LP8556 datasheet(5/63 Pages) TI1

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LP8556

www.ti.com

SNVS871I – JULY 2012 – REVISED MARCH 2016

Product Folder Links: LP8556

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(1)

A: Analog Pin, G: Ground Pin, P: Power Pin, I: Digital Input Pin, I/O: Digital Input/Output Pin

Pin Functions

TYPE(1)

DESCRIPTION

DSBGA

WQFN

NAME

A1, B1

1, 2

A connection to the drain terminal of the integrated power MOSFET.

A2, B2

3, 4

GND_SW

A connection to the source terminal of the integrated power MOSFET.

SDA

I/O

I2C data input/output pin

SCL

I2C clock input pin

PWM

PWM dimming input. Supply a 75-Hz to 25-kHz PWM signal to control

dimming. This pin must be connected to GND if unused.

EN / VDDIO

Dual-purpose pin serving both as a chip enable and as a power supply

reference for PWM, SDA, and SCL inputs. Drive this pin with a logic

gate capable of sourcing a minimum of 1 mA.

VDD

Device power supply pin. Provide 2.7-V to 20-V supply to this pin. This

pin is an input of the internal LDO regulator. The output of the internal

LDO is what powers the device.

VBOOST

Boost converter output pin. The internal feedback (FB) and overvoltage

protection (OVP) circuitry monitors the voltage on this pin. Connect the

converter output capacitor bank close to this pin.

FSET

A connection for setting the boost frequency and PWM output dimming

frequency by using an external resistor. Connect a resistor, RFSET,

between this pin and the ground reference (see Table 5). This pin may

be left floating if PWM_FSET_EN = 0 AND BOOST_FSET_EN = 0

(see Table 10).

LED3

LED driver - current sink terminal. If unused, it may be left floating.

VLDO

Internal LDO output pin. Connect a capacitor, CVLDO, between this pin

and the ground reference.

ISET

A connection for the LED current set resistor. Connect a resistor,

RISET, between this pin and the ground reference. This pin may be left

floating if ISET_EN = 0 (see Table 10).

10, 11, 15, 24,

DAP

GND

Ground pin.

LED2