ACT6390

ACT6390_14 ACTIVE-SEMI | Alldatasheet

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Innovative PowerTM - 1 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. SIMPLIFIED APPLICATION CIRCUIT ACT6390/ACT6391 1.7A/2.5A PWM Step-Up DC/DC Converters In MSOP

FEATURES

• Greater than 90% Efficiency
• Adjustable Output Voltage Up to 12V
• Internal 14V Power MOSFET
• Two Peak Current Options: − ACT6390: 1.7A, 0.2Ω − ACT6391: 2.5A, 0.15Ω
• Selectable 700kHz/1.3MHz Frequency
• Integrated Over-Voltage Protection (OVP)
• Programmable Soft-Start Function
• Thermal Shutdown
• Cycle-by-Cycle Over-Current Protection
• Small MSOP-8 Package

APPLICATIONS

• TFT LCD Monitors
• Battery-Powered Equipment
• Set-Top Boxes
• DSL and Cable Modems and Routers GENERAL DESCRIPTION The ACT6390/ACT6391 are high-performance, fixed-frequency, current-mode PWM step-up DC/DC converters that incorporate internal power MOSFETs. The ACT6390 includes an integrated 0.2Ω power MOSFET that supports peak currents of up to 1.7A, while the ACT6391’s integrated 0.15Ω power MOSFET supports currents of up to 2.5A. The ACT6390 and ACT6391 both utilize simple ex- ternal loop compensation and a pin-selectable fixed-frequency of either 700kHz or 1.3MHz, allow- ing optimization between component size, cost, and AC performance across a wide range of applica- tions. Additional functions include an externally pro- grammable soft-start function for easy inrush cur- rent control, internal over-voltage protection (OVP), cycle-by-cycle current limit protection, and thermal shutdown. Both the ACT6390 and the ACT6391 are available in the small 8-pin MSOP-8 package. Rev 1, 22-Aug-13 ACT6390 ACT6391 IN SW FB G VIN VOUT EN FREQ SS COMP 2.7V to 5.5V OFF 1.3MHz 700kHz ON

Rev 1, 22-Aug-13 Innovative PowerTM - 2 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. PIN NAME DESCRIPTION 1 COMP Error Amplifier Compensation Node. Connect to a resistor RC and capacitor CC in series to ground. 2 FB Feedback Input. Connect this pin a resistor divider from the output to set the output voltage. FB is regulated to 1.24V. 3 EN Enable Control. Connect to a logic high level to enable the IC. Connect to a logic low level to disable the IC. When unused, connect EN pin to IN (do not leave pin floating). 4 G Ground. 5 SW Switch Output. Connect this pin to the inductor and the schottky diode. To minimize EMI, mini- mize the PCB trace path between this pin and the input bypass capacitor. 6 IN Supply Input. Bypass to G with a 1µF or larger capacitor. 7 FREQ Frequency Setting Pin. A logic low sets the switching frequency at 700kHz. A logic high sets the switching frequency at 1.3MHz. This pin has an internal 5.5μA pull-down current. 8 SS Soft Start Control Input. Connect a capacitor from this pin to G to set soft-start timing duration (tSS = 2.2 x 105 x CSS). SS is discharged to ground in shutdown. SS may be left unconnected if soft start is not desired. PIN CONFIGURATION PIN DESCRIPTIONS

ORDERING INFORMATION

ACT6390MH-T 1.7A TAPE & REEL ACT6391MH-T 2.5A TAPE & REEL TEMPERATURE RANGE -40°C to 85°C -40°C to 85°C PACKAGE MSOP-8 MSOP-8 PINS COMP FB G SS IN SW EN FREQACT6390 ACT6391

Rev 1, 22-Aug-13 Innovative PowerTM - 3 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. ABSOLUTE MAXIMUM RATINGSc PARAMETER VALUE UNIT SW to G -0.3 to 14 V IN, EN, FB, FREQ, COMP to G -0.3 to 6 V SS to G -0.3 to VIN + 0.3 V Continuous SW Current A Junction to Ambient Thermal Resistance (θJA) 200 °C/W Maximum Power Dissipation 0.5 W Operating Junction Temperature -40 to 150 °C Storage Temperature -55 to 150 °C Lead Temperature (Soldering, 10 sec) 300 °C Internally Limited 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 1, 22-Aug-13 Innovative PowerTM - 4 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. (VIN = VEN = 3V, VFREQ = 0V, TA = 25°C, unless otherwise specified.)

ELECTRICAL CHARACTERISTICS

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Switch Voltage Rating 12 V Input Voltage 2.7 5.5 V Under Voltage Lockout Threshold V IN Rising 2.2 2.35 2.5 V Under Voltage Lockout Hysteresis 65 mV Quiescent Supply Current VFB = 1.3V, Not Switching 0.2 0.35 mA VFB = 1.0V, Switching ACT6390 1 4 ACT6391 1.4 4 Supply Current in Shutdown EN = G 0.1 10 µA Switching Frequency FREQ = G 490 700 910 kHz FREQ = IN 900 1300 1700 kHz Maximum Duty Cycle FREQ = G 80 86 92 FREQ = IN 86 FB Feedback Voltage 1.22 1.24 1.26 V FB Input Current V FB = 1.27V 0 80 nA FB Voltage Line Regulation V FB from 2.6V to 5.5V 0.05 0.15 %/V Error Amplifier Trans-conductance ΔI = 5µA 70 150 240 µs Error Amplifier Output Current V FB = 1.15V and 1.35V, VCOMP = 1.1V 11 µA Switch Current Limit V FB = 1V, Duty Cycle = 65% ACT6390 1.2 1.7 2.3 A ACT6391 1.8 2.5 3.4 Switch On Resistance ACT6390 0.2 0.4 Ω ACT6391 0.15 0.3 Switch Leakage Current V SW = 12V, EN = G 15 µA Current Sense Trans-resistance ACT6390 0.45 V/A ACT6391 0.3 Soft Start Pin Bias Current V SS = 1.2V 2 4.5 7 µA Soft Start Reset Resistance V SS = 1.2V, VEN = 0V 110 220 Ω Logic High Threshold EN, FREQ 1.4 V Logic Low Threshold EN, FREQ 0.4 V EN Input Current V EN = 0V or 5V 0 1 µA FREQ Pull-down Current V FREQ = 3V 2.5 5.5 8.5 µA Thermal Shutdown Temperature 160 °C Thermal Shutdown Hysteresis 20 °C

Rev 1, 22-Aug-13 Innovative PowerTM - 5 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. FUNCTIONAL BLOCK DIAGRAM FUNCTIONAL DESCRIPTION The ACT6390 and ACT6391 are highly efficient step-up DC/DC converters that employ a current- mode, fixed frequency pulse-width modulation (PWM) architecture with excellent line and load regulation. The ACT6390 and ACT6391 operate at constant switching frequency under medium to high load cur- rent conditions. At light loads, these devices oper- ate in a pulse-skipping mode in order to improve light-load efficiency. Soft-Start The ACT6390 and ACT6391 both offer a program- mable soft-start function which minimizes inrush current during startup. The soft-start period is pro- grammed by connecting a capacitor (C SS) between SS and G. Operation of the soft-start function is as follows: when the IC is di sabled, SS is actively dis- charged to G. Upon enabling the IC, C SS is charged with a 4.5µA current so t hat the voltage at SS in- creases in a controlled manner. The peak inductor current is limited by the vo ltage at SS, so that the input current is limited unt il the soft-start period ex- pires, and the regulator c an achieve its full output current rating. The soft-start period can be calculated as a simple function of the soft-start capacitor using the equa- tion: Frequency Selection The ACT6390 and ACT6391 include a pin- selectable operating frequency drive FREQ to a logic high for 1.3MHz operation, drive FREQ to a logic low for 700kHz operation. Selectable operating frequency, in combination with the external compensation network, allows a wide range of flexibility in optimizing total solution size and cost. FREQ is internally pulled down by 5.5µA, this pin may be left unconnected to achieve a 700kHz oper- ating frequency. Setting the Output Voltage The ACT6390 and ACT6391 both feature external adjustable output voltages of up to 12V. To program the output voltage, simply connect a resistive volt- age divider between the output, FB, and G, with resistors set according to the following equation: Where V FB is 1.24V. SS SS C102.2t ××= ⎡ −⎟⎟ ⎛×= 1V V2R1R FB OUT 5.5µA 4.5µA IN SS SW G FREQ FB COMP EN OSCILLATOR SLOPE COMPENSATION CONTROL AND DRIVE LOGIC SOFT START ERROR COMPARATOR CLOCK CURRENT SENSE AMPLIFIER ERROR AMPLIFIER 1.24V (1) (2)

Rev 1, 22-Aug-13 Innovative PowerTM - 6 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. (9) (11) Inductor Selection As a step-up converter, the switch duty cycle (D) is determined by the input voltage (V IN) and output voltage (VOUT), as given by the following formula: Define Where: ∆I L is the inductor ripple current in steady state, typically chosen to be about 0.3, and IL(DC) is the inductor DC current, given by: Where η is typical efficiency. Solving equations (3),(4),(5) and (6) for the inductor value, This equation can be used to determine the correct trade-off between efficiency, current ripple, size and cost. When selecting an inductor make sure that the in- ductors maximum DC current and saturation current exceed the maximum operation point, calculated by: and If the output voltage is greater than two times of input voltage, that means the duty cycle is greater than 50%, the slope compensation is required for stability. When operating in this condition ensure that the inductor value is greater than L MIN: Where R CS is the current sense trans-resistance, RCS is 0.45 Ω for ACT6390, and R CS = 0.3 Ω for ACT6391. For example: VIN = 3.3V, VOUT = 12V, f SW = 700kHz IOUT = 250mA, η = 85%, FREQ = G, K = 0.4 Select L = 10µH Assuming the minimum input voltage is 3V and low cost external components are used, yielding a low efficiency of just 80%. For stability, Which meets the slope compensation requirement. Loop Compensation The ACT6390 and ACT6391 feature a simple loop compensation scheme. Simple follow the procedure detailed below to determine suitable compensation components. For best results be sure to prototype to confirm the values, and adjust the compensation network (by inspecting the transient response, for example) as needed to optimize results for your particular application. When the converter operates with continuous in- ductor current, a right-half-plane zero exits in the loop’s gain-frequency response. To ensure stability, OUT INOUT V VVD −= (3) (4) SW ININ L fL DVDTL VIΔ × ×== (5) (6) () ηV IVI IN OUTOUT DCL () ηV VII MININ OUTMAXOUT MAX,DCL ×= (8) (12) (15) REF FB GM COMP CCOMP2 CCOMP RCOMP EA (10) ( ) SW CSINOUT MIN f75.1 RVVLL × ×−=> ()DCL L I IΔK = (7) () K η fI VV V VL SWOUT INOUT OUT IN ×× 1A25.1I MAXPEAK =+= () ( ) () () () [] SWOUT MININOUTMININ MININ OUTMAXOUT MAXLMAX,DCLMAX,PEAKL fLV VVV ηV VI IΔ2 1II −×+× Hμ99.74.0 85.0 kHz700mA250 V3.3V12 V12 V3.3 K η fI VV V VL SWOUT INOUT OUT IN ⎛ ×× ×⎟⎟ () A25.18.0V3 V12mA250I MAX,DCL =× (13) () ( ) A32.0kHz700Hμ10V12 V3V12V3IΔ MAXL =×× −×= ( ) Hμ2.3kHz70075.1 Ω45.0V3.3V12LMIN =× ×−=

Rev 1, 22-Aug-13 Innovative PowerTM - 7 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. (28) (25) (18) (27) (17) (19) (20) the cross-over frequency (unity gain-frequency) should be less than one-fifth of the right-half-plane zero fZ(RHP), and lower than one-fifteenth of switch- ing frequency fsw. Choose , then calculate CCOMP: Select R COMP to meet the transient-droop require- ments. Where: α is the transient droop percentage which can be accepted, calculated by: K: is defined in equation (4) η: is the typical efficiency. VFB: is the feedback voltage, 1.24V GM: is the trans-conductance of the error amplifier. The output capacitor is chosen to set the output pole for canceling the RCOMP, CCOMP zero. CCOMP2 is optional and can be used when the output capacitor has significant ESR. The ESR will form a zero as follows: If this zero occurs at a higher frequency than the cross-over frequency, it can be ignored. Otherwise, it should be canceled with the pole set by capacitor C COMP2, If the value of C COMP2 calculated by (23) is smaller than 10pF, CCOMP2 can be omitted. For example: Choose CCOMP = 6.8nF Assume that 200mV of transient droop can be accepted: Choose RCOMP = 180kΩ COUT can be chosen to be either 22µF or 33µF, choose 33µF to reduce droop. If a ceramic capacitor is used with an assumed ESR of 20mΩ, fZ(ESR) > fC Since the zero frequency is greater than the pole frequency ,CCOMP2 can be omitted. If a tantalum capacitor is used, whose ESR is about 0.5Ω, () LπV2 RVf 2 OUT LOAD IN RHPZ CCS MLOAD OUT FBIN C M CS LOAD OUT FB COMP fπ2R GR V VV D1fπ2 G R R V VC ×××= −××= ⎛ +×× K1ηV IVRRGVα IN OUTOUT CSCOMPMFB ηVGVα K1IVR R INMFB OUTOUTCS COMP ×××× ⎛ +×× OUT OUT V VΔα = LOAD COMPCOMP OUT R CRC ×= OUTESR ESRZ CRπ2 1f ××= COMP ESROUT 2COMP R RCC ×= kHz8.57 Hμ10πV122 mA250 V12V3.3 f 2 RHPZ ≈ ××× Choose () kHz56.11f5 1f RHPZC == nF26.6kHz56.11π2 Sμ150 Ω45.0 Ω48 V12 V24.1V3.3C 2COMP =××××= V12 mV200α == Ωk3.186 85.0V3.3Sμ150V24.160 4.01 mA250V12Ω45.0 RCOMP = ×××× ⎛ +×× Fμ5.25 A25.0 V12 nF8.6Ωk180 R CRC LOAD COMPCOMP OUT = ×=×= (30) () kHz241Ωm20Fμ33π2 1f ESRZ =××= (21) (22) (23) (24) (26) (29) ()RHPZC f5 1f = (16) Ωk233nF8.6 Fμ33Ω48 C CRR COMP OUTLOAD COMP =×=×=

Rev 1, 22-Aug-13 Innovative PowerTM - 8 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. fZ(ESR) < fC Choose CCOMP2 = 82pF Rectifier Selection For optimal performance, the rectifier should be a Schottky rectifier that is rated to handle both the output voltage as well as the peak switch current. Over Voltage Protection The ACT6390 and ACT6391 both feature internal automatic over-voltage protection (OVP). Once the outputs achieve regulation, if the voltage at FB falls below 0.125V the controller will automatically dis- able and latch off, preven ting the controller from running open-loop and potentially damaging the IC and load. To re-enable the converters, simply cycle the EN pin or remove and reapply power to the input. Shutdown Drive EN low to disable the IC and reduce the sup- ply current to just 0.1µA. As with all non- synchronous step-up DC/DC converters, the exter- nal Schottky diode provides a DC path from the in- put to the output in shutdown. As a result, the out- put drops to one diode voltage drop below the input in shutdown. Thermal Shutdown The ACT6390 and ACT6391 both feature integrated thermal overload protection. Both devices are auto- matically disabled when their junction temperatures exceed 160°C, and automat ically re-enable when the die temperature decreases by 20°C. pF8.70Ωk233 Fμ33Ω5.0 R CRC COMP OUTESR 2COMP =×=×= () kHz64.9Ω5.0Fμ33π2 1f ESRZ =××= (31) (32)

Rev 1, 22-Aug-13 Innovative PowerTM - 9 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. TYPICAL PERFORMANCE CHARACTERISTICS (VIN = VEN = 3.3V, FREQ = G, TA = 25°C, unless otherwise specified.) ACT6390 Efficiency vs. Output Current Output Current (mA) ACT6390-001 Efficiency (%) Output Current (mA) ACT6390 Efficiency vs. Output Current ACT6390-002 ACT6390 Efficiency vs. Output Current Efficiency (%) Output Current (mA) ACT6390-003 Supply Current (mA) ACT6390 No Load Supply Current vs. VIN VIN (V) ACT6390-004 10 100 1000 0.20 0.24 0.28 0.32 0.36 0.40 0 2.5 3 3.5 4 5 5.5 10 100 1000 10 100 1000 4.5 Maximum Output Current (mA) ACT6390 Maximum Output Current vs. Input Voltage Input Voltage (V) ACT6390-005 200 600 1000 1400 1800 2200 VOUT = 5V VOUT = 12V VOUT = 9V VIN = 3.3V VOUT = 5V VIN = 5V VOUT = 12V FREQ = IN L = 2.7µH FREQ = G L = 5.4µH VIN = 3.3V VOUT = 12V Efficiency (%) FREQ = IN L = 5.4µH FREQ = G L = 10µH FREQ = G L = 10µH FREQ = IN L = 5.4µH FREQ = G FREQ = G L = 10µH FREQ = IN L = 5.4µH

Rev 1, 22-Aug-13 Innovative PowerTM - 10 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. TYPICAL PERFORMANCE CHARACTERISTICS (VIN = VEN = 3.3V, FREQ = G, TA = 25°C, unless otherwise specified.) ACT6391 Efficiency vs. Output Current Output Current (mA) ACT6391-006 Efficiency (%) Output Current (mA) ACT6391 Efficiency vs. Output Current ACT6391-007 ACT6391 Efficiency vs. Output Current Efficiency (%) Output Current (mA) ACT6391-008 Supply Current (mA) ACT6391 No Load Supply Current vs. VIN VIN (V) ACT6391-009 10 100 1000 0.20 0.24 0.28 0.32 0.36 0.40 0 2.5 3 3.5 4 5 5.5 10 100 1000 10 100 1000 4.5 Maximum Output Current (mA) ACT6391 Maximum Output Current vs. Input Voltage Input Voltage (V) ACT6391-010 400 2.5 3 3.5 4.5 5 4 800 1200 1600 2000 2400 VIN = 5V VOUT = 12V VIN = 3.3V VOUT = 12V Efficiency (%) FREQ = IN L = 4.7µH FREQ = G L = 10µH FREQ = G L = 10µH FREQ = IN L = 4.7µH VIN = 3.3V VOUT = 9V FREQ = G L = 5.4µH FREQ = IN L = 4.7µH VOUT = 12V FREQ = G L = 10µH FREQ = IN L = 4.7µH VOUT = 12V VOUT = 9V VOUT = 5V FREQ = G

Rev 1, 22-Aug-13 Innovative PowerTM - 11 - www.active-semi.com Copyright © 2013 Active-Semi, Inc. PACKAGE OUTLINE MSOP-8 PACKAGE OUTLINE AND DIMENSIONS SYMBOL DIMENSION IN MILLIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 0.820 1.100 0.032 0.043 A1 0.020 0.150 0.001 0.006 A2 0.750 0.950 0.030 0.037 b 0.250 0.010 C 0.090 D 2.900 3.100 0.114 0.122 E 2.900 3.100 0.114 0.122 E1 4.750 5.050 0.187 0.199 e 0.650 TYP 0.026 TYP L 0.400 0.800 0.016 0.031 θ 0° 6° 0° 6° 0.004 0.380 0.230 0.015 0.009 E e θ L A C D b Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. User s should evaluate each product to make sure that it is suitable for their applicat ions. Active-Semi products are not intended or authorized for use as critical components in life-support dev ices 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.

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