DC1400A Linear Technology, DC1400A Datasheet - Page 12

• Manufacturer Part Number: DC1400A
• Description: BOARD EVAL LTM4608
• Manufacturer: Linear Technology
• Series: LTM®r

Specifications of DC1400A

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 1.2V, 1.5V, 1.8V, 2.5V, 3.3V
• Current - Output: 8A
• Voltage - Input: 2.5 ~ 5.5 V
• Regulator Topology: Buck
• Frequency - Switching: 1.5MHz
• Board Type: Fully Populated
• Utilized Ic / Part: LTM4608
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Power - Output: -

LTM4608A
APPLICATIONS INFORMATION
Forced Continuous Operation
In applications where fixed frequency operation is more
critical than low current efficiency, and where the lowest
output ripple is desired, forced continuous operation should
be used. Forced continuous operation can be enabled by
tying the MODE pin to GND. In this mode, inductor cur-
rent is allowed to reverse during low output loads, the I
voltage is in control of the current comparator threshold
Table 3. Output Voltage Response Versus Component Matrix (Refer to Figure 18) 0A to 3A Load Step
TYPICAL MEASURED VALUES
C
TDK
Murata
TDK
Murata
*Bulk capacitance is optional if V
12
OUT1
V
(V)
1.0
1.0
1.0
1.0
1.0
1.0
1.2
1.2
1.2
1.2
1.2
1.2
1.5
1.5
1.5
1.5
1.5
1.5
1.8
1.8
1.8
1.8
1.8
1.8
2.5
2.5
2.5
2.5
3.3
3.3
OUT
VENDORS
(CERAMIC)
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
10µF
C
IN
VALUE
22µF , 6.3V
22µF , 16V
100µF , 6.3V
100µF , 6.3V
(BULK)*
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
100µF
C
IN
IN
has very low input impedance.
(CERAMIC)
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 2
100µF × 1
100µF × 2
100µF × 2
100µF × 1
100µF × 1
100µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
22µF × 1
C
OUT1
PART NUMBER
C3216X7S0J226M
GRM31CR61C226KE15L
C4532X5R0J107MZ
GRM32ER60J107M
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 2
150µF × 1
150µF × 1
150µF × 1
(BULK)
C
OUT2
100pF
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
I
TH
100pF
100pF
100pF
100pF
100pF
100pF
120pF
120pF
100pF
100pF
68pF
None
68pF
None
68pF
None
None
None
47pF
None
None
None
47pF
None
None
None
22pF
22pF
22pF
None
C1
TH
100pF
100pF
100pF
100pF
100pF
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
47pF
47pF
47pF
47pF
C3
C
Sanyo POSCAP
C
Sanyo
OUT2
IN
throughout, and the top MOSFET always turns on with each
oscillator pulse. During start-up, forced continuous mode
is disabled and inductor current is prevented from revers-
ing until the LTM4608A’s output voltage is in regulation.
Multiphase Operation
For output loads that demand more than 8A of current,
multiple LTM4608As can be cascaded to run out of phase to
(BULK) VENDORS
VENDORS
V
(V)
3.3
3.3
2.7
2.7
3.3
3.3
2.7
2.7
3.3
3.3
2.7
2.7
3.3
3.3
2.7
2.7
3.3
3.3
5
5
5
5
5
5
5
5
5
5
5
5
IN
DROOP
(mV)
13
17
13
17
13
17
16
20
16
20
16
16
18
20
16
20
18
20
22
21
21
21
22
21
28
33
30
21
38
39
VALUE
150µF , 10V
VALUE
100µF , 10V
DEVIATION (mV)
PEAK-TO- PEAK
26
34
26
34
26
34
32
41
32
41
32
32
36
41
32
41
36
41
42
42
43
41
44
42
42
60
60
41
74
75
RECOVERY
TIME (µs)
PART NUMBER
10TPD150M
PART NUMBER
10CE100FH
10
10
10
10
12
10
12
10
12
12
12
12
12
14
10
10
10
10
10
12
7
8
7
7
8
8
8
8
8
8
LOAD STEP
(A/µs)
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4608afc
(kΩ)
14.7
14.7
14.7
6.65
6.65
6.65
6.65
6.65
6.65
4.87
4.87
4.87
4.87
4.87
4.87
3.09
3.09
3.09
3.09
2.21
2.21
14.7
14.7
14.7
R
10
10
10
10
10
10
FB