Diodes AP3202 User Manual
380kHz, 2A Asynchronous DC-DC Buck Converter AP3202
Preliminary Datasheet
General Description
The AP3202 is a 380kHz fixed frequency, current
mode, PWM buck (step-down) DC-DC converter,
capable of driving a 2A load with high efficiency,
excellent line and load regulation. The device
integrates N-channel power MOSFET switch with
low on-resistance. Current mode control provides fast
transient response and cycle-by-cycle current limit.
A standard series of inductors are available from
several different manufacturers optimized for use
with the AP3202. This feature greatly simplifies the
design of switch-mode power supplies.
This IC is available in SOIC-8 package.
Features
• Input Voltage Range: 4.75V to 18V
• Fixed 380kHz Frequency
• High Efficiency: up to 93%
• Output Current: 2A
• Current Mode Control
• Built-in Over Current Protection
• Built-in Thermal Shutdown Function
• Built-in UVLO Function
• Built-in Over Voltage Protection
• Built-in Soft-start
Applications
• LCD TV
• Set Top Box
• Portable DVD
• Digital Photo Frame
Figure 1. Package Type of AP3202
SOIC-8
Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
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Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter AP3202
Pin Configuration
M Package
(SOIC-8)
Figure 2. Pin Configuration of AP3202 (Top View)
Pin Description
Pin Number Pin Name Function
Bootstrap pin. A bootstrap capacitor is connected between the BS pin
1
2
3
4
5
6
7
8
BS
IN
SW
GND Ground pin
FB
COMP
EN
NC No Connection
and SW pin. The voltage across the bootstrap capacitor drives the
internal high-side power MOSFET
Supply input pin. A capacitor should be connected between the IN pin
and GND pin to keep the input voltage constant
Power switch output pin. This pin is connected to the inductor and
bootstrap capacitor
Feedback pin. This pin is connected to an external resistor divider to
program the system output voltage. When the FB pin voltage exceeds
20% of the nominal regulation value of 1.222V, the over voltage
protection is triggered. When the FB pin voltage is below 0.6V, the
oscillator frequency is lowered to realize short circuit protection
Compensation pin. This pin is the output of the transconductance
error amplifier and the input to the current comparator. It is used to
compensate the control loop. Connect a series RC network from this
pin to GND. In some cases, an additional capacitor from this pin to
GND pin is required
Control input pin. Forcing this pin above 1.5V or set this pin floating
enables the IC. Forcing this pin below 0.5V shuts down the IC. When
the IC is in shutdown mode, all functions are disabled to decrease the
supply current below 1µA
Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
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Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter AP3202
Functional Block Diagram
2
IN
Current
Sense
Amplifier
S
R
PWM
Comparator
1.8V
8
NC
EN
INTERNAL
PULL
HIGH
7
0.5/1.5V
Short
Protection
Comparator
Internal Bias
And Regulator
Oscillator
90k/380k
Shutdown
Comparator
0.6
5
FB
1.222
CLK
Error
Amplifier
SLOP
COMP
6
COMP
Figure 3. Functional Block Diagram of AP3202
Ordering Information
AP3202 -
Circuit Type
Package
Package
M: SOIC-8
Temperature
Range
Part Number Marking ID Packing Type
5V
1
BS
M1
Q
Q
0.22
M2
10
3
SW
4
GND
G1: Green
TR: Tape & Reel
Blank: Tube
SOIC-8
-40 to 85°C
AP3202M-G1 3202M-G1 Tube
AP3202MTR-G1 3202M-G1 Tape & Reel
BCD Semiconductor's Pb-free products, as designated with "G1" suffix in the part number, are RoHS compliant
and green.
Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
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Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter AP3202
Absolute Maximum Ratings (Note 1)
Parameter Symbol Value Unit
IN Pin Voltage VIN -0.3 to 20 V
EN Pin Voltage VEN -0.3 to VIN V
SW Pin Voltage VSW 20 V
BS Pin Voltage VBS -0.3 to VSW+6 V
FB Pin Voltage VFB -0.3 to 6 V
COMP Pin Voltage V
Thermal Resistance
Operating Junction Temperature TJ 150 ºC
Storage Temperature T
Lead Temperature (Soldering, 10sec) T
ESD (Machine Model) 200 V
ESD (Human Body Model) 2000 V
-0.3 to 6 V
COMP
θJA
-65 to 150 ºC
STG
260 ºC
LEAD
105 ºC/W
Note 1: Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to
the device. These are stress ratings only, and functional operation of the device at these or any other conditions
beyond those indicated under “Recommended Operating Conditions” is not implied. Exposure to “Absolute
Maximum Ratings” for extended periods may affect device reliability.
Recommended Operating Conditions
Parameter Symbol Min Max Unit
Input Voltage VIN 4.75 18 V
Maximum Output Current I
Operating Ambient Temperature TA -40 85 ºC
OUT(Max)
2 A
Mar. 2011 Rev. 1. 2 BCD Semiconductor Manufacturing Limited
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