eorex EP1117 1A Low Dropout Linear Regulator Features Description • 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 • On-chip Thermal Limiting: 150°C Typ. • Adjustable Output: 1.25~10.7V • Standard 3-pin SOT-223 and TO252 Power Packages 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, 3.3V and 5.0V. 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 and TO-252 power packages. Applications • PC peripheral • Low Voltage Logic Supplies • Post Regulator for Switching Power Supply Typical Application Fixed Mode Regulator 1.25V to 10.7V Adjustable Regulator VOUT VIN VIN VOUT EP1117 10uF R1 120Ω FB R2 120Ω ⎛ ⎝ VOUT= VREF × ⎜1 + 100uF R2 ⎞ ⎟ R1 ⎠ VREF =1.25V R1≒100Ω~200Ω Jul. 2006 www.eorex.com 1/10 eorex EP1117 Pin Assignment Ordering Information Pin Description Pin Name Function 1 FB/GND A resistor divider from this pin to the Vout pin and ground sets the output voltage. (Ground only for Fixed-Mode) 2 VOUT The output of the regulator. A minimum of 10uF capacitor (0.15Ω ≤ ESR ≤ 20Ω) must be connected from this pin to ground to insure stability. VIN The input pin of regulator. Typically a large storage capacitor (0.15Ω ≤ ESR ≤ 20Ω) is connected from this pin to ground to insure that the input voltage does not sag below the minimum dropout voltage during the load transient response. This pin must always be 1.3V higher than Vout in order for the device to regulate properly. 3 Jul. 2006 www.eorex.com 2/10 eorex EP1117 Absolute Maximum Rating (Note 1) Symbol Item Rating VI Input Voltage TJ Operating Junction Temperature Range Control Section Power Transistor TSTG Storage Temperature Range (Note 2) Units 15 V 0 ~ +125 0 ~ +150 °C -65 ~ +150 °C TL Lead Temperature (Soldering, 10s) +260 °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 (Note 3) Unless otherwise noted, these specifications apply over CIN = 10μF, COUT = 10μF, and TA=0°C to 70°C. Typical values refer to TA=25°C. Symbol VREF VOUT REGLINE Parameter Min. Typ. Max. Units TJ=0°C ~125°C, 10mA≤IOUT≤1A, 1.4V≤(VIN -VOUT) ≤10.75V 1.225 1.250 1.275 V EP1117-18 TJ=0°C ~125°C, 0≤IOUT≤1.5A, 3.25V≤VIN ≤9V 1.764 1.800 1.836 EP1117-25 TJ=0°C ~125°C, 0≤IOUT≤ 1A, 3.95V≤VIN≤9V 2.450 2.500 2.550 EP1117-33 TJ=0°C ~125°C, 0≤IOUT≤1A, 4.75V≤VIN ≤12V 3.235 3.300 3.365 EP1117-50 TJ=0°C ~125°C, 0≤IOUT≤1A, 6.5V≤VIN ≤12V 4.900 5.000 5.100 EP1117-adj IOUT=10mA, 1.5V≤ (Note4) (VIN -VOUT)≤10.75V 0.03 0.2 EP1117-18 IOUT=0A, (Note4) 3.25V≤VIN≤9V 1 6 EP1117-25 IOUT=0A, (Note4) 3.95V≤VIN≤9V 1 6 EP1117-33 IOUT=0A, (Note4) 4.75V≤VIN≤12V 1 6 EP1117-50 IOUT=0A, (Note4) 6.5V≤VIN≤12V 1 10 Reference Voltage Output Voltage Line Regulation Conditions Jul. 2006 V % mV www.eorex.com 3/10 eorex EP1117 Electrical Characteristics (Continued) (Note 3) Unless otherwise noted, these specifications apply over CIN = 10μF, COUT = 10μF, and TA=0°C to 70°C. Typical values refer to TA=25°C. Symbol REGLOAD VD ILIMIT Parameter Load Regulation Conditions Min. Typ. Max. Units % EP1117 (VIN -VOUT)=3V, (Note4) 0≤IOUT≤1A 0.1 0.4 EP1117-18 VIN=3.25V, (Note4) 0≤IOUT≤1A 1 10 EP1117-25 VIN=3.95V, (Note4) 0≤IOUT≤1A 1 10 EP1117-33 VIN=4.75V, (Note4) 0≤IOUT≤1A 1 10 EP1117-50 VIN=6.5V, (Note4) 0≤IOUT≤1A 1 15 1 1.05 1.1 1.1 1.2 1.3 mV Dropout Voltage IOUT=100mA (Note5) IOUT=500mA IOUT=1A Current Limit (VIN -VOUT)=5V, TJ=25°C 1.1 V A FB Pin Current (VIN -VOUT)=3V, IOUT=10mA 60 120 μA ∆IFB FB Pin Current Change 10mA≤IOUT≤1A, 1.4V≤(VIN -VOUT)≤10.75V 0.2 5 μA IO Minimum Load Current (VIN -VOUT)=10.75V 5 10 mA Ripple Rejection fRIPPLE=120Hz, VRIPPLE= 1VP-P, (VIN -VOUT)=3V TR Thermal Regulation TJ=25°C, 30ms Pulse TS Temperature Stability LS Long-Term Stability TJ=125°C, 1000Hrs VN RMS Output Noise TJ=25°C, 10Hz≤F≤10KHz, (% of VOUT) θth Thermal Resistance Junction to case, at Tab junction to ambient θJA Thermal Resistance OT Over Temperature Point IFB PSRR SOT-223 TO-252 (Note6) Junction-to-Ambient (No heat sink ;No air flow) 60 75 0.01 dB 0.02 %/W 0.5 % 0.3 % 0.003 % 15 °C/W 117 92 150 °C/W °C 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. Jul. 2006 www.eorex.com 4/10 eorex EP1117 Typical Performance Characteristics Functional Block Diagram Jul. 2006 www.eorex.com 5/10 eorex EP1117 Output Voltage The EP1117 develops a 1.25V reference voltage between the output and the FB 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. ⎛ ⎝ VOUT= VREF × ⎜1 + R2 ⎞ ⎟ +IFBR2 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×(1+R2/R1), where RP is Parasitic Line Resistance. Rp Parasitic Line Resistance VIN VIN VOUT EP1117 FB R1 Connect R1 to Case RL R2 Connect R2 to Load Figure 2-Connections for Best Load Regulation Jul. 2006 www.eorex.com 6/10 eorex EP1117 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 FB pin bypassed. With a 22μF bypassing capacitor 75dB ripple rejection is obtainable at any output level. The impedance of the FB pin capacitor, at the ripple frequency, should be<R1. R1 is normally in the range of 100Ω-200Ω. The size of the required FB pin capacitor is a function of the input ripple frequency. At 120Hz, with R1=100Ω, the FB pin capacitor should be 13μF. For fixed voltage devices, and adjustable devices without a FB pin capacitor, the output ripple will increase as the ratio of the output voltage to the reference voltage (VOUT/VREF). 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 and 4 show for the SOT-223 and TO-252 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. Both the SOT-223 and TO-252 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 Jul. 2006 www.eorex.com 7/10 eorex EP1117 Figure 4-θ(JA) vs copper area for TO-252 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) × IOUT Maximum junction temperature is equal to: TJUNCTION = TAMBIENT + (PD × θ(JA)) Note: TJUNCTION must not exceed 125°C Safe Operation Area 2.80 2.95 3.10 2.50 2.65 2.35 2.05 2.20 1.75 1.90 1.45 1.60 1.00 1.15 1.30 0.85 Output Current (mA) 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 and TO-252 packages can be obtained as Figure 5. Figure 5-Safe Operation Area of EP1117 in SOT-223 and TO-252 packages (Limited by Power Dissipation with TJUNCTION < 125°C) Jul. 2006 www.eorex.com 8/10 eorex EP1117 Package Description SOT-223 (Reference JEDEC Registration SOT-223) D B1 H E K e e1 A A1 α L c β B DIM MILLIMETERS INCHES MIN. NOM. MAX. MIN. NOM. MAX. A 1.50 − 1.80 − 0.070 A1 0.02 − 0.08 0.059 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 6.30 6.70 0.246 3.30 − 3.70 0.129 − − − 0.012 − D E e 2.30 REF. e1 4.60 REF. 0.261 0.144 0.090 REF. 0.179 REF. 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° Jul. 2006 www.eorex.com 9/10 eorex EP1117 Package Description (Continued) TO-252 D b L2 E L1 b1 e e1 A1 L H c A Seating Plane DIM MILLIMETERS MIN. NOM. c1 INCHES MAX. MIN. NOM. MAX. A 2.18 2.29 2.40 0.094 0.89 − 1.14 0.086 0.035 0.090 A1 − 0.045 b 5.20 5.35 5.50 0.205 0.211 0.217 b1 0.61 TYP. 0.024 TYP. c 0.45 0.52 0.58 0.018 0.020 0.023 c1 0.45 0.52 0.58 0.018 0.020 0.023 D 6.35 6.58 6.80 0.250 0.259 0.268 E 5.40 5.57 6.20 0.213 0.219 0.244 e 2.28 REF. e1 4.57 REF. 0.090 REF. 0.180 REF. H 9.00 9.70 10.40 0.354 L 0.51 − − 0.020 − − L1 0.64 0.83 1.02 0.025 0.033 0.040 L2 0.88 − 1.27 0.035 − 0.050 Jul. 2006 0.382 0.409 www.eorex.com 10/10