- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄384534 > ISL97801ARZ-TK (INTERSIL CORP) High Power LED Driver PDF資料下載
參數(shù)資料
| 型號： | ISL97801ARZ-TK |
| 廠商： | INTERSIL CORP |
| 元件分類： | 顯示驅動器 |
| 英文描述： | High Power LED Driver |
| 中文描述： | LED DISPLAY DRIVER, PQCC20 |
| 封裝： | 4 X 4 MM, ROHS COMPLIANT, PLASTIC, QFN-20 |
| 文件頁數(shù)： | 14/19頁 |
| 文件大小： | 707K |
| 代理商： | ISL97801ARZ-TK |
14
FN6428.1
April 2, 2007
Rectifier Diode
A high speed rectifier diode is necessary to prevent
excessive voltage overshoot, especially in the boost
configuration. Low forward voltage and reverse leakage
current will minimize losses, making Schottky diodes the
preferred choice. Similarly to the inductor, a diode with a
suitable current rating to handle current limit in the
configuration must be used.
Output Capacitor
The output capacitor acts to smooth the output voltage and
in the boost configuaration supplies load current directly
during the conduction phase of the power switch. Ripple
voltage consists of two components, the first due to charging
and discharging of the capacitor; the second due to IR drop
across the ESR of the capacitor by inductor ripple current.
In boost mode:
where:
and
In buck mode:
where:
For a low ESR ceramic capacitor, output ripple is dominated
by the charging and discharging of the output capacitor.
Care should be taken to ensure the voltage rating of the
capacitor exceeds the maximum output voltage.
Compensation
The ISL97801 employs a direct summing control loop with
current feedback. No error amplifier is used in the system.
The arrangement provides fast transient response and
makes use of the output capacitor to compensate the loop.
The effect of the pole associated with the inductor is
minimized by the current feedback. The number of LEDs,
their DC bias current and the value of feedback resistor alter
loop stability due to their effect on feedback factor which is
heavily influenced by the small signal impedance of the
LEDs. Generally, higher numbers of LEDs, lower bias levels
and smaller values of feedback resistor will require smaller
output capacitors to achieve loop stability. A combination of
low ESR electrolytic and ceramic capacitors may be used to
reduce implementation costs.
V
RIPPLE
I
OUT
---------------
S
------
×
I
LPK
ESR
×
+
=
(EQ. 4)
D
V
OUT
V
–
-------------------------------
=
(EQ. 5)
I
LPK
I
–
1
D
-------------
V
------------------------------------
V
–
(
)
+
f
s
-------–
)
×
=
(EQ. 6)
V
RIPPLE
V
----------------------------------------------
V
s
–
(
)
D
×
OUT
s
--------------------------
ESR
+
×
=
(EQ. 7)
D
V
IN
---------------
=
(EQ. 8)
TABLE 2. BOOST MODE COMPENSATION. 2.7V OPERATION
VFB
I
OUT
50mA
VOUT (V)
7
10.5
14
17.5
21
24.5
28
LED’s
2
3
4
5
6
7
8
50mV
Electrolytic
94μF
47μF
DMAX
DMAX
Ceramic
40μF
20μF
40μF
20μF
20μF
100mV
100mA
Electrolytic
94μF
Ceramic
60μF
60μF
40μF
40μF
40μF
200mV
350mA
Electrolytic
94μF
47μF
47μF
47μF
ILIM
ILIM
ILIM
Ceramic
60μF
40μF
40μF
40μF
200mV
1A
Electrolytic
ILIM
ILIM
ILIM
ILIM
ILIM
ILIM
ILIM
Ceramic
TABLE 3. BOOST MODE COMPENSATION 6V OPERATION
VFB
I
OUT
50mA
VOUT (V)
7
10.5
14
17.5
21
24.5
28
LED’s
2
3
4
5
6
7
8
50mV
Electrolytic
94μF
47μF
Ceramic
40μF
20μF
40μF
20μF
20μF
20μF
20μF
100mV
100mA
Electrolytic
141μF
47μF
Ceramic
60μF
60μF
60μF
40μF
40μF
40μF
40μF
200mV
350mA
Electrolytic
141μF
47μF
47μF
Ceramic
60μF
60μF
40μF
60μF
40μF
40μF
40μF
200mV
1A
Electrolytic
94μF
47μF
ILIM
ILIM
ILIM
ILIM
ILIM
Ceramic
40μF
40μF
ISL97801
相關PDF資料 |
PDF描述 |
|---|---|
| ISL9R1560P2 | 8A, 600V Stealth Diode(8A，600V Stealth二極管) |
| ISL9R860P2 | 8A, 600V Stealth Diode(8A，600V Stealth二極管) |
| ISO808 | Isolated 12-Bit Sampling Analog-To-Digital Converter(隔離的12位采樣A\D轉換器) |
| ISP321-1 | HIGH DENSITY MOUNTING PHOTOTRANSISTOR OPTICALLY COUPLED ISOLATORS |
| ISP321-1-88XSM | HIGH DENSITY MOUNTING PHOTOTRANSISTOR OPTICALLY COUPLED ISOLATORS |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| ISL97801BOOSTEVALZ | 功能描述:EVAL BOARD FOR ISL97801 RoHS:是 類別:編程器，開發(fā)系統(tǒng) >> 評估板 - LED 驅動器 系列:* 標準包裝:1 系列:PowerWise® 電流 - 輸出 / 通道:20mA 輸出及類型:1，非隔離 輸出電壓:17V 特點:可調(diào)光 輸入電壓:2.7 ~ 5.5 V 已供物品:板 已用 IC / 零件:LM3508 相關產(chǎn)品:LM3508TLX-ND - IC LED DRVR WHT BCKLGT 9USMDLM3508TLDKR-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLCT-ND - IC LED DRVR WHT BCKLGT 9MICROSMDLM3508TLTR-ND - IC LED DRVR WHT BCKLGT 9MICROSMD |
| ISL97900CRZ | 功能描述:LED照明驅動器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:SO-16N |
| ISL97900CRZ-T | 功能描述:LED照明驅動器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:SO-16N |
| ISL97900CRZ-T7A | 功能描述:LED照明驅動器 High Current RGB Driver/Controller, 28L 4x5 QFN,Commercial T RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:SO-16N |
| ISL97900CRZ-TK | 功能描述:LED照明驅動器 High Current RGB Driver/Controller, 28L 4x5 QFN, Commercial RoHS:否 制造商:STMicroelectronics 輸入電壓:11.5 V to 23 V 工作頻率: 最大電源電流:1.7 mA 輸出電流: 最大工作溫度: 安裝風格:SMD/SMT 封裝 / 箱體:SO-16N |
發(fā)布緊急采購，3分鐘左右您將得到回復。