APE1630 Advanced Power Electronics Corp., APE1630 Datasheet - Page 8

• 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.
Reducing output ripple
capacitor CLED across the LED(s) as shown below:
Proportionally lower ripple can be achieved with higher capacitor values. Note that the
capacitor will not affect operating frequency or efficiency, but it will increase start-up delay
and reduce the frequency of dimming, by reducing the rate of rise of LED voltage.
triangular ramp to a more sinusoidal version without altering the mean current value.
Operation at low supply voltage
the startup threshold (V
temperature coefficients of the operating. However, with the supply voltage below the
specified minimum value, the switch duty cycle will be high and the device power dissipation
will be at a maximum. Care should be taken to avoid operating the device under such
conditions in the application, in order to minimize the risk of exceeding the maximum allowed
die temperature. (See next section on thermal considerations). The drive to the switch is
turned off when the supply voltage falls below the under-voltage threshold (V
the duty cycle is high.
Thermal shutdown protection
protection function. The TSD protests the IC from over temperature (150°C). When the chip
temperature decreases (115°C), the IC recovers again.
Peak to peak ripple current in the LED(s) can be reduced, if required, by shunting a
A value of 1uF will reduce the supply ripple current by a factor three (approx.).
By adding this capacitor the current waveform through the LED(s) changes from a
The internal regulator disables the drive to the switch until the supply has risen above
This prevents the switch working with excessive 'on' resistance under conditions where
To ensure the reliability, the APE1630 is built with a thermal shutdown (TSD)
V
IN
C
IN
UVLO
). Above this threshold, the device will start to for this reason, the
4.7uF~100uF
DIM
V
IN
0.4
APE1630
GND
CSN
47uH
L
D
SW
C
1uF
LED
UVLO
-1V).
APE1630
8