Preliminary EP1117 1A Low Dropout Regulator FEATURES • Guaranteed Output Voltage Accuracy within 2% • Fast Transient Response • Load Regulation : 0.1% Typ. • Line Regulation : 0.03% Typ. • Low Dropout Voltage : 1.1V Typ. at IOUT =1A • Current Limit : 1A Typ. at TJ=25°C • On-chip Thermal Limiting : 150°C Typ. • Adjustable Output : 1.25~10.7V • Standard 3-pin SOT-223 Power Packages DESCRIPTION The EP1117 is a low dropout three-terminal adjustable or fixed-voltage regulator with 1A output current capability. The EP1117 is available in an adjustable version, with output ranging from 1.25V to 10.7V and fixed output voltages of 1.8V, 2.5V and 3.3V. Dropout voltage is guaranteed at a maximum of 1.3V at 1A. On-chip thermal limiting provides protection against any combination of overload that would create excessive junction temperatures. The EP1117 is available in the industry standard 3-pin the low profile surface mount SOT-223 APPLICATIONS • PC peripheral • Low Voltage Logic Supplies • Post Regulator for Switching Power Supply power packages which can be applications where space is limited. Package Information Rev.01 1/8 used in Preliminary EP1117 Absolute Maximum Rating (Note1) Symbol Rating (Note2) Parameter Input Voltage EP1117-adj, EP1117-33 VI Unit 15 EP1117-25, EP1117-18 V 9 Operating Junction Temperature Range TJ TSTG Control Section 0 to 125 Power Transistor 0 to 150 Storage Temperature Range -65 to +150 °C 260 °C Lead Temperature (Soldering, 10 second) TL °C Note: 1. Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note: 2.The values here show the absolute maximum rating, and for normal usage please refer the test condition in Electrical Characteristics Table. Electrical Characteristics (Note3): Unless otherwise noted, these specifications apply over CIN = 10μF, COUT = 10μF, and TA=0 to 70°C. Typical values refer to TA=25°C. Symbol VREF Parameter Conditions Reference TJ = 0~125°C, 10mA≤ IOUT ≤1A, Voltage 1.4V≤ (VIN -VOUT) ≤10.75V Min. Typ. Max. Unit 1.225 1.250 1.275 V 1.764 1.800 1.836 Output Voltage EP1117-18 TJ = 0~125°C, 0≤IOUT≤1.5A, 3.25V≤ VIN ≤9V, VOUT EP1117-25 2.450 TJ = 0~125°C, 2.500 2.550 V 0≤ IOUT≤ 1A, 3.95V≤ VIN≤9V EP1117-33 3.235 TJ = 0~125°C, 0≤IOUT≤1A, 3.300 3.365 0.03 0.2 1 6 1 6 1 6 4.75V≤VIN ≤12V Line Regulation EP1117-adj REGLINE IOUT =10mA, (Note4) 1.5V≤(VIN -VOUT)≤10.75V IOUT = 0A, 3.25V≤VIN ≤9V (Note4) EP1117-25 IOUT = 0A, 3.95V≤ VIN ≤9V (Note4) EP1117-33 IOUT = 0A, 4.75V≤VIN ≤12V (Note4) EP1117-18 % mV Load Regulation EP1117 REGLOAD (VIN -VOUT)=3V, 0≤ IOUT ≤1A (Note4) 0.1 0.4 1 10 EP1117-18 VIN = 3.25V, 0≤ IOUT ≤1A (Note4) EP1117-25 VIN = 3.95V, 0≤ IOUT ≤1A (Note4) 1 10 EP1117-33 VIN = 4.75V, 0≤ IOUT ≤1A (Note4) 1 10 Rev.01 2/8 % mV Preliminary Dropout Voltage VD IOUT = 100mA (Note5) 1 1.1 IOUT = 500mA (Note5) 1.05 1.2 1.1 1.3 IOUT = 1A ILIMIT IADJ IO LS VN θth Current Limit (VIN -VOUT) = 5V, TJ = 25°C Adjust Pin (VIN -VOUT) = 3V, IOUT = 10mA 1000 Adjust Pin 10mA≤ IOUT ≤1A, 1.4V≤ (VIN -VOUT) Current Change ≤10.75V Minimum Load (VIN -VOUT) = 10.75V Ripple Rejection Thermal fRIPPLE =120Hz, VRIPPLE = 1VP-P, (VIN -VOUT) = 3V TJ = 25°C, 30ms Pulse Regulation Temperature Stability Long -Term V mA 60 120 μA 0.2 5 μA (Note6) Current PSRR TS (Note5) Current ΔIADJ TR EP1117 TJ = 125°C, 1000Hrs. Stability RMS Output TJ = 25°C, 10Hz≤F≤10kHz, Noise (% of VOUT) Thermal Junction to Case, at Tab Junction to Resistance Ambient 60 1.7 mA 75 dB 0.01 0.02 %/ W 0.5 % 0.3 % 0.003 % 15 °C/ W 150 °C Over OT Temperature Point Quiescent Current IQ EP1117-18 VIN≤9V 5.5 10 EP1117-25 VIN≤9V 5.5 10 EP1117-33 VIN≤12V 5.5 10 mA Note 3. 100% production test at +25°C. Specifications over the temperature range are guaranteed by design and characterization. Note 4: See thermal regulation specifications for changes in output voltage due to heating effects. Load line regulations are measured at a constant junction temperature by low duty cycle pulse testing. Note 5: Dropout voltage is specified over the full output current range of the device. Dropout voltage is defined as the minimum input/output differential measured at the specified output current. Test points and limits are also shown on the Dropout Voltage curve. Note 6: Minimum load current is defined as the minimum output current required to maintain regulation. Rev.01 3/8 Preliminary EP1117 Typical Performance Characteristics Dropout Voltage vs. Output Current Output Voltage vs. Input Voltage Input Current vs. Input Voltage Current Limit vs. Input Voltage Functional Block Diagram Rev.01 4/8 Preliminary EP1117 APPLICATIONS INFORMATION 1.25V to 10.7V Adjustable Regulator Fixed Voltage Model—Basic Connections. * Needed if device is far from filter capacitors Vout = 1.250V × R1 + R 2 R1 Output Voltage The EP1117 develops a 1.25V reference voltage between the output and the adjust terminal. By placing a resistor between these two terminals, a constant Current is caused to flow through R1 and down through R2 to set the overall output voltage. Normally this current is chosen to be the specified minimum load current of 10mA. For fixed voltage devices R1 and R2 are included in the device. ⎛ R2 ⎞ Vout = VREF ⎜1 + ⎟ + I ADJ R 2 ⎝ R1 ⎠ Figure 1. Basic Adjustable Regulator Load Regulation When the adjustable regulator is used, load regulation will be limited by the resistance of the wire connecting the regulator to the load. The datasheet specification for load regulation is measured at the output pin of the EP1117. Best load regulation is obtained when the top of the resistor divider (R1) is tied directly to the output pin of the device, not to the load. For fixed voltage devices, the top of R1 is internally connected to the output, and the ground pin can be connected to low side of the load. If R1 were connected to the load, RP is multiplied by the divider ratio, the effective resistance between the regulator and the load would be: Rp X (1+ R2/R1 ), where Rp is Parasitic Line Resistance. Rev.01 5/8 Preliminary EP1117 Figure 2. Connections for Best Load Regulation Input Capacitor An input capacitor of 10μF or greater is recommended. Tantalum or aluminum electrolytic capacitors can be used for bypassing. Larger Values will improve ripple rejection by bypassing the input to the regulator. Output Capacitor The EP1117 requires an output capacitor to maintain stability and improve transient response. The EP1117 output capacitor selection is dependent upon the ESR (equivalent series resistance) of the output capacitor to maintain stability. When the output capacitor is 10μF or greater, the output capacitor should have an ESR less than 1Ω. This will improve transient response as well as promote stability. A low-ESR solid Tantalum capacitor works extremely well and provides good transient response and stability over temperature. Aluminum electrolytes can also be used, as long as the ESR of the capacitor is less than 1Ω. The value of the output capacitor can be increased without limit. Higher capacitance values help to improve transient response and ripple rejection and reduce output noise. Ripple Rejection The curves for Ripple Rejection were generated using an adjustable device with the adjust pin bypassed. With a 22μF bypassing capacitor 75dB ripple rejection is obtainable at any output level. The impedance of the adjust pin capacitor, at the ripple frequency, should be < R1. R1 is normally in the range of 100Ω-200Ω. The size of the required adjust pin capacitor is a function of the input ripple frequency. At 120Hz, with R1=100Ω, the adjust pin capacitor should be 13mF. For fixed voltage devices, and adjustable devices without an adjust pin capacitor, the output ripple will increase as the ratio of the output voltage to the reference voltage (VOUT /VREF ). Rev.01 6/8 Preliminary EP1117 Thermal Considerations The EP1117 regulators have thermal protection to limit junction temperature to 150ºC. However, device functionality is only guaranteed to a maximum junction temperature of +125ºC. A heat sink may be required depending on the maximum power dissipation and maximum ambient temperature of the application. Figure 3 show for the SOT-223 the measured values θ(JA) for different copper area sizes using a 2 layers, 1.6mm, and 6Sq. cm FR-4 PCB with 2oz. copper and a ground plane layer on the backside area used for heat sinking. It can be used as a rough guideline in estimating thermal resistance. The SOT-223 packages use a copper plane on the PCB and the PCB itself as a heat sink. To optimize the heat sinking ability of the plane and PCB, solder the tab of the package to the plane. Figure 3. θ(JA) vs. copper area for SOT-223 package The thermal resistance for each application will be affected by thermal interactions with other components on the board. Some experimentation will be necessary to determine the actual value. The power dissipation of EP1117 is equal to : PD = (VIN - VOUT) x IOUT Maximum junction temperature is equal to : TJUNCTION = TAMBIENT + (PD x θ(JA)) Note: TJUNCTION must not exceed 125°C Safe Operation Area Using the experiment result of previous Thermal Consideration (choose the one with 1.5cm * 1.5cm polygene area) and θ(JA) = 50°C/W spec, the safe operation area of EP1117 in SOT-223 packages can be obtained as Figure 4. Figure 4. Safe Operation Area of EP1117 in SOT-223 packages (Limited by Power Dissipation with TJUNCTION < 125°C) Rev.01 7/8 Preliminary EP1117 Package Description SOT-223(ReferenceJEDECRegistrationSOT-223) Millimeters Inches Dim Min. Max. Min. Max. A 1.50 1.80 0.059 0.070 A1 0.02 0.08 0.001 0.003 B 0.60 0.80 0.023 0.031 B1 2.90 3.10 0.113 0.121 c 0.28 0.32 0.011 0.012 D 6.30 6.70 0.246 0.261 E 3.30 3.70 0.129 0.144 e 2.3 BSC 0.090 BSC E1 4.6 BSC 0.179 BSC H 6.70 7.30 0.261 0.285 L 0.91 1.10 0.035 0.043 K 1.50 2.00 0.059 0.078 α 0° 10° 0° 10° β 13° 13° Rev.01 8/8