SI9140CQ VISHAY [Vishay Siliconix], SI9140CQ Datasheet - Page 14

• Manufacturer Part Number: SI9140CQ
• Description: SMP Controller For High Performance Process Power Supplies
• Manufacturer: VISHAY [Vishay Siliconix]

Si9140
Vishay Siliconix
S-58034—Rev. G, 15-Mar-99
14
Worst case current of 10 A can be handled with two paralleled
Si4435DY and two paralleled Si4410DY MOSFETs, which
results in the efficiency levels shown in Figure 9.
Good electrical designs must provide an adequate margin for
the specification, but they should not be grossly overdesigned
to lower costs. LITTLE FOOT power MOSFETs allow
designers to balance cost and performance considerations
without sacrificing either. If the design requires only an 8.5-A
continuous current, for example, one Si4410DY can be
eliminated. Table 2 shows the number of MOSFETs required
to handle the various output current levels of today’s high-
performance microprocessors. For other output power levels,
the equations below should be used to calculate the power
handling capability of the MOSFET.
TABLE 2. Converter Requirements Figure 1, 2, and 3)
Maximum
14.5 A
I
8.5 A
O
10 A
5 A
(A)
P-Channel SI4435DY
Quantity High-side
1
2
2
3
N-Channel SI4410DY
Quantity Low-side
1
1
2
2
FIGURE 9. Efficiency
FaxBack 408-970-5600, request 70026
Capacitor OS-CON 220 µF
Quantity Input (C1-C3)
2
1
2
3
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