Datasheet

LT3597
3
3597fa
elecTrical characTerisTics
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Operating Voltage
l
6 55 V
Quiescent Current from V
IN
EN/UVLO = 0.4V
BIAS = 5V, Not Switching
BIAS = 0V, Not Switching
2.1
4
2
4
6
µA
mA
mA
Minimum BIAS Voltage 3 3.1 V
Quiescent Current from BIAS EN/UVLO = 0.4V
BIAS = 5V, Not Switching
BIAS = 0V, Not Switching, Current Out of Pin
2
60
2
3
150
µA
mA
µA
EN Threshold (Falling) 0.4 0.7 V
UVLO Threshold (Falling) 1.47 1.51 1.53 V
EN/UVLO Pin Current (Hysteresis) EN/UVLO = 1.6V
EN/UVLO = 1.4V 4
10
5.1 6
nA
µA
FB1-3 Regulation Voltage 1.15 1.22 1.25 V
FB1-3 Pin Bias Current FB = 6V 200 nA
Maximum Duty Cycle R
T
= 220k (200kHz)
R
T
= 33.2k (1MHz)
90
78
95
85
%
%
Switch Saturation Voltage I
SW1-3
= 100mA 265 mV
Switch Current Limit 400 510 700 mA
DA Pin Current to Stop OSC 225 280 350 mA
Switch Leakage V
SW1-3
= 0V 700 nA
BST1-3 Pin Current I
SW1-3
= 100mA 2 mA
Switching Frequency R
T
= 220k
R
T
= 33.2k
170
900
200
1000
230
1100
kHz
kHz
SYNC Input Low 0.4 V
SYNC Input High 1.6 V
SYNC Frequency Range R
T
= 220k
R
T
= 47k
240
1000
kHz
kHz
SYNC Pin Bias Current V
SYNC
= 3.3V 200 nA
Soft-Start Time (Note 4) 2.5 ms
V
REF
Voltage I
VREF
= 0µA
l
1.96 2.0 2.04 V
Maximum V
REF
Current 200 µA
I
SET1-3
Pin Voltage R
ISET1-3
= 20k, V
CTRL
= V
CTRLM
= T
SET
= 1.5V 1.0 V
T
SET
Voltage for LED Current Derating 540 mV
T
SET
Pin Leakage Current V
TSET
= 1.0V 200 nA
I
LED1-3
LED Current R
ISET1-3
= 20k
l
98
97
100
100
102
103
mA
mA
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 24V, BOOST = 29V, BIAS = 5V, EN/UVLO = 5V, PWM1-3 = 3.3V,
CTRL1-3 = CTRLM = T
SET
= 2.0V, V
OUT1-3
= 24V, SYNC = 0V, unless otherwise specified. (Note 2)