Ltc1147 Voltage Regulator Solution - Motorola M68060 User Manual

Applications Information
devices that are needed externally in addition to the Linear Technologies devices. The con-
version efficiency is 89% and 93% for the LTC1147 and LTC1148, respectively. Figure 11-
2 and Figure 11-3 show the solutions provided by using the switching regulators. The
MAX767 provides over 90% conversion efficiency at less than $4 in 1000 piece quantities.
The MAX767 solution also requires discreet components off-chip. The MAX767 uses a
smaller inductor than the LTC1148 solution. Figure 11-4 shows a MAXIM voltage regulator
solutions. All the suggested solutions meets 3.3 V ± 5% MC68060 specifications.
5 V
C4
RC
CC
T1 = Si9430DY
50 µH Coiltronics CTX50-2-MP
L1 =
D1 = MBRD330
D2,D3,D4 = IN4001
0.05 Ω IRC LR2512-01-R050-G
R1 =
1K Ω
RC =
C1 = 1000 pF
100 µF, 20V
C2 =
1 µF
C3 =
C4 = 100 nF
CC = 3300 pF
CT = 470 pF
220 µF, 10V x2
CL =
Figure 11-2. LTC1147 Voltage Regulator Solution
11-8
C2
VIN
P-DRIVE
SHUTDOWN
SENSE +
LTC1147-3.3
I
TH
SENSE –
C
T
CT
GND
M68060 USER'S MANUAL
C3
T1
L1
C1
D1
D2
D3
D4
R1
3.3 V
2 A
CL
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