AP1580SL-13 Diodes Inc, AP1580SL-13 Datasheet - Page 7

• Manufacturer Part Number: AP1580SL-13
• Description: IC BUCK CONVERTER 3A 8-SOIC
• Manufacturer: Diodes Inc
• Type: Step-Down (Buck)r

Specifications of AP1580SL-13

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.8 ~ 36 V
• Current - Output: 3A
• Frequency - Switching: 300kHz
• Voltage - Input: 10 ~ 40 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Test Circuit
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.
AP1580 Rev. 2
+
-
220uF
A
0.1uF
Operation function test
Enable function test
EN
EN
Vcc
Vcc
Vboost
OUTPUT
GND
GND
OUTPUT
open
NOT RECOMMENDED FOR NEW
Vboost
FB
FB
DESIGN, USE AP5004
www.diodes.com
open
open
470uF
33uH
PWM CONTROL 3A STEP-DOWN CONVERTER
7 of 9
+
-
130 ohm
680 ohm
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℃.
V
+
-
A
Feedback function test
EN
Vcc
OUTPUT
GND
Vboost
FB
©
AP1580
Diodes Incorporated
July 2008