Datasheet

LTC3569
3
3569fe
For more information www.linear.com/LTC3569
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 unless otherwise noted (Notes 2, 7).
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SV
IN
Input Supply Voltage
l
2.5 5.5 V
I
VIN
Input Current Pulse-Skipping Mode EN1 = SV
IN
, EN2, EN3 = MODE = 0V,
I
OUT1
, = 0A, FB1 = 0.9V (Note 3)
230 365 µA
Input Current Burst Mode Operation EN1 = MODE = SV
IN
, EN2, EN3 = 0V,
I
OUT1
, = 0A, FB1 = 0.9V (Note 3)
47 82 µA
I
QX
Additional Input Current per Buck,
Pulse Skipping
MODE = 0V, I
OUTX
, = 0A, FBx = 0.9V
(Note 3)
140 225 µA
Additional Input Current per Buck,
Burst Mode Operation
MODE = SV
IN
, I
OUTX
, = 0A,
FBx = 0.9V (Note 3)
22 36 µA
I
QSHDN
Quiescent Current in Shutdown Mode EN1, EN2, EN3 = 0V
V
SW1
= V
SW2
= V
SW3
= 0V
0.1 1 µA
I
PK1
Peak Inductor Current SW1 1.8 2.0 2.5 A
I
PK2
, I
PK3
Peak Inductor Current SW2, SW3 0.780 1.0 1.3 A
V
FBX(MAX)
Maximum Feedback Voltage
l
0.784 0.8 0.816 V
V
FBX(STEP)
Feedback Reference Step Size Each Toggle on ENx 25 mV
V
FBX(MIN)
Minimum Feedback Voltage ENx Toggle 15 Times
l
0.405 0.425 0.44 V
V
PROGFBX
Feedback Programming Range 0.425 0.8 V
I
FBX
Feedback Pin Input Current V
FB
= 0.8V
l
±0.2 µA
I
LKSWX
Switch Pin Leakage Current V
SWX
= 1.8V, V
ENX
= SV
IN
,
V
FBX
= 0.9V
±1 µA
D
X
Maximum Duty Cycle FBx = 0V 100 %
R
P1
R
DSON
of PSW for SW1 I
SW1
= 100mA (Note 5) 195 mΩ
R
N1
R
DSON
of NSW for SW1 I
SW1
= –100mA (Note 5) 180 mΩ
R
P2
, R
P3
R
DSON
of PSW for SW2, SW3 I
SW2
, I
SW3
= 100mA (Note 5) 265 mΩ
R
N2
, R
N3
R
DSON
of NSW for SW2, SW3 I
SW2
, I
SW3
= –100mA (Note 5) 250 mΩ
RSWx_PD SWx Pull-Down in Shutdown ENx = 0V, V
SWX
= 1.2V,
(FBx < SV
IN
)
2.3 kΩ
∆V
LINEREG
Reference Voltage Line Regulation SV
IN
= 2.5V to 5.5V 0.04 0.2 %/V
∆V
LOADREG
Output Voltage Load Regulation Pulse-Skipping Mode (Note 4) 0.5 %
t
SS
Soft-Start Reference Ramp Rate 0.75 V/ms
t
EN
Enable Turn-On Delay From Last ENx Rise to Begin of
Soft-Start Ramp
125 240 µs
t
OFF
Enable Turn-Off Delay From ENx Fall to Shutdown 170 330 µs
t
PW
Enable Pulse Width 0.06 55 µs
I
ENX
Enable Leakage Current V
ENX
= 3.6V 0.02 µA
I
MODE
Mode Leakage Current V
MODE
= 3.6V 0.02 µA
V
IL
Input Low Voltage MODE, ENx 0.4 V
V
IH
Input High Voltage MODE, ENx 1.2 V
T
MODEPW
Pulse Width Applied to MODE Pin for
Synchronizing
100 ns
PGOOD Power Good Threshold V
FBX
Ramping Up
V
FBX
Ramping Down
–8
–12
%
%
T
PGOOD
PGOOD Delay Turn-On 8 µs
Turn-Off 2 µs