參數資料
型號: MP2370DJ-LF-Z
廠商: MONOLITHIC POWER SYSTEMS INC
元件分類: 穩(wěn)壓器
英文描述: 1.8 A SWITCHING REGULATOR, 1700 kHz SWITCHING FREQ-MAX, PDSO6
封裝: ROHS COMPLIANT, PLASTIC, MO-193AB, TSOT-23, 6 PIN
文件頁數: 6/8頁
文件大小: 485K
代理商: MP2370DJ-LF-Z
MP2370 – 1.2A, 24V, 1.4MHz STEP-DOWN WHITE LED DRIVER IN A TSOT23-6
MP2370 Rev. 0.96
www.MonolithicPower.com
6
9/21/2007
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
2007 MPS. All Rights Reserved.
APPLICATION INFORMATION
Setting LED Current
The current sense resistor is inserted between
the anode of WLED and GND. The current
sense resistor value is calculated as:
LED
I
V
15
.
0
1
R
=
For 1A WLED current, choose R1 = 150m
Selecting the Inductor
A 1H to 10H inductor with a DC current rating
of at least 25% percent higher than the
maximum load current is recommended for
most applications. For highest efficiency, the
inductor’s DC resistance should be less than
200m. Refer to Table 2 for suggested surface
mount inductors. For most designs, the required
inductance value can be derived from the
following equation.
SW
L
IN
OUT
IN
OUT
f
I
V
)
V
(
V
L
×
Δ
×
×
=
Where ΔIL is the inductor ripple current.
Choose the inductor ripple current to be 30% of
the maximum load current. The maximum
inductor peak current is calculated from:
2
I
L
LOAD
)
MAX
(
L
Δ
+
=
Under light load conditions below 100mA, a
larger inductance is recommended to improve
efficiency. See Table 2 for suggested inductors.
Also note that the maximum recommended load
current is 1A if the duty cycle exceeds 35%.
Selecting the Input Capacitor
The input capacitor reduces the surge current
drawn from the input supply and the switching
noise from the device. The input capacitor
impedance at the switching frequency should be
less than the output impedance of the input source
to prevent high frequency switching current from
passing through the input. Ceramic capacitors with
X5R or X7R dielectrics are highly recommended
because of their low ESR and small temperature
coefficients. For most applications, a 4.7F
capacitor is sufficient.
Selecting the Output Capacitor
The output capacitor keeps the output current
ripple small and ensures feedback loop stability.
The output capacitor impedance should be low
at the switching frequency. Ceramic capacitors
with X5R or X7R dielectrics are recommended
for their low ESR characteristics. For most
applications, a 2.2F ceramic capacitor will be
sufficient.
The MP2370 can also work properly without
output capacitor by adding a small capacitor in
the feedback loop (see Figure 2). The small
capacitor is recommended 680pF.
PC Board Layout
The high current paths (GND, IN and SW) should
be placed very close to the device with short,
direct and wide traces. The input capacitor needs
to be as close as possible to the IN and GND pins.
The external feedback resistors should be placed
next to the FB pin. Keep the switch node traces
short and away from the feedback network.
相關PDF資料
PDF描述
MP2482DN 9 A SWITCHING REGULATOR, 600 kHz SWITCHING FREQ-MAX, PDSO8
MP5010GN 1-OUTPUT TWO TERM VOLTAGE REFERENCE, 1.22 V, PBCY2
MP6-6131022R 10 CONTACT(S), FEMALE, STRAIGHT TWO PART BOARD CONNECTOR, SURFACE MOUNT
MP6-6131522R 15 CONTACT(S), FEMALE, STRAIGHT TWO PART BOARD CONNECTOR, SURFACE MOUNT
MP6-6132022R 20 CONTACT(S), FEMALE, STRAIGHT TWO PART BOARD CONNECTOR, SURFACE MOUNT
相關代理商/技術參數
參數描述
MP2371DG-LF-P 功能描述:開關變換器、穩(wěn)壓器與控制器 1.8A 24V 700kHz Nonsync Step-Down RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
MP2371DG-LF-Z 功能描述:開關變換器、穩(wěn)壓器與控制器 1.8A 24V 700kHz Nonsync Step-Down RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
MP2377DN-LF-Z 制造商:Monolithic Power Systems 功能描述:MONOLITHIC STEP-DOWN SWITCH MODE CONVERTER - Tape and Reel
MP2378DS-LF 功能描述:開關變換器、穩(wěn)壓器與控制器 2A 30V 385KHz Step-Down Converter RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel
MP2378DS-LF-Z 功能描述:開關變換器、穩(wěn)壓器與控制器 2A 30V 385KHz Step-Down Converter RoHS:否 制造商:Texas Instruments 輸出電壓:1.2 V to 10 V 輸出電流:300 mA 輸出功率: 輸入電壓:3 V to 17 V 開關頻率:1 MHz 工作溫度范圍: 安裝風格:SMD/SMT 封裝 / 箱體:WSON-8 封裝:Reel