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IA3220のメーカーはTGWです、この部品の機能は「1.3A Synchronous Step-Down Converter」です。 |
部品番号 | IA3220 |
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部品説明 | 1.3A Synchronous Step-Down Converter | ||
メーカ | TGW | ||
ロゴ | |||
このページの下部にプレビューとIA3220ダウンロード(pdfファイル)リンクがあります。 Total 7 pages
FEATURES
• High Efficiency: Up to 96%
• 1.5MHz Constant Frequency Operation
• 1300mA Output Current
• No Schottky Diode Required
• 2.3V to 6V Input Voltage Range
• Adjustable Output Voltage Range
Options from 0.6V to Vin
• 100% Duty Cycle Low Dropout Operation
• Low Quiescent Current: 35µA
• Slope Compensated Current Mode Control for
Excellent Line and Load Transient Response
• Short Circuit Protection
• Thermal Fault Protection
• Inrush Current Limit and Soft Start
• <1µA Shutdown Current
• Tiny SOT23-5 Package
APPLICATIONS
• Cellular and Smart Phones
• Wireless and DSL Modems
• PDAs
• Digital Still and Video Cameras
• MP3 Players
IA3220
1.5MHz, 1.3A Synchronous
Step-Down Converter
GENERAL DESCRIPTION
The IA3220 L are high-efficiency, high frequency
synchronous step-down DC-DC regulator ICs capable
of delivering up to 1.3A output currents. The IA3220
can operate over a wide input voltage range from 2.3V
to 6V and integrates main switch and synchronous
switch with very low RDS(ON) to minimize the
conduction loss.
It is ideal for powering portable equipment that runs
from a single cell Lithium-Ion (Li+) battery. The output
voltage can be regulated as low as 0.6V. The
IA3220 L can also run at 100% duty cycle for low
dropout operation, extending battery life in portable
system. This device offers two operation modes, PWM
mode and PFM Mode switching control, which allows
a high efficiency over the wider range of the load.
The IA3220 L is offered in a low profile (1mm) 5-pin,
thin SOT package, and is available in an adjustable
version.
TYPICAL APPLICATION
Figure 1. Typical Application Circuit
1
1 Page ELECTRICAL CHARACTERISTICS (Note 3)
IA3220
(VIN=VRUN=3.6V, VOUT=1.8V, TA = 25°C, unless otherwise noted.)
Parameter
Conditions
MIN
Input Voltage Range
2.3
UVLO Threshold
1.7
Input DC Supply Current
PWM Mode
PFM Mode
Shutdown Mode
Regulated Feedback
Voltage
(Note 4)
Vout = 90%, ILoad=0mA
Vout = 105%, ILoad=0mA
VRUN = 0V, VIN=4.2V
TA = 25°C
TA = 0°C ≤ TA ≤ 85°C
TA = -40°C ≤ TA ≤ 85°C
0.588
0.586
0.585
Reference Voltage Line
Regulation
Vin=2.5V to 6V
Output Voltage Line
Regulation
VIN = 2.5V to 6V
Output Voltage Load
Regulation
Oscillation Frequency
Vout=100%
Vout=0V
On Resistance of PMOS
ON Resistance of NMOS
Peak Current Limit
RUN Threshold
RUN Leakage Current
SW Leakage Current
ISW=100mA
ISW=-100mA
VIN= 3V, Vout=90%
VRUN=0V,VIN=Vsw=5V
0.30
TYP
1.9
140
35
0.1
0.600
0.600
0.600
0.04
0.04
0.5
1.5
300
0.13
0.1
2.0
1.0
±0.01
±0.01
MAX
6
2.1
300
70
1.0
0.612
0.613
0.615
0.40
unit
V
V
µA
µA
µA
µA
V
V
V
%/V
0.4 %
%
MHz
kHz
0.2 Ω
0.2 Ω
A
1.50 V
±1.0 µA
±1.0 µA
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
Note 2: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following
formula: TJ = TA + (PD) x (250°C/W).
Note3: 100% production test at +25°C. Specifications over the temperature range are guaranteed by design
and characterization.
Note 4: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency.
3
3Pages IA3220
APPLICATIONS INFORMATION
Setting the Output Voltage
The internal reference VREF is 0.6V(Typical).The
output voltage is divided by a resistor,R1 and R2 to
the FB pin. The output voltage is given by:
VOUT
= VREF
× (1 +
R2 )
R1
Inductor Selection
For most designs, the IA3220 L operates with
inductors of 1µH to 4.7µH. Low inductance values
are physically smaller but require faster switching,
which results in some efficiency loss. The inductor
value can be derived from the following equation:
( )L = VOUT × VIN − VOUT
VIN × ∆I L × fOSC
Where ∆IL is inductor Ripple Current. Large value
inductors result in lower ripple current and small
value inductors result in high ripple current. For
optimum voltage-positioning load transients, choose
an inductor with DC series resistance in the 50mΩ
to 150mΩ range.
Input Capacitor Selection
With the maximum load current at 1.3A, the
maximum ripple current through input capacitor is
about 0.6Arms. A typical X7R or better grade
ceramic capacitor with 6V rating and greater than
10uF capacitance can handle this ripple current well.
To minimize the potential noise problem, place this
ceramic capacitor really close to the IN and
GND pins. Care should be taken to minimize the
loop area formed by CIN, and IN/GND pins.
Output Capacitor Selection
The output capacitor is required to keep the output
voltage ripple small and to ensure regulation loop
stability. The output capacitor must have low
impedance at the switching frequency. Ceramic
capacitors with X5R or X7R dielectrics are
recommended due to their low ESR and high ripple
current ratings. The output ripple ∆ VOUT is
determined by:
∆VOUT
≤
VOUT × (VIN − VOUT
VIN × f OSC × L
)
×
ESR
+
8
×
f
1
osc
×
C3
A 10µF ceramic Capacitor can satisfy most
applications.
PC Board Layout Checklist
When laying out the printed circuit board, the
following checking should be used to ensure proper
operation of the IA3220 L. Check the following in
your layout:
1. The power traces, consisting of the GND trace,
the SW trace and the VIN trace should be kept
short, direct and wide.
2. Does the (+) plates of Cin connect to Vin as
closely as possible.This capacitor provides the
AC current to the internal power MOSFETs.
3. Keep the switching node, SW, away from the
sensitive VOUT node.
4. Keep the (-) plates of Cin and Cout as close as
possible.
6
6 Page | |||
ページ | 合計 : 7 ページ | ||
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PDF ダウンロード | [ IA3220 データシート.PDF ] |
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部品番号 | 部品説明 | メーカ |
IA3220 | 1.3A Synchronous Step-Down Converter | TGW |