LTM8027
applicaTions inForMaTion
The die temperature of the LTM8027 must be lower than
the maximum rating of 125°C, so care should be taken in
the layout of the circuit to ensure good heat sinking of the
LTM8027. The bulk of the heat flow out of the LTM8027
is through the bottom of the module and the LGA pads
into the printed circuit board. Consequently a poor printed
circuit board design can cause excessive heating, result-
ing in impaired performance or reliability. Please refer to
the PCB Layout section for printed circuit board design
suggestions.
The junction-to-air and junction-to-board thermal resis-
tances given in the Pin Configuration diagram may also
be used to estimate the LTM8027 internal temperature.
These thermal coefficients are determined per JESD 51-9
(JEDECstandard,testboardsforareaarraysurfacemount
package thermal measurements) through analysis and
physical correlation. Bear in mind that the actual thermal
resistance of the LTM8027 to the printed circuit board
depends upon the design of the circuit board.
Table 2. Recommended Component Values and Configuration
(TA = 25°C. See Typical Performance Characteristics for load Conditions)
V
RANGE
(V)
V
R
f
R
f
R
MAX
IN
OUT
ADJ
OPTIMAL
OPTIMAL
MAX
(V)
3.3
5
C
C
BIAS1
8.5V to 15V
8.5V to 15V
8.5V to 15V
AUX
(kΩ)
(kHz)
(kΩ)
(kHz)
160
230
350
500
500
500
500
(kΩ)
IN
OUT
4.5 to 60
7.5 to 60
10.5 to 60
16 to 60
20.5 to 60
26 to 60
34 to 60
301
115
210
260
300
350
400
430
154
75.0
59.0
48.7
40.2
31.6
28.7
107
2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V
2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V
2 × 4.7µF 2220 100V 4 × 47µF 1210 10V
2 × 4.7µF 2220 100V 4 × 22µF 1210 16V
2 × 4.7µF 2220 100V 4 × 22µF 1210 16V
2 × 4.7µF 2220 100V 4 × 10µF 1812 25V
2 × 4.7µF 2220 100V 4 × 10µF 1812 25V
162
68.2
40.2
23.7
23.7
23.7
23.7
8
90.9
56.2
44.2
36.5
26.7
12
15
18
24
AUX
8.5V to 15V
8.5V to 15V
4.5 to 40
4.5 to 40
7.5 to 40
10.5 to 40
16 to 40
20.5 to 40
26 to 40
34 to 40
2.5
3.3
5
8.5V to 15V
8.5V to 15V
8.5V to 15V
8.5V to 15V
AUX
487
301
145
165
210
260
300
350
400
430
124
102
185
240
315
500
500
500
500
500
88.7
64.9
45.3
23.7
23.7
23.7
23.7
23.7
2 × 10µF 2220 50V 5 × 100µF 1812 6.3V
2 × 10µF 2220 50V 4 × 100µF 1812 6.3V
2 × 10µF 2220 50V 4 × 100µF 1210 6.3V
2 × 10µF 2220 50V 4 × 47µF 1210 10V
2 × 10µF 2220 50V 4 × 22µF 1210 16V
1 × 10µF 2220 50V 4 × 22µF 1210 16V
1 × 10µF 2220 50V 4 × 10µF 1812 25V
1 × 10µF 2220 50V 4 × 10µF 1812 25V
162
75.0
59.0
48.7
40.2
31.6
28.7
8
90.9
56.2
44.2
36.5
26.7
12
15
18
24
AUX
8.5V to 15V
8.5V to 15V
4.5 to 56
4.5 to 55
10.5 to 52
16 to 48
–3.3
–5
8.5V to 15V Above Output
8.5V to 15V Above Output
8.5V to 15V Above Output
AUX
301
162
115
190
260
300
154
90.9
59.0
48.7
155
230
350
500
115
68.2
40.2
23.7
2 × 4.7µF 2220 100V 5 × 100µF 1812 6.3V
2 × 4.7µF 2220 100V 4 × 100µF 1210 6.3V
2 × 4.7µF 2220 100V 4 × 47µF 1210 10V
2 × 4.7µF 2220 100V 4 × 22µF 1210 16V
–8
90.9
56.2
–12
8027fb
16
Linear [ Linear ]
