Datasheet

LT1941
3
1941fb
The l denotes the specifi cations which apply over the full operating temperature
range, otherwise specifi cations are at T
A
= 25°C. V
IN
, V
BIAS1
, V
BIAS2
= 5V, V
BOOST1
, V
BOOST2
= 8V, unless otherwise noted. (Note 2)
ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
Switching Phase SW1 to SW2
SW1 to SW3
150
–30
180
0
210
30
Deg
Deg
Foldback Frequency V
FB
= 0V 200 kHz
RUN/SS Current 123 μA
RUN/SS Threshold 0.4 0.6 V
5GOOD Threshold V
IN
Rising 4.5 V
5GOOD Voltage Output Low I
5GOOD
= 125μA, V
IN
= 4V 0.2 0.4 V
5GOOD Leakage V
5GOOD
= 2V 10 400 nA
12GOOD Threshold V
IN
Rising 10.8 V
12GOOD Voltage Output Low I
12GOOD
= 125μA 0.2 0.4 V
12GOOD Leakage V
12GOOD
= 2V, V
IN
= 12V 10 400 nA
PGOOD Voltage Output Low I
PGOOD
= 200μA 0.2 0.4 V
PGOOD Pin Leakage V
PGOOD
= 2V 10 400 nA
3A Step-Down
FB1 Voltage
l
618
613
628 638
638
mV
mV
FB1 Pin Bias Current
l
50 500 nA
PGOOD1 Threshold Offset V
FB
Rising 54 mV
Frequency Shift Threshold on FB1 0.35 V
Error Amplifi er Transconductance 1700 μMhos
Error Amplifi er Voltage Gain 500 V/V
V
C
Switching Threshold 0.9 V
V
C1
to Switch Current Gain 5A/V
Switch 1 Current Limit (Note 3) V
IN
= 12V, V
BOOST1
, V
BOOST2
= 15V
l
3 4.3 6 A
Switch 1 V
CESAT
(Note 7) I
SW
= 2.5A 400 600 mV
BOOST1 Pin Current I
SW
= 2.5A 40 60 mA
Switch 1 Leakage Current 0.01 10 μA
Minimum Boost Voltage Above Switch (Note 4) 1.8 2.5 V
Maximum Duty Cycle
l
78 88 %
2A Step-Down
FB2 Voltage
l
618
613
628 638
638
mV
mV
FB2 Pin Bias Current
l
50 500 nA
PGOOD2 Threshold Offset V
FB
Rising 54 mV
Frequency Shift Threshold on FB2 0.35 V
Error Amplifi er Transconductance 1700 μMhos
Error Amplifi er Voltage Gain 500 V/V
V
C
Switching Threshold 0.9 V
V
C2
to Switch Current Gain 3.6 A/V
Switch 2 Current Limit (Note 3) V
IN
= 12V, V
BOOST1
, V
BOOST2
= 15V
l
2 2.9 4.1 A
Switch 2 V
CESAT
(Note 7) I
SW
= 1.5A 450 600 mV
BOOST2 Pin Current I
SW
= 1.5A 26 40 mA