BM2940A BOOKLY | Alldatasheet
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BOOKLY MICRO ELECTRONIC LIMITED CORP. GENERAL DESCRIPTION The BM2940A series of adjustable and fixed voltage regulators are designed to provide 1A output current and to operate down to 2.3V input-to-output differential. The input volage can up to +35V maximum. It has very good output short protect function than normal others LDO. And BM2490A can output larger current than normal LDO when same application condition. On-chip trimming adjusts the reference voltage to within 2% accuray. Current limit is also trimmed, minimizing the stress under overload conditions on both the regulator and power source circuitry. The BM2940A devices are pin compatible with other three-terminal SCSI regulators and are offered in the low profile surface mount SOT-223 package F E A T U R E S A P P L I C A T I O N S Three Terminal Adjustable or Fixed Voltages* High Efficiency Linear Regulators 3.3V or 5.0V Output Current of 1A Operates Down to 2.3V Dropout VGA Notebook Line Regulation: 0.2% Max. Battery Chargers Load Regulation: 0.4% Max. Battery Powered Instrumentation SOT-223 PIN DESCRIPTIONS FIXED VERSION 1- Vin 2- Ground 3- V out SOT-223 Top View 123 ABSOLUT MAXIMUM RATINGS(Note 1) Power Dissipation Input Voltage Operating Junction Temperature Control Section Power Transistor Storage temperature Internally limited 37V -15°C to 125°C 0°C to 150°C - 65°C to +150°C Soldering information Lead Temperature (10 sec) 300°C Thermal Resistance SOT-223 package φ JA= 90°C/W* * With package soldering to copper area over backside ground plane or internal power plane φJA can vary from 46°C/W to >90°C/W depending on mounting technique and the size of the copper area.
BOOKLY MICRO ELECTRONICS LIMITED CORP.
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at IOUT = 0 mA, and TJ = +25°C unless otherwise specified. Parameter Device Conditions Min Typ Max Units Output Voltage BM2940-5.0 0 ≤IOUT ≤1A , 6.5V ≤VIN ≤12V 4.800 5.000 5.200 V V Line Regulation BM2940-5.0 6.5V≤VIN ≤12V 10 50 % Parameter Device Conditions Min Typ Max Units Load Regulation (Notes 2, 3) BM2940-5.0 VIN=8V, 0≤IOUT ≤1A 10 100 % Dropout Voltage (VIN - VOUT) BM2940 -5.0 ∆VOUT , ∆VREF = 1%, IOUT = 1A (Note 4) 1.0 2.5 V Current Limit BM2940 -5.0 (VIN - VOUT) = 5V 900 1,000 1,500 mA Minimum Load Current BM2940 (V IN - VOUT) = 12V (Note 5) 5 10 mA Quiescent Current BM2940 -5.0 VIN ≤12V 10 15 mA Ripple Rejection BM2940 f =120Hz , COUT = 22µF Tantalum, IOUT = 1A, (VIN-VOUT ) = 3V, CADJ =10µF 60 75 dB BM2940-5.0 f =120Hz , COUT = 22µF Tantalum, IOUT = 1A, VIN = 6V 60 68 dB Thermal Regulation BM2940 TA = 25°C, 30ms pulse 0.008 0.04 %W Temperature Stability 1 % Parameter Device Conditions Min Typ Max Units Long Term Stability T A =125°C, 1000Hrs 0.3 1 % RMS Output Noise (% of VOUT ) TA=25°C, 10Hz ≤f ≤10kHz 0.003 % Thermal Resistance Junction-to-Case 15 °C/W Parameters identified with boldface type apply over the full operating temperature range. Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Note 2: Line and Load regulation are guaranteed up to t he maximum power dissipation of 1.2 W. Power dissipation is determined by the input/output differ ential and the output curren t. Guaranteed maximum power dissipation will not be available over the full input/output range. Note 3: See thermal regulation specifications for changes in output voltage due to he ating effects. Line and load regulation are measured at a constant junction temperature by low duty cycle pulse testing. Load regulation is measured at the output lead ~1/8” from the package. Note 4: Dropout voltage is specified over the full output current range of the device.
BOOKLY MICRO ELECTRONICS LIMITED CORP. Note 5: Minimum load current is defined as the minimum output current required to maintain regulation. When 2.5V≤ (VIN - VOUT) ≤20V the device is guaranteed to regulate if the output current is greater than 10mA. APPLICATION HINTS The BM2940 series of adjustable and fixed regulators are easy to use and are protected against short circuit and thermal overloads. Thermal prot ection circuitry will s hut-down the regulator should the junction temperature exceed 165°C at the sense point. Pin compatible with older three terminal adj ustable regulators, these devices offer the advantage of a lower dropout voltage, more precise reference tolerance and improved reference stability with temperature. Stability The circuit design used in the BM2940 series requires the use of an output capacitor as frequenc y compensation. The addition of 10µF tantalum or 22-220uF aluminum on the output will ensure stability for all operating conditions. When adjustment terminal is bypassed with a capacitor to improve ripple rejection, the requirement for output capacitor increase. The value of 22µF tantalum or 100uF aluminum covers all cases of bypassing the adjustment terminal. Without bypassing the adjustment terminal smaller capacitors can be used with equally good results. To ensure good transient response with heavy loa d current changes capacito r values on the orde r of 100mF are used in the output of many r egul ators. To furthe r improve stability and transient response of these devices lar ger values of output capacitor can be used. Protection Diodes Unlike older regulators, the BM2940 family does not need any protection diodes between the ad justment pin and the output and from the output to the input to prevent over-stressing the die. Internal resistors are limiting the internal .current paths on t he BM2940 adjustment pin, therefore even with capacitors on the adjustment pin no protection diode is needed to ensure device safety unde r short-circuit conditions. Diodes between the input and output are not usually need ed. Microsecond surge currents of 50A to 100A can be handled by the internal diode between the input and output pins of the device. In normal operations it is diffic ult to get those values of surge currents even with the use o f large output capacitances. If high value output capacitors are used, such as 1000mF to 5000mF and the input pin is instantaneously shorted to ground,
BOOKLY MICRO ELECTRONICS LIMITED CORP. Table 1. COPPER AREA TOP SIDE* BACK SIDE BOARD AREA THERMAL RESISTANCE (JUNCTION-TO-AMBIENT) 2500 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 1000 Sq. mm 2500 Sq. mm 2500 Sq. mm 45°C/W 225 Sq. mm 2500 Sq. mm 2500 Sq. mm 53°C/W 100 Sq. mm 2500 Sq. mm 2500 Sq. mm 59°C/W 1000 Sq. mm 1000 Sq. mm 1000 Sq. mm 52°C/W 1000 Sq. mm 0 1000 Sq. mm 55°C/W Ripple Rejection The ripple rejection values are measured with the adjustment pin bypassed. The impedance of the adjust pin capacitor at t he ripple frequency should be less t han the value of R1 (normally 100Ωto 200Ω) for a proper bypassing and ripple reject ion approaching the va lues shown. The size of the required adjust pin capacitor is a function of the input ripple frequency. If R1=100Ω at 120Hz the adjust pin capacitor should be >13mF. At 10kHz only 0.16mF is needed. The ripple rejection will be a f unction of output voltage, in circuits without an adjust pin bypass capacitor. The output ripple will increase directly as a ratio of the output voltage to the reference voltage (VOUT / VREF ). PACKAGE DIMENSIONS Inches (millimeters) unless otherwise noted.