EUP7903 300mA High PSRR LDO Regulators DESCRIPTION FEATURES The EUP7903 is a high current, low-dropout (LDO) linear regulator with fast transient response and high PSRR. It offers high output accuracy, extremely low dropout voltage, low quiescent current and fast start-up time. The EUP7903 is designed to work with low-ESR ceramic capacitors, reducing the amount of the PCB area necessary for power applications. Only a 1uF ceramic output capacitor can make the device stable over the whole load range. EUP7903 can be externally set either fixed output mode or adjustable output mode. Connect FB pin to GND to select the fixed output mode. Its output is one of pre-set values: 1.25V~5V (50mV per step). Operated in the adjustable mode when the FB pin is connected to an external resistors divider, its output can be adjusted from 1.25V to 5V. Other key features include over-current protection, thermal shutdown. The device is available in the small SOT23-5 package. z z z z z z 2.5V to 5.5V Input Voltage Range 180mV@300mA Dropout Voltage Excellent Transient Response Stable with 1uF Ceramic Output Capacitor 70dB PSRR at 1kHz Low 90µA Quiescent Current z Low Shutdown Current：<1µA z z z Output Current Limit Short Circuit Protection Output Voltage With High Accuracy: 2% Initial Accuracy Fixed Output Voltage：1.25V~5V (0.05V step) z z z Adjustable Output Voltage: 1.25V~5V Thermal Shutdown Output Auto-Discharge in Shutdown RoHS Compliant and 100% Lead (Fb)-Free APPLICATIONS z z z z z z Cellular Phones Bluetooth portable radios and Accessories Battery-Powered Equipment Laptop, Palmtops, Notebook Computer PDAs Digital still Camera and Video Recorders Typical Application Circuit Figure. 1 Adjustable Output DS7903 Ver 1.0 Nov. 2008 1 EUP7903 Typical Application Circuit (continued) Figure. 2 Fixed Output Block Diagram Figure. 3 DS7903 Ver 1.0 Nov. 2008 2 EUP7903 Pin Configurations Package Type Pin Configurations SOT23-5 Pin Description PIN SOT23-5 DESCRIPTION EN 1 Enable Pin. Connect this pin to ground or less than 0.4V to disable the device, connect EN to 1.5V or above to enable the device. GND 2 Signal Ground. IN 3 Input Supply of the LDO. OUT 4 Output of the LDO. FB 5 Feedback pin. This pin is the anode terminal of the error amplifier. The FB pin compares with internal reference voltage to regulate the output voltage. Connect to GND for fixed output voltage version. DS7903 Ver 1.0 Nov. 2008 3 EUP7903 Ordering Information Order Number Package Type EUP7903-15VIR1 SOT23-5 EUP7903-18VIR1 SOT23-5 EUP7903-25VIR1 SOT23-5 EUP7903-28VIR1 SOT23-5 EUP7903-33VIR1 SOT23-5 EUP7903VIR1 SOT23-5 EUP7903-XXVIR1 SOT23-5 Marking xxxxx AD1C xxxxx AD1D xxxxx AD1B xxxxx AD1E xxxxx AD1H xxxxx AD1A xxxxx xxxx Operating Temperature Range -40 °C to +85°C -40 °C to +85°C -40 °C to +85°C -40 °C to +85°C -40 °C to +85°C -40 °C to +85°C -40 °C to +85°C EUP7903 - □ □ □ □ □ □ Lead Free Code 1: Lead Free 0: Lead Packing R: Tape & Reel Operating temperature range I: Industry Standard Package Type V: SOT-23 Output Voltage 15:1.5V 18:1.8V 25:2.5V 28:2.8V 33:3.3V XX: Voltage Options (1.25V to 5V, 0.05V per step) Note：Every EUP7903 version can operate at adjustable mode by connecting FB pin to an external resistor divider. DS7903 Ver 1.0 Nov. 2008 4 EUP7903 Absolute Maximum Ratings (1) VIN,VEN --------------------------------------------------------------------------------------------0.3V to 6V VOUT -------------------------------------------------------------------------------------- -0.3V to (VIN+0.3V) Junction Temperature -------------------------------------------------------------------------------+150℃ Storage Temperature Range ----------------------------------------------------------------- -65℃ to +150℃ Lead Temperature ----------------------------------------------------------------------------------+260℃ Thermal Resistance θJA (SOT23-5) --------------------------------------------------------------220℃/W ESD Rating Human Body Model ------------------------------------------------------------------------2kV Recommend Operating Conditions (2) VIN ------------------------------------------------------------------------------------------------ 2.5V to 5.5V VEN -----------------------------------------------------------------------------------------------0V to 5.5V Operating Temperature Range --------------------------------------------------------------- -40℃ to +85℃ Note (1): Stress beyond those listed under “Absolute Maximum Ratings” may damage the device. Note (2): The device is not guaranteed to function outside the recommended operating conditions. Electrical Characteristics TA=25℃, VIN=VOUT+1V, or VIN=2.5V for VOUT<1.5V unless otherwise specified. Symbol Parameter Input Voltage VIN Input Voltage IQ Quiescent Current ISHDN Shutdown Current Power Supply Ripple PSRR Rejection VFB FB Pin Voltage Enable VENH Enable High Voltage VENL Disable Low Voltage IEN EN Input Current TST Start-up Time Output voltage VOUT Output Voltage Accuracy VLNR Output Line Regulation VLDR Output Load Regulation Conditions EUP7903 Min. Typ. Max. 2.5 VEN=3.5V, IOUT=0mA VEN=0V VIN=VNOM+1VP-P,f=100Hz, ILOAD=10mA 90 0.1 75 1.225 1.25 Nov. 2008 dB 1.275 V 0.4 1 V V µA µs 1.5 VIN=VOUT+1V, IOUT=10mA VIN=VOUT+1V, IOUT=10mA, TA =-40℃ to +85℃ VOUT+0.5V<VIN<5.5V, IOUT=10mA 1mA < IOUT <300mA, VIN=VNOM+1.0V -2 +2 % -3 +3 % 0.01 0.1 %/V 10 16 mV 240 mV -1 0.2 40 Dropout Voltage (3) 180 IOUT=300mA (Applied for VOUT≥2.3V) IOUTMAX Maximum Output Current 300 Protection ILIMIT Current Limit 330 500 TSD Thermal Shutdown Temperature No Load, VIN=VEN=5V 155 TSDHYS Thermal Shutdown Hysteresis No Load, VIN=VEN=5V 30 Note (3): Dropout is defined as VIN-VOUT when VOUT is 2% below the value of VOUT for VIN=VOUT+0.5V. Ver 1.0 V µA µA Over temperature range Over temperature range VIN=3.5V, VEN=3.5V or 0V VIN=3.5V, VOUT=2.5V VDROP DS7903 5.5 130 1 Unit 5 mA mA ℃ ℃ EUP7903 Typical Characteristics Time (4ms/div) Time (40µs/div) DS7903 Ver 1.0 Nov. 2008 6 EUP7903 Typical Characteristics (continued) Thermal Shutdown Cycle Time (40ms/div) Time (100µs/div) Time (400µs/div) DS7903 Ver 1.0 Nov. 2008 7 EUP7903 Detailed Function Description The EUP7903 is a high output current, low dropout linear regulator with fast transient response and high PSRR. It offers high output accuracy, extremely low dropout voltage, low quiescent current and fast start-up time. It is designed to work with low-ESR ceramic capacitor, reducing the amount of the PCB area. Only a 1uF ceramic capacitor can make the device stable over the whole load range. As shown in the function block diagram, the EUP7903 is composed of the bandgap reference voltage, the error amplifier, P-channel MOSFET pass transistor, internal resistor divider and some additional protection circuits. The reference voltage, connected to the cathode terminal of the error amplifier, compares with the feedback voltage to regulate the output voltage to make it constant over the whole load range. If the feedback voltage is lower than the reference voltage, the pass transistor gate is pulled low to increase its conductivity. This allows more current to flow to the output and increases the output voltage. If the feedback voltage is higher than the reference voltage, the pass transistor allows less current to flow to the output. The feedback point is the output of the internal or external resistor divider connected to the VOUT pin. Enable/Shutdown The EUP7903 is disabled when the EN pin is connected to ground or the voltage less than 0.4V, and the quiescent current is less than 1uA. Connect EN pin to 1.5V or higher to enable the device. Output Soft stop When the regulator is disabled, an internal 400Ω resistor is connected between VOUT and GND. To discharge output capacitor COUT. Adjustable Output Voltage EUP7903 has a wide output voltage range. The output voltage is programmed by an external resistor divider as shown in Figure 1. The output voltage can be calculated by the following equation: VOUT = (1 + R1 ) × VREF R2 Figure. 4 Output Voltage Select Circuit Fixed Output Voltage When the FB voltage is less than 220mV, EUP7903 will operate in the fixed output mode, its output is one of pre-set values: 1.25V~5V. There is no external component needed to set the output voltage. Current Limit The EUP7903 includes a current limit circuit to monitor the gate voltage of the pass transistor to limit the output current. When the output current is higher than the over-current limit, the circuit will clamp the gate voltage of the pass transistor to limit the output current. The typical output current limit is 500mA. Thermal Shutdown The EUP7903 monitors internal temperature. When the junction temperature exceeds 155℃, the over temperature protection (OTP) circuit turn off the pass transistor until the device is cooled down by 30℃. Then the pass transistor resumes. For continue operation, do not exceed absolute maximum junctiqwk iknf on temperature. Application Information Resistor Select Choose R2=100k to optimize accuracy, power supply rejection, noise and power consumption. And the R1 can be chosen by: R1 = R 2 ( Ver 1.0 Nov. 2008 (EQ.2) where VREF is the internal reference voltage, which is 1.25V in EUP7903. External Capacitor The EUP7903 requires external capacitors for stability. It is specifically designed to work with low-ESR capacitors requiring minimum PCB area. Input capacitor A 1uF ceramic capacitor or higher is required between the VIN pin and the GND pin. Place it as close as possible to the device. There are no requirements for the ESR on the input capacitor, but the tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance is 1uF over the whole operating temperature range. (EQ.1) Where VREF is the internal reference voltage, which is 1.25V in EUP7903. DS7903 VOUT − 1) VREF 8 EUP7903 Output capacitor The EUP7903 is designed specifically to work with very small ceramic output capacitors. A 1uF to 10uF capacitor with 5mΩ to 500mΩ ESR range is suitable for the most EUP7903 applications. The ESR of a typical 1uF ceramic capacitor is around 20mΩ, which easily meets the ESR requirement for stability. Capacitor characteristics More consideration should be taken when selecting the capacitor because its capacitance can vary with temperature. The capacitor type X7R or X5R, which operates over a temperature range of -40℃ to +85℃, will only vary within ±15%. However Z5U or T5V temperature characteristics. Their capacitance can drop by more than 50% as the temperature goes from 25℃ to 85℃. Therefore the capacitor type X7R or X5R is recommended in applications where the ambient temperature will change significantly above or below 25℃. No load Stability The EUP7903 will remain stable and in regulation with no external load. This is special important in CMOS RAM keep-alive applications. PD ( MAX ) = (125°C − 25°C) / 220 = 0.445W (EQ.5) for SOT23-5 package The maximum power dissipation depends on operating ambient temperature for fixed TJ(MAX) and thermal resistance θJA. For EUP7903 packages, the Figure 5 of derating curves allows the designer to see the effect of rising ambient temperature on the maximum power allowed. Maximum Power Dissipation(W) 0.6 (EQ.3) (EQ.4) Where TJ(MAX) is the maximum operation junction temperature 125°C, TA is the ambient temperature and the θJA is the junction to ambient thermal resistance. For recommended operating conditions specification of EUP7903, where TJ(MAX) is the maximum junction temperature of the die (125°C) and TA is the operated ambient temperature. The junction to ambient thermal resistance θJA is layout dependent. For SOT-23-5 package, the thermal resistance θJA is 220°C/W on the standard thermal test board. The maximum power dissipation at TA = 25°C can be calculated by following formula : Nov. 2008 0.2 0.1 0 25 50 75 100 o 125 150 Figure. 5. Power Dissipation for EUP7903 Package The EUP7903 is available in the SOT23-5 package. PD ( MAX) = (TJ ( MAX) − TA ) θ JA Ver 1.0 0.3 Ambient Temperature( C) The maximum power dissipation depends on the thermal resistance of IC package, PCB layout, the rate of surroundings airflow and temperature difference between junction and ambient. The maximum power dissipation can be calculated by following formula : DS7903 SOT23-5 0.4 0.0 Thermal Considerations Thermal protection limits power dissipation in EUP7903.When the device junction temperature exceeds 155°C, the OTP circuit starts the thermal shutdown function and turns the pass transistor off. The pass transistor turns on again after the junction temperature cools down 30°C. For continuous operation, do not exceed absolute maximum junction temperature 150°C. The power dissipation definition in device is: PD = ( VIN − VOUT ) × I OUT + VIN × I Q 0.5 9 EUP7903 Packaging Information SOT23-5 SYMBOLS A A1 D E1 E L b e DS7903 Ver 1.0 Nov. 2008 MILLIMETERS MIN. MAX. 1.30 0.00 0.15 2.90 1.60 2.60 3.00 0.30 0.60 0.30 0.50 0.95 10 INCHES MIN. 0.000 MAX. 0.052 0.006 0.114 0.063 0.102 0.012 0.012 0.118 0.024 0.020 0.037