LA5771MP

Ordering number : EN8273A Monolithic Linear IC LA5771MP Overview Separately-excited Step-down Switching Regulator (3.3V) The LA5771MP is a separately-excited step-down switching regulator (3.3V). Features • High efficiency • Four external parts • Time-base generator (160kHz) incorporated • Current limiter incorporated • Thermal shutdown circuit incorporated • Soft start circuit incorporated Specifications Absolute Maximum Ratings at Ta = 25°C Parameter Input voltage Output current SW pin application reverse voltage Allowable power dissipation Operating temperature Storage temperature Symbol VIN max IO max Vsw Pd max Topr Tstg Mounted on the specified board * Conditions Ratings 30 3 -1 3.9 -30 to +125 -40 to +150 Unit V A V W °C °C * Mounted on a specified board: 114.3mm×76.1mm×1.6mm, Copper foil ratio 60% FR4 Recommended Operating Conditions at Ta = 25°C Parameter Input voltage range VIN Symbol Conditions Ratings 5.5 to 28 Unit V Any and all SANYO Semiconductor Co.,Ltd. products described or contained herein are, with regard to "standard application", intended for the use as general electronics equipment (home appliances, AV equipment, communication device, office equipment, industrial equipment etc.). The products mentioned herein shall not be intended for use for any "special application" (medical equipment whose purpose is to sustain life, aerospace instrument, nuclear control device, burning appliances, transportation machine, traffic signal system, safety equipment etc.) that shall require extremely high level of reliability and can directly threaten human lives in case of failure or malfunction of the product or may cause harm to human bodies, nor shall they grant any guarantee thereof. If you should intend to use our products for applications outside the standard applications of our customer who is considering such use and/or outside the scope of our intended standard applications, please consult with us prior to the intended use. If there is no consultation or inquiry before the intended use, our customer shall be solely responsible for the use. Specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein stipulate the performance, characteristics, and functions of the described products in the independent state, and are not guarantees of the performance, characteristics, and functions of the described products as mounted in the customer' s products or equipment. To verify symptoms and states that cannot be evaluated in an independent device, the customer should always evaluate and test devices mounted in the customer' s products or equipment. 13107 MS IM B8-8794 No.8273-1/5 LA5771MP Electrical Characteristics at Ta = 25°C Parameter Output voltage Efficiency Switching frequency Line regulation Load regulation Output voltage temperature coefficient Ripple attenuation factor Current limiter operating voltage Thermal shutdown operating temperature Thermal shutdown hysteresis width VO η f ∆VOLINE ∆VOLOAD ∆VO/∆Ta RREJ IS TSD ∆TSD Symbol Conditions min VIN=15V, IO=1.0A VIN=15V, IO=1.0A VIN=15V, IO=1.0A VIN=8 to 20V, IO=1.0A VIN=15V, IO=0.5 to 1.5A Designeed target value* F=100 to 120Hz VIN=15V Designed target value* Designed target value* 3.1 165 15 128 3.17 Ratings typ 3.30 79 160 25 10 ±0.5 45 192 80 30 max 3.43 V % kHz mV mV mV/°C dB A °C °C Unit * Designed target value: No measurement made. Package Dimensions unit : mm (typ) 3275 4.5 Pd max - Ta Mounted on a specified board: 114.3mm×76.1mm×1.6mm, Copper foil ratio 60% FR4 1.3 Allowable power dissipation, Pd max - W 1.2 10.0 4.5 4.0 3.90 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -30 (8.8) 9.9 (1.6) 1.7 0.9 0.4 4.5 1 5 SANYO : SMP5 1.5 0.2 2.7 0 20 40 60 80 100 120 140 160 Ambient temperature, Ta - °C ILA07131 Pin Assignment VIN SWOUT GND VOS SS No.8273-2/5 LA5771MP Block Diagram VIN 1 + - 2 SWOUT Reg. OCP OSC Reset Drive Comp. TSD 4 VOS Amp. VREF 5 SS 3 GND Application Circuit Example L1 V IN SWOUT LA5771MP C1 VOS SS GND D1 C2 C1: 220µF/35V C2: 1000µF/6.3V C3: 1µF/50V D1: SBD L1: 68µH C3 Notes: C3 is for the soft start function. Delete C3 and keep the SS pin open when the soft function is not necessary. No.8273-3/5 LA5771MP Description of Functional Settings 1.Start delay function The SS pin has the internally-connected 22µA (typ) constant-current supply. When the voltage of SS pin exceeds the threshold voltage, the regulator starts operation. As the threshold is 0.62V(typ), the start delay time can be calculated as follows: ex. For setting at 1µF C × V 1µΑ × 0.62V = Td = = 28.2ms i 22µΑ 2.Soft start function The internal PWM waveform has the voltage value as shown in the right. If down-conversion from the voltage of VIN=15V to 3.3V output is to be made, for example, the PWM-ON duty has the value as shown below. 1.5V 0.62V PWM wave PWMduty = VOUT = 23% VIN - Vsat + VF (Note that calculation is made with Vsat=1V and VF=0.2V) The output voltage of error amplifier, which is 3.3V, is the value with PWM=23%, as calculated in the above equation, so that this voltage is determined as follows: Ver=(∆VPWM)×PWMduty+VPWML=0.88V×0.23+0.62V=0.82V (∆VPWM is the PWM amplitude value or 0.88V(typ) while VPWML is the lower limit voltage of PWM waveform or 0.62V(typ)) SS pin and error amplifier output voltages are designed to prefer the lower voltages, so that VOUT will reach the designed regulation voltage in timing when the SS pin voltage exceeds the error amplifier output. Therefore, the soft strt time is calculated as follows: Tss = C × ∆VPWM × PWMduty C × 0.88V × PWMduty = i 22µA 1µΑ × 0.88V × 0.23 = 9.2ms 22µA For the set conditions of C=1µF and PWMduty=23%: Tss = No.8273-4/5 LA5771MP Timing Chart VIN SWOUT VOUT Td Tss SANYO Semiconductor Co.,Ltd. assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all SANYO Semiconductor Co.,Ltd. products described or contained herein. SANYO Semiconductor Co.,Ltd. strives to supply high-quality high-reliability products, however, any and all semiconductor products fail or malfunction with some probability. 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SANYO Semiconductor Co.,Ltd. shall not be liable for any claim or suits with regard to a third party's intellctual property rights which has resulted from the use of the technical information and products mentioned above. This catalog provides information as of January, 2007. Specifications and information herein are subject to change without notice. PS No.8273-5/5