- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379479 > UCC2977TRPW (Texas Instruments, Inc.) Precision 500 mA regulators PDF資料下載
參數(shù)資料
| 型號： | UCC2977TRPW |
| 廠商： | Texas Instruments, Inc. |
| 英文描述： | Precision 500 mA regulators |
| 中文描述： | 鎮(zhèn)流器/背光控制器/驅(qū)動器| TSSOP封裝| 8引腳|塑料 |
| 文件頁數(shù)： | 22/28頁 |
| 文件大?。?/td> | 433K |
| 代理商： | UCC2977TRPW |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁當前第22頁第23頁第24頁第25頁第26頁第27頁第28頁
SLUS499A
–
NOVEMBER 2001
–
REVISED JANUARY 2002
22
www.ti.com
APPLICATION INFORMATION
open lamp shutdown/no-lock operation
Due to the high gain characteristics of the piezoelectric transformer, it is important that the operation of the power
stage is suspended if an open lamp occurs. Figure 19 shows the output voltage of a piezoelectric transformer
with no output load and driven with a 5-V
RMS
sinusoid on the primary. The primary frequency is swept through
the resonant frequency of the piezoelectric transformer. As seen in Figure 19 the output voltage approaches
2 kV
RMS
with open lamp disabled, a gain of 400! If the input voltage were increased to 10 V
RMS
, the output would
reach 4 kV
RMS
and possibly crack the PZT transformer.
OPEN LAMP
PROTECTION
DISABLED
Maximum
Frequency
Minimum
Frequency
PZT Resonant
Frequency
Figure 19. Damaging Voltages at Piezoelectric Transformer Secondary
In order to prevent damaging voltages at the piezoelectric transformer secondary, a 1.5-V comparator at the
OPEN/SD pin is used to shutdown the converter if an open lamp is detected. The RMS secondary voltage at
which an open lamp fault is triggered can be calculated using equation (17).
V
OPEN
1.5
V
DIODE
2
R
HV
R
OPEN
R
HV
will typically consist of several inexpensive high impedance resistors to minimize current in the divider and
to stand
–
off high voltage. R
HV
can be replaced with a single high voltage capacitor if component count is an
issue, however, impedance of the capacitor over frequency needs to be taken into consideration.
(17)
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| UCC3976TRPW | Low consumption voltage and current controller for battery chargers and adaptors |
| UCC3977TRPW | BALLAST/BACKLIGHT CONTROLLER/DRIVER|TSSOP|8PIN|PLASTIC |
| UCC35705DGKTR | HIGH - SPEED VOLTAGE MODE PULSE MODE WIDTH MODULATOR |
| UCC35706DTR | HIGH - SPEED VOLTAGE MODE PULSE MODE WIDTH MODULATOR |
| UCC35706DGKTR | Aluminum Electrolytic Radial Lead High Ripple Capacitor; Capacitance: 330uF; Voltage: 400V; Case Size: 25x50 mm; Packaging: Bulk |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| UCC29900PWR | 制造商:Texas Instruments 功能描述: |
| UCC29910AEVM-730 | 功能描述:電源管理IC開發(fā)工具 UCC29910A Eval Mod 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 |
| UCC29910APW | 功能描述:功率因數(shù)校正 IC Buck PFC Controller RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
| UCC29910APWR | 功能描述:功率因數(shù)校正 IC Buck PFC Controller RoHS:否 制造商:Fairchild Semiconductor 開關(guān)頻率:300 KHz 最大功率耗散: 最大工作溫度:+ 125 C 安裝風格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
| UCC29950D | 功能描述:PFC IC Continuous Conduction (CCM) 87kHz ~ 109kHz 16-SOIC 制造商:texas instruments 系列:- 包裝:管件 零件狀態(tài):有效 模式:連續(xù)導電（CCM） 頻率 - 開關(guān):87kHz ~ 109kHz 電流 - 啟動:- 電壓 - 電源:11 V ~ 18 V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC（0.154"，3.90mm 寬） 供應商器件封裝:16-SOIC 標準包裝:40 |
發(fā)布緊急采購，3分鐘左右您將得到回復。