RT9903BGQV RICHTEK [Richtek Technology Corporation], RT9903BGQV Datasheet
RT9903BGQV
Related parts for RT9903BGQV
RT9903BGQV Summary of contents
Page 1
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 ...
Page 2
RT9903B Typical Application Circuit 2-AA Battery 1.8V to 3.2V V BATT C1 10uF D1 SS0520 WLED (12V) C2 1uF V R15 10uF 10uF D2 SS0520 3.3V_Motor R2 C9 300k 1nF 10uFx4 R3 130k Chip ...
Page 3
V BATT C1 10uF D1 SS0520 WLED (12V) C2 1uF V R15 10uF 10uF D2 SS0520 3.3V_Motor R2 C9 300k 1nF 10uFx4 R3 130k Chip Enable C11 500pF 1.2k 2.2k 1.2k ...
Page 4
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. ...
Page 5
Absolute Maximum Ratings Supply Input Voltage (V ) --------------------------------------------------------------------------------------------- DD LX1, LX2, LX3 Pins ------------------------------------------------------------------------------------------------------- Other I/O Pin Voltage ---------------------------------------------------------------------------------------------------- Power Dissipation 25° VQFN-24L 4x4 ------------------------------------------------------------------------------------------------------------ Package Thermal Resistance (Note 3) VQFN-24L 4x4, θ ...
Page 6
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 ...
Page 7
Typical Operating Characteristics CH1 Efficiency vs. Output Current 100 V = 12V OUT 4. 2. Output Current (mA) V & ...
Page 8
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 ...
Page 9
V & Output Ripple LX3 3.3V, @I BAT DD Time (1us/Div) V & Output Ripple LX3 V = 4.2V 3.3V, @I BAT DD Time (1us/Div) V & Output Ripple LX4 V = 2V, ...
Page 10
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 V = 2V, ...
Page 11
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 ...
Page 12
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 ...
Page 13
Over Voltage The over voltage protection prevents LX2 voltage going too high. The over-voltage is detected by the junction leakage and the threshold value is around 22V. This channel is not latched shut down when OVP occurs. Step-up (Boost) DC/DC ...
Page 14
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 ...
Page 15
Outline Dimension Symbol Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 DS9903B-07 August 2007 Preliminary D2 SEE ...