Datasheet
LT3970 Series
3
3970fc
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, V
BD
= 3.3V unless otherwise noted. (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage
l
4 4.2 V
Quiescent Current from V
IN
V
EN
Low
V
EN
High
V
EN
High, –40°C to 125°C
V
EN
High, –40°C to 150°C
l
l
0.7
1.7
1.2
2.7
3.5
4
µA
µA
µA
µA
LT3970 Feedback V
oltage
–40°C to 125°C
–40°C to 150°C
l
l
1.195
1.185
1.18
1.21
1.21
1.21
1.225
1.235
1.235
V
V
V
LT3970-3.3 Output V
oltage
–40°C to 125°C
–40°C to 150°C
l
l
3.26
3.234
3.217
3.3
3.3
3.3
3.34
3.366
3.366
V
V
V
LT3970-3.42 Output V
oltage
–40°C to 125°C
l
3.379
3.352
3.42
3.42
3.461
3.488
V
V
LT3970-5 Output V
oltage
–40°C to 125°C
–40°C to 150°C
l
l
4.94
4.9
4.875
5
5
5
5.06
5.1
5.1
V
V
V
LT3970 FB Pin Bias Current (Note 3) V
FB
= 1.21V
l
0.1 20 nA
FB/Output Voltage Line Regulation 4.2V < V
IN
< 40V 0.0002 0.01 %/V
Switching Frequency R
T
= 41.2k, V
IN
= 6V
R
T
= 158k, V
IN
= 6V
R
T
= 768k, V
IN
= 6V
1.76
640
160
2.25
800
200
2.64
960
240
MHz
kHz
kHz
Switch Current Limit V
IN
= 5V, V
FB
= 0V 535 700 865 mA
Catch Schottky Current Limit V
IN
= 5V 350 400 500 mA
Switch V
CESAT
I
SW
= 200mA 175 mV
Switch Leakage Current 0.05 2 µA
Catch Schottky Forward Voltage I
SCH
= 100mA, V
IN
= V
BD
= NC 650 mV
Catch Schottky Reverse Leakage V
SW
= 12V 0.05 2 µA
Boost Schottky Forward Voltage I
SCH
= 50mA, V
IN
= NC, V
BOOST
= 0V 875 mV
Boost Schottky Reverse Leakage V
REVERSE
= 12V 0.02 2 µA
Minimum Boost Voltage (Note 4) V
IN
= 5V
l
1.4 1.8 V
BOOST Pin Current I
SW
= 200mA, V
BOOST
= 15V 7 10 mA
EN Pin Current V
EN
= 12V 1 30 nA
LT3970 EN Voltage Threshold EN Rising, V
IN
≥ 4.2V
l
0.94 1 1.06 V
LT3970-X EN Voltage Threshold EN Rising, V
IN
≥ 4.2V
l
0.93 1 1.07 V
EN Voltage Hysteresis 30 mV
LT3970 PG Threshold Offset from Feedback Voltage V
FB
Rising 80 120 160 mV
LT3970 PG Hysteresis 12 mV
LT3970-X PG Threshold Offset from Output Voltage V
FB
Rising 6.5 10 13.5 %
LT3970-X PG Hysteresis as % of Output Voltage 1.0 %
PG Leakage V
PG
= 3V 0.01 1 µA
PG Sink Current V
PG
= 0.4V
l
30 80 µA
Minimum Switch On-Time 90 ns
Minimum Switch Off-Time V
IN
= 10V
l
100 160 ns