RT2101AGQW

Reference Design Sample & Buy Design Tools ® RT2101A 2.95V to 6V Input, 3A Output, 2MHz, Synchronous Step-Down Converter General Description Features The RT2101A is a high efficiency step-down converter and capable of delivering 3A output current over a wide input voltage range from 2.95V to 6V.   AEC-Q100 Grade 2 Qualified Ω MOSFETs Integrated 45mΩ Input Range : 2.95V to 6V Adjustable PWM Frequency : 700kHz to 2MHz Output Current : 3A 95% Efficiency Adjustable Soft-Start Power Good Indicator Enable Control Under-Voltage Lockout Current Limit  Thermal Shutdown    The RT2101A provides accurate regulation for a variety of loads with ±2.5% accuracy. For reducing inductor size, it provides up to 2MHz switching frequency. The efficiency is maximized through the integrated 45mΩ MOSFETs and 550μA typical supply current.      Under-voltage lockout voltage of the RT2101A is 2.7V, and it also provides external setting by a resistor network on the enable pin.  The RT2101A provides protections such as inductor current limit under-voltage lockout and thermal shutdown. The over-temperature threshold is 145°C. Applications The RT2101A is available in WQFN-16L 3x3 package.    Marking Information Ordering Information 72= : Product Code 72=YM DNN Low-Voltage, High-Density Power Systems Distributed Power Systems Point-of-Load Conversions RT2101A Package Type QW : WQFN-16L 3x3 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) YMDNN : Date Code Note : Richtek products are :  RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.  Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit VIN VIN RT2101A EN BOOT PGOOD FB COMP GND AGND SS/TR RT/SYNC Copyright © 2022 Richtek Technology Corporation. All rights reserved. DS2101A-08 May 2022 SW VOUT is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT2101A Pin Configuration VIN EN PGOOD BOOT (TOP VIEW) 16 15 14 13 VIN VIN GND GND 1 12 2 11 GND 3 10 17 4 9 6 7 8 AGND FB COMP RT/SYNC 5 SW SW SW SS/TR WQFN-16L 3x3 Functional Pin Description Pin No. 1, 2, 16 3, 4, 17 (Exposed Pad) 5 6 7 8 9 10 to 12 Pin Name VIN GND AGND FB COMP RT/SYNC SS/TR SW Pin Function Power input. Power ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. Analog ground. Feedback input. Compensation node for converter stability. Frequency setting and external synchronous. Clock input. Soft-start and tracking. Switch node. Connect this pin to external L-C filter. 13 BOOT Bootstrap supply for high-side gate driver. Connect a capacitor between the BOOT and SW pin. 14 PGOOD Output of power good indicator. 15 EN Chip enable. Externally pulled high to enable and pulled low to disable this chip. It is internally pulled up to high when the pin is floating. Functional Block Diagram VIN Internal pull up current Over-Temperature Protection UVLO Enable Comparator EN EN Threshold RT/SYNC Shutdown Control Current Sense BOOT Oscillator Control Logic Slope Compensation Driver SW PWM Comparator SS/TR Soft-Start GND VREF Error Amplifier FB PGOOD Threshold PGOOD Comparator PGOOD Copyright © 2022 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 COMP AGND GND is a registered trademark of Richtek Technology Corporation. DS2101A-08 May 2022 RT2101A Operation The RT2101A is a synchronous step-down DC-DC converter with two integrated power MOSFETs. It can deliver up to 3A output current from a 2.95V to 6V input supply. The RT2101A's current mode architecture allows the transient response to be optimized over a wider input voltage and load range. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. The RT2101A is synchronizable to an external clock with frequency ranging from 700kHz to 2MHz. The RT2101A is available in WQFN-16L 3x3 package. High-side MOSFET peak current is measured by internal sensing resistor. The Current Signal is where Slope Compensator works together with sensing voltage sensing resistor. The error amplifier adjusts COMP voltage by comparing the feedback signal (VFB) from the output voltage with the internal 0.827V reference. When the load current increases, it causes a drop in the feedback voltage relative to the reference, the COMP voltage then rises to allow higher inductor current to match the load current. EN Comparator The RT2101A is enable when EN pin is higher than 1.25V. It is disable when EN pin lower than 1.18V. There is an internal pull-high current source to charge the EN pin to high when the EN pin is floating. PGOOD Comparator When the feedback voltage (VFB) rises above 93% or falls below 107% of reference voltage the PGOOD open drain output will be high impedance. The PGOOD open drain output will be internally pulled low when the feedback voltage (VFB) falls below 88% or rises above 113% of reference voltage. Soft-Start (SS) An internal current source (2.2μA) charges an external capacitor to build the soft-start ramp voltage (VSS). The VFB voltage will track the VSS during soft-start interval. The Soft-Start setting capacitor (CSS) for the Soft-Start time (tSS) can be easily calculated by the following equation : CSS (nF) = tSS (ms)  2.2 (A) 0.827 (V) Over-Temperature Protection (OTP) The RT2101A implement an internal over-temperature protection. When junction temperature is higher than 145°C, it will stop switching. Until the junction temperature decreases below 125°C, the RT2101A will re-soft-start from initial condition. Oscillator (OSC) The internal oscillator that provides switching frequency from 700kHz to 2MHz. It is adjusted using an external timing resistor. It also can be synchronized by an external clock in the range between 700kHz and 2MHz from RT/ SYNC pin. Copyright © 2022 Richtek Technology Corporation. All rights reserved. DS2101A-08 May 2022 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT2101A Absolute Maximum Ratings           (Note 1) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------Switch Node Voltage, SW ----------------------------------------------------------------------------------------