Datasheet

LTM4616
12
4616ff
For more information www.linear.com/LTM4616
applications inForMation
for those who wish to perform additional stability analysis.
Multiphase operation will reduce effective output ripple as
a function of the number of phases. Application Note 77
discusses this noise reduction versus output ripple cur-
rent cancellation,
but the output capacitance will be more
a function of stability and transient response. LTpowerCAD
also calculates the output ripple reduction as the number
of phases increases.
Burst Mode Operation
The LTM4616 is capable of Burst Mode operation on each
regulator in which the power MOSFETs operate intermit
-
tently b
ased o
n load demand, thus saving quiescent current.
For applications where maximizing the efficiency at very
light loads is a high priority, Burst Mode operation should
be applied. To enable Burst Mode operation, simply tie the
MODE pin to V
IN
. During this operation, the peak current of
the inductor is set to approximately 20% of the maximum
Table 3. Output Voltage Response Versus Component Matrix (Refer to Figure 18) 0A to 3A Load Step
TYPICAL MEASURED VALUES
C
OUT1
VENDORS VALUE PART NUMBER C
OUT2
VENDORS VALUE PART NUMBER
TDK 22µF, 6.3V C3216X7S0J226M Sanyo POSCAP 470µF, 4V 4TPE470M
Murata 22µF, 16V GRM31CR61C226K C
IN
(BULK) VENDORS VALUE PART NUMBER
TDK 100µF, 6.3V C4532X5R0J107MZ SUNCON 100µF, 10V 10CE100FH
Murata 100µF, 6.3V GRM32ER60J107M
V
OUT
(V)
C
IN
(CERAMIC)
C
IN
(BULK)*
C
OUT1
(CERAMIC)
C
OUT2
(BULK) I
TH
C1 C3
V
IN
(V)
DROOP
(mV)
PEAK
-TO- PEAK
DEVIA
TION (mV)
RECOVERY
TIME (µs)
LOAD
STEP
(A/µs)
R
FB
(kΩ)
1.0 10µF 100µF 100µF × 2 470µF None None None 5 20 40 40 2.5 14.7
1.0 10µF 100µF 100µF × 2 None None None 5 30 60 25 2.5 14.7
1.0 10µF 100µF 100µF × 2 None None None 2.7 30 60 25 2.5 14.7
1.0 10µF 100µF 22µF × 1 470µF None None None 2.7 25 50 25 2.5 14.7
1.2 10µF 100µF 100µF × 2 None None None 5 20 40 25 2.5 10
1.2 10µF 100µF 22µF × 1 470µF None None None 5 20 41 25 2.5 10
1.2 10µF 100µF 100µF × 2 None None None 2.7 30 60 20 2.5 10
1.2 10µF 100µF 22µF × 1 470µF None None None 2.7 30 60 25 2.5 10
1.5 10µF 100µF 100µF × 2 None None None 5 32 64 20 2.5 6.65
1.5 10µF 100µF 22µF × 1 470µF None None None 5 25 50 25 2.5 6.65
1.5 10µF 100µF 100µF × 1 None None None 3.3 22 42 25 2.5 6.65
1.5 10µF 100µF 22µF × 1 470µF None None None 3.3 25 50 25 2.5 6.65
1.5 10µF 100µF 100µF × 2 None None None 2.7 30 60 25 2.5 6.65
1.5 10µF 100µF 22µF × 1 470µF None None None 2.7 25 50 25 2.5 6.65
1.8 10µF 100µF 100µF × 1 None None None 5 42 80 25 2.5 4.87
1.8 10µF 100µF 22µF × 1 470µF None None None 5 25 50 30 2.5 4.87
1.8 10µF
100µF 100µF × 2 None None None 3.3 35 70 30 2.5 4.87
1.8 10µF 100µF 22µF × 1 470µF None None None 3.3 25 50 30 2.5 4.87
1.8 10µF 100µF 100µF × 2 None None None 2.7 35 70 30 2.5 4.87
1.8 10µF 100µF 22µF × 1 470µF None None None 2.7 35 20 30 2.5 4.87
2.5 10µF 100µF 100µF × 1 None None None 5 35 40 30 2.5 3.09
2.5 10µF 100µF 22µF × 1 470µF None None None 5 32 65 40 2.5 3.09
2.5 10µF 100µF 100µF × 1 None None None 3.3 50 100 30 2.5 3.09
2.5 10µF 100µF 22µF × 1 470µF None None None 3.3 32 65 40 2.5 3.09
3.3 10µF 100µF 100µF × 1 None None None 5 65 135 30 2.5 2.21
3.3 10µF 100µF 22µF × 1 470µF None None None 5 40 87 40 2.5 2.21
*Bulk capacitance is optional if V
IN
has very low input impedance.