Datasheet

LTC3565
3
3565fc
For more information www.linear.com/LTC3565
ELECTRICAL CHARACTERISTICS
The l 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
Input DC Supply Current (Note 4)
Active Mode
Sleep Mode
Shutdown
V
SYNC/MODE
= 3.6V, V
FB
= 0.55V
V
SYNC/MODE
= 3.6V, V
FB
= 0.8V
V
RUN
= 0V
330
40
0.1
450
60
1
µA
µA
µA
f
OSC
Oscillator Frequency RT = 125k
(Note 7)
1.3 1.5 1.7
4
MHz
MHz
f
SYNC
Synchronization Frequency (Note 7) 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)
Top Switch On-Resistance MSE Package
DD Package (Note 6)
0.15
0.15
0.2 Ω
Ω
Bottom Switch On-Resistance MSE Package
DD Package (Note 6)
0.13
0.13
0.18 Ω
Ω
I
SW(LKG)
Switch Leakage Current V
IN
= 5.5V, V
RUN
= 0V, V
FB
= 0V 0.01 1 µA
V
RUN
RUN Threshold
l
0.3 0.8 1.5 V
I
RUN
RUN Leakage Current
l
±0.01 ±1 µA
V
UVLO
Undervoltage Lockout Threshold V
IN
Ramping Down 1.9 2.2 V
PGOOD Power Good Threshold V
FB
Ramping Up from 0.45V to 0.6V
V
FB
Ramping Down from 0.69V to 0.6V
–7
7
%
%
R
PGOOD
Power Good Pull-Down On-Resistance 15 20 Ω
PGOOD Blanking V
FB
Step from 0V to 0.6V
V
FB
Step from 0.6V to 0V
40
105
µs
µs
V
SYNC-MODE
Pulse Skip
Force Continuous
Burst
V
IN
= 2.5V to 5.5V
V
IN
= 2.5V to 5.5V
V
IN
= 2.5V to 5.5V
1.2
V
IN
– 0.6
0.6
V
IN
– 1.1
V
V
V
t
SOFT-START
10% to 90% of Regulation 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.