參數(shù)資料
型號(hào)： S-8337AAEA-P8T1G
元件分類： 穩(wěn)壓器
英文描述： 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
封裝： LEAD FREE, SON-8
文件頁(yè)數(shù)： 10/51頁(yè)
文件大?。?/td> 446K
代理商： S-8337AAEA-P8T1G
STEP-UP, 1.2 MHz HIGH-FREQUENCY, PWM CONTROL SWITCHING REGULATOR CONTROLLER
S-8337/8338 Series
Rev.4.0_00
18
Seiko Instruments Inc.
4. External transistor
A bipolar (NPN) or enhancement (N-channel) MOS FET transistor can be used as the external
capacitor.
4. 1 Bipolar (NPN) type
The driving capability when the output current is increased by using a bipolar transistor is
determined by hFE and Rb of the bipolar transistor. Figure 11 shows a peripheral circuit.
Nch
Pch
Rb
VIN
IPK
EXT
Cb
2200 pF
1 k
Ω
Figure 11 External Transistor Periphery
1 k
Ω is recommended for R
b. Actually, calculate the necessary base current (Ib) from hFE of the
bipolar transistor as follows and select an Rb value lower than this.
Ib =
hFE
IPK
Rb =
Ib
VIN – 0.7
–
IEXTH
0.4
A small Rb increases the output current, but the efficiency decreases. Actually, a pulsating
current flows and a voltage drop occurs due to the wiring capacitance. Determine the optimum
value by experiment.
A speed-up capacitor (Cb) connected in parallel with Rb resistance as shown in Figure 11
decreases the switching loss and improves the efficiency.
Select Cb by observing the following equation.
Cb ≤
2
π R
b fOSC 0.7
1
However, in practice, the optimum Cb value also varies depending on the characteristics of the
bipolar transistor employed. Therefore, determine the optimum value of Cb by experiment.
相關(guān)PDF資料
PDF描述
S-8337AAEA-T8T1G 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
S-8337AAIC-T8T1G 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
S-8337ABGA-P8T1G 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
S-8337ACAC-T8T1G 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
S-8337ACDA-T8T1G 0.16 A SWITCHING CONTROLLER, 1246.3 kHz SWITCHING FREQ-MAX, PDSO8
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
S-8337AAHB-P8T1G 制造商:Seiko Instruments Inc (SII) 功能描述:STEPUP1.2MHZ PWM SWR
S-8337AAHB-T8T1G 制造商:Seiko Instruments Inc (SII) 功能描述:STEPUP1.2MHZ PWM SWR
S-8337ABAA-P8T1G 制造商:Seiko Instruments Inc (SII) 功能描述:
S-8337ABAA-T8T1G 制造商:Seiko Instruments Inc (SII) 功能描述:
S-8337ABAC-P8T1G 制造商:Seiko Instruments Inc (SII) 功能描述:STEPUP1.2MHZ PWM SWR
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*