- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄385481 > LM3501TL-16 (NATIONAL SEMICONDUCTOR CORP) Synchronous Step-up DC/DC Converter for White LED Applications PDF資料下載
參數(shù)資料
| 型號： | LM3501TL-16 |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | Synchronous Step-up DC/DC Converter for White LED Applications |
| 中文描述： | 0.53 A SWITCHING REGULATOR, 1150 kHz SWITCHING FREQ-MAX, PBGA8 |
| 封裝： | MICRO, SMD-8 |
| 文件頁數(shù)： | 14/18頁 |
| 文件大?。?/td> | 1039K |
| 代理商： | LM3501TL-16 |
Application Information
(Continued)
The minimum inductor value required for the LM3501-16 can
be calculated using the following equation:
The minimum inductor value required for the LM3501-21 can
be calculated using the following equation:
For both equations above, L is in μH, V
is the input supply
of the chip in Volts, R
is the ON resistance of the NMOS
power switch found in the Typical Performance Characteris-
tics section in ohms and D is the duty cycle of the switching
regulator. The above equation is only valid for D greater than
or equal to 0.5. For applications where the minimum duty
cycle is less than 0.5, a 22 μH inductor is the typical recom-
mendation for use with most applications. Bench-level veri-
fication of circuit performance is required in these special
cases, however. The duty cycle, D, is given by the following
equation:
where V
OUT
is the voltage at pin C1.
Typical Peak Inductor Current (mA)
(Note 10)
VIN
(V)
2.7
# LEDs
(in
series)
2
3
4
5
2
3
4
5
2
3
4
5
LED Current
30
mA
134
190
244
319
116
168
212
288
96
148
186
263
15
mA
82
118
142
191
76
110
132
183
64
102
122
179
20
mA
100
138
174
232
90
126
158
216
76
116
146
206
40
mA
160
244
322
413
136
210
270
365
116
180
232
324
50
mA
204
294
X
X
172
250
320
446
142
210
272
388
60
mA
234
352
X
X
198
290
X
X
162
246
318
456
3.3
4.2
Note 10:
C
IN
= C
OUT
= 1 μF
L = 22 μH, 160 m
DCR max. Coilcraft DT1608C-223
2 and 3 LED applications: LM3501-16 or LM3501-21; LED V
F
= 3.77V at
20mA; T
A
= 25C
4 LED applications: LM3501-16 or LM3501-21; LED V
F
= 3.41V at 20mA; T
A
= 25C
5 LED applications: LM3501-21 only; LED V
F
= 3.28V at 20mA; T
A
= 25C
The typical cycle-by-cycle peak inductor current can be cal-
culated from the following equation:
where I
is the total load current, F
is the switching
frequency, L is the inductance and
η
is the converter effi-
ciency of the total driven load. A good typical number to use
for
η
is 0.8. The value of
η
can vary with load and duty cycle.
The average inductor current, which is also the average V
SW
pin current, is given by the following equation:
The maximum output current capability of the LM3501 can
be estimated with the following equation:
where I
is the current limit. Some recommended inductors
include but are not limited to:
Coilcraft DT1608C series
Coilcraft DO1608C series
TDK VLP4612 series
TDK VLP5610 series
TDK VLF4012A series
CAPACITOR SELECTION
Choose low ESR ceramic capacitors for the output to mini-
mize output voltage ripple. Multilayer X7R or X5R type ce-
ramic capacitors are the best choice. For most applications,
a 1 μF ceramic output capacitor is sufficient.
Local bypassing for the input is needed on the LM3501.
Multilayer X7R or X5R ceramic capacitors with low ESR are
a good choice for this as well. A 1 μF ceramic capacitor is
sufficient for most applications. However, for some applica-
tions at least a 4.7 μF ceramic capacitor may be required for
proper startup of the LM3501. Using capacitors with low
ESR decreases input voltage ripple. For additional bypass-
ing, a 100 nF ceramic capacitor can be used to shunt high
frequency ripple on the input. Some recommended capaci-
tors include but are not limited to:
TDK C2012X7R1C105K
Taiyo-Yuden EMK212BJ105 G
LAYOUT CONSIDERATIONS
The input bypass capacitor C
, as shown in
Figure 2
, must
be placed close to the device and connect between the V
IN
and GND pins. This will reduce copper trace resistance
which effects the input voltage ripple of the IC. For additional
input voltage filtering, a 100 nF bypass capacitor can be
placed in parallel with C
to shunt any high frequency noise
to ground. The output capacitor, C
, should also be placed
close to the LM3501 and connected directly between the
V
OUT
and GND pins. Any copper trace connections for the
C
OUT
capacitor can increase the series resistance, which
directly effects output voltage ripple and efficiency. The cur-
rent setting resistor, R
LED
, should be kept close to the FB pin
L
www.national.com
14
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LM3501 | Synchronous Step-up DC/DC Converter for White LED Applications |
| LM3501TLX-21 | Synchronous Step-up DC/DC Converter for White LED Applications |
| LM3501TL-21 | Synchronous Step-up DC/DC Converter for White LED Applications |
| LM3501TLX-16 | PUBLICATIONS, BOOKS RoHS Compliant: NA |
| LM3519 | High Frequency Boost White LED Driver with High-Speed PWM Brightness Control |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM3501TL-16/NOPB | 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| LM3501TL-16EV | 功能描述:電源管理IC開發(fā)工具 LM3501TL-16 EVAL BOARD RoHS:否 制造商:Maxim Integrated 產(chǎn)品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| LM3501TL-21 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Synchronous Step-up DC/DC Converter for White LED Applications |
| LM3501TL-21/NOPB | 功能描述:DC/DC 開關(guān)控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關(guān)頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數(shù)量:1 最大工作溫度:+ 125 C 安裝風(fēng)格: 封裝 / 箱體:CPAK |
| LM3501TLX-16 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Synchronous Step-up DC/DC Converter for White LED Applications |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。