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RTQ2131B, 36V, 1A, Synchronous Step-Down Converter Evaluation Board

EVB_RTQ2131BGQW-QA

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The Evaluation Board demonstrates the RTQ2131B to be designed for a 5V/1.0A output from a 7V to 25V input at 2.1MHz switching frequency. The RTQ2131B can apply to other output voltages by changing the resistive divider for input voltages support up to 36V. For more application circuits, please refer to the RTQ2131B datasheet. The wide input range makes it suitable for automotive systems and car camera module. The RTQ2131B provides complete protection functions such as input under-voltage lockout, output under-voltage protection, over-current protection, and thermal shutdown. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up.

General Description

The Evaluation Board demonstrates the RTQ2131B to be designed for a 5V/1.0A output from a 7V to 25V input at 2.1MHz switching frequency. The RTQ2131B can apply to other output voltages by changing the resistive divider for input voltages support up to 36V. For more application circuits, please refer to the RTQ2131B datasheet. The wide input range makes it suitable for automotive systems and car camera module. The RTQ2131B provides complete protection functions such as input under-voltage lockout, output under-voltage protection, over-current protection, and thermal shutdown. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up.


Performance Sepcification Summary

Summary of the RTQ2131B Evaluation Board performance specificiaiton is provided in Table 1. The ambient temperature is 25°C.

Table 1. RTQ2131BGQW Evaluation Board Performance Specification Summary

Specification

Test Conditions

Min

Typ

Max

Unit

Input Voltage Range

VOUT = 5V

7

--

25

V

Output Current

0

--

1

A

Default Output Voltage

--

5

--

V

Operation Frequency

--

2100

--

kHz

Output Ripple Voltage

IOUT = 1A

--

10

--

mVp-p

Line Regulation

IOUT = 1A, VIN = 7V to 25V

--

±1

--

%

Load Regulation

VIN = 12V, IOUT = 0.001 A to 1A

--

±1

--

%

Load Transient Response

IOUT = 0A to 1A

--

±5

--

%

Maximum Efficiency

VIN = 12V, VOUT = 5V, IOUT = 1A

--

89.3

--

%



Power-up Procedure

Suggestion Required Equipments

  • RTQ2131B Evaluation Board
  • DC power supply capable of at least 36V and 1A
  • Electronic load capable of 6A
  • Function Generator
  • Oscilloscope

Quick Start Procedures

The Evaluation Board is fully assembled and tested. Follow the steps below to verify board operation. Caution : Do not turn on supplies until all connections are made. Note: When measuring the output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the output voltage ripple by touching the probe tip and ground ring directly across the last output capacitor.

Proper measurement equipment setup and follow the procedure below.

1) With power off, connect the input power supply to VIN and GND pins.

2) With power off, connect the electronic load between the VOUT and nearest GND pins.

3) Turn on the power supply at the input. Make sure that the input voltage does not exceeds 36V on the Evaluation Board.

4) Check for the proper output voltage using a voltmeter.

5) Once the proper output voltage is established, adjust the load within the operating ranges and observe the output voltage regulation, ripple voltage, efficiency and other performance.



Detailed Description of Hardware

Headers Description and Placement

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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.

Test Point/

Pin Name

Function

VIN

Input voltage positive connection. The power supply must be connected to input connectors, VIN and GND.

EN

Enable test point. The test point can be used to measure the enable signal.

VOUT

Output voltage connection. The load must be connected to output connectors, VOUT and GND.

JP1

EN jumper. Connect EN to ground to disable, connect EN to logic high to enable.

PG

Power-good indication test point. The test point can be used to measure the power-good singal.

GND

Ground. Input/Output voltage return connection.

BOOT

Bootstrap node test point. The test point can be used to measure the bootstrap voltage.

SW

Switch node test point. The test point can be used to measure the switching node.

VIN_EMI

Input voltage node before EMI solution. Optional for EMI requirement.

VCC

Linear regulator output test point. The test point can be used to measure the output node of the internal regulator.



Bill of Materials

VIN = 12V, VOUT = 5V, IOUT = 1A, fSW = 2100kHz

Reference

Count

Part Number

Value

Description

Package

Manufacturer

U1

1

RTQ2131BGQW-QA

RTQ2131B

Step-Down Converter

WDFN-10SL 3x3

RICHTEK

C1, C2, C3, C4, C16

5

N/A

N/A

Optional for EMI requirement

N/A

N/A

C5

1

GCM31CR71H225KA

2.2µF

Capacitor, ceramic, 50V, X7R, ±10%

1206

MURATA

C6, C7, C8

3

CGA3E2X7R1H104K

0.1µF

Capacitor, ceramic, 50V, X7R, ±10%

0603

TDK

C9, C10

2

GCM31CC71E106KA

10µF

Capacitor, ceramic, 25V, X7S, ±10%

1206

MURATA

C11

1

GCM188R71C105KA

1µF

Capacitor, ceramic, 16V, X7R, ±10%

0603

MURATA

C12

1

N/A

N/A

Optional

N/A

N/A

C13

1

N/A

N/A

Optional

N/A

N/A

C15

1

GCE188R71H152KA

1.5nF

Capacitor, ceramic, 50V, X7R, ±10%

0603

N/A

L1, L2

2

N/A

N/A

Optional for EMI requirement

N/A

N/A

L3

1

WE-74437336047

4.7µH

Inductor, SMT,

Isat = 5.9A, 50mΩ

5.2 x 5.2 x 2.8mm

Wurth Elektronik

R2, R4

2

WR06X1003

100kΩ

Resistor, chip, 1/10W, 1%

0603

WALSIN

R3

1

WR06X1053

105k

Resistor, chip, 1/10W, 1%

0603

WALSIN

R5

1

WR06X2002

20k

Resistor, chip, 1/10W, 1%

0603

WALSIN

R6

1

WR06X3742

37.4k

Resistor, chip, 1/10W, 1%

0603

WALSIN



Typical Applications

EVB Schematic Diagram

Technical Document Image Preview

1. The capacitance values of the input and output capacitors will influence the input and output voltage ripple.

2. MLCC capacitors have degrading capacitance at DC bias voltage, and especially smaller size MLCC capacitors will have much lower capacitance.


Measure Result

Output Ripple Measurement

Load Transient Response

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Power On from EN

Power Off from EN

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Soft-start time = 1.7ms

Short Circuit Response – Short and Recovery

Strating Progile III (Cold cranking)

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Efficiency vs. Output Current

Output Voltage vs. Output Current

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Output Voltage vs. Input Voltage

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Note : When measuring the input or output voltage ripple, care must be taken to avoid a long ground lead on the oscilloscope probe. Measure the output voltage ripple by touching the probe tip directly across the output capacitor.



Evaluation Board Layout

Figure 1 to Figure 4 are RTQ2131B Evaluation Board layout. This board size is 110mm x 80mm and is constructed on four-layer PCB with 1 OZ. Cu on the outer layers and 1 OZ. Cu in the inner layers.

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Figure 1. Top View (1st layer)


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Figure 2. PCB Layout—Inner Side (2nd Layer)


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Figure 3. PCB Layout—Inner Side (3rd Layer)


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Figure 4. Bottom View (4th Layer)

Title Last Update Share Download
Evaluation Board User Guide 2020/12/02
Bill of Materials 2020/12/02
Gerber File 2020/12/02
Schematic 2020/12/02
RTQ2131B-QA

1A, 36V, 2.1MHz Synchronous Step-Down Converter

RTQ2131B-QA

The RTQ2131B is a 1A, high-efficiency, current mode synchronous step-down converter which is optimized for automotive applications. The device operates with input voltages from 3V to 36V and is protected from load dump transients up to 42V, eases input surge protection design. The device can program the output voltage between 0.8V to VIN. The peak current mode control with simple external compensation allows the use of small inductors and results in fast transient response and good loop stability.

The RTQ2131B provides complete protection functions such as input under voltage lockout, output under voltage protection, over current protection, and thermal shutdown. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates input current surge during start-up. The RTQ2131B is available in WDFN-10SL 3x3 (Exposed Pad) package.

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