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8A, 17V Synchronous Step-Down Converter

EVB_RTQ2823AGQVF

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This document explains the function and use of the RTQ2823A evaluation board (EVB), the RTQ2823A is a high-performance, synchronous step-down converter that can deliver up to 8A output currentvwith an input supply voltage range of 4.5V to 17V. The device integrates low RDS(ON) power MOSFETs, accurate 0.6V reference and an integrated diode for bootstrap circuit to offer a very compact solution. This document explains the function and use of the RTQ2823A evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to meet individual requirements.

General Description

This document explains the function and use of the RTQ2823A evaluation board (EVB), the RTQ2823A is a high-performance, synchronous step-down converter that can deliver up to 8A output currentvwith an input supply voltage range of 4.5V to 17V. The device integrates low RDS(ON) power MOSFETs, accurate 0.6V reference and an integrated diode for bootstrap circuit to offer a very compact solution. This document explains the function and use of the RTQ2823A evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to meet individual requirements.



Performance Specification Summary

Summary of the RTQ2823AGQVF Evaluation Board performance specificiaiton is provided in Table 1. The ambient temperature is 25°C.


Table 1. RTQ2823AGQVF Evaluation Board Performance Specification Summary

Specification

Test Conditions

Min

Typ

Max

Unit

Default Input Voltage

Default = 12V

4.5

12

17

V

Output Voltage

Default = 1.2V

0.6

--

5.5

V

Maximum Output Current

--

--

8

A

Operation Frequency

Default = 800kHz

400

800

1200

kHz

Soft-Start Time

CSS = 47nF

--

4.7

--

ms



Power-up Procedure

Suggestion Required Equipments

  • DC Power Supply (Chroma, 62006P-100-25)
  • Electronic load capable of 30A
  • Four Channels Digital Real-Time Oscilloscope
  • Display Multi-meter (34405A)

Power-up & Measurement Procedure

1. Apply a 12V nominal input power supply (4.5V < VIN < 17V) to the VIN and GND terminals.

2. Set the jumper at JP1 to connect terminals H and EN, connecting EN to VIN through resistor R18 (100kΩ). The Enable pin can connected to VIN directly as well to enable operation.

3. Set the jumper at JP2 to connect terminals H and PGOOD, Connenting VCC to H through resistor RPGOOD (100kΩ).

4. Verify the output voltage (approximately 1.2V) between VOUT and GND.

5. Connect an external load up to 8A to the VOUT and GND terminals and verify the output voltage and current.



Detailed Description of Hardware

Headers Description and Placement

Technical Document Image Preview

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

EN

Enable Control Input

MODE

Current limit, switching frequency, and light load operation mode selection pin.

BOOT

Bootstrap

SW

Switch node

PGND

Power ground

VIN

Input voltage

VCC

4.7V internal LDO output

AGND

Analog GND

PGOOD

Power good indicator output

SS

Soft-start time control pin



Bill of Materials

Reference

Qty

Part Number

Description

Package

Manufacturer

U4

1

RTQ2823AGQVF

Step-Down

DC-DC Converter

VQFN-18L

3.5x3.5 (FC)

RICHTEK

C1, C2,

C7, C15

4

0603B104K500CT

0.1μF, 50V, X7R

0603

WALSIN

C3, C4,

C5, C6

4

GRM21BR61E226ME44L

22μF, 25V, X5R

0805

MURATA

C11, C12, C13, C14

4

GRM32ER61C476KE15L

47μF, 16V, ±20%, X5R,

1210

MURATA

C16

1

0603N101J500CT

100pF, 50V, NPO

0603

MURATA

C17

1

GRM188R71C473KA01

0.047μF, 16V, ±10%, X7R

0603

MURATA

C19

1

GRM188R61E475KE11D

4.7μF, 10V, ±20%, X5R

0603

MURATA

L1

1

744311068

0.68µH, RDC = 3.1mΩ

7.0x7.0x4.0

WURTH ELEKTRONIK

R1, R14

R16

3

WR06X000 PTL

RES, 0, 1%, 0.1W

0603

WALSIN

R13, R17

2

WR06X1002FTL

RES, 10k, 1%, 0.1W

0603

WALSIN

R18, R19

RPGOOD1

3

WR06X1003FTL

RES, 100k, 1%, 0.1W

0603

WALSIN

RMODE1

1

WR06X1203FTL

RES, 120k, 1%, 0.1W

0603

WALSIN

RMODE2

1

WR06X2002FTL

RES, 20k, 1%, 0.1W

0603

WALSIN



Typical Applications

EVB Schematic Diagram

RTQ2823A demo board: VIN = 12V, VOUT 1.2V / 8A

Technical Document Image Preview


Note :

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 than specified.

3. Set default soft start time 5ms by connecting C17 to 47nF.


Measurement Results

Output Ripple Measurement

Output Ripple Measurement

Technical Document Image Preview

Technical Document Image Preview

Output ripple at 10mA load: 32mVpp

Output ripple at 8A load: 10mVpp

Output Ripple Measurement

Output Ripple Measurement

Technical Document Image Preview

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Output ripple at 10mA load: 27mVpp

Output ripple at 8A load: 10mVpp

Dynamic Load 10mA to 8A Load Step (DCM mode)

Dynamic Load 10mA to 8A Load Step (FPWM Mode)

Technical Document Image Preview

Technical Document Image Preview

VPK-PK: 40mV

VPK-PK: 39mV

Start-Up Measurement from Enable

Power-Off Measurement from Enable

Technical Document Image Preview

Technical Document Image Preview

Start-up time 5ms. Soft-start 5ms.

Vout discharge during power-off

Start-Up Measurement from VIN

Power-Off Measurement from VIN

Technical Document Image Preview

Technical Document Image Preview

Start-up time 2.7ms. Soft-start 1.575ms.

VOUT discharge during power-off



Evaluation Board Layout

Figure 1 to Figure 4 are RTQ2823AGQVF Evaluation Board layout.

一張含有 文字, 電子產品, 螢幕擷取畫面 的圖片

自動產生的描述

Figure 1. Top View (1st layer)


一張含有 文字, 電子產品 的圖片

自動產生的描述

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


一張含有 文字, 電子產品 的圖片

自動產生的描述

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


一張含有 文字, 電子產品 的圖片

自動產生的描述

Figure 4. Bottom View (4th Layer)

Title Last Update Share Download
Evaluation Board User Guide 2023/05/23
Bill of Materials 2023/05/23
Schematic 2023/05/23
Gerber File 2023/05/23
RTQ2823A/RTQ2823B
RTQ2823A/RTQ2823B

The RTQ2823A/B is a high-performance, synchronous step-down converter that can deliver up to 8A output current with an input supply voltage range of 4.5V to 17V. The device integrates low RDS(ON) power MOSFETs, accurate 0.6V reference and an integrated diode for bootstrap circuit to offer a very compact solution.

The RTQ2823A/B adopts Advanced Constant On-Time (ACOT®) control architecture that provides ultrafast transient response and further reduce the external-component count. In steady states, the ACOT® operates in nearly constant switching frequency over line, load and output voltage ranges and makes the EMI filter design easier.

The device offers a variety of functions for more design flexibility. The selectable switching frequency, current limit level and PWM operation modes makes the RTQ2823A/B easy-to-use over wide application range. Independent enable control input pin and power good indicator are also provided for easy sequence control. To control the inrush current during the startup, the device provides a programmable soft start-up by an external capacitor connected to the SS pin. Fully protection features are also integrated in the device including the cycle-by-cycle current limit, OVP, UVP, input UVLO and OTP.

The RTQ2823A/B is available in a thermally enhanced VQFN-18L 3.5x3.5 (FC) package.

Part NumberDistributorStockBuy From Authorized Distributor
EVB_RTQ2823AGQVF Digikey 4 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
IC
Part NumberPackage TypePackage Qty.Free SampleDistributorStockBuy From Authorized Distributor
RTQ2823AGQVFVQFN3.5x3.5-18(FC)1,500 Request Digikey 1,458 Buy
Mouser Lead-Time: 14 weeks Not Available
WPG Lead-Time: 14 weeks Not Available
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