rt9205 Richtek Technology Corporation, rt9205 Datasheet
rt9205
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rt9205 Summary of contents
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... Dual Regulators - Synchronous Buck PWM DC-DC and Linear Controller General Description The RT9205 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 14-pin package. The RT9205/A uses an internal compensated voltage mode PWM control for simplying design ...
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... RT9205/A Typical Application Circuit www.richtek.com Figure 1. RT9205/A powered form 5V + DS9205/A-09 October 2008 ...
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... DS9205/A-09 October 2008 + + + + + + Figure 2. RT9205/A powered from 12V RT9205/A + www.richtek.com 3 ...
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... L 5uH C BOOT BOOT 0.1uF RT9205/A Layout Placement Layout Notes 1. Put C1 & near the MU drain and ML source nodes. 2. Put RT9205 near the C 3. Put C as close as to BOOT pin BOOT 4. Put C as close as to VCC pin VCC Power on Reset + + ...
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... Signal and power ground for the IC. All voltage levels are measured with respect to this pin. VCC (Pin 4) This is the main bias supply for the RT9205/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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... RT9205/A Absolute Maximum Ratings Supply Voltage VCC -------------------------------------------------------------------------------------------------- 7V BOOT & UGATE to GND --------------------------------------------------------------------------------------------- 19V Input, Output or I/O Voltage ----------------------------------------------------------------------------------------- GND-0. Package Thermal Resistance SOP-14, θ JA ------------------------------------------------------------------------------------------------------------------------------------------------------------ Ambient Temperature Range ---------------------------------------------------------------------------------------- 0°C to +70°C Junction Temperature Range ---------------------------------------------------------------------------------------- Storage Temperature Range ---------------------------------------------------------------------------------------- Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C CAUTION: ...
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... DS9205/A-09 October 2008 V CC LGATE LGATE OUT1 OUT1 V V OUT2 OUT2 2.2V OUT C = 3000uF OUT RT9205/A Dead Time = 5V UGATE Time (50ns/Div) Power Off 2.5V OUT1 V = 1.8V OUT2 Time (50ms/Div) Load Transient UGATE 2.2V OUT C = 3000uF OUT ...
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... Temperature OCSET -40 -10 20 Temperature (°C) www.richtek.com 8 V OUT UGATE RT9205 50 80 110 140 Short Hiccup 2.2V OUT Time (2ms/Div) (°C) POR (Rising/Falling) vs. Temperature 4.3 4.2 Rising 4.1 4.0 3.9 3.8 Falling 3.7 3.6 - Temperature (°C) DS9205/A-09 October 2008 V OUT UGATE RT9205A 100 150 ...
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... Oscillator Frequency vs. Temperature 315 310 305 300 295 290 285 280 275 270 -50 0 Temperature (°C) DS9205/A-09 October 2008 50 100 150 RT9205/A www.richtek.com 9 ...
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... When trigged 12V and hiccup re-start sequence will be initialized, as shown in UGATE Figure 5. For RT9205, only 3 times of trigger are allowed before latching off. But for RT9205A, UVP will be kept in hiccup mode. Hiccup is disabled during soft-start interval. R BOOT 6.0V ...
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... COUNT = 2 COUNT = OVERLOAD APPLIED TIME Figure 5 Inductor Selection The RT9205/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 ...
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... OUT2 DC loop gain filter pole P = Error Amp pole P = 300kHz ESR zero Z = can be set OUT2 The RT9205/A Bode plot is as shown in Figure Suggest Low stable in most of application conditions. V MOSFET T V < 2.5V OUT2 ...
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... Duty (%) Figure 11 Feedback Divider The reference of RT9205/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 1 kΩ to 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. Typically, value between 1nF and 0.1μ ...
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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 www.richtek.com OUT LOAD VCC GND RT9205/A FB DS9205/A-09 October 2008 ...
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... No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com Dimensions In Inches Min Max 0.336 0.344 0.150 0.157 0.053 0.069 0.013 0.020 0.047 0.053 0.007 0.010 0.004 0.010 0.228 0.244 0.016 0.050 RT9205/A www.richtek.com 15 ...