rt9245c Richtek Technology Corporation, rt9245c Datasheet
rt9245c
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rt9245c Summary of contents
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... Intel GHz CPU which is VRD10.x-compliant. The RT9245C could be operated with buck switching stages operating in interleaved phase set automatically. The multiphase architecture provides high output current while maintaining low power dissipation on power devices and low stress on input and output capacitors ...
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... RT9245C Typical Application Circuit + + + www.richtek.com Figure A. For Intel + + DS9245C-02 March 2007 ...
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... DS9245C-02 March 2007 + + + + Figure B. For AMD RT9245C + + www.richtek.com 3 ...
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... RT9245C Functional Pin Description VID4 (Pin 1), VID3 (Pin 2), VID2 (Pin 3), VID1 (Pin 4), VID0 (Pin 5) DAC voltage identification inputs for VRD10.x. These pins are internally pulled to 1.2V (VRD10.x) or 2.1V (K8) if left open. VID125/VIDSEL (Pin 6) When this pin pull low or left pen -->VR10 VID input, pull high to 5V --> ...
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... Function Block Diagram DS9245C-02 March 2007 RT9245C www.richtek.com 5 ...
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... RT9245C ID4 ID3 ID2 www.richtek.com 6 Table 1. Output Voltage Program (VRD 10.x) ...
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... RT9245C Nominal Output oltage DACOUT ID125 1 1.2250 0 1.2375 1 1.2500 0 1.2625 1 1.2750 0 1.2875 1 1.3000 0 1.3125 1 1.3250 0 1.3375 1 1.3500 0 1.3625 1 1.3750 0 1.3875 1 1.4000 0 1.4125 1 1.4250 0 1 ...
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... RT9245C VID4 VID3 Note: ( Connected to GND ( Open www ...
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... V CCHYS Enable V DVDTP V DVDHYS 20kΩ OSC RT f OSC_ADJ Δ 20kΩ OSC 20kΩ ≥ DAC ΔV DAC V < 1V DAC RT9245C + 0.3V CC Min Typ Max Units 4.0 4.2 4.5 V 0.2 0 0.94 1.0 1. 170 200 230 kHz 50 -- 400 kHz -- 1 ...
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... RT9245C Parameter DAC (VID0-VID125) Input Low DAC (VID0-VID125) Input High DAC (VID0-VID125) pull up resistor DAC Pull Up Voltage VOSS Pin Voltage Error Amplifier DC Gain Gain-Bandwidth Product Slew Rate Current Sense GM Amplifier CSN Full Scale Source Current CSN Current for OCP Protection − V ...
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... SS PWM UGATE CH3:(20V/Div) CH4:(10V/Div) LGATE Time (10ms/Div) DS9245C-02 March 2007 (kΩ) (kW) ADJ UGATE LGATE CH3:(50mV/Div) CH4:(20A/Div 60A OUT V RT9245C PWM vs 16kΩ 0 (V) COMP Power-Off @ I PWM COMP Time (10μs/Div) ...
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... RT9245C DVID at Rising (500mV/Div) V CORE VID125 (2V/Div) Time (50μs/Div) Transient Response V CORE Time (5ms/Div) www.richtek.com 12 V CORE (500mV/Div) VID125 (2V/Div) (20mV/Div) V CORE (20mV/Div) DVID at Falling Time (50μs/Div) Transient Falling Time (500ns/Div) DS9245C-02 March 2007 ...
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... GND or left float if the channel is unused. For example, for 3-Channel application, connect PWM4 high. Current Sensing Setting RT9245C senses the current flowing through inductor via into the resistor R X ADJ its DCR for channel current balance and droop tuning. ...
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... V C programmable over current trip point. OCP comparator + compares each inductor current with this reference current. CSN - R CSN RT9245C uses hiccup mode to eliminate fault detection 1k of OCP or reduce output current when output is shorted to ground 100 125 150 shows the time sharing technique of GM amplifier. ...
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... DCR )/R times current than other phases 0.3uH 0.6m 470 1uF 470 Figure 10. GM4 Setting for current ratio function I L 0.3uH 0.6m 470 1uF Figure 11. GM1~3 Setting for current ratio function RT9245C × + × DCR www.richtek.com 15 ...
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... Referring to Figure 15 100 where I make sure RT9245C could sense the inductor current, right hand side of Equation (1) should always be positive: V OUT CSN R CSN2 Since R could be simplified as : and consequently X V OUT R CSN2 Figure 14 shows that dead zone of load line at light load is eliminated by applying this technique ...
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... VID on the Fly With external pull up resistors tied to VID pins, RT9245C converters different VID codes from CPU into output voltage. Figure 16 and Figure 17 show the waveforms of VID on the fly function. VID on the PWM V CORE V FB CH1:(5V/Div) CH2:(500mV/Div) VID125 V = 1.500, I ...
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... MOSFET and low side MOSFET. V will fall slowly to avoid negative V OUT typical waveform is shown in Figure 22. www.richtek.com 18 If the fault condition is OV, V low immediately also. RT9245C will try to turn on low and 12V CC IN side MOSFET and turn off high side MOSFET 12V is not ready CC IN fall quickly to protect CPU from high voltage ...
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... PGOOD V (SS) V OUT OV Figure 23. Waveform for OV Error Amplifier Characteristic For fast response of converter to meet stringent output current transient response, RT9245C provides large slew rate capability and high gain-bandwidth performance. EA Falling Slew Rate V FB CH1:(500mV/Div) V COMP CH2:(2V/Div) Time (250ns/Div) Figure 24. EA Rising Transient with 10pF Loading; Slew ...
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... RT9245C 0dB 180° Figure 27. EA Frequency Response with closed loop gain set at 0db to observe gain-bandwidth product; -3dB at Design Procedure Suggestion a.Output filter pole and zero (Inductor, output capacitor value & ESR). b.Error amplifier compensation & sawtooth wave amp- litude (compensation network). ...
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... For most application cases, 0 good engineering value. Figure 29. The Frequency Response with No Load C2 5.6pF C3 680pF C1 RB2 15k 2.7nF RB1 - EA 1.5k + Figure 28. Type 3 compensation network DCR 1 IMAX IMAX CSN 40A 1.39m 330 IMAX R = 8.9k IMAX RT9245C www.richtek.com 21 ...
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... RT9245C www.richtek.com 22 Figure 30. The Frequency Response with Middle Load Figure 31. The Frequency Response with Heavy Load DS9245C-02 March 2007 ...
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... MOSFET driver should be closed to MOSFET. 4. The compensation, bypass and other function setting components should be near the IC and away from the noisy power path DS9245C-02 March 2007 L1 SW1 L2 SW2 Figure 32. Power Stage Ripple Current Path RT9245C V OUT C OUT R L www.richtek.com 23 ...
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... For Thermal Couple www.richtek.com 24 +12V or +5V C BOOT CORE C OUT C IN Figure 33. Layout Consideration Figure 34. Layout of power stage PWM VCC RT VOSS COMP R RT9245C CSN R CSN FB R CSPx SGND ADJ GND DS9245C-02 March 2007 + Next Locate next to FB Pin FB ...
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... TSSOP Plastic Package Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com RT9245C L A2 Dimensions In Inches Min Max 0.033 0.047 0.002 0.006 0.031 ...