NCP3066SCBSTGEVB ON Semiconductor, NCP3066SCBSTGEVB Datasheet - Page 7

• Manufacturer Part Number: NCP3066SCBSTGEVB
• Description: EVAL BOARD FOR NCP3066SCBSTG
• Manufacturer: ON Semiconductor

Specifications of NCP3066SCBSTGEVB

• Design Resources: NCP3066 Boost SOIC EVB BOM NCP3066SCBSTGEVB Gerber Files NCP3066 Boost SOIC EVB Schematic
• Current - Output / Channel: 350mA
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 16V
• Features: Brightness Control
• Voltage - Input: 12V
• Utilized Ic / Part: NCP3066
• Silicon Manufacturer: On Semiconductor
• Silicon Core Number: NCP3066
• Kit Application Type: Power Management - Voltage Regulator
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: NCP3066SCBSTG
• Other names: NCP3066SCBSTGEVBOS

optimized for LED Driver applications. Its flexible
architecture enables the system designer to directly
implement step−up, step−down, and voltage−inverting
converters with a minimum number of external components
for driving LEDs. A representative block diagram is shown
in Figure 3.
Operating Description
output voltage ripple gated regulator. In general, this mode
of operation is somewhat analogous to a capacitor charge
pump and does not require dominant pole loop
compensation for converter stability. The typical operating
waveforms are shown in Figure 12. The output voltage
waveform is shown for a step−down converter with the
ripple and phasing exaggerated for clarity. During initial
converter startup, the feedback comparator senses that the
output voltage level is below nominal. This causes the
output switch to turn on and off at a frequency and duty cycle
controlled by the oscillator, thus pumping up the output filter
capacitor. When the output voltage level reaches nominal
The NCP3066 is a monolithic power switching regulator
The NCP3066 operates as a fixed oscillator frequency
Figure 12. Typical Operating Waveforms
http://onsemi.com
INTRODUCTION
7
comparator value, the output switch cycle is inhibited. When
the load current causes the output voltage to fall below the
nominal value feedback comparator enables switching
immediately. Under these conditions, the output switch
conduction can be enabled for a partial oscillator cycle, a
partial cycle plus a complete cycle, multiple cycles, or a
partial cycle plus multiple cycles.
Oscillator
are programmed by the value of the timing capacitor C
capacitor C
internal current source and sink, generating a positive going
sawtooth waveform at Pin 3. This ratio sets the maximum
t
85.7% (typical). The oscillator peak and valley voltage
difference is 500 mV typically. To calculate the C
value for required oscillator frequency, use the equations
found in Figure 15. An online NCP3066 design tool can be
found at www.onsemi.com, which aids in selecting
component values.
ON
The oscillator frequency and off−time of the output switch
/(t
ON
+ t
T
OFF
is charged and discharged by a 1 to 6 ratio
) of the switching converter as 6/(6+1) or
T
capacitor
T
. The