Document
Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter
AP3202
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
Mar. 2011 Rev. 1. 2
SOIC-8
Figure 1. Package Type of AP3202
BCD Semiconductor Manufacturing Limited 1
Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter
AP3202
Pin Configuration
M Package (SOIC-8)
Pin Description
Figure 2. Pin Configuration of AP3202 (Top View)
Pin Number
1 2 3 4 5
6
7 8
Pin Name
BS IN SW GND FB
COMP
EN NC
Function
Bootstrap pin. A bootstrap capacitor is connected between the BS pin 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
Ground pin
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
No Connection
Mar. 2011 Rev. 1. 2
BCD Semiconductor Manufacturing Limited 2
Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter
AP3202
Functional Block Diagram
IN 2
Internal Bias And Regulator
SLOP COMP
Current Sense Amplifier
INTERNAL PULL HIGH
Oscillator 90k/380k
EN 7
Shutdown Comparator
0.5/1.5V
CLK
SQ
RQ
CoPmWpaMrator
1.8V
Short Protection Comparator
0.6 1.222
Error Amplifier
56
FB COMP
8
NC
5V
1
M1 0.22
3
BS SW
M2 10
4 GND
Figure 3. Functional Block Diagram of AP3202
Ordering Information
AP3202
-
Circuit Type
Package M: SOIC-8
G1: Green
TR: Tape & Reel Blank: Tube
Package
SOIC-8
Temperature Range
-40 to 85°C
Part Number
AP3202M-G1 AP3202MTR-G1
Marking ID
3202M-G1 3202M-G1
Packing Type
Tube 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 3
Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter
AP3202
Absolute Maximum Ratings (Note 1)
Parameter
IN Pin Voltage EN Pin Voltage SW Pin Voltage BS Pin Voltage FB Pin Voltage COMP Pin Voltage Thermal Resistance Operating Junction Temperature Storage Temperature Lead Temperature (Soldering, 10sec) ESD (Machine Model) ESD (Human Body Model)
Symbol
VIN VEN VSW VBS VFB VCOMP
θJA TJ TSTG TLEAD
Value
-0.3 to 20 -0.3 to VIN
20 -0.3 to VSW+6
-0.3 to 6 -0.3 to 6
105 150 -65 to 150 260 200 2000
Unit
V V V V V V ºC/W ºC ºC ºC V V
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
Input Voltage Maximum Output Current Operating Ambient Temperature
Symbol
VIN IOUT(Max)
TA
Min
4.75 2 -40
Max
18
85
Unit
V A ºC
Mar. 2011 Rev. 1. 2
BCD Semiconductor Manufacturing Limited 4
Preliminary Datasheet
380kHz, 2A Asynchronous DC-DC Buck Converter
AP3202
Electrical Characteristics
VIN=VEN=12V, VOUT=3.3V, unless otherwise specified. Specification with standard typeface are for TA=25oC, .