- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄375327 > AN8038S (PANASONIC CORP) AC-DC switching power supply control IC with RCC local resonance circuit for improved conformance with energy conservation laws PDF資料下載
參數(shù)資料
| 型號： | AN8038S |
| 廠商： | PANASONIC CORP |
| 元件分類： | 穩(wěn)壓器 |
| 英文描述： | AC-DC switching power supply control IC with RCC local resonance circuit for improved conformance with energy conservation laws |
| 中文描述： | 2 A SWITCHING CONTROLLER, PDSO8 |
| 封裝： | 0.225 INCH, PLASTIC, SOP-8 |
| 文件頁數(shù)： | 15/22頁 |
| 文件大?。?/td> | 179K |
| 代理商： | AN8038S |
Voltage Regulators
AN8038, AN8038S
15
I
Application Notes (continued)
[2] Operation descriptions (continued)
3. Local resonance operation (power MOSFET turn on delay circuit) (continued)
Notes on C7 value selection
Figure 5 shows the local resonance
waveform.
Select values of R9 and C9 to deter-
mine the delay time so that the power
MOSFET is turned on at the 1/2 cycle
point in the resonant frequency wave-
form. Simply stated, select values so
that the power MOSFET turns on at the
zero voltage point in the voltage wave-
form. The resonant frequency can be
roughly determined using the follow-
ing formula.
1
(Hz)
2
π √
L · C
7
C
7
: Resonance capacitor
L : Inductance of the transformer
primary winding
f
SYNC
=
Accordingly, the turn on delay time
t
PD(ON)
to turn on the power MOSFET
at the 1/2 cycle point in the resonant
frequency waveform is given by the
following formula.
t
PD(ON)
=
π √
L · C
7
(s)
Furthermore, t
PD(ON)
should be set to be larger than t
TR
, since a response time t
TR
that is the time between
transistor detection and output changeover is about 400 ns.
Note that since insertion of the resonance capacitor C7 results in increased losses, using the parasitic
capacitance of the power MOSFET itself should also be considered. However, in this case the sample-to-
sample variations and temperature variations should be considered.
Notes on R9 and C9 value selection
If an excessively low value is used for R9, the current flowing into the TR pin after power supply startup
will exceed the maximum rating for the IC, and incorrect operation (or even, in the worst case, destruction of
the device) may occur. We recommend using a value of R9 in the range that satisfies the following conditions.
V
B(
)
The TR lower limit clamp voltage (
0.15 V typical)
≥
3 mA
R9
V
B(
)
: The peak voltage when the voltage is negative
V
B(
+
)
The TR upper limit clamp voltage (1.5 V typical)
≤
3 mA
R9
V
B(
+
)
: The peak voltage when the voltage is positive
N
B
V
O
N
S
N
P
V
B(
+
)
=
V
B(
)
=
N
B
E
IN
Also, adjust t
PD(ON)
by changing the value of C9 in consideration of the resonance capacitance and
inductance of the transformer used.
V
DS
0 V
0 V
0 V
V
TR
0.25 V
t
TR
V
IN
Out
ID
0 V
1.5 V typ.
0.15 V typ.
Figure 5. Local resonance waveform
V
P
V
P
=
N
O
N
S
P
t
PD
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| AN8041S | Liquid crystal backlight control IC |
| AN8049 | 1.8-volt 3-channel step-up, step-down, and polarity inverting DC-DC converter control IC |
| AN8049SH | Dual 14-Bit nanoDAC® with 5 ppm/°C On-Chip Reference; Package: MSOP; No of Pins: 10; Temperature Range: Automotive |
| AN8049FHN | 1.8-volt 3-channel step-up, step-down, and polarity inverting DC-DC converter control IC |
| AN8060 | Low Drop Type Negative Output .4V Regulator with Reset Pin |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| AN804 | 制造商:VISHAY 制造商全稱:Vishay Siliconix 功能描述:P-Channel MOSFETs, the Best Choice for High-Side Switching |
| AN8041 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述: |
| AN8041S | 制造商:PANASONIC 制造商全稱:Panasonic Semiconductor 功能描述:Liquid crystal backlight control IC |
| AN804-4 | 制造商: 功能描述: |
| AN804-4D | 制造商:AN# - MILITARY 功能描述: |
發(fā)布緊急采購，3分鐘左右您將得到回復。