TPS56100
HIGHEFFICIENCY DSP POWER SUPPLY CONTROLLER
FOR 5V INPUT SYSTEMS
SLVS201A JUNE 1999 REVISED JULY 1999
24
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
APPLICATION INFORMATION
application example (continued)
Table 2. Power Stage Components
Ref Des
Function
4A Out
8A Out
12A Out
20A Out
C101
Input Bulk
Capacitor
Sanyo,
10TPB220M,
220
F, 10V, 20%
Sanyo,
10SA220M,
2 x 220
F, 10V, 20%
Sanyo,
10SP470M,
2 x 470
F, 10V, 20%
Sanyo,
10SP470M,
3 x 470
F, 10V, 20%
C102
Input MidFreq
Capacitor
muRata,
GRM426Y5V105Z025A,
1.0
F, 25V,
+80%20%, Y5V
muRata,
GRM426Y5V225Z016A,
2.2
F, 16V,
+80%20%, Y5V
muRata,
GRM426Y5V225Z016A,
2.2
F, 16V, +80%20%,
Y5V
muRata,
GRM426Y5V105Z025A,
3 x 1.0
F, 25V,
+80%20%, Y5V
C103
Input HiFreq
Bypass
Capacitor
muRata,
GRM39X7R104K016A,
0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
2 x 0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
3 x 0.1
F, 16V, X7R
C104
Snubber
Capacitor
muRata,
GRM39X7R102K050A,
1000pF, 50V, X7R
muRata,
GRM39X7R102K050A,
1000pF, 50V, X7R
muRata,
GRM39X7R102K050A,
2 x 1000 pF, 50V, X7R
muRata,
GRM39X7R102K050A,
3 x 1000pF, 50V, X7R
C105
Output Bulk
Capacitor
Sanyo,
4TPC150,
2 x 150
F, 4V, 20%
Sanyo,
4SP820M,
820
F, 4V, 20%
Sanyo,
4SP820M,
2 x 820
F, 4V, 20%
Sanyo,
4SP820M,
3 x 820
F, 4V, 20%
C106
Output HiFreq
Bypass Capaci-
tor
muRata,
GRM39X7R104K016A,
0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
2 x 0.1
F, 16V, X7R
muRata,
GRM39X7R104K016A,
3 x 0.1
F, 16V, X7R
L101
Input Filter
Inductor
CoilCraft,
DO1608C332,
3.3
H, 2.0A
Coiltronics,
UP2B2R2,
2.2
H, 7.2A
Coiltronics,
UP2B2R2,
2.2
H, 7.2A
Coiltronics,
UP3B1R0,
1
H, 12.5A
L102
Output Filter
Inductor
CoilCraft,
DO3316P332,
3.3
H, 6.1A
Coiltronics,
UP3B2R2,
2.2
H, 9.2A
Coiltronics,
UP4B1R5,
1.5
H, 13.4A
MicroMetals,
T688/90 Core w/7T #16,
1.0
H, 25A
R101
LoSide Gate
Resistor
3.3
, 1/16W, 5%
3.3
, 1/16W, 5%
2 x 3.3
, 1/16W, 5%
3 x 3.3
, 1/16W, 5%
R102
Snubber
Resistor
2.7
, 1/10W, 5%
2.7
, 1/10W, 5%
2 x 2.7
, 1/10W, 5%
3 x 2.7
, 1/10W, 5%
Q101
Power Switch
IR, IRF7811,
NMOS, 11m
IR, IRF7811,
NMOS, 11m
IR, 2 x IRF7811, NMOS,
11m
IR, 2 x IRF7811, NMOS,
11m
Q102
Synchronous
Switch
IR, IRF7811,
NMOS, 11m
IR, IRF7811,
NMOS, 11m
IR, 2 x IRF7811, NMOS,
11m
IR, 3 x IRF7811, NMOS,
11m
Nominal Frequency
280 kHz
250 kHz
170 kHz
Hysteresis Window
15 mV
Nominal frequency measured with Vo set to 1.5 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.