ACT30AHT

Active-Semi FEATURES • Lowest Total Cost Solution • 0.15W Standby Power • Emitter Drive Allows Safe NPN Transistor Flyback Use ACT30 Rev 5, 05-Jun-09 High Performance Off-Line Controller ActiveSwitcherTM IC Family GENERAL DESCRIPTION The ACT30 is a high performance green-energy offline power supply controller. It features a scalable driver for driving external NPN or MOSFET transistors for line voltage switching. This proprietary architecture enables many advanced features to be integrated into a small package (TO-92 or SOT23-B), resulting in lowest total cost solution. The ACT30 design has six internal terminals and is a pulse frequency and width modulation IC with many flexible packaging options. One combination of internal terminals is packaged in the spacesaving TO-92 package (A/B versions) for 65kHz or 100kHz switching frequency and with 400mA or 800mA current limit. Consuming only 0.15W in standby, the IC features over-current, hiccup mode short circuit, and undervoltage protection mechanisms. The ACT30 is ideal for use in high performance universal adaptors and chargers. For highest performance versus cost and smallest PCB area, use the ACT30 in combination with the ACT32 CV/CC Controller. • • • • • • • • Hiccup Mode Short Circuit Current Mode Operation Over-Current Protection Under-voltage Protection with Auto-Restart Proprietary Scalable Output Driver Flexible Packaging Options (Including TO-92) 65kHz or 100kHz Switching Frequency Selectable 0.4A to 1.2A Current Limit APPLICATIONS • • • • • Battery Chargers Power Adaptors Standby Power Supplies Appliances Universal Off-Line Power Supplies Figure 1: Simplified Application Circuit HIGH VOLTAGE DC R1 D2 R2 IC1 DRV Q1 + C1 D1 GND VDD OPTOCOUPLER Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -1- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi ORDERING INFORMATION PART NUMBER ACT30AHT ACT30BHT ACT30AYT Rev 5, 05-Jun-09 ACT30 SWITCHING FREQUENCY 65kHz 65kHz 65kHz CURRENT LIMIT 400mA 800mA 400mA JUNCTION TEMPERATURE -40˚C to 150˚C -40˚C to 150˚C -40˚C to 150˚C PACKAGE TO-92 TO-92 SOT23-B PINS 3 3 3 PIN CONFIGURATION ACT30A ACT30B TO-92 SOT23-B PIN DESCRIPTIONS PIN TO-92 1 2 3 SOT23-B 1 3 2 NAME VDD GND DRV DESCRIPTION Power Supply Pin. Connect to optocoupler's emitter. Internally limited to 5.5V max. Bypass to GND with a proper compensation network. Ground. Driver Output (TO-92 Only). Connect to emitter of the high voltage NPN or MOSFET. For ACT30A/C, DRV pin is internally connected to DRV1. For ACT30B/D, DRV pin is internally connected to both DRV1 and DRV2. Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -2- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi ABSOLUTE MAXIMUM RATINGS PARAMETER VDD, FREQ to GND VDD Current DRV, DRV1, DRV2 to GND Continuous DRV, DRV1, DRV2 Current Maximum Power Dissipation Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) TO-92 SOT23-B Rev 5, 05-Jun-09 ACT30 UNIT V mA V A W ˚C ˚C ˚C VALUE -0.3 to 6 20 -0.3 to 18 Internally limited 0.6 0.39 -40 to 150 -55 to 150 300 : Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability. ELECTRICAL CHARACTERISTICS (VVDD = 4V, TJ = 25°C, unless otherwise specified.) PARAMETER VVDD Start Voltage DRV1 Start Voltage DRV1 Short-Circuit Detect Threshold VVDD Under-Voltage Threshold VVDD Clamp Voltage Startup Supply Current Supply Current Switching Frequency Maximum Duty Cycle Minimum Duty Cycle Effective Current Limit VVDD to DRV1 Current Coefficient VDD Dynamic Impedance DRV1 or DRV2 Driver OnResistance DRV1 Rise Time DRV1 Fall Time DRV1 and DRV2 Switch Off Current SYMBOL VSTART VDRVST VSCDRV VUV IDDST IDD fSW DMAX DMIN ILIM GGAIN RVDD RDRV1, RDRV2 TEST CONDITIONS Rising edge ACT30A DRV1 must be higher than this voltage to start up. ACT30B MIN 4.75 TYP 5 8.6 9.6 MAX UNIT 5.25 10.5 11.5 7.25 3.63 5.95 0.45 1 80 83 V V V V mA mA kHz % % 480 920 mA A/V kΩ Ω ns ns 30 µA V 6.35 Falling edge 10mA VVDD = 4V before VUV ACT30A/B or FREQ = 0 ACT30A, VVDD = 4V ACT30B, VVDD = 4V VVDD = 4.6V ACT30A VVDD = VUV + 0.1V ACT30B with DRV1 = DRV2 340 680 50 67 60 3.17 5.15 6.8 3.35 5.45 0.23 0.7 65 75 3.5 400 800 -0.29 9 IDRV1 = IDRV2 = 0.05A 1nF load, 15Ω pull-up 1nF load, 15Ω pull-up Driver off, VDRV1 = VDRV2 = 10V 3.6 30 20 12 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -3- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi FUNCTIONAL BLOCK DIAGRAM DRV1 VDD 9k BIAS & UVLO REGULATOR Rev 5, 05-Jun-09 ACT30 2 DRV2 + 3.6V (ACT30A/C) 4.6V (ACT30B/D) HICCUP CONTROL FREQ 1 OSC & RAMP CURRENT 200k PFWM SWITCHING CONTROL LOGIC ERROR COMP SLEW 20k 1X 56X 56X ILIM VC GENERATOR 40 20k 4.75V 10µA/V GND GND : FREQ terminal wire-bonded to VDD in ACT30C/D (TO-92) : DRV2 terminal wire-bonded to DRV1 in ACT30B/D (TO-92) FUNCTIONAL DESCRIPTION As seen in the Functional Block Diagram, the main components include switching control logic, two onchip medium-voltage power-MOSFETs with parallel current sensor, driver, oscillator and ramp generator, current limit VC generator, error comparator, hiccup control, bias and under voltagelockout, and regulator circuitry. As seen in the Functional Block Diagram, the design has six internal terminals. VVDD is the power supply terminal. DRV1 and DRV2 are linear driver outputs that can drive the emitter of an external high voltage NPN transistor or N-channel MOSFET. This emitter-drive method takes advantage of the high VCBO of the transistor, allowing a low cost transistor such as ‘13003 (VCBO = 700V) or ‘13002 (VCBO = 600V) to be used for a wide AC input range. The slew-rate limited driver coupled with the turn-off characteristics of an external NPN transitor result in lower EMI. The driver peak current is designed to have a negative voltage coefficient with respect to supply voltage VVDD, so that lower supply voltage automatically results in higher DRV1 peak current. This way, the optocoupler can control VVDD directly to affect driver current. Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. Startup Sequence Figure 1 shows a Simplified Application Circuit for the ACT30. Initially, the small current through resistor R1 charges up the capacitor C1, and the BJT acts as a follower to bring up the DRV1 voltage. An internal regulator generates a VVDD voltage equal to VDRV1 – 3.6V for ACT30A (VDRV1 – 4.6V for ACT30B) but limits it to 5.5V max. As VVDD crosses 5V, the regulator sourcing function stops and VVDD begins to drop due to its current consumption. As VVDD voltage decreases below 4.75V, the IC starts to operate with increasing driver current. When the output voltage reaches regulation point, the optocoupler feedback circuit stops VVDD from decreasing further. The switching action also allows the auxiliary windings to take over in supplying the C1 capacitor. Figure 2 shows a typical startup sequence for the ACT30. To limit the auxiliary voltage, use a 12V zener diode for ACT30A or a 13V zener diode for ACT30B (D1 diode in Figure 1). Even though up to 2MΩ startup resistor (R1) can be used due to the very low startup current, the actual R1 value should be chosen as a compromise between standby power and startup time delay. -4- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi Figure 2: Startup Waveforms Rev 5, 05-Jun-09 ACT30 pulse-skipped VAC VDRV1 VDRVST 5V VVDD IPRIMARY VOUT Normal Operation In normal operation, the feedback signal from the secondary side is transmitted through the optocoupler as a current signal into VVDD pin, which has dynamic impedance of 9kΩ. The resulting VVDD voltage affects the switching of the IC. As seen in the Functional Block Diagram, the Current Limit VC Generator uses the VVDD voltage difference with 4.75V to generate a proportional offset at the negative input of the Error Comparator. The drivers turn on at the beginning of each switching cycle. The current sense resistor current, which is a fraction of the transformer primary current, increases with time as the primary current increases. When the voltage across this current sense resistor plus the oscillator ramp signal equals Error Comparator's negative input voltage, the drivers turn off. Thus, the peak DRV1 current has a negative voltage coefficient of -0.29A/V and can be calculated from the following: 3.6Ω (rather than as digital output switches). The current limit can then be calculated through linear combination as shown in Figure 3. For TO-92 package, the ACT30A are preprogrammed to 400mA current limit and the ACT30B are preprogrammed to 800mA current limit, for SOT23B package, the ACT30A are preprogrammed to 400mA current limit. Figure 3: Driver Output Configurations I LIM = 400 mA IDRV 1PEAK = 0.29 A / V × (4.75V − VVDD ) for VVDD < 4.75V and duty cycle < 50%. When the output voltage is lower than regulation, the current into VVDD pin is zero and VVDD voltage decreases. At VVDD = VUV = 3.35V, the peak DRV1 current has maximum value of 400mA. DRV1 DRV2 ⎛ 7 .2 Ω + R D I LIM = 400 mA × ⎜ ⎜ 3 .6 Ω + R D ⎝ ⎞ ⎟ ⎟ ⎠ I LIM = 800 mA Current Limit Adjustment The IC's proprietary driver arrangement allows the current limit to be easily adjusted between 400mA and 1.2A. To understand this, the drivers have to be utilized as linear resistive devices with typically Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. RD ⎞ ⎛ I LIM = 400 mA × ⎜ 2 + ⎟ 3 .6 Ω ⎠ ⎝ -5- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi Pulse Modulation The PFWM Switching Control Logic block operates in different modes depending on the output load current level. At light load, the VVDD voltage is around 4.75V. The energy delivered by each switching cycle (with minimum on time of 500ns) to the output causes VVDD to increase slightly above 4.75V. The FPWM Switching Control Logic block is able to detect this condition and prevents the IC from switching until VVDD is below 4.75V again. This results in a pulse-modulation action with fixed pulse width and varying frequency, and low power consumption because the switching frequency is reduced. Typical system standby power consumption is 0.15W. Rev 5, 05-Jun-09 ACT30 Short Circuit Hiccup When the output is short circuited, the ACT30 enters hiccup mode operation. In this condition, the auxiliary supply voltage collapses. An on-chip detector compares DRV1 voltage during the offtime of each cycle to 6.8V. If DRV1 voltage is below 6.8V, the IC will not start the next cycle, causing both the auxiliary supply voltage and VVDD to reduce further. The circuit enters startup mode when VVDD drops below 3.35V. This hiccup behavior continues until the short circuit is removed. In this behavior, the effective duty cycle is very low resulting in very low short circuit current. To make sure that the IC enters hiccup mode easily, the transformer should be constructed so that there is close coupling between secondary and auxiliary, so that the auxiliary voltage is low when the output is short-circuited. This can be achieved with the primary/auxiliary/secondary sequencing from the bobbin. Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -6- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi APPLICATIONS INFORMATION External Power Transistor The ACT30 allows a low-cost high voltage power NPN transistor such as ‘13003 or ‘13002 to be used safely in a flyback configuration. The required collector voltage rating for VAC = 265V with full output load is at least 600V to 700V. As seen in Figure 4, the breakdown voltage of an NPN is significantly improved when it is driven at its emitter. Thus, the ACT30 and ’13002 or ‘13003 combination meet the necessary breakdown safety requirement even though RCC circuits using ‘13002 or ‘13003 do not. Table 1 lists the breakdown voltage of some transistors appropriate for use with the ACT30. Table 1: Recommended Power Transistor List DEVICE MJE13002 IC Rev 5, 05-Jun-09 Figure 4: NPN Reverse Bias Safe Operation Area ACT30 Base-Drive Safe Region (RCC) Emitter-Drive Safe Region (ACT30) VCEO VCBO VC VCBO VCEO IC hFEMIN PACKAGE 8 8 8 TO-126 TO-126 TO-92 600V 300V 1.5A MJE13003, 700V 400V 1.5A KSE13003 STX13003 700V 400V 1A The power dissipated in the NPN transistor is equal to the collector current times the collector-emitter voltage. As a result, the transistor must always be in saturation when turned on to prevent excessive power dissipation. Select an NPN transistor with sufficiently high current gain (hFEMIN > 8) and a base drive resistor (R2 in Figure 1) low enough to ensure that the transistor easily saturates. Figure 5: A 3.75W Charger Using ACT30A in Combination with TL431 F1 AC1 D4 D1 L1 R1 D3 AC2 C1 C2 R2A D2 R2B C4 R3 R6 D5 C19 C7 IC2A Opto R13 C8 T1 EE-16 C10 R18 L2 5V/750mA D8 R9 R10 R11 C9 D6 R5 D7 R7 Z1 Q2 IC3 TL431 R12 R16 R15 GND IC2B Opto R14 1 IC1 3 ACT30A 2 R8 C3 C5 C6 C20 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -7- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi Application Example The application circuit in Figure 5 provides a 5V/0.75A constant voltage/constant current output. The performance of this circuit is summarized in Table 2. Table 2: System Performance of Circuit in Figure 5 110VAC Standby Power Current Limit Full Load Efficiency 0.09W 0.75A 65% 220VAC 0.15W 0.75A 67% Rev 5, 05-Jun-09 ACT30 Layout Considerations The following should be observed when doing layout for the ACT30: 1) Use a "star point" connection at the GND pin of ACT30 for the VDD bypass components (C5 and C6 in Figure 5), the input filter capacitor (C2 in Figure 5) and other ground connections on the primary side. 2) Keep the loop across the input filter capacitor, the transformer primary windings, and the high voltage transistor, and the ACT30 as small as possible. 3) Keep ACT30 pins and the high voltage transistor pins as short as possible. 4) Keep the loop across the secondary windings, the output diode, and the output capacitors as small as possible. 5) Allow enough copper area under the high voltage transistor, output diode, and current shunt resistor for heat sink. Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -8- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi PACKAGE OUTLINE Rev 5, 05-Jun-09 ACT30 TO-92 PACKAGE OUTLINE AND DIMENSIONS (AMMO TAPE PACKING) D1 P ∆P ∆k Φ H L1 F1 F2 P2 P1 Q1 P0 H0 D b e e1 t2 t1 SYMBOL A A1 b c D D1 E e e1 Φ h DIMENSION IN MILIMETERS MIN 3.300 1.100 0.380 0.360 4.400 3.430 4.300 4.700 W W1 DIMENSION IN INCHES MIN 0.130 0.043 0.015 0.014 0.173 0.135 0.169 0.185 W0 W2 SYMBOL ∆k F1, F2 H H0 L1 P ∆P P0 P1 P2 Q1 t1 t2 W W0 W1 W2 DIMENSION IN MILIMETERS MIN -1.000 2.200 19.00 15.50 2.500 12.40 -1.000 12.50 3.550 6.050 3.800 0.350 0.150 17.50 5.500 8.500 13.00 1.000 12.90 4.150 6.650 4.200 0.450 0.250 19.00 6.500 9.500 1.000 DIMENSION IN INCHES MIN -0.039 0.087 0.748 0.610 0.098 0.488 -0.039 0.492 0.140 0.238 0.150 0.014 0.006 0.689 0.217 0.335 0.512 0.039 0.508 0.163 0.262 0.165 0.018 0.010 0.748 0.256 0.374 0.039 MAX 3.700 1.400 0.550 0.510 4.700 MAX 0.146 0.055 0.022 0.020 0.185 MAX 1.000 2.800 21.00 16.50 MAX 0.039 0.110 0.827 0.650 1.270 TYP 2.440 2.640 1.600 0.000 0.380 0.050 TYP 0.096 0.104 0.063 0.000 0.015 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -9- www.active-semi.com Copyright © 2009 Active-Semi, Inc. Active-Semi SOT23-B PACKAGE OUTLINE AND DIMENSIONS D b L1 θ 0.25 Rev 5, 05-Jun-09 ACT30 SYMBOL A DIMENSION IN MILLIMETERS MIN 1.900 0.000 0.900 0.300 0.080 2.800 1.200 2.250 DIMENSION IN INCHES MIN 0.035 0.000 0.035 0.012 0.003 0.110 0.047 0.089 MAX 1.150 0.100 1.050 0.500 0.150 3.000 1.400 2.550 MAX 0.045 0.004 0.041 0.020 0.006 0.118 0.055 0.100 E1 A1 E A2 b L c D E E1 e e1 c A1 A2 A e e1 L L1 θ 0.950 TYP 1.800 2.000 0.037 TYP 0.071 0.079 0.550 REF 0.300 0° 0.500 8° 0.022 REF 0.012 0° 0.020 8° Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of the use of any product or circuit described in this datasheet, nor does it convey any patent license. Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact sales@active-semi.com or visit http://www.active-semi.com. For other inquiries, please send to: 2728 Orchard Parkway, San Jose, CA 95134-2012, USA Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. - 10 - www.active-semi.com Copyright © 2009 Active-Semi, Inc.