Purpose
The RT2101A is a synchronous step-down converter with the input voltage range from 2.95V to 6V and provides 3A output current. This document explains the function and use of the RT2101A evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to suit individual requirements.
Introduction
General Product Information
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. The RT2101A provides accurate regulation for a variety of loads with ±3% 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. The RT2101A is available in WQFN-16L 3x3 package.
Product Feature
- Integrated 45mW
MOSFETs
- 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
Key Performance Summary Table
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Key Features
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Evaluation Board Number : PCB038_V1
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Input Voltage Range
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2.95V to 6V
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Max Output Current
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3A
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Default Output Voltage
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1.8V
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Default Marking & Package Type
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RT2101AGQW, WQFN-16L 3x3
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Operation Frequency
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Adjustable from 700kHz to 2MHz
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Bench Test Setup Conditions
Headers Description and Placement
Carefully inspect all the components used in the EVB according to the following Bill of Materials table, and then make sure all the components are undamaged and correctly installed. If there is any missing or damaged component, which may occur during transportation, please contact our distributors or e-mail us at evb_service@richtek.com.
Test Points
The EVB is provided with the test points and pin names listed in the table below.
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Test point/
Pin name
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Signal
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Comment (expected waveforms or voltage levels on test points)
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VIN
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Input voltage
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Power input.
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EN
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Enable test point
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Chip Enable. Externally pulled high to enable and pulled low to disable thischip. It is internally pulled up to high when the pin is floating.
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GND
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Ground
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Power Ground.
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PGOOD
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Power good test point
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Output of power good indicator.
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BOOT
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Bootstrap supply test point
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Bootstrap supply for high-side gate driver. Connect a 0.1µF ceramic capacitor between the BOOT and SW pins.
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LX
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Switch node test point
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Connect this pin to an external L-C filter.
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RT/SYNC
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Clock input
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Frequency Setting and External Synchronous.
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Power-up & Measurement Procedure
1. Apply a 12V nominal input power supply (2.95V < VIN < 6V) to the VIN and GND terminals.
2. Set the jumper at JP1 to connect terminals 1 and 2, connecting EN to enable operation.
3. Verify the output voltage (approximately 1.8V) between VOUT and GND.
4. Connect an external load up to 3A to the VOUT and GND terminals and verify the output voltage and current.
Output Voltage Setting
Set the output voltage with the resistive divider (R1, R2) between VOUT and GND with the midpoint connected to FB. The output is set by the following formula :
Schematic, Bill of Materials & Board Layout
EVB Schematic Diagram
Bill of Materials
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Reference
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Qty
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Part number
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Description
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Package
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Manufacturer
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U1
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1
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RT2101AGQW
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DC-DC Converter
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WQFN-16L 3x3
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Richtek
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R1
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1
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RTT031182FTP
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11.8k
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R-0603
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旺詮
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R2
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1
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WR06X1002FTL
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10k
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R-0603
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WALSIN
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R3
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1
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WR06X7871FTL
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7.68k
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R-0603
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WALSIN
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R4
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1
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WR06X1803FTL
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180k
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R-0603
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WALSIN
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R5
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1
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WR06X1003FTL
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100k
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R-0603
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WALSIN
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C1
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1
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C2012X5R1C106KT
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10µF/16V/X5R
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C-0805
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TDK
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C3
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1
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C1608X5R1E105KT000E
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1µF/25V/X5R
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C-0603
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TDK
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C5, C6
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2
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GRM32ER61C226KE20L
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22µF/16V/X7R
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C-1210
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muRata
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C8
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1
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C1608X7R1H104KT000N
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0.1µF/50V/X7R
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C-0603
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TDK
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C10
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1
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0603B103K500
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10nF/50V/x7R
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C-0603
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WALSIN
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C11
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1
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0603B332K500
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3.3nF/50V/X7R
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R-0603
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WALSIN
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L1
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1
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7447714015
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1.5µH/10A
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10 x 10 x 5 mm
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WE
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PCB Layout
Top View (1st layer)
Bottom View (4th Layer)