sc250wltrt Semtech Corporation, sc250wltrt Datasheet
sc250wltrt
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sc250wltrt Summary of contents
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POWER MANAGEMENT Description The SC250 is a synchronous step-down converter designed specifi cally for use as an adaptive voltage supply for CDMA and WCDMA RF Power Amplifi ers (PAs). The output voltage can be adjusted dynamically between 0.3V and (Vin ...
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POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifi cations below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specifi the Electrical Characteristics section is not recommended. Parameter Input Supply Voltage ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Symbol Quiescent Current Shutdown Current VDAC Regulated Output V Mode VDAC Pass-Through V Mode Threshold VDAC to VOUT Transfer Ratio R of Bypass P-Channel FET R of P-Channel ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Parameter Symbol Pass-Through Transition OS Over/Undershoot Pass-Through Transition t Settling Time PASS-ST Thermal Shutdown Thermal Shutdown T Hysteresis Auto Pass-Through PT Threshold ( OUT Auto Pass-Through PT Threshold Hysteresis © 2006 Semtech ...
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... Marking Information 250 yw Marking for the 2.3 x 2.3mm MLPD 8 Lead Package Datecode (Reference Package Marking Design Guidelines, Appendix A) © 2006 Semtech Corp. Ordering Information DEVICE SC250WLTRT 8 PGND SC250EVB Ordering Information Note Available on tape and reel only. A reel contains 3000 devices. 2) Device is WEEE and RoHS compliant. ...
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POWER MANAGEMENT Block Diagram VIN 2 VREF 3 GND VDAC 5 © 2006 Semtech Corp. References Control Logic PWM Comparator SENSE Error Amp. Oscillator Slope Generator 6 SC250 PRELIMINARY 6 VOUT SENSE Current Sense ...
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POWER MANAGEMENT Pin Descriptions Pin # Pin Name Pin Function 1 LX Inductor connection to the switching FETs 2 VIN Input voltage connection 2.85V, 20mA reference supply 3 VREF to supply a resistive divider GND Ground connection ...
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POWER MANAGEMENT Applications Information SC250 Detailed Description The SC250 adaptive power controller is a step-down, fi xed frequency pulse-width modulated DC-DC converter designed for use with RF Power Amplifi ers (PAs) in CDMA and WCDMA handsets and modules. The SC250 ...
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POWER MANAGEMENT Applications Information (Cont.) Under-Voltage Lockout Under-voltage lockout protection is used to prevent erroneous operation. As the input decreases, the device shuts down when the voltage drops below 2.35V and will not restart until the input voltage exceeds approximately ...
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POWER MANAGEMENT Applications Information (Cont.) PCB Layout Considerations Poor layout can degrade the performance of the DC- DC converter and can be a contributory factor in EMI problems, ground bounce and resistive voltage losses. Poor regulation and instability can result. ...
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POWER MANAGEMENT Typical Characteristics Effi ciency vs. Load Current V 100 90 V =3. =3. =4. 0.001 0.01 I (V) OUT Effi ciency vs. Load Current ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Control Transfer Function I 6.0 5.0 V 4.0 V =3. =3. =2.7V IN 2.0 1.0 0.0 0 0.2 0.4 0.6 0.8 V (V) DAC Dynamic Supply Current vs. V ...
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POWER MANAGEMENT Typical Characteristics (Cont.) V vs. Temperature (V OUT 1.56 1.54 I =100mA OUT 1.52 1.5 I =10mA I =300mA OUT OUT 1.48 1.46 -60 -40 - (° vs. V REF 2.9 2.85 2.8 ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Maximum Output Current, V 1.6 1.4 V =5.0V IN 1.2 1 0.8 0.6 V =3.5V IN 0.4 0 1.1 1.2 1.3 I (A) OUT PMOS Current Limit vs. Temperature 1280 1260 1240 1220 ...
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POWER MANAGEMENT Typical Characteristics (Cont.) R vs. Temperature, V DSON 450 400 PMOS 350 NMOS 300 250 200 150 100 PASS (°C) V Step Response (Pass-through) DAC Time (40μs/div) Condition V =3.6V, Load=15Ω, ...
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POWER MANAGEMENT Typical Characteristics (Cont.) Load Step response (V =3.25V) OUT Time (40μs/div) Condition V =4.2V, Load=600mA-60mA Enable Start-Up Time (20μs/div) Condition V =4.2V, Load=15Ω OUT Output Ripple Waveform (V OUT Time (1μs/div) Condition V =3.6V, ...
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POWER MANAGEMENT Outline Drawing - MLPD-W8, 2.3 x 2.3 Marking Information © 2006 Semtech Corp. 17 SC250 PRELIMINARY www.semtech.com ...
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... POWER MANAGEMENT Land Pattern - MLPD-W8, 2.3 x 2.3 Contact Information Phone: (805) 498-2111 FAX (805)498-3804 © 2006 Semtech Corp. Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 www.semtech.com 18 SC250 PRELIMINARY www.semtech.com ...