ACT6305 ETC2
Document overview
- Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
- PDF pages: 9
Technical content
Synchronous Step-Up DC-DC Converter
FEATURES
0.95V Typical Startup Voltage Up to 94% Efficiency Fully Integrated Power Stage Fixed 3.3V / 5V or Adjustable Output Voltage NanoStandbyTM Shutdown Mode Tiny SOT 23-5 Package
APPLICATIONS
Hand-Held Devices One to Three Cell Battery Operated Devices PDAs Cellular Phones Digital Cameras GPS GENERAL DESCRIPTION The ACT6305 is a high-efficiency synchronous step-up DC-DC converter that consumes just 17µA of quiescent supply current and is capable of delivering more than 400mA output current using only three external components. This device achieves a typical startup voltage of just 0.95V, making this device ideal for applications operating from 1 or 2 alkaline cells. This device incorporates an internal synchronous rectifier, and achieves excellent peak efficiencies of up to 94% and features a proprietary control scheme that ensures high efficiency over a wide load current range. The ACT6305 features pin-selectable output voltages of 3.3V or 5V, or it can also be set externally to any voltage between 2V and 5V. The ACT6305 is available in the tiny SOT23-5 Package. Figure 1. Typical Application Circuit
ORDERING INFORMATION
PART NUMBER TEMPERATURE RANGE PACKAGE PINS TOP MARK ACT6305UC -40° C to 85° C SOT23-5 5 HBCA PIN CONFIGURATION PIN DESCRIPTION PIN NUMBER PIN NAME PIN DESCRIPTION 1 FB Output Voltage Selected and Feedback Input. Connect to G to select VOUT = 5V. Connect to OUT to select VOUT = 3.3V. Connect to a resistor divider to set output voltage between 2V and 5V. 2 G Ground. 3 EN Shutdown Input. Drive EN to IN or to a logic high for normal operation, drive to G or to a logic low to disable the regulator.
4 LX Inductor Connection
5 OUT Output. ACT6305 regulates the voltage at this pin. OUT also provides power to the IC. Active-Semi, Inc. - 2 - www.active-semi.com OUT LX FB G EN SOT23-5 ACT6305 UC
(Note: Exceeding these limits may damage the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability.) PARAMETER VALUE UNIT OUT, EN to G -0.3 to 6 V FB, LX to G -0.3 to VOUT + 0.3 V Continuous LX Current Internally Limited A Maximum Power Dissipation (derate 5mW/°C above TA = 50°C) 0.53 W Junction to Ambient Thermal Resistance (θ JA) 190 °C/W Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10 sec) -40 to 150 -55 to 150 300
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, VIN = 1.5V, VOUT = 3.3V, TA = 25°C unless otherwise specified.) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Minimum Operating Input Voltage 0.6 V Startup Voltage 0.95 1.1 V Output Voltage VOUT FB = OUT FB = G 3.2 4.85 3.3 3.4 5.15 V Startup to Normal Transition Voltage Threshold 1.85 V FB Feedback Voltage VFB VOUT = 2V to 5V 1.16 1.18 1.2 V FB Input Current FB = 1.3V 0.1 µA Power Switch Current Limit ILIM 1 1.2 1.4 A Power Switch On Resistance RONN ILX = 100mA 0.15 0.3 Ω Synchronous Rectifier On Resistance RONP ILX = 100mA 0.25 0.5 LX Leakage Current SHDN = G, VLX = 0 or 3.3V 0.1 1 µA Output Voltage Range External Feedback divider 2 5 V Quiescent Current at OUT IQ VFB = 1.3V 17 34 µA Shutdown Supply Current ISD SHDN = G 0.1 1 µA Maximum On Time Programming High Time tONMAX VOUT = 2V to 5.5V 1 50 5 ns 75 µs Finish High Time tFINISH 500 µs Off Timeout tOFF 300 500 µs Input Current 1 µA Active-Semi, Inc. - 3 - www.active-semi.com
Figure 2. Functional Block Diagram efficiency across a very wide load range. load current during startup.
APPLICATION INFORMATION
The ACT6305 uses proprietary circuitry that enables it to provide an one of three different output voltage options; the ATC6305 provides fixed output voltage options of 3.3V or 5V, or may be adjusted over a 1.2V to 5V range by connecting an external resistive voltage divider. (as shown Figure 3). FB = OUT VOUT = 3.3V FB = G VOUT = 5V FB connected to resistive divider VOUT = 1.18V (1+R1/R2) Figure 3. OUTPUT CAPACITOR SELECTION A minimum value of capacitance is required to maintain loop stability and normal operation of the IC. The output capacitor value should be in the range of 22µF to 100µF. To obtain small output ripple, use a large capacitor with low ESR; ceramic capacitors should be used for highest performance. If a tantalum capacitor is used, choose only low ESR types and a smaller low-ESR capacitor of about 1µF can be connected in parallel to filter high frequency noise. INDUCTOR SELECTION For most applications, the inductor value should be in the range of 10µH to 47µH. Smaller inductors provide faster load transient response and have a smaller physical size, but they also result in higher ripple current and reduce the maximum available output current. Choose inductors with low series resistance to obtain the highest efficiency. BOARD LAYOUT To reduce noise and increase efficiency, high current traces should be wide and direct, and an extended ground plane should be used. Switching current paths should be laid out as tightly as possible, with the inductor and input and output capacitors located close to the IC, in order to reduce electromagnetic radiation. If the external resistor divider is used, place the resistors very close to the FB and G pins, and keep them away from the high switching current paths. Active-Semi, Inc. - 5 - www.active-semi.com
TYPICAL PERFORMANCE CHARACTERISTICS Active-Semi, Inc. - 6 - www.active-semi.com
TYPICAL PERFORMANCE CHARACTERISTICS CONT'D Active-Semi, Inc. - 7 - www.active-semi.com Title
TYPICAL PERFORMANCE CHARACTERISTICS CONT'D Active-Semi, Inc. - 8 - www.active-semi.com DCM Mode Connection Low ESR Output Capacitor VOUT(50mV/Div) V(LX) (2V/Div) Time: 5µs/Div VOUT V(LX) VOUT = 3.3V VIN = 1.2V ILOAD = 10mA Current Limit Condition Low ESR Output Capacitor VOUT (100mV/Div) V(LX) (2V/Div) Time: 2.5µs/Div VOUT V(LX) VOUT = 3.3V VIN = 2.4V ILOAD = 408mA Heavy Load Condition Low ESR Output Capacitor VOUT(100mV/Div) DCM Mode Connection High ESR Output Capacitor VOUT(100mV/Div) Heavy Load Condition High ESR Output Capacitor VOUT(100mV/Div) VOUT = 3.3V VIN = 1.2V ILOAD = 10mA VOUT = 3.3V VIN = 2.4V ILOAD = 408mA V(LX) (2V/Div) Time: 2.5µs/Div V(LX) (2V/Div) Time: 25µs/Div V(LX) (2V/Div) Time: 5µs/Div VOUT V(LX) VOUT = 5.2V VIN = 3.6V ILOAD = 400mA VOUT V(LX) VOUT = 3.3V VIN = 2.4V ILOAD = 340mA VOUT V(LX) VOUT = 3.3V VIN = 2.4V ILOAD = 112mA
SOT23-5 PACKAGE OUTLINE AND DIMENSIONS SYMBOL DIMENSION IN MILLIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 1.050 1.250 0.041 0.049 A1 0.000 0.100 0.000 0.004 A2 1.050 1.150 0.041 0.045 b 0.300 0.400 0.012 0.016 c 0.100 0.200 0.004 0.008 D 2.820 3.020 0.111 0.119 E 1.500 1.700 0.059 0.067 E1 2.650 2.950 0.104 0.116 e 0.950 TYP 0.037 TYP e1 1.800 2.000 0.071 0.079 L 0.700 REF 0.028 REF L1 0.300 0.600 0.012 0.024 θ 0° 8° 0° 8° Active-Semi, Inc. - 9 - www.active-semi.com 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 data sheet, 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 www.active-semi.com. For other inquiries, please send to: