LT1
170/LT1
171/LT1172
The
q
denotes the specifications which apply over the full operating tem-
perature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
C
= 0.5V, V
FB
= V
REF
, output pin open, unless otherwise noted.
SYMBOL PARAMETER
V
REF
I
B
g
m
Reference Voltage
Feedback Input Current
Error Amplifier
Transconductance
Error Amplifier Source or
Sink Current
Error Amplifier Clamp
Voltage
Reference Voltage Line
Regulation
A
V
I
Q
Error Amplifier Voltage Gain
Minimum Input Voltage (Note 5)
Supply Current
Control Pin Threshold
Normal/Flyback Threshold
on Feedback Pin
V
FB
Flyback Reference Voltage
(Note 5)
Change in Flyback Reference
Voltage
Flyback Reference Voltage
Line Regulation (Note 5)
Flyback Amplifier
Transconductance (g
m
)
Flyback Amplifier Source
and Sink Current
BV
Output Switch Breakdown
Voltage
Output Switch
“On” Resistance (Note 3)
Control Voltage to Switch
Current Transconductance
I
LIM
Switch Current Limit
(LT1170)
I
FB
= 50µA
q
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
q
q
TYP
1.244
1.244
350
MAX
1.264
1.274
750
1100
6000
7000
350
400
2.30
0.52
0.03
UNITS
V
V
nA
nA
µmho
µmho
µA
µA
V
V
%/V
V/V
Measured at Feedback Pin
V
C
= 0.8V
V
FB
= V
REF
∆I
C
=
±25µA
1.224
1.214
q
3000
2400
150
120
1.80
0.25
4400
200
V
C
= 1.5V
q
Hi Clamp, V
FB
= 1V
Lo Clamp, V
FB
= 1.5V
3V
≤
V
IN
≤
V
MAX
V
C
= 0.8V
0.9V
≤
V
C
≤
1.4V
q
q
0.38
500
800
2.6
6
3.0
9
1.08
1.25
0.54
17.6
18.0
9
0.03
650
70
70
V
mA
V
V
V
V
V
V
%/V
µmho
µA
µA
V
V
V
3V
≤
V
IN
≤
V
MAX
, V
C
= 0.6V
Duty Cycle = 0
q
0.8
0.6
0.4
15.0
14.0
4.5
0.9
0.45
16.3
6.8
0.01
0.05
≤
I
FB
≤
1mA
I
FB
= 50µA
7V
≤
V
IN
≤
V
MAX
∆I
C
=
±10µA
V
C
= 0.6V
I
FB
= 50µA
3V
≤
V
IN
≤
V
MAX
,
I
SW
= 1.5mA
LT1170
LT1171
LT1172
LT1170
LT1171
LT1172
Duty Cycle = 50%
Duty Cycle = 50%
Duty Cycle = 80% (Note 4)
Duty Cycle = 50%
Duty Cycle = 50%
Duty Cycle = 80% (Note 4)
Duty Cycle = 50%
Duty Cycle = 50%
Duty Cycle = 80% (Note 4)
T
J
≥
25°C
T
J
<
25°C
T
J
≥
25°C
T
J
<
25°C
T
J
≥
25°C
T
J
<
25°C
q
q
q
q
q
q
q
q
q
150
Source
Sink
LT1170/LT1171/LT1172
LT1170HV/LT1171HV/LT1172HV
LT1172S8
q
q
q
q
q
q
q
q
300
32
40
90
90
80
0.15
0.30
0.60
8
4
2
15
25
65
75
60
V
SAT
0.24
0.50
1.00
Ω
Ω
Ω
A/V
A/V
A/V
5
5
4
2.5
2.5
2.0
1.25
1.25
1.00
10
11
10
5.0
5.5
5.0
3.0
3.5
2.5
A
A
A
A
A
A
A
A
A
(LT1171)
(LT1172)
3
LINER [ LINEAR TECHNOLOGY ]
