A7230AMP8R [AITSEMI]
DC-DC CONVERTER BUCK (STEP-DOWN) HIGH EFFICIENCY SYNCHRONOUS;型号: | A7230AMP8R |
厂家: | AiT Semiconductor |
描述: | DC-DC CONVERTER BUCK (STEP-DOWN) HIGH EFFICIENCY SYNCHRONOUS 功效 DC-DC转换器 |
文件: | 总10页 (文件大小:335K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
DESCRIPTION
FEATURES
The A7230A is a wide input range, high efficiency,
DC-to-DC step-down switching regulator, capable of
delivering up to 3A of output current. Current mode
Wide Input Operating Range from 5V to 20V
Capable of Delivering 3A
Up to 94% efficiency
PWM control
allows the use of small external
High efficiency (>85%) at light load
No External Schottky Diode Needed
Current Mode control
components ,such as ceramic input and output
caps,as well as small inductors,while still providing
low output ripples. On top of the integrated internal
synchronous rectifier that eliminates external Schottky
diode, Overall A7230A is a highly efficient and robust
solution for DC-DC step-down applications that
requires wide input ranges.
0.923V Reference for Low Output voltages
Logic Control Shutdown
Thermal shutdown and UVLO
Start-up current run-away protection
Short circuit protection
Available in PSOP8 package
The A7230A is available in PSOP8 Package.
APPLICATION
ORDERING INFORMATION
LCD TVs
Green Electronics/ Appliances
Distributed Power Systems
Notebook computers
FPGA power supplies
LED drivers
Package Type
Part Number
A7230AMP8R
A7230AMP8VR
PSOP8
MP8
SPQ: 2,500pcs/Reel
V: Halogen free Package
R: Tape & Reel
Note
AiT provides all RoHS products
TYPICAL APPLICATION
3.3V/3A Step Down Regulator
REV1.0
- MAY 2016 RELEASED -
- 1 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
PIN DESCRIPTION
Top View
Description
Pin #
Symbol
1
2
3
4
BST
IN
Bootstrap pin. Connect a 100nF capacitor from this pin to SW
Supply Voltage. Bypass with a 10μF ceramic capacitor to GND
Inductor Connection. Connect an inductor between SW and the regulator output.
Ground
SW
GND
Feedback Input. Connect an external resistor divider from the output to FB and
5
FB
GND to set VOUT
.
Compensation pin. COMP is used to compensate the regulation control loop.
Connect a series RC network from COMP to GND to compensate the regulation
control loop.
6
COMP
7
8
EN
SS
Enable pin for the IC. Drive this pin to high to enable the par,low to disable.
Soft start pin. Connect a 0.1uF capacitor from this pin to GND
REV1.0
- MAY 2016 RELEASED -
- 2 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
ABSOLUTE MAXIMUM RATINGS
Input Voltage Range, SW, EN Voltage
TJ, Junction Temperature
BST Voltage
-0.3V ~ 22V
125℃
-0.3V ~ SW +5V
-0.3V ~ 6V
FB Voltage
SW to Ground Current
TO, Operating Temperature
Internally Limited
-40°C ~ 85℃
10℃/W
θJC, Package Thermal Resistance
PSOP8
TS, Storage Temperature
-55°C ~ 150℃
Stress beyond above listed “Absolute Maximum Ratings” may lead permanent damage to the device. These are stress ratings only and
operations of the device at these or any other conditions beyond those indicated in the operational sections of the specifications are not
implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
VIN = 12V, Typical values are at TA = 25℃, unless otherwise specified.
Parameter
Symbol
VDD
Conditions
Min
5
Typ
4.2
Max
20
Unit
V
Input Voltage Range
UVLO, IN UVLO Rising
Feedback Voltage
UVLO_UP Rising, Hysteresis=140mV
V
VREF
IFB
0.900 0.923 0.946
V
Feedback Leakage Current
0.1
60
0.4
μA
Active, VFB=1V, No Switching
μA
Quiescent Current
IQ
Shutdown
0.1
360
185
100
4.4
3
μA
Switching Frequency
PMOS RDSON
fSOC
VEN = 2V, VIN = 12V
kHz
mohm
mohm
A
RDSONP
NMOS RDSON
RDSONN
Peak Current Limit
EN Input Low Voltage
ILIMIT
VEN
1.3
V
VIN = 12V, VSW=0 or 12V,
EN=GND
SW Leakage Current
ISW
10
μA
Over Temperature
Protection
TSD
150
°C
REV1.0
- MAY 2016 RELEASED -
- 3 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
TYPICAL PERFORMANCE CHARACTERISTICS
VIN=12V, VOUT=3.3V, L=10uH, COUT47uF, TA =25°C, unless otherwise stated
Figure 1. Steady State Test
Figure 2. Startup through Enable
Figure 3. Shutdown through Enable
Figure 4. Heavy Load Operation
Figure 5. Medium Load Operation
Figure 6. Light Load Operation
REV1.0
- MAY 2016 RELEASED -
- 4 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
Figure 7. Short Circuit Protection
Figure 8. Short Circuit Recovery
Figure 9. Load Transient
REV1.0
- MAY 2016 RELEASED -
- 5 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
BLOCK DIAGRAM
REV1.0
- MAY 2016 RELEASED -
- 6 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
DETAILED INFORMATION
The A7230A is a synchronous,current-mode,step-down regulator. It regulates input voltages from 5V to 20V
down to an output voltage as low as 0.923V, and is capable of supplying up to 3A of load current.
Current-Mode Control
The A7230A utilizes current-mode control to regulate the output voltage. The output voltage is measured at
the FB pin through a resistive voltage divider and the error is amplified by the internal transconductance error
amplifier. COMP pin is output of the internal error amplifier and is compared to the switch current measured
internally to control the output current limit.
PFM Mode
The A7230A operates in PFM mode at light load. In PFM mode, switch frequency is continuously controlled in
proportion to the load current i.e. switch frequency is decreased when load current drops to boost power
efficiency at light load by reducing switch-Ioss, while switch frequency is increased when load current rises,
minimizing both load current and output voltage ripples.
Shut-Down Mode
The A7230A operates in shut-down mode when voltage at EN pin is driven below 0.3V. In shut-down mode,
the entire regulator is off and the supply current consumed by the A7230A drops below 1uA
Power Switch
N-Channel MOSFET switches are integrated on the A7230A to down convert the input voltage to the
regulated output voltage. Since the top MOSFET needs a gate voltage great than the input voltage, a boost
capacitor connected between BST and SW pins is required to drive the gate of the top switch. The boost
capacitor is charged by the internal 3.3V rail when SW is low.
VIN Under-Voltage Protection
A resistive divider can be connected between VIN and ground,with the central tap connected to EN,so that
when VIN drops to the pre-set value, EN drops below 1.2V to trigger input under voltage lockout protection.
Output Current Run-Away Protection
At start-up, due to the high voltage at input and low voltage at output, current inertia of the output inductance
can be easily built up, resulting in a large start-up output current.
REV1.0
- MAY 2016 RELEASED -
- 7 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
A valley current limit is designed in the A7230A so that only when output current drops below the valley
current limit can the bottom power switch be turned off. By such control mechanism, the output current at
start-up is well controlled.
Output Short Protection
When output is shorted to ground,output current rapidly reaches its peak current limit and the top power
switch is turned off. Right after the top power switch is turned off, the bottom power switch is turned on and
stay on until the output current falls below the valley current limit. When output current is below the valley
current limit, the top power switch will be turned on again and if the output short is still present, the top power
switch is turned off when the peak current limit is reached and the bottom power switch is turned on. This
cycle goes on until the output short is removed and the regulator comes into normal operation again.
Thermal Protection
When the temperature of the A7230A rises above 150°C, it is forced into thermal shut-down. Only when core
temperature drops below 125°C can the regulator becomes active again.
PCB Layout Note
1.
Place the input decoupling capacitor as close to A7230A (VIN pin and PGND) as possible to eliminate
noise at the input pin.
2.
3.
Put the feedback trace as far away from the inductor and noisy power traces as possible.
The ground plane on the PCB should be as large as possible for better heat dissipation.
REV1.0
- MAY 2016 RELEASED -
- 8 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
PACKAGE INFORMATION
Dimension in PSOP8 Package (Unit: mm)
Symbol
A
Min
1.35
0.00
1.25
0.50
0.38
0.37
0.17
0.17
4.80
3.10
5.80
3.80
2.20
Max
1.75
0.15
1.65
0.70
0.51
0.47
0.25
0.23
5.00
3.50
6.20
4.00
2.60
A1
A2
A3
b
b1
c
c1
D
D1
E
E1
E2
e
1.27BSC
L
0.45
0.80
L1
L2
R
R1
h
1.04REF
0.25BSC
0.07
0.07
0.30
0°
-
-
0.50
8°
θ
θ1
θ2
θ3
θ4
15°
11°
15°
11°
19°
15°
19°
15°
REV1.0
- MAY 2016 RELEASED -
- 9 -
A7230A
AiT Semiconductor Inc.
www.ait-ic.com
DC-DC CONVERTER BUCK (STEP-DOWN)
3A, 20V HIGH EFFICIENCY SYNCHRONOUS
IMPORTANT NOTICE
AiT Semiconductor Inc. (AiT) reserves the right to make changes to any its product, specifications, to
discontinue any integrated circuit product or service without notice, and advises its customers to obtain the
latest version of relevant information to verify, before placing orders, that the information being relied on is
current.
AiT Semiconductor Inc.'s integrated circuit products are not designed, intended, authorized, or warranted to
be suitable for use in life support applications, devices or systems or other critical applications. Use of AiT
products in such applications is understood to be fully at the risk of the customer.
As used herein may
In order to
involve potential risks of death, personal injury, or server property, or environmental damage.
minimize risks associated with the customer's applications, the customer should provide adequate design and
operating safeguards.
AiT Semiconductor Inc. assumes to no liability to customer product design or application support. AiT
warrants the performance of its products of the specifications applicable at the time of sale.
REV1.0
- MAY 2016 RELEASED -
- 10 -
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