ACT4060A ACTIVE-SEMI | Alldatasheet
Document overview
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Technical content
Innovative PowerTM - 1 - www.active-semi.com Copyright © 2009 Active-Semi, Inc.
FEATURES
- 2A Output Current
- Up to 96% Efficiency
- 4.5V to 24V Input Range
- 10µA Shutdown Supply Current
- 400kHz Switching Frequency
- Adjustable Output Voltage
- Cycle-by-Cycle Current Limit Protection
- Thermal Shutdown Protection
- Frequency FoldBack at Short Circuit
- Stability with Wide Range of Capacitors, Including Low ESR Ceramic Capacitors
- SOP-8 Package
APPLICATIONS
- TFT LCD Monitors
- Portable DVDs
- Car-Powered or Battery-Powered Equipments
- Set-Top Boxes
- Telecom Power Supplies
- DSL and Cable Modems and Routers
- Termination Supplies GENERAL DESCRIPTION The ACT4060A is a current-mode step-down DC/DC converter that provides up to 2A of output current at 400kHz switching frequency. The device utilizes Active-Semi’s proprietary high voltage proc- ess for operation with input voltages up to 24V. The ACT4060A provides fast transient response and eases loop stabilization while providing excel- lent line and load regulation. This device features a very low ON-resistance power MOSFET which pro- vides peak operating efficiency up to 96%. In shut- down mode, the ACT4060A consumes only 10μA of supply current. This device also integrates protection features in- cluding cycle-by-cycle current limit, thermal shut- down and frequency fold-back at short circuit. The ACT4060A is available in a SOP-8 package and requires very few external devices for opera- tion. TYPICAL APPLICATION CIRCUIT ACT4060A Rev 0, 28-Apr-09 Wide Input 2A Step Down Converter ACT4060A BS IN EN COMP FB SW G ENABLE Up to 24V 2.5V/2A
Rev 0, 28-Apr-09 Innovative PowerTM - 2 - www.active-semi.com Copyright © 2009 Active-Semi, Inc.
ORDERING INFORMATION
PART NUMBER TEMPERATURE RANGE PACKAGE PINS PACKING ACT4060ASH -40°C to 85°C SOP-8 8 TUBE ACT4060ASH-T -40°C to 85°C SOP-8 8 TAPE & REEL PIN DESCRIPTIONS PIN NAME DESCRIPTION 1 BS Bootstrap. This pin acts as the positive rail for the high-side switch’s gate driver. Connect a 10nF capacitor between BS and SW. 2 IN Input Supply. Bypass this pin to G with a low ESR capacitor. See Input Capacitor in the Application Information section. 3 SW Switch Output. Connect this pin to the switching end of the inductor. 4 G Ground. 5 FB Feedback Input. The voltage at this pin is regulated to 1.293V. Connect to the resistor divider between output and ground to set output voltage. 6 COMP Compensation Pin. See Stability Compensation in the Application Information section. 7 EN Enable Input. When higher than 1.3V, this pin turns the IC on. When lower than 0.7V, 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 with a 2µA pull-up current. 8 N/C Not Connected. PIN CONFIGURATION SOP-8
Rev 0, 28-Apr-09 Innovative PowerTM - 3 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. ABSOLUTE MAXIMUM RATINGSc PARAMETER VALUE UNIT IN Supply Voltage -0.3 to 28 V SW Voltage -1 to VIN + 1 V BS Voltage V SW - 0.3 to VSW + 8 V EN, FB, COMP Voltage -0.3 to 6 V Continuous SW Current Internally Limited A Junction to Ambient Thermal Resistance (θ JA) 105 °C/W Maximum Power Dissipation 0.76 W Operating Junction Temperature -40 to 150 °C Storage Temperature -55 to 150 °C Lead Temperature (Soldering, 10 sec) 300 °C
ELECTRICAL CHARACTERISTICS
(VIN = 12V, TA = 25°C, unless otherwise specified.) PARAMETER SYMBOL TEST COND ITIONS MIN TYP MAX UNIT Input Voltage V IN V OUT = 3.3V, ILOAD = 0A to 1A 4.5 24 V High-Side Switch On Resistance R ONH 0.18 Ω Low-Side Switch On Resistance R ONL 4.5 Ω SW Leakage V EN = 0 0 10 µA Current Limit I LIM 2.4 2.85 A COMP to Current Limit Transconductance GCOMP V IN = 12V, VOUT = 5V 1.8 A/V Error Amplifier Transconductance G EA ΔICOMP = ±10µA 650 µA/V Error Amplifier DC Gain A VEA 4000 V/V Switching Frequency f SW 350 400 450 kHz Short Circuit Switching Frequency V FB = 0 60 kHz Maximum Duty Cycle D MAX V FB = 1.1V 95 % Minimum Duty Cycle V FB = 1.4V 0 % Enable Threshold Voltage Hy steresis = 0.1V 0.7 1 1.3 V Enable Pull-Up Current Pin pulled up to 4.5V typically when left unconnected 2 µA Supply Current in Shutdown V EN = 0 10 20 µA IC Supply Current in Operation V EN = 3V, VFB = 1.4V 0.55 mA Thermal Shutdown Temperature Hysteresis = 10°C 160 °C c: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rati ng conditions for long periods m ay affect device reliability.
Rev 0, 28-Apr-09 Innovative PowerTM - 4 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. FUNCTIONAL BLOCK DIAGRAM FUNCTIONAL DESCRIPTION As seen in Functional Block Diagram , the AC- T4060A is a current mode pulse width modulation (PWM) converter. The converter operates as fol- lows: A switching cycle starts when the rising edge of the Oscillator clock output caus es 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 con- nected to IN, the inductor current ramps up to store energy in the magnetic fiel d. The inductor current level is measured by the Current Sense Amplifier and added to the Oscillator ramp signal. If the re- sulting 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 volt- age below ground, causing the inductor current to decrease and magnetic energy to be transferred to output. This state continue s 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 V SW + 6V when the Low-Side Power Switch turns on. The COMP voltage is the integration of the error between FB input and the internal 1.293V refer- ence. If FB is lower than the reference voltage, COMP tends to go higher to increase current to the output. Current limit happens when COMP reaches its maximum clamp value of 2.55V. The Oscillator normally sw itches at 400kHz. How- ever, if FB voltage is less than 0.7V, then the switching frequency decreases until it reaches a typical value of 60kHz at V FB = 0.5V. Shutdown Control The ACT4060A has an enable input EN for turning the IC on or off. When EN is less than 0.7V, the IC is in 10μA low current shutdown mode and output is discharged through the Low-Side Power Switch. When EN is higher than 1.3V, the IC is in normal operation mode. EN is internally pulled up with a 2μA current source and can be left unconnected for always-on operation. Note that EN is a low voltage input with a maximum voltage of 6V, it should never be directly connected to IN. Thermal Shutdown The ACT4060A automatically turns off when its junction temperature exceeds 160°C. IN EN COMP FB BS SW LOGIC THERMAL SHUTDOWN REGULATOR REFERENCE OSCILLATOR RAMP FOLDBACK CONTROL 1.293V ERROR AMPLIFIER ENABLE 0.18Ω HIGH-SIDE POWER SWITCH G + - + - PWM COMP CURRENT SENSE AMPLIFIER 4.5Ω LOW-SIDE POWER SWITCH
Rev 0, 28-Apr-09 Innovative PowerTM - 7 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. Figure 3: ACT4060A 3.3V/2A Output Applicationc c: D1 is a 40V, 3A Schottky diode with low forward voltage, an IR 30BQ040 or SK34 equivalent. C4 can be either a ceramic capacit or (Panasonic ECJ-3YB1C226M) or SP-CAP (Specialty Polymer) Aluminum Electrol ytic Capacitor such as Panasonic EEFCD0J470XR. The SP-Cap is based on aluminum el ectrolytic capacitor technology, but uses a solid polymer electrolyte and has very stable cap aci- tance characteristics in both operating temperature and frequency compared to ceramic, polymer, and low ESR tantalum capacitors. IC1 ACT4060A BS IN EN COMP FB SW G ENABLE Up to 24V VIN VOUT D1 C4 R2 (OPTIONAL)R3 ITEM DESCRIPTION MANUFACTURER QTY REFERENCE
1 IC, ACT4060A Active-Semi 1 U1
15µH ± 20%, ISAT = 2.7A, IDC = 2.4A@ ΔT = 40°C Taiyo Yuden NR 8040T 150M 1 L1 15µH ± 10%, ISAT = 2.88A, IDC = 2.47A@ ΔT = 40°C Wurth Electronik 744776115 10µH ± 20%, ISAT = 3.4A, IDC = 2.5A@ΔT = 40°C Taiyo Yuden NR 6045T 100M 10µH ± 10%, ISAT = 2.95A, IDC = 2.3A@ ΔT = 40°C Wurth Electronik 74477510 Schottky Diode SK34/40V, 3A, SMB Transys electronics 1 Schottky Diode B340C/40V, 3A, SMB Diodes Inc 1
4 Ceramic cap 10µF/35V, X7R, 1210 Murata, TDK,Taiyo Yuden 1 C1
5 Ceramic cap 2.2nF/6.3V, X7R, 0603 Murata, TDK,Taiyo Yuden 1 C2
6 Ceramic cap 10nF/50V, X7R, 0603 Murata, TDK,Taiyo Yuden 1 C3
Ceramic cap 22µF/10V, X7R, 1210 Murata, TDK,Taiyo Yuden 1 C4 SP cap 47µF/6.3V, 50mΩ Kemet, Panasonic 8 Ceramic cap 220pF/6.3V, X7R, 0603 Mu rata, TDK,Taiyo Yuden 1 C5 (OPTIONAL) 9 Resistor, 15.5k Ω, 1/16W, 1%, 0603 FengHua, Neohm, Yageo
10 Resistor, 10k Ω, 1/16W, 1%, 0603 R2
11 Resistor, 12k Ω, 1/16W, 5%, 0603 R3
Table 3: ACT4060A Bill of Materials (Apply for 3.3V Output Application)
Rev 0, 28-Apr-09 Innovative PowerTM - 8 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. Figure 4: ACT4060A 5V/2A Output Applicationc c: D1 is a 40V, 3A Schottky diode with low forward voltage, an IR 30BQ040 or SK34 equivalent. C4 can be either a ceramic capacit or (Panasonic ECJ-3YB1C226M) or SP-CAP (Specialty Polymer) Aluminum Electrol ytic Capacitor such as Panasonic EEFCD0J470XR. The SP-Cap is based on aluminum el ectrolytic capacitor technology, but uses a solid polymer electrolyte and has very stable cap aci- tance characteristics in both operating temperature and frequency compared to ceramic, polymer, and low ESR tantalum capacitors. IC1 ACT4060A BS IN EN COMP FB SW G ENABLE Up to 24V VIN VOUT D1 C4 R2 (OPTIONAL)R3 ITEM DESCRIPTION MANUFACTURER QTY REFERENCE 15µH ± 20%, ISAT =2.7A, IDC = 2.4A@ ΔT = 40°C Taiyo Yuden NR 8040T 150M 1 L1 15µH ± 10%, ISAT = 2.88A, IDC = 2.47A@ ΔT = 40°C Wurth Electronik 744776115 Schottky Diode SK34/40V, 3A, SMB Transys electronics 1 D1 Schottky Diode B340C/40V, 3A, SMB Diodes Inc
4 Ceramic cap 10µF/35V, X7R, 1210 Murata, TDK, Taiyo Yuden 1 C1
5 Ceramic cap 2.2nF/6.3V, X7R, 0603 Murata, TDK, Taiyo Yuden 1 C2
6 Ceramic cap 10nF/50V, X7R, 0603 Murata, TDK, Taiyo Yuden 1 C3
Ceramic cap 22µF/10V, X7R, 1210 Murata, TDK, Taiyo Yuden 1 C4 SP cap 47µF/6.3V, 50mΩ Kemet, Panasonic 8 Ceramic cap 220pF/6.3V, X7R, 0603 Mura ta, TDK, Taiyo Yuden 1 C5 (OPTIONAL) 9 Resistor, 28.7k Ω, 1/16W, 1%, 0603 FengHua, Neohm, Yageo
11 Resistor, 15k Ω, 1/16W, 5%, 0603 R3
Table 4: ACT4060A Bill of Materials (Apply for 5V Output Application)
Rev 0, 28-Apr-09 Innovative PowerTM - 9 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. TYPICAL PERFORMANCE CHARACTERISTICS (Circuit of Figure 3, unless otherwise specified.) Efficiency vs. Output Current Efficiency (%) 100 Output Current (mA) ACT4060A-001 100 1000 10000 VOUT = 2.5V VIN = 12V Efficiency vs. Output Current ACT4060A-002 VOUT = 5V Output Current (mA) 100 1000 10000 VIN = 7V VIN = 12V Input Voltage (V) Switching Frequency (kHz) ACT4060A-005 Switching Frequency vs. Input Voltage 405 390 385 395 400 VOUT = 2.5V IOUT = 1A 410 Temperature (°C) Feedback Voltage (V) ACT4060A-006 -50 0 50 Feedback Voltage vs. Temperature 150 1.25 1.29 100 1.33 1.27 1.31 380 Efficiency (%) 100 8 4 6 10 12 14 16 18 20 VIN = 7V ACT4060A-004 Maximum Output Current vs. Duty Cycle Maximum Output Current (mA) 3000 4000 1000 2000 Duty Cycle (% ) 20 0 40 80 100 60 5000 ACT4060A-003 Efficiency vs. Output Current Efficiency (%) 100 VIN = 5V VOUT = 3.3V VIN = 12V Output Current (mA) 10 100 1000 10000
Rev 0, 28-Apr-09 Innovative PowerTM - 10 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. TYPICAL PERFORMANCE CHARACTERISTICS CONT’D (Circuit of Figure 3, unless otherwise specified.) ACT4060A-007 Shutdown Current vs. Input Voltage Input Voltage (V) Shutdown Current (µA) 5 10 5 15 20 25
Rev 0, 28-Apr-09 Innovative PowerTM - 11 - www.active-semi.com Copyright © 2009 Active-Semi, Inc. PACKAGE OUTLINE SOP-8 PACKAGE OUTLINE AND DIMENSIONS SYMBOL DIMENSION IN MILLIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 1.350 1.750 0.053 0.069 A1 0.100 0.250 0.004 0.010 A2 1.350 1.550 0.053 0.061 B 0.330 0.510 0.013 0.020 C 0.190 0.250 0.007 0.010 D 4.700 5.100 0.185 0.201 E 3.800 4.000 0.150 0.157 E1 5.800 6.300 0.228 0.248 e 1.270 TYP 0.050 TYP L 0.400 1.270 0.016 0.050 θ 0° 8° 0° 8° θ C D B e Active-Semi, Inc. reserves the right to modify the circuitry or spec ifications without notice. Users should evaluate each produ ct to make sure that it is suitable for their applications. Active-Semi pr oducts are not intended or authorized for use as critical compon ents in life- support devices or systems. Active-Semi, Inc. does not assume an y liability arising out of the use of any product or circuit de scribed 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: