ACT30 Active-Semi Rev 5, 05-Jun-09 High Performance Off-Line Controller ActiveSwitcherTM IC Family FEATURES GENERAL DESCRIPTION • Lowest Total Cost Solution • 0.15W Standby Power • Emitter Drive Allows Safe NPN Transistor 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. Flyback Use • • • • • • • • Hiccup Mode Short Circuit Current Mode Operation 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. Over-Current Protection Under-voltage Protection with Auto-Restart Proprietary Scalable Output Driver Flexible Packaging Options (Including TO-92) 65kHz or 100kHz Switching Frequency Consuming only 0.15W in standby, the IC features over-current, hiccup mode short circuit, and undervoltage protection mechanisms. Selectable 0.4A to 1.2A Current Limit APPLICATIONS • • • • • 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. Battery Chargers Power Adaptors Standby Power Supplies Appliances Universal Off-Line Power Supplies Figure 1: Simplified Application Circuit HIGH VOLTAGE DC R1 D2 Q1 R2 IC1 DRV + C1 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. D1 GND -1- VDD OPTOCOUPLER www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 ORDERING INFORMATION PART NUMBER SWITCHING FREQUENCY CURRENT LIMIT JUNCTION TEMPERATURE PACKAGE PINS ACT30AHT 65kHz 400mA -40˚C to 150˚C TO-92 3 ACT30BHT 65kHz 800mA -40˚C to 150˚C TO-92 3 ACT30AYT 65kHz 400mA -40˚C to 150˚C SOT23-B 3 PIN CONFIGURATION ACT30A ACT30B SOT23-B TO-92 PIN DESCRIPTIONS PIN NAME DESCRIPTION 1 VDD Power Supply Pin. Connect to optocoupler's emitter. Internally limited to 5.5V max. Bypass to GND with a proper compensation network. 2 3 GND Ground. 3 2 DRV 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. TO-92 SOT23-B 1 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -2- www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 ABSOLUTE MAXIMUM RATINGSc PARAMETER VDD, FREQ to GND VALUE UNIT -0.3 to 6 V 20 mA -0.3 to 18 V Internally limited A VDD Current DRV, DRV1, DRV2 to GND Continuous DRV, DRV1, DRV2 Current Maximum Power Dissipation TO-92 0.6 SOT23-B 0.39 W Operating Junction Temperature -40 to 150 ˚C Storage Temperature -55 to 150 ˚C 300 ˚C Lead Temperature (Soldering, 10 sec) c: 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 SYMBOL TEST CONDITIONS MIN TYP 4.75 5 5.25 8.6 10.5 9.6 11.5 6.35 6.8 7.25 V Falling edge 3.17 3.35 3.63 V 10mA 5.15 5.45 5.95 V 0.23 0.45 mA 0.7 1 mA kHz VVDD Start Voltage VSTART Rising edge DRV1 Start Voltage VDRVST ACT30A DRV1 must be higher than this voltage to start up. ACT30B DRV1 Short-Circuit Detect Threshold VSCDRV VVDD Under-Voltage Threshold VUV VVDD Clamp Voltage Startup Supply Current IDDST Supply Current IDD Switching Frequency fSW Maximum Duty Cycle DMAX Minimum Duty Cycle DMIN Effective Current Limit ILIM VVDD = 4V before VUV MAX UNIT ACT30A/B or FREQ = 0 50 65 80 ACT30A, VVDD = 4V 67 75 83 ACT30B, VVDD = 4V 60 VVDD = 4.6V VVDD = VUV + 0.1V 3.5 V V % % ACT30A 340 400 480 ACT30B with DRV1 = DRV2 680 800 920 mA VVDD to DRV1 Current Coefficient GGAIN -0.29 A/V VDD Dynamic Impedance RVDD 9 kΩ DRV1 or DRV2 Driver OnResistance RDRV1, RDRV2 IDRV1 = IDRV2 = 0.05A 3.6 Ω DRV1 Rise Time 1nF load, 15Ω pull-up 30 ns DRV1 Fall Time 1nF load, 15Ω pull-up 20 ns DRV1 and DRV2 Switch Off Current Driver off, VDRV1 = VDRV2 = 10V 12 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -3- 30 µA www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 FUNCTIONAL BLOCK DIAGRAM DRV1 VDD 2 + REGULATOR 3.6V (ACT30A/C) 4.6V (ACT30B/D) BIAS & UVLO 9k DRV2 HICCUP CONTROL FREQ OSC & RAMP CURRENT 1 PFWM SWITCHING CONTROL LOGIC SLEW 20k 200k ILIM VC GENERATOR 1X 56X 56X ERROR COMP 40 20k 4.75V 10µA/V GND GND c: FREQ terminal wire-bonded to VDD in ACT30C/D (TO-92) d: DRV2 terminal wire-bonded to DRV1 in ACT30B/D (TO-92) FUNCTIONAL DESCRIPTION Startup Sequence 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. 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. 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. To limit the auxiliary voltage, use a 12V zener diode for ACT30A or a 13V zener diode for ACT30B (D1 diode in Figure 1). 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. 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. ACT30 Active-Semi Rev 5, 05-Jun-09 Figure 2: Startup Waveforms pulse-skipped VAC VDRVST VDRV1 5V VVDD IPRIMARY VOUT 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. 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. Figure 3: Driver Output Configurations 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: I LIM = 400 mA ⎛ 7 .2 Ω + R D I LIM = 400 mA × ⎜⎜ ⎝ 3 .6 Ω + R D 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 I LIM = 800 mA Current Limit Adjustment RD ⎞ ⎛ I LIM = 400 mA × ⎜ 2 + ⎟ 3 .6 Ω ⎠ ⎝ 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. -5- www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 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. 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. ACT30 Active-Semi Rev 5, 05-Jun-09 Figure 4: APPLICATIONS INFORMATION NPN Reverse Bias Safe Operation Area External Power Transistor IC 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. Base-Drive Safe Region (RCC) MJE13002 IC hFEMIN PACKAGE 600V 300V 1.5A 8 TO-126 MJE13003, 700V 400V 1.5A KSE13003 8 TO-126 STX13003 8 TO-92 700V 400V 1A VC 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. Recommended Power Transistor List VCBO VCEO VCBO VCEO Table 1: DEVICE Emitter-Drive Safe Region (ACT30) Figure 5: A 3.75W Charger Using ACT30A in Combination with TL431 F1 AC1 C10 D4 D1 T1 EE-16 L1 R1 D3 C4 R2B AC2 R3 R9 R6 D6 D5 5V/750mA R10 R11 C7 C2 R2A L2 D8 C19 D2 C1 R18 IC2A Opto C9 R13 R5 C8 D7 IC3 TL431 Q2 R7 R12 R16 Z1 R15 GND R14 IC2B Opto 1 3 IC1 2 ACT30A R8 C6 C20 C3 C5 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -7- www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 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 220VAC Standby Power 0.09W 0.15W Current Limit 0.75A 0.75A Full Load Efficiency 65% 67% 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. ACT30 Active-Semi Rev 5, 05-Jun-09 PACKAGE OUTLINE TO-92 PACKAGE OUTLINE AND DIMENSIONS (AMMO TAPE PACKING) D1 P ∆P ∆k H0 L1 F1 F2 P2 P1 W b W0 W1 D H W2 Φ Q1 P0 t1 e t2 e1 SYMBOL DIMENSION IN MILIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 3.300 3.700 0.130 0.146 A1 1.100 1.400 0.043 b 0.380 0.550 c 0.360 D 4.400 D1 3.430 E 4.300 e e1 Φ h DIMENSION IN INCHES MAX MIN MAX ∆k -1.000 1.000 -0.039 0.039 0.055 F1, F2 2.200 2.800 0.087 0.110 0.015 0.022 H 19.00 21.00 0.748 0.827 0.510 0.014 0.020 H0 15.50 16.50 0.610 0.650 4.700 0.173 0.185 L1 2.500 P 12.40 13.00 0.488 0.512 ∆P -1.000 1.000 -0.039 0.039 P0 12.50 12.90 0.492 0.508 0.104 P1 3.550 4.150 0.140 0.163 0.063 P2 6.050 6.650 0.238 0.262 0.015 Q1 3.800 4.200 0.150 0.165 t1 0.350 0.450 0.014 0.018 t2 0.150 0.250 0.006 0.010 W 17.50 19.00 0.689 0.748 W0 5.500 6.500 0.217 0.256 W1 8.500 9.500 0.335 0.374 0.135 4.700 2.640 0.169 0.380 0.185 0.050 TYP 0.096 1.600 0.000 DIMENSION IN MILIMETERS MIN 1.270 TYP 2.440 SYMBOL 0.000 W2 Innovative PowerTM ActiveSwitcherTM is a trademark of Active-Semi. -9- 0.098 1.000 0.039 www.active-semi.com Copyright © 2009 Active-Semi, Inc. ACT30 Active-Semi Rev 5, 05-Jun-09 SOT23-B PACKAGE OUTLINE AND DIMENSIONS D θ b 0.25 MAX MIN MAX A 1.900 1.150 0.035 0.045 A1 0.000 0.100 0.000 0.004 A2 0.900 1.050 0.035 0.041 b 0.300 0.500 0.012 0.020 c 0.080 0.150 0.003 0.006 c D 2.800 3.000 0.110 0.118 E 1.200 1.400 0.047 0.055 E1 2.250 2.550 0.089 0.100 L1 MIN E E1 DIMENSION IN INCHES L SYMBOL DIMENSION IN MILLIMETERS e e A A2 A1 e1 e1 L 0.950 TYP 1.800 2.000 0.550 REF 0.037 TYP 0.071 0.079 0.022 REF L1 0.300 0.500 0.012 0.020 θ 0° 8° 0° 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 [email protected] 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.