參數資料
型號: LM2622-ADJMWC
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 穩(wěn)壓器
英文描述: 2.3 A SWITCHING REGULATOR, 1500 kHz SWITCHING FREQ-MAX, UUC
封裝: WAFER
文件頁數: 4/19頁
文件大?。?/td> 478K
代理商: LM2622-ADJMWC
Application Information
Triple Output TFT Bias
The circuit in
Figure 3 shows how the LM2622 can be
configured to provide outputs of 8V, 8V, and 23V, conve-
nient for biasing TFT displays. The 8V output is regulated,
while the 8V and 23V outputs are unregulated.
The 8V output is generated by a typical boost topology. The
basic operation of the boost converter is described in the
OPERATION section. The output voltage is set with R
FB1
and R
FB2 by:
C
FB is placed across RFB1 to act as a pseudo soft-start. The
compensation network of R
C and CC are chosen to optimally
stabilize the converter. The inductor also affects the stability.
When operating at 600 kHz, a 10uH inductor is recom-
mended to insure the converter is stable at duty cycles
greater than 50%. Refer to the COMPENSATION section for
more information.
The -8V output is derived from a diode inverter. During the
second cycle, when the transistor is open, D2 conducts and
C1 charges to 8V minus a diode drop ()0.4V if using a
Schottky). When the transistor opens in the first cycle, D3
conducts and C1’s polarity is reversed with respect to the
output at C2, producing -8V.
The 23V output is realized with a series of capacitor charge
pumps. It consists of four stages: the first stage includes C4,
D4, and the LM2622 switch; the second stage uses C5, D5,
and D1; the third stage includes C6, D6, and the LM2622
switch; the final stage is C7 and D7. In the first stage, C4
charges to 8V when the LM2622 switch is closed, which
causes D5 to conduct when the switch is open. In the second
stage, the voltage across C5 is VC4 + VD1 - VD5 = VC4 )
8V when the switch is open. However, because C5 is refer-
enced to the 8V output, the voltage at C5 is 16V when
referenced to ground. In the third stage, the 16V at C5
10127308
FIGURE 3. Triple Output TFT Bias (600 kHz operation)
LM2622
www.national.com
12
相關PDF資料
PDF描述
LM2630MTC-ADJ/NOPB SWITCHING CONTROLLER, 345 kHz SWITCHING FREQ-MAX, PDSO20
LM2630MTC-ADJX SWITCHING CONTROLLER, 345 kHz SWITCHING FREQ-MAX, PDSO20
LM2631MTCX-ADJ/NOPB SWITCHING CONTROLLER, 400 kHz SWITCHING FREQ-MAX, PDSO20
LM2636MWC SWITCHING CONTROLLER, 2000 kHz SWITCHING FREQ-MAX, UUC
LM2636MX/NOPB SWITCHING CONTROLLER, 2000 kHz SWITCHING FREQ-MAX, PDSO20
相關代理商/技術參數
參數描述
LM2622EVAL 功能描述:BOARD EVALUATION LM2622 RoHS:否 類別:編程器,開發(fā)系統(tǒng) >> 評估板 - DC/DC 與 AC/DC(離線)SMPS 系列:- 產品培訓模塊:Obsolescence Mitigation Program 標準包裝:1 系列:True Shutdown™ 主要目的:DC/DC,步升 輸出及類型:1,非隔離 功率 - 輸出:- 輸出電壓:- 電流 - 輸出:1A 輸入電壓:2.5 V ~ 5.5 V 穩(wěn)壓器拓撲結構:升壓 頻率 - 開關:3MHz 板類型:完全填充 已供物品:板 已用 IC / 零件:MAX8969
LM2622MM-ADJ 功能描述:DC/DC 開關控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數量:1 最大工作溫度:+ 125 C 安裝風格: 封裝 / 箱體:CPAK
LM2622MM-ADJ/NOPB 功能描述:DC/DC 開關控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數量:1 最大工作溫度:+ 125 C 安裝風格: 封裝 / 箱體:CPAK
LM2622MMX-ADJ 制造商:Texas Instruments 功能描述:Conv DC-DC Single Step Up 2V to 12V 8-Pin MSOP T/R
LM2622MMX-ADJ/NOPB 功能描述:DC/DC 開關控制器 RoHS:否 制造商:Texas Instruments 輸入電壓:6 V to 100 V 開關頻率: 輸出電壓:1.215 V to 80 V 輸出電流:3.5 A 輸出端數量:1 最大工作溫度:+ 125 C 安裝風格: 封裝 / 箱體:CPAK