RT4831A

Four-Channel LCD Backlight Driver with Integrated Bias Power

The RT4831A is an integrated four-channel backlight WLED driver with LCD bias supply for portable device. The backlight WLED driver supports up to 4P8S WLED configuration. Meanwhile, the driver maximum acceptable output voltage is 29V. Each channel current is controlled by the I²C interface and/or the external PWM input to achieve 11 bit LED current steps from 60μA to 30mA in exponential or linear mapping curves. The LCD bias supply is implemented with a Boost, a LDO and an inverting charge pump to provide positive and negative voltage. The LCD bias provides up to 150mA output current and the output voltage can be programmed via I²C interface from ±4V to ±6.5V with 50mV/step. The RT4831A is available in a WL-CSP-24B 1.84x2.68 (BSC) package.

Applications

LCD Panels with up to 32 LEDs
Smartphone
Tablet

Key Spec.
	RT4831A
Status	Active
Vin (min) (V)	2.7
Vin (max) (V)	5
Number of Channels	3
Number of Buck Converters	0
Number of Boost Converters	2
Number of Negative Outputs	1
Number of LED Drivers	1
Number of LDO Regulators	1
Application	LCD Bias
Features	Adjustable Current Limit;Adjustable Frequency;Enable Input;OCP;OVP;SCP
Package Type	WL-CSP1.84x2.68-24(BSC)

Features

System
Hardware Enable Pin
I²C Controlled Interface
Over-Temperature Protection

Backlight WLED Driver
2.7V to 5V Input Voltage Range
Drives Up to 4P8S WLED Configuration (29V Maximum Output Voltage)
External PWM Input and I²C Brightness Control
11 Bit Exponential and Linear Dimming Control
Programmable Over-Voltage Protection
Programmable Over-Current Protection
Auto Operating Frequency (250kHz, 500kHz, 1MHz)
WLED Current Ramp Up / Ramp Down Smoothen

LCD Bias Supply
2.7V to 5V Input Voltage Range
Programmable Positive / Negative Output Voltage from ±4V to ±6.5V with 50mV/Step
Programmable Boost Output Voltage from 4V to 7.15V with 50mV/Step
150mA Output Current Capability
Output Short-Circuit Protection

Datasheet
Title	Version	Last Update	Download
RT4831A: Four-Channel LCD Backlight Driver with Integrated Bias Power	V5.0	2019/12/06

Technical Documents
Title	Item Type	Last Update	Download
Richtek Product Selection Guide [Jan., 2024]	Selection Guide	2024/01/18

Part Number	Package Type	Package Qty.	Free Sample	Distributor	Stock	Buy From Authorized Distributor
RT4831AWSC	WL-CSP1.84x2.68-24(BSC)	3,000	Request	Digikey	2,275	Buy
				Mouser	Lead-Time: 14 weeks	Not Available
				WPG	Lead-Time: 14 weeks	Not Available

Please confirm with our distributor or sales representative for actual stock status.