RT9170 μA Quiescent Current CMOS LDO Regulator 300mA, 15μ General Description Features The RT9170 is CMOS ultra low quiescent current and low dropout (ULDO) regulators. The devices are capable of supplying 300mA of output current continuously. z The RT9170's performance is optimized for batterypowered systems to deliver 15μA ultra low quiescent current and extremely low dropout voltage. Regulator ground current increases only slightly in dropout, further prolonging the battery life. The other features include ultra low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. z z z z z z z z z z The devices are available in fixed output voltages range of 1.2V to 3.3V with 0.1V per step. The RT9170 regulators are available in SOT-23-3, SOT-23-5 and 3-lead SOT-89 packages. Ordering Information RT9170- z Applications z z z z Package Type V: SOT-23-3 B: SOT-23-5 X : SOT-89 μA) Ultra-Low Quiescent Current (Typically 15μ Guaranteed 300mA Output Current Low Dropout : 240mV at 300mA Wide Operating Voltage Ranges : 2V to 5.5V Fast Transient Response Tight Load and Line Regulation TTL-Logic-Controlled Enable Input Current Limiting & Thermal Protection Only 1μ μF Output Capacitor Required for Stability High Power Supply Rejection Ratio Custom Voltage Available RoHS Compliant and 100% Lead (Pb)-Free z Cellular Phones and Pagers Battery-Powered Equipment Laptop, Palmtops, Notebook Computers Hand-Held Instruments PCMCIA Cards Pin Configurations Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Output Voltage 12 : 1.2V 13 : 1.3V : 32 : 3.2V 33 : 3.3V (TOP VIEW) VIN EN NC 3 5 4 2 1 1 GND 2 3 VOUT GND SOT-23-3 VIN VOUT SOT-23-5 Note : RichTek Pb-free and Green products are : `RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. `Suitable for use in SnPb or Pb-free soldering processes. `100%matte tin (Sn) plating. Marking Information For marking information, contact our sales representative directly or through a RichTek distributor located in your area, otherwise visit our website for detail. DS9170-11 March 2007 1 GND 2 3 VIN VOUT (TAB) SOT-89 www.richtek.com 1 RT9170 Typical Application Circuit VIN VIN CIN 1uF VOUT RT9170- Chip Enable EN CB COUT 1uF VOUT GND Functional Pin Description Pin No. Pin Name Pin Function RT9170- CV RT9170- CB RT9170- CX 3 2 2 VIN Power Input Voltage 2 3 3 VOUT Output Voltage 1 1 1 GND Ground - 5 - EN Chip Enable (Active Low) - 4 - NC No Connection Function Block Diagram VIN + - Current Limit & Thermal Shutdown EN VOUT GND www.richtek.com 2 DS9170-11 March 2007 RT9170 Absolute Maximum Ratings z z z z z z (Note 1) Supply Input Voltage -------------------------------------------------------------------------------------------------- 7V Power Dissipation, PD @ TA = 25°C SOT-23-3 ---------------------------------------------------------------------------------------------------------------- 0.4W SOT-23-5 ---------------------------------------------------------------------------------------------------------------- 0.4W SOT-89 ------------------------------------------------------------------------------------------------------------------- 0.571W Package Thermal Resistance (Note 7) SOT-23-3, θJA ---------------------------------------------------------------------------------------------------------- 250°C/W SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------- 250°C/W SOT-89, θJA ------------------------------------------------------------------------------------------------------------- 175°C/W Junction Temperature ------------------------------------------------------------------------------------------------- 150°C Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions z z z (Note 3) Supply Input Voltage -------------------------------------------------------------------------------------------------- 2V to 5.5V Enable Input Voltage -------------------------------------------------------------------------------------------------- 0V to 5.5V Junction Temperature Range ---------------------------------------------------------------------------------------- −40°C to 125°C Electrical Characteristics (VIN = VOUT + 1V, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units Output Voltage Accuracy ΔVOUT IOUT = 1mA −2 -- +2 % Current Limit ILIM RLOAD = 1Ω 300 -- -- mA IQ VEN ≤ 0.6V, IOUT = 0mA -- 15 -- μA Dropout Voltage VDROP IOUT = 300mA -- 240 -- mV Line Regulation ΔVLINE −0.3 0.018 +0.3 %/V Quiescent Current (Note 5) VIN = (VOUT + 0.3V) to 5.5V, IOUT = 1mA Load Regulation (Note 4) ΔVLOAD 1mA < IOUT < 300mA -- 0.01 0.04 %/mA Standby Current (Note 6) ISTBY VEN ≥ 2V (Shutdown), VIN = 5.5V -- 0.1 -- μA Logic-Low Voltage VIL VIN = 2V to 5.5V, Enable -- -- 0.6 Logic-High Voltage VIH VIN = 2V to 5.5V, Shutdown 2 -- -- f = 1kHz, COUT = 1μF -- −40 -- dB -- 150 -- °C EN Threshold Power Supply Rejection PSRR Thermal Shutdown Temperature TSD DS9170-11 March 2007 V www.richtek.com 3 RT9170 Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. 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 for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions Note 4. Regulation is measured at constant junction temperature by using a 20ms current pulse. Devices are tested for load regulation in the load range from 1mA to 300mA. Note 5. Quiescent, or ground current, is the difference between input and output currents. It is defined by IQ = IIN - IOUT under no load condition (IOUT = 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 6. Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal (VEN ≥ 2V). It is measured with VIN = 5.5V. Note 7. θJA is measured in the natural convection at TA = 25°C on a low effective thermal conductivity test board of JEDEC 51-3 thermal measurement standard. www.richtek.com 4 DS9170-11 March 2007 RT9170 Typical Operating Characteristics Temperature Stability Quiescent Current vs. Load Current 2.55 18 No Load 17 Quiescent Current (uA) 1 Output Voltage (V)1 2.53 2.51 2.49 ILOAD = 250mA 2.47 2.45 2.43 2.41 VIN = 3.5V VOUT = 2.5V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) 2.39 2.37 16 15 14 13 VIN = 3.5V VOUT = 2.5V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) 12 11 2.35 10 -35 -15 5 25 45 65 85 105 125 0 0.05 0.1 Temperature (° C) Quiescent Current vs. Temperature 0.2 0.25 0.3 Quiescent Current vs. Supply Voltage 18 18 16 16 ILOAD = 200mA Quiescent Current (uA) 1 Quiescent Current (uA) 1 0.15 Load Current (A) 14 No Load 12 10 8 6 VIN = 3.5V VOUT = 2.5V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) 4 2 -15 5 25 12 No Load 10 ILOAD = 200mA 8 6 4 VOUT = 2.5V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) 2 0 0 -35 14 45 65 85 105 2 125 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) Temperature (° C) Output Voltage vs. Supply Voltage Dropout Voltage vs. Load Current 2.55 300 VOUT = 3.3V 2.53 TJ = 125°C Output Voltage (V)1 Dropout Voltage (mV) 250 200 TJ = 25°C 150 TJ = -40°C 100 2.51 2.49 2.47 50 VOUT = 2.5V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) ILOAD = 1mA 2.45 0 0 0.05 0.1 0.15 0.2 Load Current (A) DS9170-11 March 2007 0.25 0.3 2.5 3 3.5 4 4.5 5 5.5 Supply Voltage (V) www.richtek.com 5 RT9170 Current Limit vs. Temperature Load Regulation Deviation vs. Temperature 1.60 -0.0005 1.40 -0.001 Current Limit (A) Load Regulation Deviation (%/mA) 0 -0.0015 -0.002 -0.0025 -0.003 -0.0035 1.20 1.00 VIN = 5V VOUT = 3.3V RL = 1Ω 0.80 -0.004 VOUT = 2.5V 0.60 -0.0045 -35 -15 5 25 45 65 85 105 -50 125 -25 0 25 50 75 100 125 Temperature (° C) Temperature (° C) PSRR Current Limit 0 VIN = 3.5V VOUT = 2.5V COUT = 1uF (Ceramic) ILOAD = 250mA 3.0 -20 Current Limit (A) PSRR(dB)1 -10 ILOAD = 10mA -30 -40 -50 2.5 CIN = 10uF (Ceramic) X5R COUT = 10uF (Ceramic) X5R VIN = 5V RL = 1Ω 2.0 1.5 1.0 0.5 -60 0 -70 10 100 1K 10K 100K 1M Time (5ms/Div) Frequency (Hz) 6 4 2 VIN = 5V VOUT = 3.3V CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) ILOAD = 300mA 0 2 0 Time (25ms/DIV) www.richtek.com 6 Enable Respone EN Voltage (V) Output Voltage (V) EN Voltage (V) Output Voltage (V) Enable Respone 3 2 1 VIN = 5V VOUT = 3.3V CIN = 1uF(Ceramic) COUT = 1uF(Ceramic) ILOAD = 300mA 0 2 1 0 Time (5ms/Div) DS9170-11 March 2007 RT9170 CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) Input Voltage Deviation (V) VIN = 3.5V, VOUT = 2.5V TA = 25°C Line Transient Response 6 250 0 VOUT = 2.5V 5 TA = 25°C 200 0 -200 Time (0.5ms/Div) COUT = 1uF (Ceramic) IOUT = 250mA 4 3 ≈ ≈ ≈ ≈ Output Voltage Deviation (mV) Output Voltage Deviation (mV) Load Current (mA) Load Transient Response 100 0 -100 Time (0.5ms/Div) Noise VIN = 3.5V, VOUT = 2.5V 300 IOUT = 250mA CIN = 1uF (Ceramic) COUT = 1uF (Ceramic) Noise(uV) 200 100 0 -100 -200 -300 Times (2.5ms/Div) DS9170-11 March 2007 www.richtek.com 7 RT9170 Application Information Like any low-dropout regulator, the RT9170 requires input and output decoupling capacitors. The device is specifically designed for portable applications requiring minimum board space and smallest components. These capacitors must be correctly selected for good performance (see Capacitor Characteristics Section). Please note that linear regulators with a low dropout voltage have high internal loop gains which require care in guarding against oscillation caused by insufficient decoupling capacitance. Input Capacitor An input capacitance of ≅ 1μF is required between the device input pin and ground directly (the amount of the capacitance may be increased without limit). The input capacitor MUST be located less than 1 cm from the device to assure input stability (see PCB Layout Section). A lower ESR capacitor allows the use of less capacitance, while higher ESR type (like aluminum electrolytic) require more capacitance. Capacitor types (aluminum, ceramic and tantalum) can be mixed in parallel, but the total equivalent input capacitance/ ESR must be defined as above to stable operation. There are no requirements for the ESR on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will be ≅ 1μF over the entire operating temperature range. Output Capacitor The RT9170 is designed specifically to work with very small ceramic output capacitors. A ceramic capacitor (temperature characteristics X7R, X5R, Z5U, or Y5V) in 1μF to 10μF with 5mΩ to 50mΩ range is suitable for the RT9170 application. The recommended minimum capacitance for the device is 1μF, X5R or X7R dielectric ceramic, between VOUT and GND for stability, but it may be increased without limit. Higher capacitance values help to improve transient. The output capacitor's ESR is critical because it forms a zero to provide phase lead which is required for loop stability. www.richtek.com 8 No Load Stability The device will remain stable and in regulation with no external load. This is specially import in CMOS RAM keepalive applications. Input-Output (Dropout) Volatge A regulator's minimum input-to-output voltage differential (dropout voltage) determines the lowest usable supply voltage. In battery-powered systems, this determines the useful end-of-life battery voltage. Because the device uses a PMOS, its dropout voltage is a function of drain-tosource on-resistance, RDS(ON), multiplied by the load current : VDROPOUT = VIN -VOUT = RDS(ON) x IOUT Current Limit The RT9170 monitors and controls the PMOS' gate voltage, limiting the output current to 0.3A (min). The output can be shorted to ground for an indefinite period of time without damaging the part. Short-Circuit Protection The device is short circuit protected and in the event of a peak over-current condition, the short-circuit control loop will rapidly drive the output PMOS pass element off. Once the power pass element shuts down, the control loop will rapidly cycle the output on and off until the average power dissipation causes the thermal shutdown circuit to respond to servo the on/off cycling to a lower frequency. Please refer to the section on thermal information for power dissipation calculations. Capacitor Characteristics It is important to note that capacitance tolerance and variation with temperature must be taken into consideration when selecting a capacitor so that the minimum required amount of capacitance is provided over the full operating temperature range. In general, a good tantalum capacitor will show very little capacitance variation with temperature, but a ceramic may not be as good (depending on dielectric type). DS9170-11 March 2007 RT9170 Aluminum electrolytics also typically have large temperature variation of capacitance value. range of 125°C to -40°C. ESR will vary only about 2X going from the high to low temperature limits. Equally important to consider is a capacitor's ESR change with temperature: this is not an issue with ceramics, as their ESR is extremely low. However, it is very important in Tantalum and aluminum electrolytic capacitors. Both show increasing ESR at colder temperatures, but the increase in aluminum electrolytic capacitors is so severe they may not be feasible for some applications. The increasing ESR at lower temperatures can cause oscillations when marginal quality capacitors are used (if the ESR of the capacitor is near the upper limit of the stability range at room temperature). Ceramic : For values of capacitance in the 10μF to 100μF range, ceramics are usually larger and more costly than tantalums but give superior AC performance for bypassing high frequency noise because of very low ESR (typically less than 10mΩ). However, some dielectric types do not have good capacitance characteristics as a function of voltage and temperature. Z5U and Y5V dielectric ceramics have capacitance that drops severely with applied voltage. A typical Z5U or Y5V capacitor can lose 60% of its rated capacitance with half of the rated voltage applied to it. The Z5U and Y5V also exhibit a severe temperature effect, losing more than 50% of nominal capacitance at high and low limits of the temperature range. X7R and X5R dielectric ceramic capacitors are strongly recommended if ceramics are used, as they typically maintain a capacitance range within ±20% of nominal over full operating ratings of temperature and voltage. Of course, they are typically larger and more costly than Z5U/Y5U types for a given voltage and capacitance. Tantalum : Solid tantalum capacitors are recommended for use on the output because their typical ESR is very close to the ideal value required for loop compensation. They also work well as input capacitors if selected to meet the ESR requirements previously listed. Tantalums also have good temperature stability: a good quality tantalum will typically show a capacitance value that varies less than 10-15% across the full temperature DS9170-11 March 2007 Aluminum : This capacitor type offers the most capacitance for the money. The disadvantages are that they are larger in physical size, not widely available in surface mount, and have poor AC performance (especially at higher frequencies) due to higher ESR and ESL. Compared by size, the ESR of an aluminum electrolytic is higher than either Tantalum or ceramic, and it also varies greatly with temperature. A typical aluminum electrolytic can exhibit an ESR increase of as much as 50X when going from 25°C down to -40°C. It should also be noted that many aluminum electrolytics only specify impedance at a frequency of 120Hz, which indicates they have poor high frequency performance. Only aluminum electrolytics that have an impedance specified at a higher frequency (between 20kHz and 100kHz) should be used for the device. Derating must be applied to the manufacturer's ESR specification, since it is typically only valid at room temperature. Any applications using aluminum electrolytics should be thoroughly tested at the lowest ambient operating temperature where ESR is maximum. Thermal Considerations The RT9170 series can deliver a current of up to 300mA over the full operating junction temperature range. However, the maximum output current must be derated at higher ambient temperature to ensure the junction temperature does not exceed 125°C. With all possible conditions, the junction temperature must be within the range specified under operating conditions. Power dissipation can be calculated based on the output current and the voltage drop across regulator. PD = (VIN - VOUT) IOUT + VIN IGND www.richtek.com 9 RT9170 The final operating junction temperature for any set of conditions can be estimated by the following thermal equation : EN NC PD (MAX) = ( TJ (MAX) - TA ) / θJA Where TJ (MAX) is the maximum junction temperature of the die (125° C) and T A is the maximum ambient temperature. The junction to ambient thermal resistance (θJA) for SOT-23-3 and SOT-23-5 packages at recommended minimum footprint is 250° C/W, 175°C/W for SOT-89 package (θJA is layout dependent). Visit our website in which “Recommended Footprints for Soldering Surface Mount Packages” for detail. VOUT GND VIN PCB Layout Good board layout practices must be used or instability can be induced because of ground loops and voltage drops. The input and output capacitors MUST be directly connected to the input, output, and ground pins of the device using traces which have no other currents flowing through them. SOT-23-5 Board Layout The best way to do this is to layout CIN and COUT near the device with short traces to the VIN, VOUT, and ground pins. The regulator ground pin should be connected to the external circuit ground so that the regulator and its capacitors have a “single point ground”. It should be noted that stability problems have been seen in applications where “vias” to an internal ground plane were used at the ground points of the device and the input and output capacitors. This was caused by varying ground potentials at these nodes resulting from current flowing through the ground plane. Using a single point ground technique for the regulator and it's capacitors fixed the problem. Since high current flows through the traces going into VIN and coming from VOUT, Kelvin connect the capacitor leads to these pins so there is no voltage drop in series with the input and output capacitors. Optimum performance can only be achieved when the device is mounted on a PC board according to the diagram below: www.richtek.com 10 DS9170-11 March 2007 RT9170 Outline Dimension H D L C B e A A1 b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.508 0.014 0.020 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 1.803 2.007 0.071 0.079 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-3 Surface Mount Package DS9170-11 March 2007 www.richtek.com 11 RT9170 H D L B C b A A1 e Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.889 1.295 0.035 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.356 0.559 0.014 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024 SOT-23-5 Surface Mount Package www.richtek.com 12 DS9170-11 March 2007 RT9170 D D1 A B C C1 e e H A b Symbol b1 b Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 1.397 1.600 0.055 0.063 b 0.356 0.483 0.014 0.019 B 2.388 2.591 0.094 0.102 b1 0.406 0.533 0.016 0.021 C 3.937 4.242 0.155 0.167 C1 0.787 1.194 0.031 0.047 D 4.394 4.597 0.173 0.181 D1 1.397 1.753 0.055 0.069 e 1.448 1.549 0.057 0.061 H 0.356 0.432 0.014 0.017 3-Lead SOT-89 Surface Mount Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)89191466 Fax: (8862)89191465 Email: [email protected] DS9170-11 March 2007 www.richtek.com 13