ZXSC300
SINGLE OR MULTI CELL LED DRIVER SOLUTION
DESCRIPTION
The ZXSC300 is a single or multi cell LED driver The circuit can start up under full load and operates
designed for applications where step-up voltage down to an input voltage of 0.8 volts. The solution
conversion from very low input voltages is required. configuration ensures optimum efficiency over a wide
These applications mainly operate from single 1.5V or range of load currents, several circuit configurations
1.2V battery cells. The circuit generates constant are possible depending on battery life versus
current pulses that are ideal for driving single or brightness considerations.
multipleLED’sover a wide rangeofoperatingvoltages.
The ZXSC300 is offered in the SOT23-5 package which,
The ZXSC300 is a PFM controller IC that drives an when combined with a SOT23 switching transistor,
external Zetex switching transistor with a very low generates a high efficiency small size circuit solution.
saturation resistance. These transistors are the best The IC and discrete combination offers the ultimate
switching devices available for this type of switching cost vs performance solution for single cell LED driving
conversion enabling high efficiency conversion with applications.
input voltages below 1 volt. The drive output of the
ZXSC controller generates a dynamic drive signal for
the switching transistor.
FEATURES
APPLICATIONS
• 94% efficiency
• LED flashlights and torches
• Minimum operating input voltage 0.8V
• Fixed output current
• LED backlights
• White LED driving
• Multiple LED driving
• Solar Equipment
• Low saturation voltage switching transistor
• SOT23-5 package
TYPICAL APPLICATION CIRCUIT
ORDERING INFORMATION
DEVICE
Reel
Tapewidth Quantity
per reel
L1
VBATT
100µH
ZXSC300E5TA
7”
8mm
3,000
U1
Q1
FMMT617
Vcc
DEVICE MARKING C300
Package SOT23-5
LED1
V
drive
WHITE LED
Isense
Gnd
ZXSC300
R1
0.33R
ISSUE 3 - NOVEMBER 2006
1