Top View

A

B

C

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Bottom View

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C

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LM3535

SNVS598A – AUGUST 2010 – REVISED MAY 2013

www.ti.com

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam

during storage or handling to prevent electrostatic damage to the MOS gates.

DESCRIPTION (CONTINUED)

The LM3535 provides multi-zone Ambient Light Sensing (1 or 2 ALS inputs depending on option) allowing

autonomous backlight intensity control in the event of changing ambient light conditions. A PWM input is also

provided to give the user a means to adjust the backlight intensity dynamically based upon the content of the

display.

The LM3535 provides excellent efficiency without the use of an inductor by operating the charge pump in a gain

of 3/2 or in Pass-Mode. The proper gain for maintaining current regulation is chosen, based on LED forward

voltage, so that efficiency is maximized over the input voltage range.

The LM3535 is available in a tiny 20-bump, 0.4mm pitch, thin DSBGA package.

Connection Diagram

Figure 3. 20 Bump DSBGA Package

Package Number YFQ0020

PIN DESCRIPTIONS

Bump Number

Pin Names

Pin Descriptions

A3

Input voltage. Input range: 2.7V to 5.5V.

A2

Charge Pump Output Voltage

A1, C1, B1, B2

C1+, C1-, C2+, C2-

Flying Capacitor Connections

D3, E3, E4, D4

D1A-D4A

LED Drivers - GroupA

C4, B4

D53, D62

LED Drivers - Configurable Current Sinks. Can be assigned to GroupA or GroupB

LED Driver/ ALS Interrupt - GroupB Current Sink or ALS Interrupt Pin. In ALS Interrupt

B3

D1B / INT

mode, a pull-up resistor is required. A '0’ means a change has occurred, while a ‘1’ means

no ALS adjustment has been made.

C3

D1C / ALS

LED Driver / ALS Input - Indicator LED current sink or Ambient Light Sensor Input

D2

PWM

External PWM Input - Allows the current sinks to be turned on and off at a frequency and

duty cycle externally controlled. Minimum On-Time Pulse Width = 15µsec.

E1

HWEN

Hardware Enable Pin. High = Normal Operation, Low = RESET

C2

SDIO

Serial Data Input/Output Pin

E2

SCL

Serial Clock Pin

GND

(LM3535)

A4

Ground for LM3535 or Ambient Light Sensor B for LM3535-2ALS

ALSB

(LM3535-2ALS)

D1

GND

Ground

2

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