AP1580(2007) 查看數據表（PDF） - Diodes Incorporated.
零件编号
产品描述 (功能)
比赛名单
AP1580 Datasheet PDF : 9 Pages
| |||
Test Circuit
AP1580
PWM CONTROL 3A STEP-DOWN CONVERTER
open
OUTPUT
Vcc
FB
open
A
EN
Vboost open
GND
OUTPUT Vboost
A
Vcc
FB
+
-
EN
GND
Enable function test
33uH
0.1uF
+
-
220uF
Vboost OUTPUT
Vcc
FB
EN GND
680 ohm
+
470uF -
V
130 ohm
Operation function test
Feedback function test
Function Description
PWM Control
The AP1580 consists of DC/DC converters that employ a
pulse-width modulation (PWM) system. The PWM controller is
internally clocked by a fixed 300KHz oscillator.
In converters of the AP1580, the pulse width varies in a range
from 0 to 90%, according to the load current. The ripple voltage
produced by the switching can easily be removed through a filter
because the switching frequency remains constant. Therefore,
these converters provide a low-ripple power over broad ranges of
input voltage and load current.
Enable Control
This input provides an electrical ON/OFF control of the power
supply. Connecting this pin to ground or to any voltage less than
0.8V will completely turn OFF the regulator. The current drain
from the input supply when OFF is only 2uA.
C BOOST
A capacitor must be connected from pin 3 to the switch output,
pin 4. This capacitor boosts the gate drive to the internal
MOSFET above Vin to fully turn it ON. This minimizes conduction
losses in the power switch to maintain high efficiency. The
recommended value for C Boost is 0.1uF.
FEEDBACK
This is the input to a two-stage high gain amplifier, which drivers
the PWM controller. It is necessary to connect pin 2 to the actual
output of the power supply to set the DC output voltage. Two
external resistors are required to set the DC output voltage. For
stable operation of the power supply, it is important to prevent
coupling of any inductor flux to the feedback input.
Current Limit
The current limit threshold is set by the internal circuit that
minimum switching current is 4A. The output voltage will be
reduced immediately and switching frequency will be dropped to
30KHz when switching current over limit threshold.
Thermal shutdown
The thermal shutdown temperature depends on internal junction
temperature. When junction temperature rises up to 140℃, the
device will be shut down and it will be recovered after
temperature reduced lower than 90℃.
AP1580 Rev. 1
7 of 9
www.diodes.com
JANUARY 2007
© Diodes Incorporated
Share Link: 