LTC3569
4
3569fe
For more information www.linear.com/LTC3569
elecTrical characTerisTics
I
SVIN
vs Temperature
Efficiency vs Load Current
OUT2 = 1.8V
Efficiency vs Load Current
OUT3 = 1.2V
Typical perForMance 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: Current into a pin is positive and current out of a pin is negative.
All voltages referenced to SGND.
Note 3: Dynamic supply current is higher due to the internal gate charge
being delivered at the switching frequency.
Note 4: Specification is guaranteed by design and not 100% tested in
production.
Note 5: Switch on-resistance verified 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 exceeds 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 7: The LTC3569 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC3569E is guaranteed to meet specified performance 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 LTC3569I is guaranteed to meet
specified performance over the full –40°C to 125°C operating junction
temperature range.
TEMPERATURE (°C)
–50
I
SVIN
(µA)
300
250
150
50
200
100
0
50
3569 G01
1501000
BUCK1 ONLY PULSE-SKIPPING V
IN
= 3.5V
BUCK1 ONLY Burst Mode OPERATION
V
IN
= 3.5V
SLOPE ≅ 185nA/°C
SLOPE ≅ 132nA/°C NO LOAD
I
LOAD
(mA)
EFFICIENCY (%)
3569 G02
100
90
80
70
60
50
40
30
20
10
0
0.01 0.1 100 1000101
V
IN
= 3V
V
IN
= 5V
Burst Mode OPERATION
PULSE-SKIPPING
I
LOAD
(mA)
EFFICIENCY (%)
3569 G03
100
90
80
70
60
50
40
30
20
10
0
0.01 0.1 100 1000101
V
IN
= 3V
V
IN
= 5V
Burst Mode OPERATION
PULSE-SKIPPING
T
A
= 25°C, unless otherwise noted.
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 unless otherwise noted (Notes 2, 7).
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
R
PGOOD
PGOOD Pull-Down On-Resistance V
FBX
< 0.4V 380 525 Ω
UVLO Undervoltage Lockout
l
2.5 V
f
OSC
Fixed Oscillator Frequency V
RT
= SV
IN
l
1.9 2.25 2.8 MHz
f
CLK(MAX)
Maximum Programmable Oscillator Frequency R
T
= 100k
l
3.0 MHz
f
CLK(MIN)
Minimum Programmable Oscillator Frequency R
T
= 453k
l
1.0 MHz
f
SYNC
Sync Frequency V
RT
= SV
IN
3 MHz
R
T
= 453k 1.2 MHz
