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3.5A, 1.2MHz, Synchronous Step-Down Converter

EVB_RT8086BGQUF

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The RT8086B is a high efficiency, synchronous step-down DC/DC converter. The available input voltage range is from 2.8V to 5.5V and the regulated output voltage is adjustable from 0.6V to 3.3V while delivering up to 3.5A of output current.Product Feature. The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The current mode constant on-time operation with internal compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The RT8086B is available in the UQFN-12L 2x2 (FC) package.

Purpose

The RT8086B is a current mode COT step-down converter with the input voltage range from 2.8V to 5.5V and provides 3.5A outputcurrent. This document explains the function and use of the RT8086B 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 RT8086B is a high efficiency, synchronous step-down DC/DC converter. The available input voltage range is from 2.8V to 5.5V and the regulated output voltage is adjustable from 0.6V to 3.3V while delivering up to 3.5A of output current.Product Feature. The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The current mode constant on-time operation with internal compensation allows the transient response to be optimized over a wide range of loads and output capacitors. The RT8086B is available in the UQFN-12L 2x2 (FC) package.


Product Features

  • High Efficiency Up to 95%
  • Low RDS(ON) Switches : 50mΩ/40mΩ
  • 0.6V Reference Allows for Low Output Voltage
  • Internal Compensation
  • Input Voltage Range : 2.8V to 5.5V
  • Adjustable Output Voltage from 0.6V to 3.3V
  • 1.2MHz Switching Frequency
  • Start-Up into Pre-Biased Load
  • Built in Soft-Start
  • Power Good Indication
  • Cycle-by-Cycle Current Limit
  • Input Under Voltage Lockout
  • Output Under Voltage Protection (Hiccup)
  • Thermal Shutdown Protection
  • RoHS Compliant and Halogen Free

 

Key Performance Summary Table

Key Features

Evaluation Board Number : PCB064_V1

Default Input Voltage

3.3V

Max Output Current

3.5A

Default Output Voltage

1.2V

Default Marking & Package Type

RT8086BGQUF, UQFN-12L 2x2 (FC)

Operation Frequency

1.2MHz Switching Frequency



Bench Test Setup Conditions

Headers Description and Placement

Technical Document Image Preview

Please carefully inspect the EVB IC and external components, comparing them to the following Bill of Materials, to ensure that all components are installed and undamaged. If any components are missing or damaged during transportation, please contact the distributor or send e-mail to 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

Signal

Comment (expected waveforms or voltage levels on test points)

PVIN

Input voltage

Power Input. The available input voltage range is from 2.8V to 5.5V. A 10µF or larger input capacitor is needed to reduce voltage spikes at the input.

PGND

Ground

Power Ground.

AGND

Ground

Analog Ground.

NC

No Internal Connection

No Internal Connection.

VOUT

Output Voltage

Sense Input Pin for Output Voltage.

FB

Feedback Input Voltage

Feedback Input. This pin used to set the output voltage of the converter to regulate to the desired value via an external resistive divider. The feedback reference voltage is 0.6V typically.

LX

Switch Node test pin

Switch Node. Output of the internal high side and low side MOSFETs.

EN

Enable test point

Enable Control Input. A logic-high (1.2V < EN < 5.5V) enables the converter; a logic-low forces the IC into shutdown mode.

PGOOD

PGOOD test point

Power Good Indicator. The output of this pin is an open drain with internal pull-up resister to VIN. The output of this pin is pulled to high when the FB voltage is within 10%; otherwise it is Low.

VIN

Input Voltage

Supply Voltage for Internal Control Circuit. It is connected to PVIN inside the chip.



Power-up & Measurement Procedure

1. Apply a 3.3V nominal input power supply (2.8V to 5.5V) to the VIN and GND terminals

2. Connect an external load up to 3.5A 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 External Input and GND with the midpoint connected to VREFIN. The output is set by the following formula :

Technical Document Image Preview



Schematic, Bill of Materials & Board Layout

EVB Schematic Diagram

Technical Document Image Preview



Bill of Materials

Reference

Qty

Part Number

Description

Package

Manufacture

C1

1

0603X106M6R3

10µF/X5R/6.3V/0603

C-0603

WALSIN

C2, C3

2

C1608X7R1H104KT000N

0.1µF/X7R/50V/0603

C-0603

TDK

C4, C5

2

0603X106M6R3

10µF/X5R/6.3V/0603

C-0603

WALSIN

C6

1

C1608X7R1H104KT000N

0.1µF/X7R/50V/0603

C-0603

TDK

C30

1

NC

GP1, GP2

2

GND

J1

1

VIN

J2

1

VOUT

L1

1

PIFE25201B-1R0M

1.0µH

Cyntec

R1, R2

2

0603 200K 1%

200k

R-0603

WALSIN

R3, R4

2

0603 100K 1%

100K

R-0603

WALSIN

TP1

1

SW

TP4

1

PG

TP5

1

EN

TP6

1

VOUT

U1

1

RT8086BGQUF

DC/DC Converter

UQFN-12L 2x2 (FC)

RICHTEK

Z1, Z2, Z3, Z4

4

SIP-1P-M

Z5, Z6

2

FK_1



PCB Layout

Technical Document Image Preview

Top View (1st layer)

Technical Document Image Preview

PCB Layout—Inner Side (2nd Layer)

Technical Document Image Preview

PCB Layout—Inner Side (3rd Layer)

Technical Document Image Preview

Bottom View (4th Layer)

Title Last Update Share Download
Evaluation Board User Guide 2016/05/25
Bill of Materials 2016/05/25
Gerber File 2016/05/25
Schematic 2016/05/25
RT8086B

3.5A, 1.2MHz, Synchronous Step-Down Converter

RT8086B

The RT8086B is a high efficiency, synchronous step-down DC-DC converter. The available input voltage range is from 2.8V to 5.5V and the regulated output voltage is adjustable from 0.6V to 3.3V while delivering up to 3.5A of output current.

The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode.

The current mode constant on-time operation with internal compensation allows the transient response to be optimized over a wide range of loads and output capacitors. TheRT8086B is available in the UQFN-12L 2x2 (FC) package.

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EVB_RT8086BGQUF Not available Buy from Distributor
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