-mail: [email protected] China (Shanghai) Room 1601/1610, Tower 1 Kerry Everbright City No. 218 Tianmu Road West Shanghai, P.R.C. 200070 Phone: +86-21-6354-6323 Fax: +86-21-6354-6325 e-mail: [email protected] China (Shenzhen) Rm A, B & C 4th Floor, Block C, Electronics Science and Technology Bldg., 2070 Shennan Zhong Rd, Shenzhen, Guangdong, China, 518031 Phone: +86-755-8379-3243 Fax: +86-755-8379-5828 e-mail: [email protected] Germany Rueckertstrasse 3 D-80336, Munich Germany Phone: +49-89-5527-3910 Fax: +49-89-5527-3920 e-mail: [email protected] India #1, 14th Main Road Vasanthanagar Bangalore-560052 India Phone: +91-80-4113-8020 Fax: +91-80-4113-8023 e-mail: [email protected] Italy Via De Amicis 2 20091 Bresso MI Italy Phone: +39-028-928-6000 Fax: +39-028-928-6009 e-mail: [email protected] Japan Kosei Dai-3 Bldg. 2-12-11, Shin-Yokohama, Kohoku-ku Yokohama-shi Kanagwan 222-0033 Japan Phone: +81-45-471-1021 Fax: +81-45-471-3717 e-mail: [email protected] Korea RM 602, 6FL Korea City Air Terminal B/D, 159-6 Samsung-Dong, Kangnam-Gu, Seoul, 135-728, Korea Phone: +82-2-2016-6610 Fax: +82-2-2016-6630 e-mail: [email protected] Taiwan 5F, No. 318, Nei Hu Rd., Sec. 1 Nei Hu Dist. Taipei, Taiwan 114, R.O.C. Phone: +886-2-2659-4570 Fax: +886-2-2659-4550 e-mail: [email protected] Europe HQ 1st Floor, St. James’s House East Street, Farnham Surrey GU9 7TJ United Kingdom Phone: +44 (0) 1252-730-141 Fax: +44 (0) 1252-727-689 e-mail: [email protected] Applications Hotline World Wide +1-408-414-9660 Singapore 51 Newton Road Applications Fax #15-08/10 Goldhill Plaza World Wide +1-408-414-9760 Singapore, 308900 Phone: +65-6358-2160 Fax: +65-6358-2015 e-mail: [email protected]