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RT4801H Dual Output LCD Bias for Smartphones and Tablets

EVB_RT4801HWSC

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The RT4801H is a highly integrated Boost and LDO and inverting charge pump to generate positive and negative output voltage. The output voltages can be adjusted from ±4V to ±6V with 100mV steps by I2C interface protocols. With its input voltage range of 2.5V to 5.5V, RT4801H is optimized for products powered by single-cell batteries and symmetrical output currents up to 80mA. The RT4801H is available in the WL-CSP-15B 1.31x2.07 (BSC) package.

Purpose

The RT4801H is a dual output LCD bias with the input voltage range from 2.5V to 5.5V and provides 80mA output current. This document explains the function and use of the RT4801H evaluation board (EVB), and provides information to enable operation, output voltage setting of the evaluation board.


Introduction

General Product Information

The RT4801H is a highly integrated Boost and LDO and inverting charge pump to generate positive and negative output voltage. The output voltages can be adjusted from ±4V to ±6V with 100mV steps by I2C interface protocols. With its input voltage range of 2.5V to 5.5V, RT4801H is optimized for products powered by single-cell batteries and symmetrical output currents up to 80mA. The RT4801H is available in the WL-CSP-15B 1.31x2.07 (BSC) package.


Product Feature

  • 2.5V to 5.5V Supply Voltage Range
  • Up to 90% Efficiency with Small Magnetics
  • Support Up to 80mA Output Current
  • Low 1µA Shutdown Current
  • Internal Soft-start Function
  • Short Circuit Protection Function
  • Over-Voltage Protection Function
  • Over-Current Protection Function
  • Over-Temperature Protection Function
  • Elastic Positive and Negative Voltage On/Off Control by ENP/ENN
  • Voltage Output from 4V to 6V per 0.1V
  • Low Input Noise and EMI
  • Output with Programmable Fast Discharge when IC Shutdown
  • Adjustable Output Voltage by I2C Compatible Interface
  • Available in the 15-Ball WL-CSP Package


Key Performance Summary Table

Key Features

Evaluation Board Number: PCB084_V1

Default Input Voltage

3.7V

Max Output Current

80mA

Default Output Voltage

VOP = 5V, VON = -5V

Default Marking & Package Type

RT4801HWSC, WL-CSP-15B 1.31x2.07 (BSC)


Bench Test Setup Conditions

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

Signal

Comment (expected waveforms or voltage levels on test points)

VIN

Input voltage

Input voltage with range 2.5V to 5.5V.

ENP

VOP Enable

Enable control pin for VOP.

ENN

VON Enable

Enable control pin for VON.

GND

Ground

Ground.

I2C

I2C Control

Pins to set function and output voltage.

VOP

Positive output voltage

Default voltage: 5V±1%.

VON

Negative output voltage

Default voltage: -5V±1%.

LXP

Switching Node of Boost Converter Test Pin

Switching Node of Boost Converter.


Power-up & Measurement Procedure

Connect input voltage (2.5V < VIN < 5.5V).

1. To use a jumper at “H” option to tie ENP or ENN test pin to input voltage VIN via CP3 or external voltage via CP2 for enabling the device. Inversely, to use a jumper at “L” option to tie ENP or ENN test pin to ground GND for disabling the device.

2. To verify the output voltage VOP and VON (±5V) via I2C connector.

3. To connect an external load up to 80mA and verify the output voltage and current.


Output Voltage Setting

The output voltage can be programmed by a MCU through the dedicated I2C interface according to the VOP/VON voltage selection table. The device slave address is 0xE6.


Table1. VOP Voltage Selection

Name

Register Address

DATA

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

VOP (V)

VOP

00h

00h

Reserved

Reserved

Reserved

0

0

0

0

0

4

VOP

00h

01h

Reserved

Reserved

Reserved

0

0

0

0

1

4.1

VOP

00h

02h

Reserved

Reserved

Reserved

0

0

0

1

0

4.2

VOP

00h

03h

Reserved

Reserved

Reserved

0

0

0

1

1

4.3

VOP

00h

04h

Reserved

Reserved

Reserved

0

0

1

0

0

4.4

VOP

00h

05h

Reserved

Reserved

Reserved

0

0

1

0

1

4.5

VOP

00h

06h

Reserved

Reserved

Reserved

0

0

1

1

0

4.6

VOP

00h

07h

Reserved

Reserved

Reserved

0

0

1

1

1

4.7

VOP

00h

08h

Reserved

Reserved

Reserved

0

1

0

0

0

4.8

VOP

00h

09h

Reserved

Reserved

Reserved

0

1

0

0

1

4.9

VOP

00h

0Ah

Reserved

Reserved

Reserved

0

1

0

1

0

5

VOP

00h

0Bh

Reserved

Reserved

Reserved

0

1

0

1

1

5.1

VOP

00h

0Ch

Reserved

Reserved

Reserved

0

1

1

0

0

5.2

VOP

00h

0Dh

Reserved

Reserved

Reserved

0

1

1

0

1

5.3

VOP

00h

0Eh

Reserved

Reserved

Reserved

0

1

1

1

0

5.4

VOP

00h

0Fh

Reserved

Reserved

Reserved

0

1

1

1

1

5.5

VOP

00h

10h

Reserved

Reserved

Reserved

1

0

0

0

0

5.6

VOP

00h

11h

Reserved

Reserved

Reserved

1

0

0

0

1

5.7

VOP

00h

12h

Reserved

Reserved

Reserved

1

0

0

1

0

5.8

VOP

00h

13h

Reserved

Reserved

Reserved

1

0

0

1

1

5.9

VOP

00h

14h

Reserved

Reserved

Reserved

1

0

1

0

0

6


Table 2. VON Voltage Selection

Name

Register Address

DATA

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

VON (V)

VON

01h

00h

Reserved

Reserved

Reserved

0

0

0

0

0

-4

VON

01h

01h

Reserved

Reserved

Reserved

0

0

0

0

1

-4.1

VON

01h

02h

Reserved

Reserved

Reserved

0

0

0

1

0

-4.2

VON

01h

03h

Reserved

Reserved

Reserved

0

0

0

1

1

-4.3

VON

01h

04h

Reserved

Reserved

Reserved

0

0

1

0

0

-4.4

VON

01h

05h

Reserved

Reserved

Reserved

0

0

1

0

1

-4.5

VON

01h

06h

Reserved

Reserved

Reserved

0

0

1

1

0

-4.6

VON

01h

07h

Reserved

Reserved

Reserved

0

0

1

1

1

-4.7

VON

01h

08h

Reserved

Reserved

Reserved

0

1

0

0

0

-4.8

VON

01h

09h

Reserved

Reserved

Reserved

0

1

0

0

1

-4.9

VON

01h

0Ah

Reserved

Reserved

Reserved

0

1

0

1

0

-5

VON

01h

0Bh

Reserved

Reserved

Reserved

0

1

0

1

1

-5.1

VON

01h

0Ch

Reserved

Reserved

Reserved

0

1

1

0

0

-5.2

VON

01h

0Dh

Reserved

Reserved

Reserved

0

1

1

0

1

-5.3

VON

01h

0Eh

Reserved

Reserved

Reserved

0

1

1

1

0

-5.4

VON

01h

0Fh

Reserved

Reserved

Reserved

0

1

1

1

1

-5.5

VON

01h

10h

Reserved

Reserved

Reserved

1

0

0

0

0

-5.6

VON

01h

11h

Reserved

Reserved

Reserved

1

0

0

0

1

-5.7

VON

01h

12h

Reserved

Reserved

Reserved

1

0

0

1

0

-5.8

VON

01h

13h

Reserved

Reserved

Reserved

1

0

0

1

1

-5.9

VON

01h

14h

Reserved

Reserved

Reserved

1

0

1

0

0

-6


Schematic, Bill of Materials & Board Layout


EVB Schematic Diagram

Technical Document Image Preview


Bill of Materials

Reference

Qty

Part number

Description

Package

Manufacturer

U1

1

RT4801HWSC

Dual Output LCD Bias IC

WL-CSP-15B 1.31x2.07 (BSC)

RICHTEK

C1, C6, C8

3

GRM188R61C475KAAJ

4.7µF/16V/0603

C-0603

Murata

C5, C9

2

GRM188R61C106KAAL

10µF/16V/0603

C-0603

Murata

L1

1

1269AS-H

2.2µH

2520

TOKO

R4, R5

2

RC0603JR-074K7L

4.7K/0603

R-0603

Yageo


PCB Layout

Technical Document Image Preview

Top View (1st layer)

Technical Document Image Preview

Bottom View (4th Layer)

Title Last Update Share Download
Evaluation Board User Guide 2016/12/15
Bill of Materials 2016/12/15
Gerber File 2016/12/15
Schematic 2016/12/15
Part NumberFree SampleBuy From Authorized Distributor
EVB_RT4801HWSC Not available Buy from Distributor
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