The AP3201A 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 AP3201A. This feature greatly simplifies the
design of switch-mode power supplies.
This IC is available in HMSOP-10 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
• Programmable Soft-start
Applications
• LCD TV
• Set Top Box
• Portable DVD
• Digital Photo Frame
HMSOP-10
Figure 1. Package Type of AP3201A
Mar. 2011 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
Mar. 2011 Rev. 1. 0 BCD Semiconductor Manufacturing Limited
NC No connection or tied to ground
Bootstrap pin. A bootstrap capacitor is connected between the BS pin
BS
and SW pin. The voltage across the bootstrap capacitor drives the
internal high-side power MOSFET
IN
SW
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
GND Ground pin
Feedback pin. This pin is connected to an exte rnal resistor divider to
program the system output voltage. When the FB pin voltage exceeds
FB
20% of the nominal regulation value of 0.920V, 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
COMP
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
EN
enables the IC. Forcing this pin below 0.5V shut s down the IC. When
the IC is in shutdown mode, all functions are disabled to decrease the
supply current below 1µA
Soft-start control input pin. SS controls the soft start period. Connect
SS
a capacitor from SS to GND to set the soft-start period. A 0.1µF
capacitor sets the soft-start period to 10ms. To disable the soft-start
feature, leave SS unconnected
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
SS Pin Voltage VSS -0.3 to 6 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
θ
JA
-65 to 150 ºC
STG
260 ºC
LEAD
60 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. 0 BCD Semiconductor Manufacturing Limited
VIN=VEN=12V, V
ºC, and those in boldface type apply over the full operating temperature range (TA=-40 ºC to 85 ºC)
Parameter SymbolConditions Min Typ Max Unit
Input Voltage VIN 4.75 18 V
Quiescent Current IQ VFB=1.0V, VEN=2V 1.0 1.5 mA
=3.3V, unless otherwise specified. Specification with standard typeface are for TA=25
OUT
Shutdown Supply Current I
Feedback Voltage VFB
Feedback Over Voltage
Threshold
Feedback SCP Voltage Threshold V
Feedback Bias Current IFB VFB=1V -0.1 0.1
High-side Switch On-resistance (Note 2) R
Low-side Switch On-resistance (Note 2) R
High-side Switch Leakage Current I
High-side Switch Current Limit I
Low-side Switch Current Limit I
EN Pin Threshold
EN Pull-up Current I
Input UVLO Threshold V
Input UVLO Hysteresis V
Oscillator Frequency F
Short Circuit Oscillator
Frequency
Maximum Duty Cycle D
Minimum Duty Cycle D
VEN=0V 1 10
SHDN
0.9020.920 0.938
1.1 V
V
FBOV
FBSCP
0.6 V
µA
V
µA
ISW=0.5A
DSONH
ISW=0.05A
DSONL
=18V, VEN=0V
V
IN
LEAKH
2.8 3.8 A
LIMH
From drain to source0.15 A
LIML
V
1.5
ENH
V
0.5
ENL
VEN=0V 1.0
EN-PH
VIN Rising 3.5 3.9 4.4 V
UVLO
0.3 V
HYS
380 kHz
OSC1
90 kHz
F
OSC2
VFB=0.8V 90 %
MAX
VFB=1.0V 0 %
MIN
=0V
V
SW
0.1 10
0.22
10
Ω
Ω
µA
V
µA
Error Amplifier Voltage Gain (Note 3) AEA 400 V/V
Error Amplifier Transconductance GEA 700
COMP to Current Sense
Transconductance
Thermal Shutdown (Note 3) T
Thermal Shutdown Hysteresis (Note 3) T
Soft-start Time (Note 3) tSS
2.4 A/V
G
CS
160 ºC
OTSD
30 ºC
HYS
=500mA
I
C
OUT
SS
=0.1µF
10 ms
Soft-start Current ISS 6
µA/V
µA
Mar. 2011 Rev. 1. 0 BCD Semiconductor Manufacturing Limited