RT8016 RICHTEK | Alldatasheet
Document overview
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Technical content
Features
zzzzz +2.5V to +5.5V Input Range zzzzz Adjustable Output From 0.6V to VIN zzzzz 1A Output Current zzzzz 95% Efficiency zzzzz No Schottky Diode Required zzzzz 1.5MHz Fixed Frequency PWM Operation zzzzz Small 6-Lead WDFN Package zzzzz RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Personal Information Appliances z Wireless and DSL Modems z MP3 Players z Portable Instruments 1.5MHz, 1A, High Efficiency PWM Step-Down DC/DC Converter General Description The RT8016 is a high-efficiency Pulse-Width-Modulated (PWM) step-down DC-DC converter. Capable of delivering 1A output current over a wide input voltage range from 2.5V to 5.5V, the RT8016 is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources such as cellular phones, PDAs and hand-held devices. Two operating modes are available including : PWM/Low- Dropout autoswitch and shut-down modes, the Internal synchronous rectifier with low R DS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application. The RT8016 enters Low-Dropout mode when normal PWM cannot provide regulated output voltage by continuously turning on the upper PMOS. The RT8016 enters shut- down mode and consumes less than 0.1uA when EN pin is pulled low. The RT8016 also offers a range of 1V to 3.3V with 0.1V per step or adjustable output voltage by two external resistor. The switching ripple is easily smoothed-out by small package filtering elements due to a fixed operating frequency of 1.5MHz. This along with small WDFN-6L 2x2 package provides small PCB area application. Other features include soft start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection.
Ordering Information
(TOP VIEW) WDFN-6L 2x2 Note : Richtek products are : \ RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. \ Suitable for use in SnPb or Pb-free soldering processes. Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. GND VIN FB/VOUT GND LX EN 5 RT8016- Package Type QW : WDFN-6L 2x2 (W-Type) Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) Output Voltage Default : Adjustable 10 : 1.0V 11 : 1.1V 32 : 3.2V 33 : 3.3V
©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Figure 1. Fixed Voltage Regulator Figure 2. Adjustable Voltage Regulator and (R1 x C1) should be in the range between 3x10 -6 and 6x10-6 for component selection. Figure 3. Layout Guide for RT8016
- The distance that C IN connects to V IN is as close as possible (Under 2mm).
- COUT should be placed near RT8016.
2 COUT
6 VOUT
DS8016-04 February 2012 www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Function Block Diagram Functional Pin Description Pin No. Pin Name Pin Function 2 EN Chip Enable (Active High). 3 VIN Power Input. 4 LX Pin for Switching. 1, 5 GND Ground Pin. 6 FB/VOUT Feedback/Output Voltage Pin. 7 (Exposed Pad) NC No Internal Connection. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. COMP RC RS1 RS2 EN VIN LX FB/VOUT UVLO & Power Good Detector VREF Slope Compensation Current Sense OSC & Shutdown Control Current Limit Detector DriverControl LogicPWM ComparatorError Amplifier GND Current Source Controller Mux Current Detector
DS8016-04 February 2012www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Absolute Maximum Ratings (Note 1) z Power Dissipation, PD @ TA = 25°C z Package Thermal Resistance (Note 2) z ESD Susceptibility (Note 3)
Electrical Characteristics
Parameter Symbol Test Conditions Min Typ Max Unit Input Voltage Range VIN 2.5 -- 5.5 V Quiescent Current I Q I OUT = 0mA, VFB = VREF + 5% -- 50 70 μA Shutdown Current ISHDN EN = GND -- 0.1 1 μA Reference Voltage VREF For Adjustable Output Voltage 0.588 0.600 0.612 V Adjustable Output Range VOUT (Note 6) VREF -- VIN − 0.2V V Output Voltage Accuracy Fix ΔVOUT VIN = (VOUT + ΔV) to 5.5V or VIN > 2.5V which ever is larger. (Note 5) −3 -- 3 % Adjustable ΔVOUT VIN = VOUT + ΔV to 5.5V (Note 5) 0A < IOU T < 1A −3 -- 3 % FB Input Current IFB V FB = VIN −50 -- 50 nA P-MOSFET RON R DS(ON)_P IOUT = 200mA Ω N-MOSFET RON R DS(ON)_N IOUT = 200mA Ω P-Channel Current Limit ILIM_P VIN = 2.5V to 5.5 V 1.4 2 2.6 A EN High-Level Input Voltage VEN_H 1.5 -- VIN V Recommended Operating Conditions (Note 4)
DS8016-04 February 2012 www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Parameter Symbol Test Conditions Min Typ Max Unit EN Low-Level Input Voltage V EN_L -- -- 0.4 V Under Voltage Lock Out threshold UVLO -- 1.8 -- V Hysteresis -- 0.1 -- V Oscillator Frequency fOSC V IN = 3.6V, IOU T = 100mA 1.2 1.5 1.8 MHz Thermal Shutdown Temperature TSD -- 160 -- °C Max. Duty Cycle 100 -- -- % LX Current Source VIN = 3.6V, VLX = 0V or VLX = 3.6V 1 -- 100 μA Minimum On-Time t ON -- 120 140 ns Note 1. Stresses beyond those listed “Absolute Maximum Ratings ” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Note 2. θ JA is measured at TA = 25°C on a single-layer and four-layer test board of JEDEC 51. The measurement case position of θJC is on the lead of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. ΔV = IOUT x PRDS(ON) Note 6. Guarantee by design. Note 7. The start up time is about 300 μs.
DS8016-04 February 2012www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Typical Operating Characteristics Output Voltage vs. Output Current 1.200 1.202 1.204 1.206 1.208 1.210 1.212 1.214 1.216 1.218 1.220 Output Current (A) Output Voltage (V) VIN = 3.6V VIN = 5V Efficiency vs. Output Current 100 0.001 0.01 0.1 1 Output Current (A) Efficiency (%) VOUT = 1.2V, COUT = 10uF, L = 2.2H VIN = 3.6V VIN = 5V UVLO Threshold vs. Temperature 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 -50 -25 0 25 50 75 100 125 Temperature Input Voltage (V) (°C) VOUT = 1.2V, IOUT = 0A Rising Falling Output Voltage vs. Temperature 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 -50 -25 0 25 50 75 100 125 Temperature Output Voltage (V) (°C) VIN = 3.6V, IOUT = 0A EN Threshold vs. Temperature 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 -40 -15 10 35 60 85 110 135 Temperature EN Voltage (V) (°C) VIN = 3.6V, VOUT = 1.2V, IOUT = 0A Rising Falling EN Threshold vs. Input Voltage 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Input Voltage (V) EN Voltage (V) VOUT = 1.2V, IOUT = 0A Rising Falling
DS8016-04 February 2012 www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Output Ripple Voltage Time (500ns/Div) VIN = 5V, VOUT = 1.2V, IOUT = 1A VOUT (10mV/Div) VLX (5V/Div) Output Ripple Voltage Time (500ns/Div) VIN = 3.6V, VOUT = 1.2V, IOUT = 1A VOUT (10mV/Div) VLX (5V/Div) Current Limit vs. Temperature 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 -40 -15 10 35 60 85 110 135 Temperature Output Current (A) VIN = 3.6V (°C) VIN = 5V VIN = 3.3V VOUT = 1.2V Current Limit vs. Input Voltage 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 Input Voltage (V) Output Current (A) VOUT = 1.2V Frequency vs. Temperature 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 -40 -15 10 35 60 85 110 135 Temperature Frequency (MHz) VIN = 3.6V, VOUT = 1.2V, IOUT = 300mA (°C) Frequency vs. Input Voltage 1.20 1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 Input Voltage (V) Frequency (MHz) VIN = 3.6V, VOUT = 1.2V, IOUT = 300mA
DS8016-04 February 2012www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Load Transient Response Time (50 μs/Div) VIN = 3.6V, VOUT = 1.2V IOUT = 50mA to 0.5A VOUT (50mV/Div) IOUT (500mA/Div) Load Transient Response Time (50 μs/Div) VIN = 3.6V, VOUT = 1.2V IOUT = 50mA to 1A VOUT (50mV/Div) IOUT (500mA/Div) Power Off from EN Time (100 μs/Div) VIN = 3.6V, VOUT = 1.2V, IOUT = 1A VOUT (1V/Div) VEN (2V/Div) IIN (500mA/Div) Power On from VIN Time (250 μs/Div) VEN = 3.6V, VOUT = 1.2V, IOUT = 1A VOUT (1V/Div) VIN (2V/Div) IIN (500mA/Div) Power On from EN Time (100 μs/Div) VIN = 3.6V, VOUT = 1.2V, IOUT = 1A VOUT (1V/Div) VEN (2V/Div) IIN (500mA/Div) Power On from EN Time (100 μs/Div) VIN = 3.6V, VOUT = 1.2V, IOUT = 10mA VOUT (1V/Div) VEN (2V/Div) IIN (500mA/Div)
DS8016-04 February 2012 www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Load Transient Response Time (50 μs/Div) VIN = 5V, VOUT = 1.2V IOUT = 50mA to 0.5A VOUT (50mV/Div) IOUT (500mA/Div) Load Transient Response Time (50 μs/Div) VIN = 5V, VOUT = 1.2V IOUT = 50mA to 1A VOUT (50mV/Div) IOUT (500mA/Div)
DS8016-04 February 2012www.richtek.com ©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. ⎡ +≤ OUT LOUT 8fC 1ESR ΔIΔV Applications Information The basic RT8016 application circuit is shown in Typical Application Circuit. External component selection is determined by the maximum load current and begins with the selection of the inductor value and operating frequency followed by C IN and COUT. Inductor Selection For a given input and output voltage, the inductor value and operating frequency determine the ripple current. The ripple current ΔI L increases with higher VIN and decreases with higher inductance. Having a lower ripple current reduces the ESR losses in the output capacitors and the output voltage ripple. Highest efficiency operation is achieved at low frequency with small ripple current. This, however, requires a large inductor. A reasonable starting point for selecting the ripple current is ΔI L = 0.4(IMAX). The largest ripple current occurs at the highest VIN. To guarantee that the ripple current stays below a specified maximum, the inductor value should be chosen according to the following equation : Inductor Core Selection Once the value for L is known, the type of inductor must be selected. High efficiency converters generally cannot afford the core loss found in low cost powdered iron cores, forcing the use of more expensive ferrite or mollypermalloy cores. Actual core loss is independent of core size for a fixed inductor value but it is very dependent on the inductance selected. As the inductance increases, core losses decrease. Unfortunately, increased inductance requires more turns of wire and therefore copper losses will increase. Ferrite designs have very low core losses and are preferred at high switching frequencies, so design goals can concentrate on copper loss and preventing saturation. Ferrite core material saturates “hard”, which means that IN OUTOUTL V V1Lf VΔI Δ×= IN(MAX) OUT L(MAX) OUT V V1If VL inductance collapses abruptly when the peak design current is exceeded. This results in an abrupt increase in inductor ripple current and consequent output voltage ripple. Do not allow the core to saturate! Different core materials and shapes will change the size/ current and price/current relationship of an inductor. Toroid or shielded pot cores in ferrite or permalloy materials are small and don't radiate energy but generally cost more than powdered iron core inductors with similar characteristics. The choice of which style inductor to use mainly depends on the price vs size requirements and any radiated field/EMI requirements. C IN and COUT Selection The input capacitance, C IN, is needed to filter the trapezoidal current at the source of the top MOSFET. To prevent large ripple voltage, a low ESR input capacitor sized for the maximum RMS current should be used. RMS current is given by : V V VII OUT IN IN OUT OUT(MAX)RMS −= This formula has a maximum at V IN = 2V OUT, where IRMS = I OUT/2. This simple worst-case condition is commonly used for design because even significant deviations do not offer much relief. Note that ripple current ratings from capacitor manufacturers are often based on only 2000 hours of life which makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Several capacitors may also be paralleled to meet size or height requirements in the design. The selection of C OUT is determined by the effective series resistance (ESR) that is required to minimize voltage ripple and load step transients, as well as the amount of bulk capacitance that is necessary to ensure that the control loop is stable. Loop stability can be checked by viewing the load transient response as described in a later section. The output ripple, ΔV OUT, is determined by :
©Copyright 2012 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. high voltage coefficient and audible piezoelectric effects. can also lead to significant ringing. of the output voltage as shown in Figure 4. Figure 4. Setting the Output Voltage actual power lost is of no consequence.
- The VIN quiescent current appears due to two factors
be more pronounced at higher supply voltages.
DS8016-04 February 2012www.richtek.com Richtek Technology Corporation 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnish ed by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringeme nts of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of R ichtek or its subsidiaries. Outline Dimension Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.175 0.250 0.007 0.010 b 0.200 0.350 0.008 0.014 D 1.950 2.050 0.077 0.081 D2 1.000 1.450 0.039 0.057 E 1.950 2.050 0.077 0.081 E2 0.500 0.850 0.020 0.033 e 0.650 0.026 L 0.300 0.400 0.012 0.016 W-Type 6L DFN 2x2 Package D E A e b L SEE DETAIL A 1 122 Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. DETAIL A Pin #1 ID and Tie Bar Mark Options