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General Description
The AP1517 is a current mode boost DC-DC converter. Its PWM circuitry with built-in 0.12
power MOSFET make this regulator highly power efficient. The internal compensation network also
minimizes as much as 6 external component counts. The non-inverting input of error amplifier connects
to a 0.6V precision reference voltage and internal soft-start function can reduce the inrush current. The
A P1517 is available in the SOP-8(EP) PACkage.
Features
Adjustable Output up to 12V
Internal Fixed PWM frequency: 1.0MHz
Precision Feedback Reference Voltage: 0.6V (±2%)
Internal 0.12, 4A, 18V Power MOSFET
Shutdown Current: 0.1μA
Over Temperature Protection
Over Voltage Protection
Adjustable Over Current Protection: 0.5A ~ 4.0A
Package: SOP-8L
Applications
Chargers
LCD Displays
Digital Cameras
Handheld Devices
Portable Products
Typical Application Circuit
AP1517 AP1517
AP1517
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深圳市世微半导体有限公司
Function Block Diagram
Pin Descriptions
SOP-8L(EP)
Name No. I / O Description
PGND 1 P IC Ground
OC 2 I Adjustable Current Limit (Floating Available)
Vcc 3 P IC Power Supply
EN 4 I Enable Control (Active High)
GND 5 P IC Ground
FB 6 I Error Amplifier Inverting Input
NC 7 NA Not Connected
LX 8 O Power Switch Output
EP 9 P Exposed PAD-Must connect to Ground
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
Ordering Information
Part Number Code Operating Temperature Package MOQ Description
AP1517XR-G1 -40°C ~ 85°C SOP-8L(EP) 2500EA Tape & Reel
Absolute Maximum Ratings
Parameter Symbol Conditions Min. Typ. Max. Unit
Supply Voltage VCC 0 6 V
LX Voltage VLX 0 18 V
EN,FB Voltage 0 6 V
θJA SOP-8L(EP) +60 °C / W
Thermal Resistance (Note1)
θJC SOP-8L(EP) +4 °C / W
Junction Temperature TJ +150 °C
Operating Temperature TOP -40 +85 °C
Storage Temperature TST -65 +150 °C
Lead Temperature (soldering, 10 sec) +260 °C
Note1:
θJA is measured in the natural convection at TA=25°C on a low effective thermal conductivity test
board of JEDEC 51-3 thermal measurement standard.
IR Re-flow Soldering Curve
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
Recommended Operating Conditions
Parameter Symbol Conditions Min. Typ. Max. Unit
Supply Voltage VIN 2.6 5.5 V
Operating Temperature Range TA Ambient Temperature -40 +85 °C
DC Electrical Characteristics (VCC=3.3V, TA=25°C, unless otherwise specified)
Parameter Symbol Conditions Min. Typ. Max. Unit
System Supply Input
Input Supply Range VCC 2.6 5.5 V
Under Voltage Lockout VUVLO 2.2 V
UVLO Hysteresis 0.1 V
Quiescent Current ICC VFB=0.66V, No switching 0.19 mA
Average Supply Current ICC VFB=0.55V, Switching 2.84 mA
Shutdown Supply Current ICC VEN=GND 0.1 μA
Oscillator
Operation Frequency FOSC VFB=1.0V 0.8 1.0 1.2 MHZ
Frequency Change with Voltage △f / △V VCC=2.6V to 5.5V 5 %
Maximum Duty Cycle TDUTY 90 %
Reference Voltage
Reference Voltage VREF 0.588 0.6 0.612 V
Line Regulation VCC=2.6V～5.5V 0.2 % / V
Enable Control
Enable Voltage VEN 0.96 V
Shutdown Voltage VEN 0.6 V
MOSFET
On Resistance of Driver RDS (ON) ILX=2A 0.12 Ω
Protection
OCP Current IOCP 4 A
Adjustable OCP Current IOCP
With External Resistor：
12k~96k
0.5 4 A
OTP Temperature TOTP +150 °C
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
6/8
Function Description
Operation
The AP1517is a current mode boost converter. The c onstant switching frequency is 1MHz and
operates with pulse width modulation (PWM). Build-in 18V / 4A MOSFET provides a high output
voltage. The control loop architecture is peak current mode control; therefore slope compensation
circuit is added to the current signal to allow stable operation for duty cycles larger than 50%.
Soft Start Function
Soft start circuitry is integrated into AP1517 to a void inrush current during power on. After the IC
is enabled, the output of error amplifier is clamped by the internal soft-start function, which causes
PWM pulse width increasing slowly and thus reducing input surge current.
Current Limit Program
A resistor between OC and GND pin programs peak switch current. The resistor value should be
between 12k and 96k. The current limit will be set from 4A to 0.5A. Keep traces at this pin as short as
possible. Do not put capacitance at this pin. To set the over current trip point according to the following
equation:
R3
48000
IOCP =
Over Temperature Protection (OTP)
AP1517 will turn off the power MOSFET automatically when the internal junction temperature is
over 150°C. The power MOSFET wake up when the junction temperature drops 30°C under the OTP
threshold temperature.
Over Voltage Protection (OVP)
In some condition, the resistive divider may be unconnected, which will cause PWM signal to
operate with maximum duty cycle and output voltage is boosted higher and higher. The power
MOSFET will be turned off immediately, when the output voltage exceeds the OVP threshold level. The
AP15177’s OVP threshold is 16V.
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
Application Information
Inductor Selection
Inductance value is decided based on different condition. 3.3uH to 4.7μH inductor value is
recommended for general application circuit. There are three important inductor specifications, DC
resistance, saturation current and core loss. Low DC resistance has better power efficiency. Also, it
avoid inductor saturation which will cause circuit system unstable and lower core loss at 1 MHz.
Capacitor Selection
The output capacitor is required to maintain the DC voltage. Low ESR capacitors are preferred to
reduce the output voltage ripple. Ceramic capacitor of X5R and X7R are recommended, which have
low equivalent series resistance (ESR) and wider operation temperature range.
Diode Selection
Schottky diodes with fast recovery times and low forward voltages are recommended. Ensure the
diode average and peak current rating exceed the average output current and peak inductor current. In
addition, the diode’s reverse breakdown voltage must exceed the output voltage.
Output Voltage Programming
The output voltage is set by a resistive voltage divider from the output voltage to FB. The output
voltage is:
= +
R2
R1
VOUT 0.6V 1
Layout Considerations
1. The power traces, consisting of the GND trace, the LX trace and the VCC trace should be kept
short, direct and wide.
2. LX、L and D switching node, wide and short trace to reduce EMI.
3. Place CIN near VCC pin as closely as possible to maintain input voltage steady and filter out the
pulsing input current.
4. The resistive divider R1and R2 must be connected to FB pin directly as closely as possible.
5. FB is a sensitive node. Please keep it away from switching node, LX.
6. The GND of the IC, CIN and COUT should be connected close together directly to a ground
plane.
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
8/8
Typical Application
General Boost Converter
AP1517
1MHz, 4A Step-Up Current Mode PWM Converter
AP1517
SHIWEI SEMICONDUCTOR Co.,LTD. www.shiweidz.com
深圳市世微半导体有限公司
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