4–A Out 8–A Out 12–A Out 20–A Out 40–A Out
C101
Input Bulk
Capacitor
Sanyo,
16SV100M,
100–uF, 16–V, 20%
Sanyo,
16SA470M,
2 x 470–uF , 16–V, 20%
Sanyo,
16SA470M,
2 x 470–uF , 16–V, 20%
Sanyo,
16SA470M,
3 x 470–uF , 16–V, 20%
Sanyo,
16SA470M,
4 x 470–uF , 16–V, 20%
C102
Input
Mid–Freq
Capacitor
muRata,
GRM42–6Y5V105Z025A
1.0–uF, 25–V,
+80%–20%,
Y5V
muRata,
GRM42–6Y5V225Z016A
2.2–uF, 16–V,
+80%–20%,
Y5V
muRata,
GRM42–6Y5V225Z016A
2.2–uF, 16–V,
+80%–20%,
Y5V
muRata,
GRM42–6Y5V105Z025A
3 x 1.0–uF , 25–V,
+80%–20%,
Y5V
muRata,
GRM42–6Y5V105Z025A
4 x 1.0–uF , 25–V,
+80%–20%,
Y5V
C103
Input
Hi–Freq
Bypass
Capacitor
muRata,
GRM39X7R104K016A
0.1–uF, 16–V, X7R
muRata,
GRM39X7R104K016A,
0.1–uF, 16–V, X7R
muRata,
GRM39X7R104K016A,
2 x 0.1–uF , 16–V, X7R
muRata,
GRM39X7R104K016A,
3 x 0.1–uF , 16–V, X7R
muRata,
GRM39X7R104K016A,
4 x 0.1–uF , 16–V, X7R
C104
Snubber
Capacitor
muRata,
GRM39X7R102K050A,
1000–pF, 50–V, X7R
muRata,
GRM39X7R102K050A,
1000–pF, 50–V, X7R
muRata,
GRM39X7R102K050A,
2 x 1000–pF , 50–V, X7R
muRata,
GRM39X7R102K050A,
3 x 1000–pF , 50–V, X7R
muRata,
GRM39X7R102K050A,
4 x 1000–pF , 50–V, X7R
C105
Output Bulk
Capacitor
Sanyo,
6TPB150M,
3 x 150–uF , 6.3–V, 20%
Sanyo,
4SP820M,
820–uF, 4–V, 20%
Sanyo,
4SP820M,
2 x 820–uF , 4–V, 20%
Sanyo,
4SP820M,
3 x 820–uF , 4–V, 20%
Sanyo,
4SP820M,
4 x 820–uF , 4–V, 20%
C106
Output
Hi–Freq
Bypass
Capacitor
muRata,
GRM39X7R104K016A,
0.1–uF, 16–V, X7R
muRata,
GRM39X7R104K016A,
0.1–uF, 16–V, X7R
muRata,
GRM39X7R104K016A,
2 x 0.1–uF , 16–V, X7R
muRata,
GRM39X7R104K016A,
3 x 0.1–uF , 16–V, X7R
muRata,
GRM39X7R104K016A,
4 x 0.1–uF , 16–V, X7R
L101
Input
Filter
Inductor
CoilCraft,
DO1608C–332,
3.3–uH, 2.0–A
Coiltronics,
UP2B–2R2,
2.2–uH, 7.2–A
Coiltronics,
UP2B–2R2,
2.2–uH, 7.2–A
Coiltronics,
UP3B–1R0,
1–uH, 12.5–A
Coiltronics,
UP3B–1R0,
1–uH, 12.5–A
L102
Output
Filter
Inductor
CoilCraft,
DO3316P–332,
3.3–uH, 6.1–A
Coiltronics,
UP3B–2R2,
2.2–uH, 9.2–A
Coiltronics,
UP4B–1R5,
1.5–uH, 13.4–A
MicroMetals,
T68–8/90 Core w/7T
#16, 1.0–uH, 25–A
Pulse Engineering,
P1605,
1.0–uH, 50–A
R101
Lo–Side
Gate
Resistor
3.3–Ohm,
1/16–W, 5%
3.3–Ohm,
1/16–W, 5%
2 x 3.3–Ohm,
1/16–W, 5%
3 x 3.3–Ohm,
1/16–W, 5%
4 x 3.3–Ohm,
1/16–W, 5%
R102
Snubber
Resistor
2.7–Ohm,
1/10–W, 5%
2.7–Ohm,
1/10–W, 5%
2 x 2.7–Ohm,
1/10–W, 5%
3 x 2.7–Ohm,
1/10–W, 5%
4 x 2.7–Ohm,
1/10–W, 5%
Q101
Power
Switch
Siliconix, Si4410,
NMOS, 13–mOhm
Siliconix, Si4410,
NMOS, 13–mOhm
Siliconix, 2 x Si4410,
NMOS, 13–mOhm
Siliconix, 2 x Si4410,
NMOS, 13–mOhm
IR, 2 x IRF7811,
NMOS, 11–mOhm
Q102
Synchronous
Switch
Siliconix, Si4410,
NMOS, 13–mOhm
Siliconix, Si4410,
NMOS, 13–mOhm
Siliconix, 2 x Si4410,
NMOS, 13–mOhm
Siliconix, 3 x Si4410,
NMOS, 13–mOhm
IR, 4 x IRF7811,
NMOS, 11–mOhm
Nominal Frequency†220 KHz 330 KHz 240 KHz 140 KHz 168 KHz
Hysteresis Window 20 mV 20 mV 20 mV 20 mV 10 mV
†
Nominal frequency measured with Vo set to 2 V.
The values listed above are recommendations based on actual test circuits. Many variations of the above are
possible based upon the desires and/or requirements of the user. Performance of the circuit is equally, if not
more, dependent upon the layout than on the specific components, as long as the device parameters are not
exceeded. Fast-response, low-noise circuits require critical attention to the layout details. Even though the
operating frequencies of typical power supplies are relatively low compared to today’s microprocessor circuits,
the power levels and edge rates can cause severe problems both in the supply and the load. The power stage,
having the highest current levels and greatest dv/dt rates, should be given the greatest attention.