LTC3607
3
3607fb
For more information www.linear.com/LTC3607
elecTrical characTerisTics
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SV
IN
Operating Voltage Range
l
4.5 15 V
PV
IN
Operating Voltage Range
l
4.5 15 V
V
OUT
Output Voltage Range 0.6 PV
IN
V
V
FB
Feedback Voltage (Note 3)
l
0.591
0.588
0.6
0.6
0.609
0.61
2
V
V
I
FB
Feedback Pin Input Current 30 nA
ΔV
LINE REG
Reference Voltage Line Regulation V
IN
= 4.5V to 15V (Note 3) 0.1 0.15 %/V
ΔV
LOAD REG
Output Voltage Load Regulation MODE/SYNC = 0V (Note 3) 0.5 %
I
S
Input DC Supply Current
Active Mode
Sleep Mode (Both Channels)
Sleep Mode (Single Channel)
Shutdown
(Note 4)
V
FB1
= V
FB2
= 0.5V
V
FB1
= V
FB2
= 0.64V
V
FB(1 or 2)
= 0.64V
RUN1 = RUN2 = 0V
3.2
55
35
0.1
90
60
1
mA
µA
µA
µA
f
OSC
Oscillator Frequency V
FB1, 2
= 0.6V
l
1.8 2.25 2.7 MHz
f
SYNC
Synchronization Frequency 1.0 4.0 MHz
I
LIM
Peak Switch Current Limit V
FB1, 2
= 0.5V, Duty Cycle < 35% 0.75 1 1.25 A
R
DS(ON)
Top Switch On-Resistance
Bottom Switch On-Resistance
(Not
e 6)
(Note 6)
0.6
0.25
Ω
Ω
UVLO SV
IN
Undervoltage Lockout Threshold SV
IN
Rising 3.4 4.3 V
PGOOD PGOOD1/2 Overvoltage Threshold V
FB1, 2
Rising
V
FB1, 2
Hysteresis
8.5
–3
11 %
%
PGOO
D1/2 Undervoltage Threshold V
FB1, 2
Ramping Down
V
FB1, 2
Hysteresis
–11 –8.5
3
%
%
PGOOD
1/2 On-Resistance Channel 1 or Channel 2 Active
RUN1 = RUN2 = 0V
70
700
Ω
Ω
t
PGOOD
Power Good Blanking Time 64 Cycles
I
PGOOD
PGOOD Leakage 1 µA
V
RUN
RUN1/2 V
IL
RUN1/2 V
IH
l
l
0.55
3.0
V
V
I
RUN
RUN1/2 Leakage Current
l
0.01 1 µA
V
MODE/SYNC
MODE/SYNC V
IL
MODE/SYNC V
IH
l
l
0.3
1.0
V
V
t
SOFTSTART
Internal Soft-Start Time V
FB
from 10% to 90% Full Scale
PV
IN1
= PV
IN2
= SV
IN
= 4.5V
0.35 ms
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, unless otherwise specified. (Note 2)
Note 1. Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2. The LTC3607 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3607E is guaranteed to meet specifications from
0°C to 85°C junction temperature. Specifications over the –40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3607I is guaranteed over the full –40°C to 125°C operating junction
temperature range.
The junction temperature (T
J
) is calculated from the ambient temperature
(T
A
) and power dissipation (P
D
) according to the formula:
T
J
= T
A
+ (P
D
• θ
JA
°C/W)
where θ
JA
is the package thermal impedance. Note that the maximum
ambient temperature is consistent with these specifications determined by
specific operating conditions in conjunction with board layout, the rated
package thermal resistance and other environmental factors.
Note 3. The LTC3607 is tested in a proprietary test mode that connects
V
FB
to the output of the error amplifier to an external servo loop.
Note 4. Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 5. T
J
is calculated from the ambient T
A
and power dissipation P
D
according to the following formula: T
J
= T
A
+ (PD • θ
JA
).
Note 6. The QFN switch on-resistance is guaranteed by correlation to
wafer level measurements.
Note 7. 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 specified maximum operating junction
temperature may impair device reliability.
