1

ZXSC300

ISSUE 4 - SEPTEMBER 2007

SINGLE OR MULTI CELL LED DRIVER SOLUTION

Q1

FMMT617

R1

0.33R

L1

100µH

LED1

WHITE LED

Gnd

U1

ZXSC300

TYPICAL APPLICATION CIRCUIT

ORDERING INFORMATION

DEVICE

Reel

Tapewidth

Quantity

per reel

ZXSC300E5TA

7”

8mm

3,000

DEVICE MARKING C300

Package SOT23-5

DESCRIPTION

The ZXSC300 is a single or multi cell LED driver

designed for applications where step-up voltage

conversion from very low input voltages is required.

These applications mainly operate from single 1.5V or

1.2V battery cells. The circuit generates constant

current pulses that are ideal for driving single or

multiple LED’s over a wide range of operating voltages.

The ZXSC300 is a PFM controller IC that drives an

external Zetex switching transistor with a very low

saturation resistance. These transistors are the best

switching devices available for this type of switching

conversion enabling high efficiency conversion with

input voltages below 1 volt. The drive output of the

ZXSC controller generates a dynamic drive signal for

the switching transistor.

FEATURES

The circuit can start up under full load and operates

down to an input voltage of 0.8 volts. The solution

configuration ensures optimum efficiency over a wide

range of load currents, several circuit configurations

are possible depending on battery life versus

brightness considerations.

The ZXSC300 is offered in the SOT23-5 package which,

when combined with a SOT23 switching transistor,

generates a high efficiency small size circuit solution.

The IC and discrete combination offers the ultimate

cost vs performance solution for single cell LED driving

applications.

APPLICATIONS