- 您现在的位置：买卖IC网 > PDF目录383324 > MAX15020 (Maxim Integrated Products, Inc.) 2A, 40V Step-Down DC-DC Converter with Dynamic Output-Voltage Programming PDF资料下载
参数资料
| 型号： | MAX15020 |
| 厂商： | Maxim Integrated Products, Inc. |
| 元件分类： | DC/DC变换器 |
| 英文描述： | 2A, 40V Step-Down DC-DC Converter with Dynamic Output-Voltage Programming |
| 中文描述： | 2A、40V降压型DC-DC转换器，可动态设置输出电压 |
| 文件页数： | 12/19页 |
| 文件大小： | 363K |
| 代理商： | MAX15020 |
M
2A, 40V Step-Down DC-DC Converter with
Dynamic Output-Voltage Programming
12
______________________________________________________________________________________
Applications Information
Setting the ON/
OFF
Threshold
When the voltage at ON/
OFF
rises above 1.225V, the
MAX15020 turns on. Connect a resistive divider from IN
to ON/
OFF
to GND to set the turn-on voltage (see
Figure 2). First select the ON/
OFF
to the GND resistor
(R2), then calculate the resistor from IN to ON/
OFF
(R1)
using the following equation:
where V
IN
is the input voltage at which the converter
turns on, V
ON/
OFF
= 1.225V and R2 is chosen to be
less than 600k
.
If ON/
OFF
is connected to IN directly, the UVLO feature
monitors the supply voltage at IN and allows operation
to start when V
IN
rises above 7.2V.
Setting the Output Voltage
Connect a resistor-divider from OUT to FB to GND to
set the output voltage (see Figure 2). First calculate the
resistor (R7) from OUT to FB using the guidelines in the
Compensation Design section. Once R7 is known, cal-
culate R8 using the following equation:
where V
FB
= REFIN and REFIN = 0 to 3.6V.
Setting the Output-Voltage Slew Rate
The output-voltage rising slew rate tracks the V
SS
slew
rate, given that the control loop is relatively fast com-
pared with the V
SS
slew rate. The maximum V
SS
upswing slew rate is controlled by the soft-start current
charging the capacitor connected from SS to GND
according to the formula below:
when driving V
SS
with a slow-rising voltage source at
REFIN, V
OUT
will slowly rise according to the V
REFIN
slew rate.
The output-voltage falling slew rate is limited to the dis-
charge rate of C
SS
assuming there is enough load cur-
rent to discharge the output capacitor at this rate. The
C
SS
discharge current is 15μA. If there is no load, then
the output voltage falls at a slower rate based upon
leakage and additional current drain from C
OUT
.
Inductor Selection
Three key inductor parameters must be specified for
operation with the MAX15020: inductance value (L),
peak inductor current (I
PEAK
), and inductor saturation
current (I
SAT
). The minimum required inductance is a
function of operating frequency, input-to-output voltage
differential, and the peak-to-peak inductor current
(
I
L
). Higher
I
L
allows for a lower inductor value while
a lower
I
L
requires a higher inductor value. A lower
inductor value minimizes size and cost and improves
large-signal and transient response, but reduces effi-
ciency due to higher peak currents and higher peak-to-
peak output voltage ripple for the same output
capacitor. Higher inductance increases efficiency by
reducing the ripple current. Resistive losses due to
extra wire turns can exceed the benefit gained from
lower ripple current levels especially when the induc-
tance is increased without also allowing for larger
inductor dimensions. A good compromise is to choose
I
P-P
equal to 40% of the full load current.
Calculate the inductor using the following equation:
V
IN
and V
OUT
are typical values so that efficiency is
optimum for typical conditions. The switching frequen-
cy (f
SW
) is fixed at 300kHz or 500kHz and can vary
between 100kHz and 500kHz when synchronized to an
external clock (see the Oscillator/Synchronization Input
(SYNC) section). The peak-to-peak inductor current,
which reflects the peak-to-peak output ripple, is worst
at the maximum input voltage. See the Output
Capacitor Selection section to verify that the worst-case
output ripple is acceptable. The inductor saturating
current (I
SAT
) is also important to avoid runaway cur-
rent during continuous output short circuit. Select an
inductor with an I
SAT
specification higher than the max-
imum peak current limit of 4.5A.
L
V
V
×
V
V
f
I
IN
OUT
SW
OUT
L
IN
=
×
×
(
)
dV
dt
R
R
R
dV
dt
R
R
R
I
C
OUT
SS
SS
SS
=
+
×
=
+
7
8
8
7
8
8
R
R
V
V
OUT
FB
8
7
1
=
R
R
V
V
IN
/
ON OFF
1
2
1
=
×
相关PDF资料 |
PDF描述 |
|---|---|
| MAX1508YETA | TV 5C 5#20 PIN RECP |
| MAX1508 | Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN |
| MAX1508Y | Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN |
| MAX1508Z | Linear Li+ Battery Charger with Integrated Pass FET. Thermal Regulation. and ACOK-bar in 3mm x 3mm TDFN |
| MAX1508ETA | Linear Li Battery Charger with Integrated Pass FET, Thermal Regulation, and ACOKin 3mm x 3mm TDFN |
相关代理商/技术参数 |
参数描述 |
|---|---|
| MAX15020ATP+ | 功能描述:直流/直流开关转换器 2A 40V Step-Down w/Dynamic Output-V RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX15020ATP+T | 功能描述:直流/直流开关转换器 2A 40V Step-Down w/Dynamic Output-V RoHS:否 制造商:STMicroelectronics 最大输入电压:4.5 V 开关频率:1.5 MHz 输出电压:4.6 V 输出电流:250 mA 输出端数量:2 最大工作温度:+ 85 C 安装风格:SMD/SMT |
| MAX15020EVKIT+ | 功能描述:电源管理IC开发工具 MAX15020 Eval Kit RoHS:否 制造商:Maxim Integrated 产品:Evaluation Kits 类型:Battery Management 工具用于评估:MAX17710GB 输入电压: 输出电压:1.8 V |
| MAX15021ATB+ | 功能描述:直流/直流开关调节器 DUAL 4A/2A RoHS:否 制造商:International Rectifier 最大输入电压:21 V 开关频率:1.5 MHz 输出电压:0.5 V to 0.86 V 输出电流:4 A 输出端数量: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:PQFN 4 x 5 |
| MAX15021ATI/V+ | 制造商:Maxim Integrated Products 功能描述:DUAL, 4A/2A, 4MHZ, STEP-DOWN DC-DCREGULATOR WITH TRACKING/SE - Rail/Tube |
发布紧急采购，3分钟左右您将得到回复。