APE1630 Advanced Power Electronics Corp., APE1630 Datasheet - Page 6

• Manufacturer Part Number: APE1630
• Manufacturer: Advanced Power Electronics Corp.

Specifications of APE1630

• Support Voltage (min.): 8V
• Support Voltage (max.): 32V
• Frequency: 1MHz
• Output Current: 1A
• Package: SOT89-5

Advanced Power
Electronics Corp.
Output current adjustment by PWM control
DIM pin, as shown below, to adjust the output current to a value below the nominal average
value set by resistor R
between 0% and 100%. The LED brightness is controlled by adjusting the relative ratios of
the on time to the off time. A 25% brightness level is achieved by turning the LED on at full
current for 25% of one cycle. To ensure this switching process between on and off state is
invisible by human eyes, the switching frequency must be greater than 100 Hz. Above 100
Hz, the human eyes average the on and off times, seeing only an effective brightness that is
proportional to the LED’s on-time duty cycle. The advantage of PWM dimming is that the
forward current is always constant; therefore the LED color does not vary with brightness as
it does with analog dimming. Pulsing the current provides precise brightness control while
preserving the color purity. The dimming frequency of APE1630 can be as high as 20 kHz.
Shutdown mode
current will fall to a low standby level of 70µA nominal.
A Pulse Width Modulated (PWM) signal with duty cycle PWM can be applied to the
PWM dimming provides reduced brightness by modulating the LED’s forward current
Taking the DIM pin to a voltage below 0.3V will turn off the output and the supply
V
IN
I
(0≦D≦100%, 0.3V＜V
OUT
S
C
:
=
IN
0
1 .
R
4.7uF~100uF
×
S
D
PWM
pulse
DIM
＜2.5V)
V
IN
0.4
R
S
APE1630
GND
CSN
47uH
L
D
SW
APE1630
6