rt9903b Richtek Technology Corporation, rt9903b Datasheet
rt9903b
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rt9903b Summary of contents
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... Channel DC/DC Converters IC with High-Efficiency Step-Up General Description The RT9903B is a complete power-supply solution for digital still cameras and other hand-held devices. It integrates a high-efficiency fours step-up DC-DC converters and a charge pump. The two Step-up DC-DC converters (CH1,CH2) accept inputs from 1.5V to 5.5V and regulate a resistor- adjustable output up to 17V ...
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... C12 C13 C10 4.7nF 6.8nF 56nF www.richtek.com 2 Preliminary C15 4.7uF L1 17 4.7uH VDD LX1 AGND FB1 16 PGND RT9903B BATT L2 4.7uH R4 LX2 10k 6 CS4 Q1 5 EXT4 FB2 Si2302 7 FB4 13 EN1 14 EN2 12 EN3 15 EN4 19 COMP1 23 COMP2 NC 10 COMP3 8 COMP4 ...
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... R11 5.1M 1nF R12 360k D5 BAT54WSPT C24 2.2uF NC C25 D6 1uF ZENER Diode If -CCD = -6V 5.6V_ZD If -CCD = -8V 3.6V_ZD LX2 FB2 - Oscillator + Soft Start Thermal + Protection - 10uA EXT4 CS4 FB4 PGND (Exposed Pad) RT9903B +12V (+LCD) +15V (+CCD) -6V (+CCD) C26 R13 10uF 8.2k RT www.richtek.com 3 ...
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... RT9903B Functional Pin Description Pin No. Pin Name Connection. 2 PGND Power Ground. 3 PGND Power Ground Frequency Setting Resistor Connection Pin. 5 EXT4 CH4 External Power Switch. 6 CS4 CH4 Current Sense Input Pin. 7 FB4 CH4 Feedback Input. 8 COMP4 CH4 Feedback Compensation Pin. ...
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... V = 0V, EN1 EN2 V = 3.3V EN3 EN4 V = 3.6V, VDD 0.15V FB4 REF I VDD4 0V, EN1 EN2 3.3V EN3 EN4 RT9903B − 0 − 0.3V to 20V − 0. 1.923W − 40°C to 85°C − 65°C to 150°C Min Typ Max 2.4 -- 5 ...
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... RT9903B Parameter Oscillator Free Running Frequency CH1, CH2, CH3 Maximum Duty Cycle CH4 Maximum Duty Cycle Reference Voltage (CH1, CH2, CH3, CH4) Feedback Reference Voltage Feedback Reference Voltage Error Amplifier GM Compensation Source Current Compensation Sink Current Power Switch CH1 On Resistance of MOSFET ...
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... Output Ripple LX1 V = 4.2V 3.3V, @I BAT DD Time (1us/Div) DS9903B-07 August 2007 Preliminary 30mA OUT = 30mA OUT RT9903B V & Output Ripple LX1 V = 2.5V 3.3V, @I BAT DD OUT Time (1us/Div) V & Output Ripple LX1 V = 3.8V 3.3V, @I BAT DD OUT Time (1us/Div) CH2 Efficiency vs. Output Current ...
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... RT9903B V & Output Ripple LX2 V = 2.5V 3.3V, @I BAT DD Time (1us/Div) V & Output Ripple LX2 V = 3.8V 3.3V, @I BAT DD Time (1us/Div) CH3 Efficiency vs. Input Voltage 100 4 series WLED 20mA LED 2.4 2.8 Input Voltage (V) www.richtek.com 8 Preliminary = 30mA OUT = 30mA OUT 3.2 3.6 4 4.4 V & Output Ripple ...
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... BAT DD Time (1us/Div) V & Output Ripple LX4 3.3V, @I BAT DD Time (1us/Div) DS9903B-07 August 2007 Preliminary = 20mA OUT = 20mA OUT = 100mA OUT RT9903B V & Output Ripple LX3 V = 3.8V 3.3V, @I BAT DD OUT Time (1us/Div) CH4 Efficiency vs. Output Current 100 V = 3.3V OUT ...
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... RT9903B V & Output Ripple LX4 V = 2.5V 3.3V, @I BAT DD Time (1us/Div) V & Output Ripple LX4 3.3V, @I BAT DD Time (1us/Div) CH4 Load Transient Response 3.3V, @I BAT DD Time (1ms/Div) www.richtek.com 10 Preliminary = 100mA OUT = 100mA OUT = 100mA to 350mA OUT V & Output Ripple LX4 V = 2.5V 3.3V, @I ...
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... CH4 Load Transient Response 3.3V, @I BAT DD Time (1ms/Div) DS9903B-07 August 2007 Preliminary = 100mA to 350mA OUT RT9903B Frequency vs 2500 2000 1500 1000 500 100 150 R (kΩ) RT Resistor 200 250 300 www.richtek.com 11 ...
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... RT9903B Application Information The RT9903B is a four-Channel DC/DC converter for digital still cameras and other hand-held device. The four channels DC/DC converters are as follows: CH1: Step-up, asynchronous voltage mode DC/DC converter with an internal power MOSFET, current limit protection, and over voltage protection. This channel is designed to supply output voltage from 3 ...
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... OUT LOAD then : f = 66kHz RHPZ Step-2 Calculate C C Choose f = 10kHz, and then C C simplified loop-gain formula. Loop gain = RT9903B + Inductor DC(ON) External_MOS ) much less than that C ) are OUT ) and capacitor the inductor IN OUT = 1.8V 3.3V, and IN OUT = 6.6Ω ...
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... RT9903B Where Gm is the transconductance of error amplifier, and R is the current sense amplifier transresistance our design 200us and then C = 4.34nF from calculation. C Choose C = 4.7nF. C Step-3 Calculate calculated such that transient droop requirements C are met. For example, in our design transient droop is allowed, then the error amplifier moves 0 ...
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... Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com DETAIL A Pin #1 ID and Tie Bar Mark Options Dimensions In Inches Min Max 0.031 0.039 0.000 0.002 0.007 0.010 0.007 0.012 0.156 0.159 0.091 0.108 0.156 0.159 0.091 0.108 0.020 0.014 0.018 RT9903B 1 2 www.richtek.com 15 ...