LTC3619B_15 Datasheet, PDF (3/20 Pages) Linear Technology – 400mA/800mA Synchronous Step-Down DC/DC with Average Input Current Limit

LTC3619B
Electrical Characteristics The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 3)
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
I_FB
V_FBREG
ΔV_LINEREG
ΔV_LOADREG
I_S
f_OSC
I_LIM(PEAK)
Feedback Pin Input Current
Feedback Voltage (Channels 1, 2)
V_FB Line Regulation
V_FB Load Regulation (Channel 1)
V_FB Load Regulation (Channel 2)
Supply Current
Active Mode (Note 4)
Shutdown
Oscillator Frequency
Peak Switch Current Limit
Channel 1 (400mA)
Channel 2 (800mA)
l
±30
nA
LTC3619BE, –40°C < T_J < 85°C (Note 7) l 0.588 0.600 0.612
V
LTC3619BI, –40°C < T_J < 125°C (Note 7) l 0.582 0.600 0.618
V
V_IN = 2.5V to 5.5V (Note 7)
0.01 0.25
%/V
I_LOAD = 0mA to 400mA (Note 7)
I_LOAD = 0mA to 800mA (Note 7)
0.5
%
0.5
%
V_FB1 = V_FB2 = 0.95 × V_FBREG
V_RUN1 = V_RUN2 = 0V, V_IN = 5.5V
600
875
µA
1
µA
V_FB = V_FBREG
l 1.8
2.25
2.7
MHz
V_IN = 5V, V_FB < V_FBREG, Duty Cycle <35%
550
800
mA
1800 2400
mA
I_INLIM
Input Average Current Limit
RLIM = 116k
RLIM = 116k, LTC3619BE
RLIM = 116k, LTC3619BI
450
475
500
mA
l 437
475
513
mA
l 427
475
523
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
Ω
0.35
Ω
0.27
Ω
0.25
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
–7
%
5
7
%
9
11
%
–9
–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
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.
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 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.
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)
3619bfb
3