- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄300050 > UCC284SDR-12EP (TEXAS INSTRUMENTS INC) 12 V FIXED NEGATIVE LDO REGULATOR, 0.5 V DROPOUT, PDSO8 PDF資料下載
參數(shù)資料
| 型號： | UCC284SDR-12EP |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 固定負(fù)電壓單路輸出LDO穩(wěn)壓器 |
| 英文描述： | 12 V FIXED NEGATIVE LDO REGULATOR, 0.5 V DROPOUT, PDSO8 |
| 封裝： | PLASTIC, MS-012AA, SOIC-8 |
| 文件頁數(shù)： | 6/21頁 |
| 文件大小： | 506K |
| 代理商： | UCC284SDR-12EP |
VIN TO VOUT DELAY TIME
WITH CT CAPACITOR REMOVED
VIN TO VOUT DELAY TIME
WITH QUICK START-UP CIRCUIT
operation of the quick start-up circuit
R4 +
V
IN
(V)
T
D
seconds
1.6
CT (F)
ohms
(7)
t
M +
2.6
1.6
t
D
seconds
(8)
SLVS862A – NOVEMBER 2008 – REVISED NOVEMBER 2008 ....................................................................................................................................... www.ti.com
With the quick start-up circuit, the delay time between VIN and VOUT during start-up can be reduced
dramatically. Figure 11 shows that with the quick start-up circuit, the VIN to VOUT delay time has been reduced
to approximately 1 ms.
Figure 11.
Figure 12.
During normal start-up, the UCC284 does not turn on until the voltage on the SD/CT pin reaches approximately
–1.6 V with respect to ground. It takes a certain amount of time for the CT capacitor to charge to this point. For a
circuit that has a very large load, the CT capacitor needs to be large in order for the overcurrent timing to work
properly. A large value of capacitance on the SD/CT pin increases the VIN to VOUT delay time.
The quick start-up circuit uses Q1 to quickly pull the SD/CT pin in a negative direction during start-up, thus
decreasing the VIN-to-VOUT delay time. When VIN is applied to the circuit, Q1 turns on and starts to charge the
CT capacitor. The current pulled through R4 determines the rate at which CT is charged. R4 can be calculated
as follows:
tD is the approximate VIN-to-VOUT delay time desired.
Q1 needs to be turned off after a fixed time to prevent the SD/CT pin from going too far negative with respect to
GND. If the SD/CT pin is allowed to go too far negative with respect to GND, the output turns off again or
possibly even damages the SD/CT pin. The maximum amount of time that Q1 should be allowed to be on is
referred to as tM and can be calculated as follows:
14
Copyright 2008, Texas Instruments Incorporated
Product Folder Link(s): UCC284-EP
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| UCC284SDR-5EP | 5 V FIXED NEGATIVE LDO REGULATOR, 0.55 V DROPOUT, PDSO8 |
| UCN5804B | STEPPER MOTOR CONTROLLER, 1.5 A, PDIP16 |
| UDQ2916LB-T | STEPPER MOTOR CONTROLLER, 1 A, PDSO24 |
| UE25-CM55-10H | 5 CONTACT(S), FEMALE, RIGHT ANGLE TELECOM AND DATACOM CONNECTOR, SURFACE MOUNT, RECEPTACLE |
| UE25-CM55-1AH | 5 CONTACT(S), FEMALE, RIGHT ANGLE TELECOM AND DATACOM CONNECTOR, SURFACE MOUNT, RECEPTACLE |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| UCC284SDR-5EP | 功能描述:低壓差穩(wěn)壓器 - LDO EP Sgl Out LDO,500mA RoHS:否 制造商:Texas Instruments 最大輸入電壓:36 V 輸出電壓:1.4 V to 20.5 V 回動電壓（最大值）:307 mV 輸出電流:1 A 負(fù)載調(diào)節(jié):0.3 % 輸出端數(shù)量: 輸出類型:Fixed 最大工作溫度:+ 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-20 |
| UCC28500 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:BiCMOS PFC/PWM Combination Controller |
| UCC28500-12 | 制造商:TI 制造商全稱:Texas Instruments 功能描述:BiCMOS PFC/PWM COMBINATION CONTROLLER |
| UCC28500DW | 功能描述:功率因數(shù)校正 IC BiCMOS PFC/PWM Comb 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(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
| UCC28500DWG4 | 功能描述:功率因數(shù)校正 IC BiCMOS PFC/PWM Comb 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(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-8 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。