BL2940 1A Low-Dropout Voltage Regulator General Description The BL2940 is a low dropout regulator designed to provide output current up to 1A with a typical 500mV dropout Voltage and a maximum of 1V. It is capable of reducing the ground current when the differential between the input voltage and the output voltage outrun 3V. The BL2940 offers low quiescent current (typical current 30mA at 1A and an 1 1 SOT-223 TO-252 input-output differential of 5V). Higher quiescent currents only exist when the regulator is in the dropout mode (VIN-VOUT≤3V). 1 The BL2940 is available in SOT-223 ,TO-252 ,TO-220 and TO-263 package. Features 500mV Typical Dropout at 1A Output Current In Excess of 1A Low Quiescent Current Reverse-Battery Protection Current Limit and Thermal Shutdown Mirror Image Insertion Protection 1 TO-220 TO-263 Applications Powering VGA & Sound Card LCD Monitor Battery Powered Equipments / Laptop & Notebook SMPS Post Regulator / DC to DC Modules High Efficiency Linear Power Supply Adjustable Power Supply Bar Code Scanners www. belling. com. cn Page 1 of 15 BL2940 Functional Block Diagram Pin Configuration SOT-223 TO-220 www. belling. com. cn TO-252 TO-263 Page 2 of 15 BL2940 Pin Description Pin Number SOT-223、TO-252 TO-220、TO-263 Pin Name Function Description 1 INPUT Input pin 2 GND Ground 3 OUTPUT Output pin Absolute Maximum Ratings (Ta=25℃) Parameter Name Input Voltage Internal Power Dissipation Maximum Junction Temperature Storage Temperature Range Operating Temperature *Note Symbol Vin PD TJ TSTG SOT-223 TO-252 TO-220 TO-263 TOPR Value 26 Internally limited 150 -65 ~ +150 -40 ~ +85 -40 ~ +125 -40 ~ +125 -40 ~ +125 Unit V ℃ ℃ ℃ Note：Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. www. belling. com. cn Page 3 of 15 BL2940 Electrical Characteristics (VIN=VO+5V, IOUT=1A, CO=22µF, TA = TJ = 25℃, Unless otherwise specified. ) Parameter Name Symbol Output Voltage Vout Line Regulation LNR Load Regulation LDR Output Impedance Ro Quiescent Current IQ Output Noise Voltage Ripple Rejection Long Term Stability RR Dropout Voltage VD Short Circuit Current Maximum Line Transient Reverse Polarity DC Input Voltage Reverse Polarity Transient Input Voltage eN Test Conditions 5mA≤IO≤1A BL2940-5V Min Max Min Typ Max Unit 6.25V ≤ VIN ≤ 26V 4.85 5.00 5.15 9.4V ≤ VIN ≤ 26V 7.76 8.00 8.24 V 20 50 20 80 mV 35 50 55 80 mV VO+2V ≤ VIN ≤ 26V IO = 5mA 50mA ≤ IO ≤ 1A 100mADC and 20mArms, fO =120Hz 35 VO+2V ≤ VIN ≤ 26V IO =5mA 10Hz ~ 100kHz, IO =5mA fO =120Hz, 1Vrms IO =100mA Typ BL2940-8V 10 15 10 150 60 mΩ 55 72 54 15 mA 240 µVrms 66 dB IO =1A 0.5 0.8 0.5 0.8 mV/ 1000Hr V IO =100mA 110 150 110 150 mV 20 Isc 32 1.6 1.9 1.6 1.9 A 60 75 60 75 V TIN RO =100Ω T ≤ 100ms VRIN RO =100Ω -30 -15 -30 -15 V VTRRI RO =100Ω T ≤ 100ms -75 -50 -75 -50 V Note: Output current will decrease with temperature increase but will not drop below 1A at the maximum specified temperature. www. belling. com. cn Page 4 of 15 BL2940 Electrical Characteristics (Cont.) (VIN=VO+5V, IO=1A, CO=22µF, TA = TJ = 25℃, unless otherwise specified. ) Parameter Name Symbol Output Voltage Vout Line Regulation LNR Load Regulation LDR Output Impedance Ro Quiescent Current IQ Output Noise Voltage eN Ripple Rejection RR Test Conditions 5mA ≤ IO ≤ 1A BL2940-9V Min Short Circuit Current Maximum Line Transient Reverse Polarity DC Input Voltage Reverse Polarity Transient Input Voltage Min Max Unit V 20 90 20 100 mV 60 90 65 100 mV 60 VO+2V≤VIN≤26V IO =5mA 10 15 10 270 52 mΩ 65 64 51 15 mA 300 µVrms 63 dB IO =1A 0.5 0.8 0.5 0.8 mV/ 1000Hr V IO =100mA 110 150 110 150 mV 34 VD Typ 11.5V ≤ VIN ≤ 26V 9.70 10.0 10.3 Long term Stability Dropout Voltage Max 10.5V ≤ VIN ≤ 26V 8.73 9.00 9.27 VO+2V≤VIN≤26V IO =5mA 50mA≤IO≤1A 100mADC and 20mArms, fO =120Hz 10Hz ~ 100kHz, IO =5mA fO =120Hz, 1Vrms IO =100mA Typ BL2940-10V Isc 36 1.6 1.9 1.6 1.9 A 45 55 45 55 V TIN RO =100Ω T≤1ms VRIN RO =100Ω -30 -15 -30 -15 V VTRRI RO =100Ω T≤1ms -55 -45 -55 -45 V Note: Output current will decrease with temperature increase but will not drop below 1A at the maximum specified temperature. www. belling. com. cn Page 5 of 15 BL2940 Electrical Characteristics (Cont.) (VIN=VO+5V, IO=1A, CO=22µF, TA = TJ = 25℃, Unless otherwise specified. ) Parameter Name Symbol Output Voltage Vout Line Regulation LNR Load Regulation LDR Output Impedance Ro Quiescent Current IQ Output Noise Voltage eN Ripple Rejection RR Test Conditions 5mA≤IO≤1A BL2940-12V Min Min VD Max Unit V 20 120 20 150 mV 55 120 70 150 mV 80 VO+2V≤VIN≤26V IO =5mA 10 15 10 360 54 mΩ 100 66 52 15 mA 450 µVrms 64 dB IO =1A 0.5 0.8 0.5 0.8 mV/ 1000Hr V IO =100mA 110 150 110 150 mV 48 Dropout Voltage Typ 16.75V≤VIN≤26V 14.55 15.0 15.45 Long term Stability Short Circuit Current Maximum Line Transient Reverse Polarity DC Input Voltage Reverse Polarity Transient Input Voltage Max 13.6V≤VIN≤26V 11.64 12.0 12.36 VO+2V≤VIN≤26V IO =5mA 50mA≤IO≤1A 100mADC and 20mArms, fO =120Hz 10Hz-100kHz, IO =5mA fO =120Hz, 1Vrms IO =100mA Typ BL2940-15V Isc 60 1.6 1.9 1.6 1.9 A 45 55 45 55 V TIN RO =100Ω T≤1ms VRIN RO =100Ω -30 -15 -30 -15 V VTRRI RO =100Ω T≤1ms -55 -45 -55 -45 V Note: Output current will decrease with temperature increase but will not drop below 1A at the maximum specified temperature. www. belling. com. cn Page 6 of 15 BL2940 Typical Application BL2940 Note：1.C1 is required if regulator is located far from power supply filter. 2.COUT must be higher than 22μF for stability, and locate as close as possible to the regulator. Application Information External Capacitors The output capacitor is critical to maintaining regulator stability, and must meet the required conditions for both ESR (Equivalent Series Resistance) and minimum amount of capacitance. Minimum Capacitance: The minimum output capacitance required to maintain stability is 22 μF (this value may be increased without limit). Larger values of output capacitance will give improved transient response. ESR Limits: The ESR of the output capacitor will cause loop instability if it is too high or too low. The acceptable range of ESR plotted versus load current is shown in the graph below. It is essential that the output capacitor meet these requirements, or oscillations can result. ESR Limits www. belling. com. cn Page 7 of 15 BL2940 It is important to note that for most capacitors, ESR is specified only at room temperature. However, the designer must ensure that the ESR will stay inside the limits shown over the entire operating temperature range for the design. For aluminum electrolytic capacitors, ESR will increase by about 30X as the temperature is reduced from 25°C to −40°C. This type of capacitor is not well-suited for low temperature operation. Solid tantalum capacitors have a more stable ESR over temperature, but are more expensive than aluminum electrolytics. A cost-effective approach sometimes used is to parallel an aluminum electrolytic with a solid Tantalum, with the total capacitance split about 75/25% with the Aluminum being the larger value. If two capacitors are paralleled, the effective ESR is the parallel of the two individual values. The “flatter” ESR of the Tantalum will keep the effective ESR from rising as quickly at low temperatures. www. belling. com. cn Page 8 of 15 BL2940 Characteristics Curve www. belling. com. cn Page 9 of 15 BL2940 www. belling. com. cn Page 10 of 15 BL2940 www. belling. com. cn Page 11 of 15 BL2940 www. belling. com. cn Page 12 of 15 BL2940 Outline Dimensions TO-252 www. belling. com. cn Unit: mm Page 13 of 15 BL2940 SOT-223 TO-220 www. belling. com. cn Unit: mm Unit: mm Page 14 of 15 BL2940 TO-263 www. belling. com. cn Unit: mm Page 15 of 15