Datasheet
LTC3411A
3
3411afc
For more information www.linear.com/LTC3411A
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating junction
temperature range, otherwise specifications are at T
A
= 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
= 0.75V
V
SYNC/MODE
= 3.6V, V
FB
= 0.84V
V
SHDN/RT
= 3.6V
330
40
0.1
450
60
1
µA
µA
µA
V
SHDN/RT
Shutdown Threshold High Active
Oscillator Resistor
V
IN
– 0.6
125k
V
IN
– 0.4
1M
V
Ω
f
OSC
Oscillator Frequency R
T
= 125k
(Note 7)
2.25 2.5 2.8
4
MHz
MHz
f
SYNC
Synchronization Frequency (Note 7) 0.4 4 MHz
I
LIM
Peak Switch Current Limit V
FB
= 0.5V 1.6 2.1 2.6 A
R
DS(ON)
Top Switch On-Resistance MS Package
DD Package (Note 6)
0.15
0.15
0.18 Ω
Ω
Bottom Switch On-Resistance MS Package
DD Package (Note 6)
0.13
0.13
0.16 Ω
Ω
I
SW(LKG)
Switch Leakage Current V
IN
= 5.5V, V
SHDN/RT
= 5.5V, V
SW
= 0V
or 5.5V
0.01 1 µA
V
UVLO
Undervoltage Lockout Threshold V
IN
Ramping Down 1.8 2.1 2.4 V
PGOOD Power Good Threshold V
FB
Ramping Up from 0.68V to 0.8V
V
FB
Ramping Down from 0.92V to 0.8V
–5
5
–7
7
%
%
Power Bad Threshold V
FB
Ramping Down from 0.8V to 0.68V
V
FB
Ramping Up from 0.8V to 0.9V
–10
10
–12
12
%
%
R
PGOOD
Power Good Pull-Down On-Resistance 15 30 Ω
PGOOD Blanking V
FB
Step from 0V to 0.8V
V
FB
Step from 0.8V 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 0.5 0.8 1.0 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 LTC3411A is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3411AE 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
LTC3411AI is guaranteed over the full –40°C to 125°C operating junction
temperature range. 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 LTC3411A 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:
LTC3411AEDD: T
J
= T
A
+ (P
D
• 43°C/W)
LTC3411AEMS: T
J
= T
A
+ (P
D
• 120°C/W)
Note 6: For the DD package, switch on-resistance is sampled at 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.