Features

• Wide input range: 2.7V~5.5V

• High efficiency step-up 3-Channel LED driver

• 3-Ch current sinks, up to 8-LEDs per string

 Up to 29.8mA/Ch in backlight mode and up

to 59.6mA/Ch in flash mode

 +/-0.6 current matching at 20.2mA

 +/-1.5 current accuracy at 20.2mA

• I2C/PWM dual dimming control scheme

 11-bit I2C exponential or linear mapping with

programmable transition ramp time

 Wide range PWM dimming with programable

transition ramp time

▪ 100Hz to 100kHz frequency

▪ 0.2 to 100 duty cycle at 20kHz

• Programmable current sink turn on/off ramp

time and shape

• Selectable boost converter switching frequency

1MHz or 500kHz with 20 shift up option

• Programmable input PWM hysteresis to

minimize jitter at low PWM duty cycle

• Programmable OVP (25.9V/32V) and current

limit (2.6A/1.8A)

• Programmable flash current and timeout

• LED open/short protection

• Status reporting through I2C interface

Applications

• Smartphone/Tablet Backlight and Selfie Flash

Brief Description

KTD3137 is the ideal power solution for LED backlighting

and selfie flash in medium to large size LCD panels. It is a

highly integrated step-up DC-DC converter operating with

an input voltage from 2.7V to 5.5V, accommodating 1-cell

lithium ion batteries or 5V supply. It includes a high voltage

power NMOS, as well as three current sinks, resulting in a

simpler and smaller solution with fewer external

components. High switching frequency allows the use of a

smaller inductor and capacitor.

Each of the three regulated current sinks can regulate up

to 29.8mA in backlight mode. With a maximum of 32V at

the output of the step-up converter, each string can

connect up to 8-LED in series for a 24-LED application.

KTD3137 is equipped with I2C interface for various

controls. For additional flexibility, PWM dimming with wide

range frequency and duty cycle is included to support

Content Adaptive Brightness Control (CABC).

KTD3137 also adds selfie flash function to the existing

backlight solution by boosting the sink current up to

59.6mA/Ch and integrating a flash timeout of up to 1.5sec.

Various protection features are built into KTD3137,

including cycle-by-cycle inductor current limit protection,

output overvoltage protection, LED fault (open or short)

protection and thermal shutdown protection.

KTD3137 is available in a RoHS compliant 12-ball 1.19mm

x 1.64mm WLCSP or a 16-lead 3mm x 3mm x 0.75mm

Thin-QFN package.