Purpose
The RT4813A is a Boost converter with the input voltage range from 1.8V to 5.5V and provide an average output current limit range from 2.5A to 3.25A. This document explains the function and use of the RT4813A evaluation board (EVB), and provides information to enable operation, output voltage setting of the evaluation board.
Introduction
General Product Information
The RT4813A allows systems to take advantage of new battery chemistries that can supply significant energy when the battery voltage is lower than the required voltage for system power ICs. By combining built-in power transistors, synchronous rectification, and low supply current; this IC provides a compact solution for systems using advanced Li-Ion battery chemistries.
The RT4813A is a boost regulator designed to provide a minimum output voltage from a single-cell Li-Ion battery, even when the battery voltage is below system minimum. In boost mode, output voltage regulation is guaranteed to a minimum load current of 2.5A. Quiescent current in Shutdown Mode is less than 1µA, which maximizes battery life.
Product Feature
-
CMCOT Topology and Small Output Ripple when VIN Close VOUT Voltage
-
Operates from a Single Li-ion Cell : 1.8V to 5.5V
-
Adjustable Output Voltage: 1.8V to 5.5V
-
PSM Operation
-
Up to 96% Efficiency
-
Input Over Current Limit
-
Input/Output Over Voltage Protection
-
Average Output Current Limit Range : 3250mA to 2500mA
-
Internal Compensation
-
Output Discharge
-
Output Short Protection
-
True Load Disconnect
Key Performance Summary
Table
|
Key Features
|
Evaluation Board Number: PCB090_V1
|
|
Default Input Voltage
|
3.6V
|
|
Max Output Current
|
3.25A
|
|
Default Output Voltage
|
VOUT = 5V
|
|
Default Marking & Package Type
|
RT4813AGQUF, UQFN-9L 2x2 (FC)
|
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.
|
Test point/
Pin name
|
Signal
|
Comment (expected waveforms or voltage levels on test points)
|
|
VIN
|
Input voltage
|
Input voltage with range 1.8V to 5.5V.
|
|
EN
|
VOUT Enable
|
Enable control pin for VOUT.
|
|
SW
|
Switching Node
|
Switching Node.
|
|
PGND/GND
|
Ground
|
Ground.
|
|
SDA/SCL
|
I2C Control
|
Pins to set functions such as ILIM_OFF / IPCHG.
|
|
VOUT
|
Output Voltage
|
Default voltage : 5V±1%.
|
|
FB
|
Feedback Voltage
|
Default voltage : 0.5V±1%.
|
Power-up & Measurement Procedure
1. Connect input voltage (1.8V < VIN < 5.5V).
2. To use a jumper at “H” option to tie EN pin to input voltage VIN via JP1 or external voltage for enabling the device. Inversely, to use a jumper at “L” option to tie EN pin to ground GND for disabling the device.
3. To verify the output voltage VOUT via the dividing resistors.
4. To connect an external load up to 1A and verify the output voltage and current.
I2C Register Setting
The register as the table shown can be programmed by a MCU through the dedicated I2C interface. The device slave address is 0x39.
Schematic, Bill of Materials & Board Layout
EVB Schematic Diagram
Bill of Materials
|
Reference
|
Qty
|
Part number
|
Description
|
Package
|
Manufacture
|
|
U1
|
1
|
RT4813AGQUF
|
Boost Converter
|
UQFN-9L 2x2 (FC)
|
Richtek
|
|
C1, C2, C3, C4
|
4
|
GRM21BR61A226ME51
|
22µF/10V/X7R/0805
|
C-0805
|
Murata
|
|
C5
|
1
|
GRM185R61C105KE44D
|
1µF/16V/X5R/0603
|
C-0603
|
Murata
|
|
C6
|
1
|
GRM32ER61A107ME20L
|
100µF/10V/X5R/1210
|
C-1210
|
Murata
|
|
L1
|
1
|
SPM6530T-1R5M100
|
1.5µH
|
L-SH8018
|
TDK
|
|
R1
|
1
|
PFR059093FNH
|
909K/0402/1%
|
R-0402
|
乾坤
|
|
R2
|
1
|
PFR05104FNH
|
100K/0402/1%
|
R-0402
|
乾坤
|
PCB Layout
Top View (1st layer)
PCB Layout—Inner Side (2nd Layer)
PCB Layout—Inner Side (3rd Layer)
Bottom View (4th Layer)