rt9259a Richtek Technology Corporation, rt9259a Datasheet
rt9259a
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rt9259a Summary of contents
Page 1
... Synchronous Buck PWM DC-DC and Linear Power Controller General Description The RT9259A is a dual-channel DC/DC controller specifically designed to deliver high quality power where 12V power source is available. This part consists of a synchronous buck controller and an LDO controller. The synchronous buck controller integrates MOSFET drivers that support 12V+12V bootstrapped voltage for high efficiency power conversion ...
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... RT9259A Typical Application Circuit www.richtek.com 2 RT9259A 1 BOOT 14 UGATE 8 VCC12 DRV PHASE 6 11 FBL LGATE 2 12 RT_DIS PGND 7 GND VREF COMP 10 OCSET R OCSET DS9259A-02 March 2007 ...
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... MOSFET has turned off. UGATE (Pin 14) Upper gate driver output. Connect to gate of the high-side power N-Channel MOSFET. This pin is monitored by the adaptive shoot-through protection circuitry to determine when the upper MOSFET has turned off. RT9259A , an internal 40μA OCSET ) OCSET − ...
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... RT9259A Function Block Diagram Reference 0.8V REF_OUT VREF V REF1 FBL VCC12 - + DRV + Inhibit Shutdown RT_DIS Oscillator GND www.richtek.com 4 Voltage Bias 0. REF2 SSE + + + COMP FB Power 5V On Reset Regulator POR 0. Soft-Start & Fault Logic PH_M SSE - 1.5V + Inhibit Driver Logic PWM DS9259A-02 March 2007 VCC12 ...
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... Symbol Test Conditions Rising VCCRTH CC V VCCHYS I UGATE, LGATE Open VCC 110kΩ OSC RT RT9259A − 15V − 10V to 30V − 0. +15V CC − 0.3V to 42V − 0. 0.3V PHASE BOOT + 0. 0.3V CC − 40°C to 150°C − ...
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... RT9259A Parameter Reference Voltage PWM Error Amplifier Reference Linear Driver Reference V Buffer Source Current REF Error Amplifier DC Gain Gain-Bandwidth Product Slew Rate Gate Driver Upper Drive Source Upper Drive Sink Lower Drive Source Lower Drive Sink Protection Under Voltage Protection Soft-Start Time Interval ...
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... DS9259A-02 March 2007 UGATE PHASE (5V/Div) LGATE OCP (10V/Div) (10V/Div) (0.5A/Div) (200mV/Div) UGATE (5V/Div) LGATE (500mV/Div) V OUT1 (10V/Div) RT_Dis (500mV/Div) RT9259A Dead Time No Load, Rising UGATE V IN1 PHASE LGATE Time (25ns/Div) Power Off Time (5μs/Div) Start Up No Load V IN1 RT_Dis PHASE V OUT1 Time (1ms/Div) www ...
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... RT9259A Start Up I LOAD (2.5A/Div) V OUT1 (500mV/Div) Time (1ms/Div) Transient Response UGATE (20V/Div) (100mV/Div) V OUT1 I L (10A/Div) Time (2.5μs/Div) Transient Response LDO (2mV/Div) V OUT2 I L (0.5A/Div) Time (100μs/Div) www.richtek.com 8 No Load (500mV/Div) (500mV/Div) (100mV/Div) (20V/Div) (10A/Div 12V ...
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... The LDO controller drives an external N-MOSFET for lower power requirement. Internal 5VDD Regulator It is highly recommended to power the RT9259A with well- decoupled 12V to VCC12 pin. VCC12 powers the RT9259A control circuit, low side gate driver and bootstrap circuit for high side gate driver. A bootstrap diode is embedded to facilitates PCB design and reduce the total BOM cost ...
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... UVP is triggered if one of the feedback voltages is under (50 with a 30us delay. As shown in Figure 4, REFX the RT9259A PWM controller is shut down when V lower than the UVP threshold. In Figure 5, the RT9259A shuts down after 4 time UVP hiccups triggered by FBL. www.richtek.com 10 UGATE (20V/Div) ...
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... Figure 6. Shorted then Start Up Time (5μs/Div) Figure 7. Shorted then Start Up (Extended Figure 3) Feedback Compensation The RT9259A is a voltage mode controller. The control loop is a single voltage feedback path including a compensator and modulator as shown Figure 8. The modulator consists of the PWM comparator and power stage ...
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... A is the junction to ambient thermal resistance. is 100°C/W on the standard JEDEC 51-7 four-layers = ( 125°C − 25°C) / 100°C/W = 1.000 W for D(MAX) J(MAX) . For RT9259A packages, the Figure 11 of derating DS9259A-02 March 2007 Compensation Gain 100k ...
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... Ambient Temperature (°C) Figure 11. Derating Curves for RT9259A Packages PCB Layout Considerations MOSFETs switch very fast and efficiently. The speed with which the current transitions from one device to another causes voltage spikes across the interconnecting impedances and parasitic circuit elements. The voltage spikes can degrade efficiency and radiate noise, that results in over-voltage stress on devices ...
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... RT9259A Outline Dimension J I 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 Dimensions In Millimeters Min Max 8.534 8.738 3.810 3.988 1.346 1.753 0.330 0.508 1.194 1 ...