RT9203 RICHTEK [Richtek Technology Corporation], RT9203 Datasheet
RT9203
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RT9203 Summary of contents
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... Dual Regulators - Synchronous Buck PWM DC-DC and Linear Controller General Description The RT9203 dual-output power controllers designed for high performance graphics cards and personal computers. The IC integrates a synchronous buck controller, a linear controller and protection functions into a small 8-pin package. The RT9203/A uses an internal compensated voltage mode PWM control for simplying design ...
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... RT9203/A Typical Application Circuit www.richtek.com 2 Preliminary Figure 1. RT9203/A powered from 5V DS9203/A-10 March 2007 ...
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... DS9203/A-10 March 2007 Preliminary + + + + + Figure 2. RT9203/A powered from 12V RT9203/A + www.richtek.com 3 ...
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... RT9203/A GND C VCC 1uF VCC Layout Notes 1. Put C1 & near the MU drain and ML source nodes. 2. Put RT9203 near the C 3. Put C BOOT 4. Put C VCC Function Block Diagram VCC VCC DRV LDO FBL 0.8 Reference 0.8V Error FB GND www.richtek.com 4 Preliminary C OUT 1000uF ...
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... Connect the LGATE pin to the gate of lower MOSFET. This pin provides the gate drive for the lower MOSFET. VCC (Pin 5) This is the main bias supply for the RT9203/A. This pin also provides the gate bias charge for the gate of lower MOSFET. The voltage at this pin is monitored for ensuring a proper power-on reset (POR) ...
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... RT9203/A Absolute Maximum Ratings Supply Voltage VCC ------------------------------------------------------------------------------------------------ 7V l BOOT & UGATE to GND ------------------------------------------------------------------------------------------- 19V l Input, Output or I/O Voltage --------------------------------------------------------------------------------------- GND-0. Power Dissipation 25° SOP-8 ------------------------------------------------------------------------------------------------------------------ 0.625W Package Thermal Resistance l SOP-8, ------------------------------------------------------------------------------------------------------------- 160°C/W JA Ambient Temperature Range -------------------------------------------------------------------------------------- 0° +70°C l Junction Temperature Range -------------------------------------------------------------------------------------- 40° +125°C l Storage Temperature Range --------------------------------------------------------------------------------------- 65° ...
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... Parameter Protection FB Over-Voltage Trip FB & FBL Under-Voltage Trip Soft-Start Interval DS9203/A-10 March 2007 Preliminary Symbol Test Conditions FB Rising FB & FBL Falling RT9203/A Min Typ Max Units 0 0 www.richtek.com 7 ...
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... RT9203/A Typical Operating Characteristics Dead Time UGATE Time (50ns/Div) Power 2.5V OUT1 V = 1.8V OUT2 Time (2.5ms/Div) Load Transient UGATE V OUT Time (5us/Div) www.richtek.com 8 Preliminary LGATE OUT1 V OUT2 2.2V OUT C = 3000uF OUT Dead Time LGATE Time (50ns/Div) Power ...
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... V = 2.2V CC OUT 50 80 110 140 ( C) RT9203/A Short Hiccup 2.2V OUT Time (2ms/Div) Reference vs. Temperature 0.803 0.802 0.801 0.800 0.799 0.798 0.797 0.796 - Temperature POR (Rising/Falling) vs. Temperature 4.3 4.2 Rising 4.1 4.0 3.9 3.8 Falling 3.7 3.6 - Temperature V OUT UGATE RT9203A 100 150 ( C) 100 150 ( C) www.richtek.com 9 ...
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... RT9203/A Oscillator Frequency vs. Temperature 315 310 305 300 295 290 285 280 275 270 -50 0 Temperature www.richtek.com 10 Preliminary 50 100 150 ( C) DS9203/A-10 March 2007 ...
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... When trigged, a hiccup re-start = 12V and V UGATE LGATE sequence will be initialized, as shown in Figure 5. For RT9203, Only 3 times of trigger are allowed before latching off. But for RT9203A, UVP will be kept in hiccup mode. Hiccup is disabled during soft-start interval. RT9203/A BOOT 6.0V Regulation ...
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... COUNT = OVERLOAD APPLIED TIME Figure 5 Inductor Selection The RT9203/A was designed for V application mainly. Figure 6 shows the typical topology and waveforms of step-down converter. The ripple current of inductor can be calculated as follows: ( OUT RIPPLE ON L Because operation frequency is fixed at 300kHz, ...
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... DC loop gain G = 35dB OUT2 LC filter pole P = Error Amp pole P = 300kHz ESR zero Z = can be set OUT2 The RT9203/A Bode plot is as shown in Figure stable in most of application conditions. Suggest Low V V MOSFET OUT T C ...
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... Duty (%) Figure 11 Feedback Divider The reference of RT9203/A is 0.8V. The output voltage can be set using a resistor-divider as shown in Figure 12. Put the R1 and R2 as close as possible to FB pin. R2 value should be less than avoid noise coupling issue. The C1 capacitor is a speed-up capacitor for reducing output ripple to meet with the requirement of fast transient load ...
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... The PCB traces between the PWM controller and the gate of MOSFET and also the traces connecting source of MOSFETs should be sized to carry 2A peak currents. IQ1 5V Q1 IQ2 Q2 GND LGATE UGATE Figure 13 DS9203/A-10 March 2007 Preliminary IL V OUT LOAD VCC GND RT9203/A FB RT9203/A www.richtek.com 15 ...
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... RT9203/A 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 www.richtek.com 16 Preliminary Dimensions In Millimeters Min Max 4.801 5.004 3.810 3.988 1.346 1.753 0.330 0.508 1.194 1 ...