- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄192316 > SC2612CMSTRT (Semtech Corporation) 600kHz/200kHz Step-Down DC/DC Converter PDF資料下載
參數(shù)資料
| 型號： | SC2612CMSTRT |
| 廠商： | Semtech Corporation |
| 英文描述： | 600kHz/200kHz Step-Down DC/DC Converter |
| 中文描述： | 600kHz/200kHz降壓型DC / DC轉(zhuǎn)換器 |
| 文件頁數(shù)： | 8/12頁 |
| 文件大?。?/td> | 453K |
| 代理商： | SC2612CMSTRT |
5
2003 Semtech Corp.
www.semtech.com
POWER MANAGEMENT
SC2612A/C
Theory of Operation
The SC2612 is a step down DC/DC controller designed
for minimum cost and size without sacrificing accuracy
and protection. Overcurrent protection is implemented
by a simple undervoltage detection scheme and is dis-
abled until soft start has been completed to eliminate
false trips due to output capacitor charging. The SS/EN
pin is held low, as are the DH and DL pins, until the
undervoltage lockout points are exceeded. Once the VCC
and BST pins both rise above their undervoltage lockout
points, the SS capacitor begins to charge, controlling the
duty cycle of the switcher, and therefore slowly ramping
up the switcher output voltage. Once the SS capacitor is
charged, the current limit circuitry is enabled. If a short
circuit is applied , the output will be pulled down below
it’s trip point and shut down. The device may be restarted
by either cycling power, or momentarily pulling SS/EN low.
Component Selection
OUTPUT INDUCTOR
OUTPUT INDUCTOR - A good starting point for output
filter component selection is to choose an inductor value
that will give an inductor ripple current of approximately
20% of max. output current.
Inductor ripple current is given by:-
OSC
IN
O
RIPPLE
L
f
L
V
I
×
÷÷
è
-
×
=
1
So choose inductor value from:-
OSC
O
IN
O
f
I
V
L
×
÷÷
è
-
×
=
1
5
OUTPUT CAP
OUTPUT CAPAAAAACIT
CIT
CITOR(S)
OR(S)
OR(S) - The output capacitors should
be selected to meet output ripple and transient response
criteria. Output ripple voltage is caused by the inductor
ripple current flowing in the output capacitor’s ESR (There
is also a component due to the inductor ripple current
charging and discharging the output capacitor itself, but
this component is usually small and can often be ignored).
Given a maximum output voltage ripple requirement, ESR
is given by:-
OSC
IN
O
RIPPLE
O
ESR
f
L
V
R
×
÷÷
è
-
×
<
1
Output voltage transient excursions are a function of load
current transient levels, input and output voltages and
inductor and capacitor values.
Capacitance and R
ESR values to meet a required tran-
sient condition can be calculated from:-
release)
(load
transients
positive
for
V
and
n)
applicatio
(load
transients
negative
for
V
where
V
I
L
C
I
V
R
O
A
O
IN
A
T
ESR
=
-
=
×
>
<
2
values for positive and negative transients must be cal-
culated seperately and the worst case value chosen. For
Capacitor values, the calculated value should be doubled
to allow for duty cycle limitation and voltage drop issues.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| SC311-6-TE12LA | 0.5 A, 600 V, SILICON, SIGNAL DIODE |
| SC40-19SEKWA | 7 SEG NUMERIC DISPLAY, SUPER BRIGHT ORANGE, 101.2 mm |
| SC40000 | RELAY SOCKET |
| SC40010 | RELAY SOCKET |
| SC40001 | RELAY SOCKET |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| SC2612E | 制造商:SEMTECH 制造商全稱:Semtech Corporation 功能描述:500kHz Step-Down DC/DC Converter |
| SC2612ES.TRT | 制造商:SEMTECH 功能描述:I.C. |
| SC2612ESTRT | 制造商:Semtech Corporation 功能描述:Conv DC-DC Single Step Down 4.5V to 15V 8-Pin SOIC T/R |
| SC2614ML.TR | 制造商:Semtech Corporation 功能描述: |
| SC2614MLTR | 制造商:Semtech Corporation 功能描述:DDR Power Solution 18-Pin MLP T/R |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。