Datasheet
LTC3619B
3
3619bfb
elecTrical characTerisTics
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: Guaranteed by long term current density limitations.
Note 3: The LTC3619B is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3619BE is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3619BI is guaranteed
to meet specified performance over the full –40°C to 125°C operating
junction temperature range. Note that the maximum ambient temperature
is determined by specific operating conditions in conjunction with board
layout, the rated package thermal resistance and other environmental
factors.
The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 3)
Note 4: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 5: The switch on-resistance is guaranteed by correlation to wafer
level measurements.
Note 6: This IC includes overtemperature protection that is
intended
to protect the device during momentar
y 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.
Note 7: The converter is tested in a proprietary test mode that connects
the output of the error amplifier to the SW pin, which is connected to an
external servo loop.
Note 8: T
J
is calculated from the ambient temperature T
A
and the power
dissipation as follows: T
J
= T
A
+ (P
D
)(θ
JA
°C/W)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
FB
Feedback Pin Input Current
l
±30 nA
V
FBREG
Feedback Voltage (Channels 1, 2) LTC3619BE, –40°C < T
J
< 85°C (Note 7)
LTC3619BI, –40°C < T
J
< 125°C (Note 7)
l
l
0.588
0.582
0.600
0.600
0.612
0.618
V
V
ΔV
LINEREG
V
FB
Line Regulation V
IN
= 2.5V to 5.5V (Note 7) 0.01 0.25 %/V
ΔV
LOADREG
V
FB
Load Regulation (Channel 1)
V
FB
Load Regulation (Channel 2)
I
LOAD
= 0mA to 400mA (Note 7)
I
LOAD
= 0mA to 800mA (Note 7)
0.5
0.5
%
%
I
S
Supply Current
Active Mode (Note 4)
Shutdown
V
FB1
= V
FB2
= 0.95 × V
FBREG
V
RUN1
= V
RUN2
= 0V, V
IN
= 5.5V
600
875
1
µA
µA
f
OSC
Oscillator Frequency V
FB
= V
FBREG
l
1.8 2.25 2.7 MHz
I
LIM(PEAK)
Peak Switch Current Limit
Channel 1 (400mA)
Channel 2 (800mA)
V
IN
= 5V, V
FB
< V
FBREG
, Duty Cycle <35%
550
1800
800
2400
mA
mA
I
INLIM
Input Average Current Limit RLIM = 116k
RLIM = 116k, LTC3619BE
RLIM = 116k, LTC3619BI
l
l
450
437
427
475
475
475
500
513
523
mA
mA
mA
R
DS(ON)
Channel 1 (Note 5)
Top Switch On-Resistance
Bottom Switch On-Resistance
Channel 2 (Note 5)
Top Switch On-Resistance
Bottom Switch On-Resistance
V
IN
= 5V, I
SW
= 100mA
V
IN
= 5V, I
SW
= 100mA
V
IN
= 5V, I
SW
= 100mA
V
IN
= 5V, I
SW
= 100mA
0.45
0.35
0.27
0.25
Ω
Ω
Ω
Ω
I
SW(LKG)
Switch Leakage Current V
IN
= 5V, V
RUN
= 0V 0.01 1 µA
t
SOFTSTART
Soft-Start Time V
FB
from 0.06V to 0.54V 0.3 0.95 1.3 ms
V
RUN
RUN Threshold High
l
0.4 1 1.2 V
I
RUN
RUN Leakage Current 0V ≤ V
RUN
≤ 5V
l
0.01 1 µA
PGOOD Power Good Threshold Entering Window
V
FB
Ramping Up
V
FB
Ramping Down
Leaving Window
V
FB
Ramping Up
V
FB
Ramping Down
–5
5
–7
7
9
–9
11
–11
%
%
%
%
PGOOD Blanking Power Good Blanking Time PGOOD Rising and Falling, V
IN
= 5V 90 µs
R
PGOOD
Power Good Pull-Down On-Resistance 8 15 30 Ω
I
PGOOD
PGOOD Leakage Current V
PGOOD
= 5V ±1 µA