SC121ULTRT Semtech, SC121ULTRT Datasheet
SC121ULTRT
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SC121ULTRT Summary of contents
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... Small external components and the space saving MLPD-UT-6, 1.5×2.0×0.6 (mm) package make this device an excellent choice for small handheld applications that require the longest possible battery life OUT EN FB GND C IN SC121 © 2010 Semtech Corporation SC121 Low Voltage Synchronous Boost Regulator 3.3V C OUT 1 ...
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... MLPD-UT; 1.5×2, 6 LEAD θ = 84°C/W JA Marking Information — MLPD-UT 121 yw MLPD-UT; 1.5×2, 6 LEAD yw = date code Ordering Information Device SC121ULTRT SC121EVB OUT 6 Notes: (1) Available in tape and reel only. A reel contains 3,000 devices (2) Lead-free packaging, only. Device is WEEE and RoHS compliant, and halogen-free. EN ...
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Absolute Maximum Ratings IN, OUT, LX -0.3 to +6 ...
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Electrical Characteristics (continued) Parameter P-Channel ON Resistance N-Channel ON Resistance N-Channel Current Limit P-Channel Startup Current Limit LX Leakage Current PMOS LX Leakage Current NMOS Logic Input High Logic Input Low Logic Input Current High Logic Input Current Low NOTES: ...
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Typical Characteristics — V Effi ciency vs. I OUT = 499k Ω Ω 4.7 μ 100 0.1 0.2 ...
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Typical Characteristics — V Temperature Reg. — Low Load (V = 499k Ω Ω 4.7 μ 1. 0.8V IN 1.78 1.76 ...
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Typical Characteristics — V Effi ciency vs. I OUT ο FB grounded 4.7 μ 100 2.95V 0.1 0.2 0.5 ...
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Typical Characteristics — V Temperature Reg. — Low Load (V FB grounded 4.7 μ 1mA OUT 3. 2.95V 3. 2. 1.0V IN 3.26 3.24 3.22 ...
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Typical Characteristics — V Effi ciency vs. I OUT = 976k Ω 412k Ω 4.7 μ 100 ...
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Typical Characteristics — V Temperature Reg. — Low Load (V = 976k Ω 412k Ω 4.7 μ 4 3. 1.2V IN 3.95 ...
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Typical Characteristics — V Effi ciency vs. I OUT = 931k Ω 294k Ω 4.7 μ 100 1. ...
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Typical Characteristics — V Temperature Reg. — Low Load (V = 931k Ω 294k Ω 4.7 μ 2.2V IN ...
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Typical Characteristics (continued) PWM Operation V = 3.3V 1.5V 50mA OUT IN OUT V ripple OUT (10mV/div (100mA/div (5V/div) Time = (400ns/div) Startup Max Load Current vs 931k Ω , ...
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Pin Descriptions MLPD Pin # Pin Name Pin Function 1 LX Switching node — connect an inductor from the input supply to this pin. 2 GND Signal and power ground. Battery or supply input — requires an external 10μF bypass ...
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Block Diagram IN EN Oscillator and Slope Generator Output Voltage FB Selection Logic V OUT Comp Start-up Oscillator Slope Comp. PWM Comp. + PWM Control - Error Amp REF + - 1.2 V ...
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Applications Information Detailed Description The SC121 is a synchronous step-up fi xed frequency Pulse Width Modulated (PWM) DC-DC converter utilizing a 1.2MHz fi xed frequency current mode architecture designed to provide output voltages in the range 1.8V to ...
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Applications Information (continued) PWM Operation The PWM cycle runs xed frequency (f with a variable duty cycle (D). PWM operation continually draws current from the input supply, except for low output loads in which current fl ows ...
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Applications Information (continued) duty cycle must remain between 20% and 90% for the device to operate within specifi cation. Note that startup with a regulated active load is not the same as startup with a resistive load. The resistive load ...
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Applications Information (continued) Note that this is a negative quantity, since V 0 < D < 1. For a constant load in steady-state, the inductor current must satisfy ΔI + Δ Substituting the two L-on L-off expressions and ...
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Applications Information (continued) PCB Layout Considerations Poor layout can degrade the performance of the DC-DC converter and can contribute to EMI problems, ground bounce, and resistive voltage losses. Poor regulation and instability can result. The following simple design rules can ...
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Outline Drawing — MLPD-UT-6 1.5x2 A PIN 1 INDICATOR (LASER MARK) A aaa LxN N NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS TERMINALS. B ...
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Land Pattern — MLPD-UT-6 1.5x2 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ...
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... IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER’S OWN RISK. Should a customer purchase or use Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its offi cers, employees, subsidiaries, affi liates, and distributors harmless against all claims, costs damages and attorney fees which could arise. ...