參數(shù)資料
型號(hào): R1280D002X
廠商: Ricoh Co., Ltd.
英文描述: Linear Sensor Photodiode Array; 896x1 Sensor-Elements Organization; 200 Dots-Per-Inch (DPI) Sensor Pitch; High Linearity and Uniformity; Wide Dynamic Range 2000:1 (66 dB); Low Image Lag 0.5% Typ; Operation to 5MHz
中文描述: 2聲道的PWM DC / DC控制器
文件頁數(shù): 8/26頁
文件大?。?/td> 344K
代理商: R1280D002X
Rev.1.10 - 8 -
I
Operation of Step-up DC/DC Converter and Output Current
Step-up DC/DC Converter makes higher output voltage than input voltage by releasing the energy accumulated
during on time of Lx Transistor on input voltage.
<Basic Circuit>
Inductor
Diode
C
L
Lx Tr
V
IN
V
OUT
I
OUT
ILxmax
ILxmin
Ton
Toff
T=1/fosc
Tf
IL
Discontinuous Mode
t
ILxmax
ILxmin
Ton
Toff
T=1/fosc
t
IL
Iconst
Continuous Mode
<Current through L>
GND
i1
i2
Step 1. Lx Tr. is on, then the current IL=i1 flows, and the energy is charged in L. In proportion to the on time of Lx Tr.
(Ton), IL=i1 increases from IL=ILxmin=0 and reaches ILxmax.
Step 2. When the Lx Tr. is off, L turns on Schottky Diode (SD), and IL=i2 flows to maintain IL=ILxmax.
Step 3. IL=i2 gradually decreases, and after Tf passes, IL=ILxmin=0 is true, then SD turns off. Note that in the case of
the continuous mode, before IL=ILxmin=0 is true, Toff passes, and the next cycle starts, then Lx Tr. turns on again.
In this case, ILxmin>0, therefore IL=ILxmin>0 is another starting point and ILx max increases.
With the PWM controller, switching times during the time unit are fixed. By controlling Ton, output voltage is
maintained.
I
Output Current and Selection of External Components
Output Current of Step-up Circuit and External Components
There are two modes, or discontinuous mode and continuous mode for the PWM step-up switching regulator
depending on the continuous characteristic of inductor current.
During on time of the transistor, when the voltage added on to the inductor is described as V
IN
, the current is V
IN
×
t/L.
Therefore, the electric power, P
ON
, which is supplied with input side, can be described as in next formula.
T
ON
ON
V
IN
2
×
t/L dt
0
Formula 1
With the step-up circuit, electric power is supplied from power source also during off time. In this case, input current is
described as (V
OUT
-V
IN
)
×
t/L, therefore electric power, P
OFF
is described as in next formula.
相關(guān)PDF資料
PDF描述
R3112D R3112D SERIES MARK SPECIFICATION
R3112D091A R3112D SERIES MARK SPECIFICATION
R3112D091C R3112D SERIES MARK SPECIFICATION
R3112D101A R3112D SERIES MARK SPECIFICATION
R3112D101C R3112D SERIES MARK SPECIFICATION
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
R128203701 功能描述:RF 連接器 PR DR EMMAN FOR PE 2/50 C100 RoHS:否 制造商:Bomar Interconnect 產(chǎn)品:Connectors 射頻系列:BNC 型式:Jack (Female) 極性: 觸點(diǎn)電鍍:Gold 阻抗: 端接類型:Solder 主體類型:Straight Bulkhead 電纜類型:
R128203701W 功能描述:RF 連接器 PR DR EMMAN FOR RoHS:否 制造商:Bomar Interconnect 產(chǎn)品:Connectors 射頻系列:BNC 型式:Jack (Female) 極性: 觸點(diǎn)電鍍:Gold 阻抗: 端接類型:Solder 主體類型:Straight Bulkhead 電纜類型:
R128233701 功能描述:RF 連接器 PR DR FLOT S ERT 2,6/50S C100 RoHS:否 制造商:Bomar Interconnect 產(chǎn)品:Connectors 射頻系列:BNC 型式:Jack (Female) 極性: 觸點(diǎn)電鍍:Gold 阻抗: 端接類型:Solder 主體類型:Straight Bulkhead 電纜類型:
R128233701W 功能描述:RF 連接器 PR DR FLOT S ERT RoHS:否 制造商:Bomar Interconnect 產(chǎn)品:Connectors 射頻系列:BNC 型式:Jack (Female) 極性: 觸點(diǎn)電鍍:Gold 阻抗: 端接類型:Solder 主體類型:Straight Bulkhead 電纜類型:
R128233827 制造商:Radiall 功能描述:CONN BMA F 0HZ TO 12.4GHZ 50OHM CRMP ST PNL MNT AU OVER CPR - Bulk