ꢀ ꢁꢂ ꢂ ꢃ ꢄ ꢂꢅ ꢆ ꢀ ꢁꢂ ꢇꢃ ꢄꢂ ꢅ
ꢈ ꢉ ꢊ ꢋꢅ ꢌ ꢍꢅ ꢎ ꢏꢐ ꢐ ꢑꢒ ꢓꢏꢔ ꢁꢎꢓ ꢕꢖꢗ ꢍꢘꢒ ꢕꢖ ꢙ ꢑꢚ ꢕ ꢒꢁ ꢛꢕꢖ ꢙ ꢘꢍꢙ ꢔ ꢜꢅꢒꢐ ꢘꢑ
SLLS636D – DECEMBER 2004 – REVISED MARCH 2005
APPLICATION INFORMATION
calculations of key parameters
CALCULATION
STEP DOWN
Vout ) VF
Vin min * Vsat * Vout
VOLTAGE INVERTING
STEP UP
Ť
Ť
Vout ) VF * Vin min
Vout ) VF
(
)
t
/t
on off
Vin min * Vsat
Vin * Vsat
(
)
(
)
1
f
1
f
1
f
(t + t
on off
)
ton ) toff
ton ) toff
ton ) toff
t
off
t
t
t
on
on
on
) 1
) 1
) 1
t
t
t
off
off
off
ǒ
Ǔ
ǒ
Ǔ
ǒ
Ǔ
t
on
ton ) toff * toff
ton ) toff * toff
ton ) toff * toff
*5
*5
*5
C
T
4 10
t
4 10
t
4 10
t
on
on
on
ton
toff
ton
toff
I
2Iout max
ǒ Ǔ
ǒ Ǔ
2Iout max
) 1
2Iout max
) 1
pk(switch)
(
)
(
)
(
)
0.3
0.3
0.3
R
sc
Ipk switch
Ipk switch
Ipk switch
(
)
(
)
(
)
ǒV
Ǔ
ǒV
Ǔ
ǒV
Ǔ
) * Vsat * Vout
) * Vsat
(
in min
) * Vsat
(
(
in min
in min
L
t
t
on max
t
ǒ
Ǔ ǒ Ǔ
ǒ Ǔ
(min)
(
)
(
)
(
)
on max
on max
Ipk switch
Ipk switch
( )
Ipk switch
(
)
(
)
ǒ
Ǔ
Ioutton
Ipk switch ton ) toff
Ioutton
Vripple pp
Ǔ
(
)
9
9
C
O
Vripple pp
8Vripple pp
ǒ
Ǔ
ǒ
ǒ
Ǔ
11
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