Document
AP2952A
Description
The AP2952A is a monolithic synchronous buck regulator. The device integrates 130mΩ MOSFETS that provide 2A continuous load current over a wide operating input voltage of 4.75V to 18V. Current mode control provides fast transient response and cycle-by-cycle current limit. An adjustable soft-start prevents inrush current at turn-on. In shutdown mode, the supply current drops below 1μA. This device, available in an 8-pin SOP package, provides a very compact system solution with minimal reliance on external components.
Applications
Distributed Power Systems Networking Systems FPGA, DSP, ASIC Power Supplies Green Electronics/ Appliances Notebook Computers
Chipown
2A, 18V Synchronous Rectified Step-Down Converter
Features
2A Output Current Wide 4.75V to 18V Operating Input Range Integrated 130mΩ Power MOSFET Switches Output Adjustable from 0.925V to 15V Up to 95% Efficiency Programmable Soft-Start Fixed 450KHz Frequency Cycle-by-Cycle Over Current Protection Input Under Voltage Lockout Thermally Enhanced 8-Pin SOP Package
Package
Typical Application Circuit
Figure 1. Typical Application Circuit
Efficy(%)
100 90 80 70 60 50 40 30 20 10 0 0
Vout=5V
Vin=9V Vin=12V Vin=18V
400 800 1200 1600 2000
Load(mA)
Figure 2. Typical Efficiency Curve
8/F, ChuangYuan Building No.21-1 Changjiang Road, Wuxi New Destrict Tel: +86(510)8521-7718 http://www.chipown.com.cn
V2.0
1/9
AP2952A
Chipown
Absolute Maximum Ratings(1)
Supply Voltage (VIN)..................................-0.3V to 20V
Switch Voltage (VSW)......................–1V to VIN + 0.3V Bootstrap Voltage (VBS) ..........Vsw-0.3V to VSW + 6V Enable/UVLO Voltage (VEN)....................–0.3V to +6V Comp Voltage (VCOMP) ..........................–0.3V to +6V Feedback Voltage (VFB) ...........................–0.3V to +6V Junction Temperature .................................... +150℃
Lead Temperature (Soldering, 10s)................... +260℃ Storage Temperature......................... –65°C to +150℃
Recommended Operating Conditions(2)
Input Voltage (VIN) ........................................ 4.75V to 18V Output Voltage (VSW) .................................... 0.925 to 15V Operating Temperature...................................–40℃to +85℃
Thermal Resistance(3) θJA θJC
SOP8-PP ..............................50...... 10... ℃/W
Notes: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its
operating conditions. 3) Measured on approximately 1”square of 1 oz copper.
Electrical Characteristics
VIN = 12V, TA = +25℃, unless otherwise noted.
Parameter Shutdown Supply Current Supply Current Feedback Voltage Feedback Overvoltage Threshold Error Amplifier Voltage Error Amplifier Transconductance High-Side Switch-On Resistance Low-Side Switch-On Resistance High-Side Switch Leakage Upper Switch Current Limit Lower Switch Current Limit COMP to Current Sense Transconductance Oscillator Frequency Short Circuit Frequency Maximum Duty Cycle Minimum On Time
EN Shutdown Threshold Voltage EN Shutdown Threshold Voltage Hysterisis
EN Lockout Threshold Voltage EN Lockout Hysterisis Input UVLO Threshold Rising
Condition VEN ≤ 0.3V VEN =2.0V, VFB = 1.0V 4.75V≤VIN ≤18V
ΔIC = ±10μA
VEN = 0V, VSW = 0V
VFB = 0V VFB = 1.0V VEN Rising
VIN Rising
Min Typ Max Units
1 3 µA 1.3 1.5 mA
900 925 946 mV 1.1 V 400 V/V 800 µA/V
130 mΩ
130 mΩ
10 µA
2.4 3.4
A
1.1 A
3.5 А/V
450 KHz
150 KHz
90 % 220 nS
1.1 1.5 2.0
V
40 mV
2.2 2.5 2.7
V
210 mV
3.8 4.1 4.4 V
Input UVLO Threshold Hysteresis Soft-start Current Soft-start Period Thermal Shutdown
VSS = 0V CSS = 0.1μF
210 mV 6 µA 15 ms
160 °C
8/F, ChuangYuan Building No.21-1 Changjiang Road, Wuxi New Destrict Tel: +86(510)8521-7718 http://www.chipown.com.cn
V2.0
2/9
AP2952A
Ordering Information
Part number
AP2952AS8T
1. Y=year W=week
AP2952AS8R
Pin Configuration
Mark1 2952 YYWW1
2952 YYWW1
Chipown
Package SOP8&IC tube
SOP8&Embossed tape
Temperature –40℃ to +85℃
–40℃ to +85℃
8 27 36 45
Pin Description
Pin #
Name
1 BS
2 IN
3 SW
Description
High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET switch. Connect a 0.01μF or greater capacitor from SW to BS to power the high side switch.
Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN with a 4.75V to 18V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise on the input to the IC. See Input Capacitor.
Power Switching Output. SW is the switching node that supplies power to the output. Connect the output LC filter from SW to the output load. Note that a capacitor is required from SW to BS to power the high-side switch.
4 GND Ground(Connect Exposed Pad to Pin 4)..
Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
5
FB
resistive voltage divider from the output voltage. The feedback threshold is 0.925V. See Setting the Ou.