ACT4050YH-T

Active-Semi FEATURES • • • • • • • • • • 3.5A Output Current Up to 96% Efficiency 4.5V to 15V Input Range 12µA Shutdown Supply Current 400kHz Switching Frequency Adjustable Output Voltage From 0.817V Cycle-by-Cycle Current Limit Protection Thermal Shutdown Protection Frequency Fold-Back at Short Circuit ACT4050 Rev 2, 01-Jul-11 Wide Input 3.5A Step Down Converter GENERAL DESCRIPTION The ACT4050 is a current-mode step-down DC/DC converter that provides up to 3.5A of output current at 400kHz switching frequency. The device utilizes Active-Semi’s proprietary high voltage process for operation with input voltages up to 15V. The ACT4050 provides fast transient response and eases loop stabilization while providing excellent line and load regulation. This device features a very low ON-resistance power MOSFET which provides peak operating efficiency up to 96%. In shutdown mode, the ACT4050 consumes only 12μA of supply current. This device also integrates protection features including cycle-by-cycle current limit, thermal shutdown and frequency fold-back at short circuit. The ACT4050 is available in a SOP-8/EP (Exposed Pad) package and requires very few external devices for operation. Stability with Wide Range of Capacitors, Including Low ESR Ceramic Capacitors • SOP-8/EP (Exposed Pad) Package APPLICATIONS • • • • • • Digital TV Portable DVDs Car-Powered or Battery-Powered Equipments Set-Top Boxes Telecom Power Supplies Consumer Electronics TYPICAL APPLICATION CIRCUIT Efficiency vs. Load Current 100 ACT4050-001 VIN = 7V 90 VIN = 12V Efficiency (%) 80 70 60 VOUT = 5V 0 500 1000 1500 2000 2500 3000 3500 50 Load Current (mA) Innovative PowerTM -1- www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi ORDERING INFORMATION PART NUMBER ACT4050YH ACT4050YH-T TEMPERATURE RANGE -40°C to 85°C -40°C to 85°C PACKAGE SOP-8/EP SOP-8/EP PINS 8 8 ACT4050 Rev 2, 01-Jul-11 PACKING TUBE TAPE & REEL PIN CONFIGURATION SOP-8/EP PIN DESCRIPTIONS PIN 1 2 3 4 5 6 7 8 EP NAME BS IN SW GND FB COMP EN N/C EP DESCRIPTION Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver. Connect a 10nF capacitor between BS and SW. Input Supply. Bypass this pin to GND with a low ESR capacitor. See Input Capacitor in the Application Information section. Switch Output. Connect this pin to the switching end of the inductor. Ground. Feedback Input. The voltage at this pin is regulated to 0.817V. Connect to the resistor divider between output and ground to set output voltage. Compensation Pin. See Stability Compensation in the Application Information section. Enable Input. When higher than 1.3V, this pin turns the IC on. When lower than 0.9V, this pin turns the IC off. Output voltage is discharged when the IC is off. When left unconnected, EN is pulled up to 4.5V typical with a 2µA pull-up current. Not Connected. Exposed Pad shown as dashed box. The exposed thermal pad should be connected to board ground plane and pin 4. The ground plane should include a large exposed copper pad under the package for thermal dissipation (see package outline). The leads and exposed pad should be flush with the board, without offset from the board surface. Innovative PowerTM -2- www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi ABSOLUTE MAXIMUM RATINGS PARAMETER IN Supply Voltage SW Voltage BS Voltage EN, FB Voltage Continuous SW Current Junction to Ambient Thermal Resistance (θJA) Maximum Power Dissipation Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) VALUE -0.3 to 15 ACT4050 Rev 2, 01-Jul-11 UNIT V V V V A °C/W W °C °C °C -1 to VIN + 1 VSW - 0.3 to VSW + 8 -0.3 to 6 Internally Limited 46 1.8 -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 (VIN = 12V, TA = 25°C, unless otherwise specified.) PARAMETER Input Voltage Feedback Voltage High-Side Switch On Resistance Low-Side Switch On Resistance SW Leakage High-Side Switch Peak Current Limit COMP to Current Limit Transconductance Error Amplifier Transconductance Error Amplifier DC Gain Switching Frequency Short Circuit Switching Frequency Maximum Duty Cycle Minimum On Time Minimum Duty Cycle Enable Threshold Voltage Enable Pull-Up Current Supply Current in Shutdown IC Supply Current in Operation Thermal Shutdown Temperature Innovative PowerTM SYMBOL VIN VFB RONH RONL TEST CONDITIONS VOUT = 3V, ILOAD = 0V to 1A 5V ≤ VIN ≤ 15V MIN 4.5 0.8 TYP MAX 15 UNIT V V Ω Ω 0.817 0.15 4.5 0.834 VEN = 0 ILIM GCOMP GEA AVEA fSW VFB = 0 DMAX Ton_Min VFB = 0.9V Hysteresis = 0.1V Pin pulled up to 4.5V typically when left unconnected VEN = 0 VEN = 3V, VFB = 0.9V Hysteresis = 10°C -3- 0 5.4 2.5 10 µA A A/V µA/V V/V Duty Cycle = 50% ΔICOMP = ±10µA 650 4000 350 400 60 95 400 0 0.8 1.1 2 12 0.5 160 20 1 1.4 450 kHz kHz % ns % V µA µA mA °C VFB = 0.7V www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi FUNCTIONAL BLOCK DIAGRAM ACT4050 Rev 2, 01-Jul-11 FUNCTIONAL DESCRIPTION As seen in Functional Block Diagram, the ACT4050 is a current mode pulse width modulation (PWM) converter. The converter operates as follows: A switching cycle starts when the rising edge of the Oscillator clock output causes the High-Side Power Switch to turn on and the Low-Side Power Switch to turn off. With the SW side of the inductor now connected to IN, the inductor current ramps up to store energy in the magnetic field. The inductor current level is measured by the Current Sense Amplifier and added to the Oscillator ramp signal. If the resulting summation is higher than the COMP voltage, the output of the PWM Comparator goes high. When this happens or when Oscillator clock output goes low, the High-Side Power Switch turns off and the Low-Side Power Switch turns on. At this point, the SW side of the inductor swings to a diode voltage below ground, causing the inductor current to decrease and magnetic energy to be transferred to output. This state continues until the cycle starts again. The High-Side Power Switch is driven by logic using BS as the positive rail. This pin is charged to VSW + 6V when the Low-Side Power Switch turns on. The COMP voltage is the integration of the error between FB input and the internal 0.817V reference. If FB is lower than the reference voltage, Innovative PowerTM COMP tends to go higher to increase current to the output. Current limit happens when COMP reaches its maximum clamp value of 2.15V. The Oscillator normally switches at 400kHz. However, if FB voltage is less than 0.7V, then the switching frequency decreases until it reaches a typical value of 60kHz at VFB = 0.5V. Shutdown Control The ACT4050 EN pin contains a precision 1.1V comparator with 100mV hysteresis, as well as a 2µA pull-up current source. This combination can be used to control the on/off operation of ACT4050 using several methods: 1) First, "always-on" operation can be enabled simply by floating the EN pin. Any time power is applied to VIN, the EN pull-up current source will bring the pin above 1.1V and enable the IC. In this case, under-voltage lockout will be controlled by an internal 4.2V comparator on VIN. 2) Second, an open-drain or open-collector logic device can be used to pull the EN pin low to provide digital ON/OFF control. When the logic pull-down is disabled, the internal 2µA pull-up current will bring the EN pin high and enable the chip. 3) Third, a known startup delay time can be created by adding a small capacitor from EN to GND in -4www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi addition to the open-drain or open-collector logic device. When the logic pull-down is disabled, the voltage at EN will ramp up at a rate determined by the 2µA EN pull-up current and the capacitor. Once the voltage at EN exceeds the 1.1V threshold, the device will be enabled. For the case of using multiple ACT4050, time-based output sequencing can be generated by placing different capacitors at each ACT4050 EN pin. The start up time delay can be calculated as a simple function of the EN capacitor using the equation: T (ms) = 0.55 × CEN (nF) Table 1: Enable Delay Time vs. EN Capacitor Value CAPACITOR VALUE 2.2nF 3.3nF 10nF DELAY TIME (ms) 1.2 1.9 5.5 ACT4050 Rev 2, 01-Jul-11 4) Fourth, by using the 1.1V precision comparator in the EN circuitry, "power-OK" type output sequencing can be generated. By connecting the EN pin of one ACT4050 to the output of another device, the ACT4050 will only start up once the second device's output has exceeded the 1.1V level. A resistor divider can be used to adjust the ACT4050 startup to any point on the second device's output range. 5) Finally, the EN comparator can be used for "Line UVLO" to prevent the ACT4050 from starting up before the input voltage is high enough to support the output. By using a resistor divider from VIN to GND (center tap = 1.1V EN threshold), the device can be enabled and disabled based on the voltage at VIN. Since the internal UVLO voltage is 4.2V, Line UVLO is recommended for outputs above this 4.2V level to ensure clean startup. For the example of a 5V output, it is desirable to prevent IC startup until VIN has exceeded the 5V level. To start the IC at 6V input, we place a 10kΩ/47kΩ resistor divider from VIN to EN to GND, which enables the IC at VIN greater than 6.3V and disables the IC when VIN decreases below 5.2V. Thermal Shutdown The ACT4050 automatically turns off when its junction temperature exceeds 160°C and automatically turns on again when the junction temperature falls below 140°C . Innovative PowerTM -5www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi APPLICATIONS INFORMATION Output Voltage Setting Figure 1: Output Voltage Setting VOUT ACT4050 FB RFB2 RFB1 ACT4050 Rev 2, 01-Jul-11 LLIM is the internal current limit, as shown in Electrical Characteristics Table. Input Capacitor The input capacitor needs to be carefully selected to maintain sufficiently low ripple at the supply input of the converter. A low ESR capacitor is highly recommended. Since large current flows in and out of this capacitor during switching, its ESR also affects efficiency. The input capacitance needs to be higher than 10µF. The best choice is the ceramic type, however, low ESR tantalum or electrolytic types may also be used provided that the RMS ripple current rating is higher than 50% of the output current. The input capacitor should be placed close to the IN and G pins of the IC, with the shortest traces possible. In the case of tantalum or electrolytic types, they can be further away if a small parallel 0.1µF ceramic capacitor is placed right next to the IC. Figure 1 shows the connections for setting output voltage. Select the proper ratio of the feedback resistors RFB1 and RFB2 based on output voltage. Typically, use RFB2 ≈ 10kΩ determine RFB1 from the following equation: ⎞ ⎛ VOUT R FB 1 = R FB 2 ⎜ − 1⎟ 0 . 817 V ⎠ ⎝ the two the and (1) Note: To achieve best performance with 12V input application, we recommend to use output voltage greater than 1.4V. Inductor Selection The inductor maintains a continuous current to the output load. This inductor current has a ripple that is dependent on the inductance value: higher inductance reduces the peak-to-peak ripple current. The trade off for high inductance value is the increase in inductor core size and series resistance, and the reduction in current handling capability. In general, select an inductance value L based on ripple current requirement: Output Capacitor The output capacitor also needs to have low ESR to keep low output voltage ripple. The output ripple voltage is: VRIPPLE = IOUTMAX K RIPPLE RESR + VIN 28 × f SW LC OUT 2 (6) L= VOUT × (VIN − VOUT ) VIN fSW IOUTMAX K RIPPLE (2) where VIN is the input voltage, VOUT is the output voltage, fSW is the switching frequency, IOUTMAX is the maximum output current, and KRIPPLE is the ripple factor. Typically, choose KRIPPLE = 30% to correspond to the peak-to-peak ripple current being 30% of the maximum output current. With a selected inductor value the peak-to-peak inductor current is estimated as: I LPK - PK where IOUTMAX is the maximum output current, KRIPPLE is the ripple factor, RESR is the ESR of the output capacitor, fSW is the switching frequency, L is the inductor value, and COUT is the output capacitance. In the case of ceramic output capacitors, RESR is very small and does not contribute to the ripple. Therefore, a lower capacitance value can be used for ceramic type. In the case of tantalum or electrolytic capacitors, the ripple is dominated by RESR multiplied by the ripple current. In that case, the output capacitor is chosen to have sufficiently low ESR. For ceramic output capacitor, typically choose a capacitance of about 22µF. For tantalum or electrolytic capacitors, choose a capacitor with less than 50mΩ ESR. = V OUT × ( IN - V OUT V L × V IN × fSW ) (3) The peak inductor current is estimated as: I LPK = I LOADMAX + 1 I 2 LPK - PK Rectifier Diode (4) Use a Schottky diode as the rectifier to conduct current when the High-Side Power Switch is off. The Schottky diode must have current rating higher than the maximum output current and a reverse voltage rating higher than the maximum input voltage. The selected inductor should not saturate at ILPK. The maximum output current is calculated as: I OUTMAX = I LIM 1 I 2 LPK - PK (5) -6www.active-semi.com Copyright © 2011 Active-Semi, Inc. Innovative PowerTM Active-Semi STABILITY COMPENSATION Figure 2: Stability Compensation ACT4050 Rev 2, 01-Jul-11 STEP 2. Set the zero fZ1 at 1/4 of the cross over frequency. If RCOMP is less than 15kΩ, the equation for CCOMP is: CCOMP = COMP 1.6 × 10 −5 RCOMP (F) (13) ACT4050 CCOMP CCOMP2 RCOMP If RCOMP is limited to 15kΩ, then the actual cross over frequency is 3.4 / (VOUTCOUT). Therefore: CCOMP = 1.2 ×10 −5 VOUT COUT (F) (14) : CCOMP2 is needed only for high ESR output capacitor The feedback loop of the IC is stabilized by the components at the COMP pin, as shown in Figure 2. The DC loop gain of the system is determined by the following equation: STEP 3. If the output capacitor’s ESR is high enough to cause a zero at lower than 4 times the cross over frequency, an additional compensation capacitor CCOMP2 is required. The condition for using CCOMP2 is: ⎛ 1 .1 × 10 −6 R ESRCOUT ≥ Min ⎜ ,0 .012 × VOUT ⎜C OUT ⎝ And the proper value for CCOMP2 is: ⎞ ⎟ (Ω) (15) ⎟ ⎠ AVDC = 0 . 82 V AVEA G COMP I OUT (7) The dominant pole P1 is due to CCOMP: G EA fP1 = 2 π AVEA C COMP The second pole P2 is the output pole: fP 2 = I OUT 2 π V OUT C OUT CCOMP 2 = (8) COUT RESRCOUT RCOMP (16) Though CCOMP2 is unnecessary when the output capacitor has sufficiently low ESR, a small value CCOMP2 such as 100pF may improve stability against PCB layout parasitic effects. Table 3 shows some calculated results based on the compensation method above. Table 2: (9) The first zero Z1 is due to RCOMP and CCOMP: fZ1 = 1 2 π R COMP C COMP (10) Typical Compensation for Different Output Voltages and Output Capacitors VOUT COUT RCOMP CCOMP CCOMP2 And finally, the third pole is due to RCOMP and CCOMP2 (if CCOMP2 is used): fP 3 = 1 2πR COMP C COMP2 2.5V 3.3V 5V 2.5V 3.3V 5V 2.5V 3.3V 5V 2x22μF Ceramic 2x22μF Ceramic 2x22μF Ceramic 47μF SP CAP 47μF SP CAP 47μF SP CAP 470μF/6.3V/30mΩ 470μF/6.3V/30mΩ 470μF/6.3V/30mΩ 8.2kΩ 12kΩ 15kΩ 15kΩ 15kΩ 15kΩ 15kΩ 15kΩ 15kΩ 2.2nF 1.5nF 1.5nF 1.5nF 1.8nF 2.7nF 15nF 22nF 27nF None None None None None None 1nF 1nF None (11) The following steps should be used to compensate the IC: STEP 1. Set the cross over frequency at 1/10 of the switching frequency via RCOMP: R COMP 2 π VOUT C OUT fSW = 10 G EA GCOMP × 0 .82 V (Ω) (12) : CCOMP2 is needed for high ESR output capacitor. Figure 3 shows an example ACT4050 application circuit generating a 2.5V/3.5A output. = 1 . 88 × 10 8 V OUT C OUT but limit RCOMP to 15kΩ maximum. Innovative PowerTM -7- www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi Figure 3: ACT4050 1.8V/3.5A Output Application ACT4050 Rev 2, 01-Jul-11 : D1 is a 30V, 5A Schottky diode with low forward voltage, a B530C equivalent. C4 can be either a ceramic capacitor (Panasonic ECJ-3YB1C226M) or SP-CAP (Specialty Polymer) Aluminum Electrolytic Capacitor such as Panasonic EEFCD0J470XR. The SP-Cap is based on aluminum electrolytic capacitor technology, but uses a solid polymer electrolyte and has very stable capacitance characteristics in both operating temperature and frequency compared to ceramic, polymer, and low ESR tantalum capacitors. Table 3: ACT4050EV Bill of Materials (Apply for 1.8V Output Application) ITEM DESCRIPTION MANUFACTURER QTY REFERENCE 1 2 3 4 5 6 7 8 9 10 11 IC, ACT4050 Resistor, 12.1kΩ , 1%, SMT, 0603 Resistor, 10kΩ, 1%, SMT, 0603 Resistor, 10kΩ, 5%, SMT, 0603 Capacitor, Ceramic, 10µF/35V, X7R, SMT, 1206 Active-Semi FengHua, Neohm, Yageo FengHua, Neohm, Yageo FengHua, Neohm, Yageo Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden 1 1 1 1 1 2 1 1 1 1 1 U1 R1 R2 R3 C1 C4 C3 C2 C5 (OPTIONAL) D1 L1 Capacitor, Ceramic, 22µF/6.3V, X7R, SMT, Panasonic, Kemet, Murata, 1206 TDK, FengHua, Taiyo Yuden Capacitor, Ceramic, 10nF/50V, X7R, SMT, 0603 Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Capacitor, Ceramic, 2.7nF/6.3V, X7R, SMT, Panasonic, Kemet, Murata, 0603 TDK, FengHua, Taiyo Yuden Capacitor, Ceramic, 220pF/6.3V, X7R, SMT, 0603 Schottky Diode SK53/30V, 5A, SMC Inductor, CDRH8D43-6R8NC, 6.8µH Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Diodes Sumida Innovative PowerTM -8- www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi Figure 4: ACT4050 3.3V/3.5A Output Application ACT4050 Rev 2, 01-Jul-11 : D1 is a 30V, 5A Schottky diode with low forward voltage, a B530C equivalent. C4 can be either a ceramic capacitor (Panasonic ECJ-3YB1C226M) or SP-CAP (Specialty Polymer) Aluminum Electrolytic Capacitor such as Panasonic EEFCD0J470XR. The SP-Cap is based on aluminum electrolytic capacitor technology, but uses a solid polymer electrolyte and has very stable capacitance characteristics in both operating temperature and frequency compared to ceramic, polymer, and low ESR tantalum capacitors. Table 4: ACT4050EV Bill of Materials (Apply for 3.3V Output Application) ITEM DESCRIPTION MANUFACTURER QTY REFERENCE 1 2 3 4 5 6 7 8 9 10 11 IC, ACT4050 Resistor, 30.5kΩ , 1%, SMT, 0603 Resistor, 10kΩ, 1%, SMT, 0603 Resistor, 12kΩ, 5%, SMT, 0603 Capacitor, Ceramic, 10µF/35V, X7R, SMT, 1206 Capacitor, Ceramic, 22µF/6.3V, X7R, SMT, 1206 Capacitor, Ceramic, 10nF/50V, X7R, SMT, 0603 Capacitor, Ceramic, 1.5nF/6.3V, X7R, SMT, 0603 Capacitor, Ceramic, 220pF/6.3V, X7R, SMT, 0603 Schottky Diode SK53/30V, 5A, SMC Inductor, CDRH8D43-100NC, 10µH Active-Semi FengHua, Neohm, Yageo FengHua, Neohm, Yageo FengHua, Neohm, Yageo Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Diodes Sumida 1 1 1 1 1 2 1 1 1 1 1 U1 R1 R2 R3 C1 C4 C3 C2 C5 (OPTIONAL) D1 L1 Innovative PowerTM -9- www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi Figure 5: ACT4050 5V/3A Output Application ACT4050 Rev 2, 01-Jul-11 : D1 is a 30V, 5A Schottky diode with low forward voltage, a B530C equivalent. C4 can be either a ceramic capacitor (Panasonic ECJ-3YB1C226M) or SP-CAP (Specialty Polymer) Aluminum Electrolytic Capacitor such as Panasonic EEFCD0J470XR. The SP-Cap is based on aluminum electrolytic capacitor technology, but uses a solid polymer electrolyte and has very stable capacitance characteristics in both operating temperature and frequency compared to ceramic, polymer, and low ESR tantalum capacitors. Table 5: ACT4050EV Bill of Materials (Apply for 5V Output Application) ITEM DESCRIPTION MANUFACTURER QTY REFERENCE 1 2 3 4 5 6 7 8 9 10 11 IC, ACT4050 Resistor, 51kΩ , 1%, SMT, 0603 Resistor, 10kΩ, 1%, SMT, 0603 Resistor, 15kΩ, 5%, SMT, 0603 Capacitor, Ceramic, 10µF/35V, X7R, SMT, 1206 Capacitor, Ceramic, 22µF/6.3V, X7R, SMT, 1206 Capacitor, Ceramic, 10nF/50V, X7R, SMT, 0603 Capacitor, Ceramic, 1.5nF/6.3V, X7R, SMT, 0603 Capacitor, Ceramic, 220pF/6.3V, X7R, SMT, 0603 Schottky Diode SK53/30V, 5A, SMC Inductor, CDRH8D43-100NC, 10µH Active-Semi FengHua, Neohm, Yageo FengHua, Neohm, Yageo FengHua, Neohm, Yageo Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Panasonic, Kemet, Murata, TDK, FengHua, Taiyo Yuden Diodes Sumida 1 1 1 1 1 2 1 1 1 1 1 U1 R1 R2 R3 C1 C4 C3 C2 C5 (OPTIONAL) D1 L1 Innovative PowerTM - 10 - www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 5, unless otherwise specified.) ACT4050 Rev 2, 01-Jul-11 Efficiency vs. Load Current 100 VIN = 5V 90 100 ACT4050-001 Efficiency vs. Load Current ACT4050-002 VIN = 7V 90 VIN = 12V Efficiency (%) VIN = 7V 80 VIN = 12V Efficiency (%) VOUT = 3.3V 80 70 70 60 60 VOUT = 5V 0 500 1000 1500 2000 2500 3000 3500 50 0 500 1000 1500 2000 2500 3000 3500 50 Load Current (mA) Load Current (mA) Shutdown Current vs. Input Voltage Inductor Peak Current Limit (mA) 25 6000 5500 5000 4500 4000 3500 3000 2500 2000 0 ACT4050-003 Inductor Peak Current Limit vs. Duty Cycle ACT4050-004 Shutdown Current (µA) 20 15 10 5 0 4 6 8 10 12 14 20 40 60 80 100 Input Voltage (V) Duty Cycle (% ) Switching Frequency vs. Temperature 490 0.85 0.84 ACT4050-005 460 430 400 370 340 310 280 250 -40 Feedback Voltage vs. Temperature ACT4050-006 Switching Frequency (MHz) Feedback Voltage (V) 0.83 0.82 0.81 0.80 0.79 0.78 0.77 0.76 0.75 0 40 80 130 -40 0 40 80 130 Temperature (°C) Temperature (°C) Innovative PowerTM - 11 - www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi TYPICAL PERFORMANCE CHARACTERISTICS CONT’D (Circuit of Figure 5, unless otherwise specified.) ACT4050 Rev 2, 01-Jul-11 Start-up/Shutdown by VIN Pin ACT4050-007 Start-up/Shutdown by VIN Pin ACT4050-008 CH1 CH1 CH2 VIN = 12V VOUT = 5V No Load CH1: VIN, 5.0V/div CH2: VOUT, 2V/div TIME: 100µs/div CH2 VIN = 12V VOUT = 5V 1Ω Load CH1: VIN, 5.0V/div CH2: VOUT, 2V/div TIME: 100µs/div VIN = 12V VOUT = 5V ILOAD = 1A Start-up/Shutdown by EN Pin ACT4050-009 Start-up/Shutdown by EN Pin ACT4050-010 CH1 CH1 CH2 CH2 VIN = 12V VOUT = 5V No Load CH1: VEN, 2.0V/div CH2: VOUT, 2.0V/div TIME: 400µs/div VIN = 12V VOUT = 5V 2Ω Load CH1: VEN, 2.0V/div CH2: VOUT, 2.0V/div TIME: 200µs/div Switching Waveform ACT4050-011 Switching Waveform ACT4050-012 CH1 CH1 VIN = 12V VOUT = 5V ILOAD = 1A CH2 CH2 VIN = 12V VOUT = 3.3V ILOAD = 1A CH1: VOUT, 20mV/div (AC COUPLED) CH2: VSW, 5.0V/div TIME: 1µs/div CH1: VOUT, 20mV/div (AC COUPLED) CH2: VSW, 5.0V/div TIME: 1µs/div Innovative PowerTM - 12 - www.active-semi.com Copyright © 2011 Active-Semi, Inc. Active-Semi PACKAGE OUTLINE SOP-8/EP PACKAGE OUTLINE AND DIMENSIONS E SYMBOL ACT4050 Rev 2, 01-Jul-11 DIMENSION IN MILLIMETERS MIN MAX DIMENSION IN INCHES MIN MAX D1 A D 1.350 0.000 1.350 0.330 0.170 4.700 3.202 3.800 5.800 2.313 0.400 0° 1.700 0.100 1.550 0.510 0.250 5.100 3.402 4.000 6.200 2.513 1.270 8° 0.053 0.000 0.053 0.013 0.007 0.185 0.126 0.150 0.228 0.091 0.016 0° 0.067 0.004 0.061 0.020 0.010 0.200 0.134 0.157 0.244 0.099 0.050 8° A1 A2 b E2 E1 θ ? c b e A1 L A2 A c D D1 E E1 E2 e L θ 1.270 TYP 0.050 TYP 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. ® is a registered trademark of Active-Semi. - 13 www.active-semi.com Copyright © 2011 Active-Semi, Inc. Innovative PowerTM