LTC3565_12 Datasheet, PDF (3/22 Pages) Linear Technology – 1.25A, 4MHz, Synchronous Step-Down DC/DC Converter

LTC3565
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_J = 25°C. V_IN = 3.6V, R_T = 125k unless otherwise specified. (Note 2)
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
I_S
f_OSC
f_SYNC
Input DC Supply Current (Note 4)
Active Mode
Sleep Mode
Shutdown
Oscillator Frequency
Synchronization Frequency
V_SYNC/MODE = 3.6V, V_FB = 0.55V
V_SYNC/MODE = 3.6V, V_FB = 0.8V
V_RUN = 0V
RT = 125k
(Note 7)
(Note 7)
330
450
μA
40
60
μA
0.1
1
μA
1.3
1.5
1.7
MHz
4
MHz
0.4
4
MHz
I_LIM
Peak Switch Current Limit
V_IN = 3V, V_FB = 0.5V
1.5
2.1
2.5
A
R_DS(ON)
I_SW(LKG)
V_RUN
I_RUN
Top Switch On-Resistance
Bottom Switch On-Resistance
Switch Leakage Current
RUN Threshold
RUN Leakage Current
MSE Package
DD Package (Note 6)
MSE Package
DD Package (Note 6)
V_IN = 5.5V, V_RUN = 0V, V_FB = 0V
0.15
0.2
Ω
0.15
Ω
0.13
0.18
Ω
0.13
Ω
0.01
1
μA
l
0.3
0.8
1.5
V
l
±0.01
±1
μA
V_UVLO
Undervoltage Lockout Threshold
V_IN Ramping Down
1.9
2.2
V
PGOOD
R_PGOOD
Power Good Threshold
V_FB Ramping Up from 0.45V to 0.6V
V_FB Ramping Down from 0.69V to 0.6V
Power Good Pull-Down On-Resistance
–7
%
7
%
15
20
Ω
PGOOD Blanking
V_SYNC-MODE
t_SOFT-START
Pulse Skip
Force Continuous
Burst
V_FB Step from 0V to 0.6V
V_FB Step from 0.6V to 0V
10% to 90% of Regulation
40
μs
105
μs
0.63
V
1.1
V_IN – 0.75
V_IN – 1.05
V
V
0.6
0.9
1.2
ms
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 LTC3565 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3565E is guaranteed to meet performance 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
LTC3565I is guaranteed over the full –40°C to 125°C operating junction
temperature range. Note that the maximum ambient temperature
consistent with these specifications is determined by specific operating
conditions in conjunction with board layout, the rated package thermal
resistance and other environmental factors.
Note 3: The LTC3565 is tested in a feedback loop which servos V_FB to the
midpoint for the error amplifier (V_ITH = 0.7V).
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 formulas:
LTC3565EDD: T_J = T_A + (P_D • 43°C/W)
LTC3565EMSE: T_J = T_A + (P_D • 40°C/W)
Note 6: Switch on-resistance is guaranteed by correlation to wafer level
measurements and assured by design characterization and correlation with
statistical process controls.
Note 7: 4MHz operation is guaranteed by design but not production tested
and is subject to duty cycle limitations (see Applications Information).
Note 8: 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.
3565fb
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