Datasheet

LTC3604
4
3604f
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Load Current
Burst Mode Operation
Effi ciency vs Load Current
Forced Continuous Mode
Effi ciency vs Frequency
Forced Continuous Mode
Reference Voltage vs
Temperature
ELECTRICAL CHARACTERISTICS
Note 3: T
J
is calculated from the ambient temperature, T
A
, and power
dissipation, P
D
, according to the following formula:
T
J
= T
A
+ (P
D
• θ
JA
)
where θ
JA
= 45°C/W for the QFN package and θ
JA
= 38°C/W for the MSOP
package.
Note 4: Maximum allowed current draw when used as a regulated output
is 5mA. This supply is only intended to provide additional DC load current
as needed and not intended to regulate large transient or ac behavior as
these waveforms may impact LTC3604 operation.
Effi ciency vs Input Voltage
Burst Mode Operation
Note 5: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may impair device reliability.
Effi ciency vs Load Current
T
A
= 25°C, V
IN
= 12V, f
O
= 1MHz, L = 1.5μH unless otherwise noted.
TEMPERATURE (°C)
–50 –25
0.595
V
REF
(V)
0.599
0.605
0
50
75
3604 G06
0.597
0.603
0.601
25
100
125
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.001 0.1 1 10
3604 G01
0
0.01
V
IN
= 4V
V
IN
= 8V
V
IN
= 12V
V
OUT
= 1.8V
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.001 0.1 1 10
3604 G02
0
0.01
V
IN
= 4V
V
IN
= 8V
V
IN
= 12V
V
OUT
= 1.8V
LOAD CURRENT (A)
30
EFFICIENCY (%)
90
100
20
10
80
50
70
60
40
0.001 0.1 1 10
3604 G03
0
0.01
V
OUT
= 3.3V
V
OUT
= 5V
BURST
FORCED
CONTINUOUS
INPUT VOLTAGE (V)
4
EFFICIENCY (%)
75
80
85
10
14
3604 G04
70
65
60
68 12
90
95
100
16
I
LOAD
= 500mA
I
LOAD
= 100mA
I
LOAD
= 10mA
I
LOAD
= 2.5A
FREQUENCY (MHz)
0.5
82
EFFICIENCY (%)
84
86
88
90
92
94
1 1.5 2 2.5
3604 G05
3
V
OUT
= 1.8V
I
LOAD
= 800mA
L = 1.5µH
L = 0.68µH