rt8100 Richtek Technology Corporation, rt8100 Datasheet
rt8100
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rt8100 Summary of contents
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... Synchronous buck PWM DC/DC with Dual Voltage Control Mode General Description The RT8100 is an advanced DC/DC synchronous buck PWM controller with several innovative functions for specific customer’ s ASIC only. The part features RichTek’ s innovative design and topology say “analogous current mode” for current sensing and full functions for various applications including adjustable soft start, free-run and adjustable operation frequency and enable ...
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... SS 6 CSP 5 2 CSN I_IND 7 COMP Figure 1. 12V-5V PI Application Circuit 15 4 BOOT RR 16 12VCC 14 UGATE 1 5VSB PHASE RT8100 11 12 PVCC LGATE CSP 5 2 CSN I_IND 7 COMP Figure 2. 12V-5V Internal V REF Application Circuit ...
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... Figure 3. Single 5V PI Application Circuit 15 4 BOOT RR 16 12VCC 14 UGATE 1 5VSB 5VSB 5VSB PHASE RT8100 11 12 PVCC LGATE CSP 5 2 CSN I_IND 7 COMP Figure 4. Single 5V Internal Application Circuit REF RT8100 V OUT OUT opt. www.richtek.com 3 ...
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... RT8100 Functional Pin Description 5VSB(Pin 1), 12VCC (Pin 16) The 5VSB pin is the external standby 5V power. The 12VCC pin is the external 12V power. RT (Pin 2) Timing Resistor. Connect a resistor from RT to GND to set the clock frequency. The free running frequency is 200kHz. I_IND (Pin 3) Current indicating pin. This pin uses voltage level to indicate the current of inductor ...
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... Ramp CLK Current RR Generator Operation RT8100 is a highly flexible, high performance and high precision synchronous buck controller specifically designed for high-end graphic core power supply as well as DDR applications, with highly reduced external components and costs. RT8100 uses RichTek proprietary Analogous Current ...
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... RT8100 Power on reset The POR circuitry monitors the supply voltage of the chip. When the chip power supply exceeds 4.2V, the chip releases the reset state and works according to the settings. Once the supply voltage is lower than 4.0V, POR circuitry resets the chip. V detection ...
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... Power Supply Current Soft Start Soft Start Current DS8100-03 August 2007 Preliminary (Note 1) (Note 3) Symbol Test Conditions 12V 5VSBRTH V 5VSBHYS 5V, 12V = 12V, V VCC RT8100 +15V PHASE BOOT + 0.3V CC Min Typ Max 4 3.8 4.2 4 ...
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... RT8100 Parameter Oscillator Free Running Frequency Frequency Variation Frequency Range Maximum Duty Cycle Up-Ramp Setting Pin Reference Voltage Feedback Voltage Error Amplifier DC Gain Gain-Bandwidth Product Trans-conductance MAX Current (Source & Sink) Current Sense GM Amplifier Input Offset Voltage I OMAX Gate Driver Upper Drive Source ...
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... GND RT 600 500 400 300 200 100 100 (k π (kΩ) RT Dead Time (Falling) UGATE PHASE UGATE PHASE − (5V/Div) LGATE Time (25ns/Div) Load Transient Regulation (Falling) UGATE LGATE OUT I Load Time (50us/Div) RT8100 RT R connected to 5VSB RT 1000 10000 www.richtek.com 9 ...
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... RT8100 PI Power Off UGATE (10V/Div) SS (5V/Div) PI (500mV/Div) V OUT (500mV/Div) Time (1ms/Div) Power Off UGATE (10V/Div) 5VSB (2V/Div) V OUT (500mV/Div) SS (2V/Div) Time (50ms/Div) Standalone OCP SS (2V/Div) V OUT (500mV/Div) PI (1V/Div) UGATE (10V/Div) Time (50ms/Div) www.richtek.com 10 Preliminary UGATE (10V/Div) SS (5V/Div) PI (500mV/Div) V OUT (500mV/Div) UGATE ...
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... Output Current (A) DS8100-03 August 2007 Preliminary RT8100 www.richtek.com 11 ...
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... RT8100 Application Information Current Sense, Ramp Setting RT8100 senses the inductor current through inductor DCR and feeds the current signal back to the control loop. The current sensing circuitry Figure 5 consists filter, a current sensing GM together with two external resistors. The current flowing the inductor as well as the ...
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... DCR. DCR = CSN MAX μ Modulator Frequency Equations RT8100 is a analogous current mode buck converter using the high gain error amplifier with transconductance (OTA, Operational Transconductance Amplifier), as Figure 6 shown. The Transconductance : ΔI OUT GM = ΔV M Δ (EA+) - (EA-) ; Δ E/A output current. ...
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... V COMP and FB) Protection OCP The RT8100 use cycle by cycle current comparison. The Pole F P2 over current level is set occurs and SS > (5VSB −1.3), a constant current of 10μA starts to discharge the capacitor connected to SS pin right away. When OC occurs UGATE and LGATE will be off. ...
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... PI about 15μs in tracking mode. RT8100 uses an external resistor R able over current trip point. OCP comparator compares inductor current with this reference current. RT8100 uses hiccup mode to eliminate fault detection of OCP or reduce output current when output is shorted to ground. × ...
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... Position the output inductor and output capacitors between the upper MOSFET and lower MOSFET and the load. 14. Because RT8100 use DCR sense topology, DCR sense point is output inductor from end to end. 15. CSN and FB must be independent path. Below PCB gerber files are our test board for your ...
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... Figure 13. Component Side Figure 14. Bottom DS8100-03 August 2007 Preliminary RT8100 www.richtek.com 17 ...
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... RT8100 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 18 Preliminary SEE DETAIL Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated ...