LT1172CQ Linear Technology, LT1172CQ Datasheet - Page 4

• Manufacturer Part Number: LT1172CQ
• Description: IC SWTCHNG REGULATOR HI-EFF 5-DD
• Manufacturer: Linear Technology
• Type: Step-Down (Buck), Step-Up (Boost), Inverting, Cuk, Flyback, Forward Converterr

Specifications of LT1172CQ

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1.25 ~ 40 V
• Current - Output: 1.25A
• Frequency - Switching: 100kHz
• Voltage - Input: 3 ~ 40 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: D²Pak, TO-263 (5 leads + tab)
• Power - Output: 100W
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

ELECTRICAL CHARACTERISTICS
LT1170/LT1171/LT1172
SYMBOL PARAMETER
V
I
g
A
I
V
BV
V
I
ΔI
f
temperature range, otherwise specifications are at T
4
B
Q
LIM
ΔI
m
V
REF
FB
SAT
SW
IN
Reference Voltage
Feedback Input Current
Error Amplifier Transconductance
Error Amplifier Source or Sink Current
Error Amplifier Clamp Voltage
Reference Voltage Line Regulation
Error Amplifier Voltage Gain
Minimum Input Voltage (Note 5)
Supply Current
Control Pin Threshold
Normal/Flyback Threshold on Feedback Pin
Flyback Reference Voltage (Note 5)
Change in Flyback Reference Voltage
Flyback Reference Voltage Line Regulation
(Note 5)
Flyback Amplifier Transconductance (g
Flyback Amplifier Source and Sink Current
Output Switch Breakdown Voltage
Output Switch “On” Resistance (Note 3)
Control Voltage to Switch Current
Transconductance
Switch Current Limit (LT1170)
Supply Current Increase During Switch
On-Time
Switching Frequency
(LT1171)
(LT1172)
m
)
CONDITIONS
Measured at Feedback Pin
V
V
ΔI
V
Hi Clamp, V
Lo Clamp, V
3V ≤ V
V
0.9V ≤ V
3V ≤ V
Duty Cycle = 0
I
0.05 ≤ I
I
7V ≤ V
ΔI
V
I
3V ≤ V
I
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)
FB
FB
FB
SW
C
FB
C
C
C
C
C
= 0.8V
= 1.5V
= 0.8V
= 0.6V
A
= 50μA
= 50μA
= 50μA
= ±25μA
= ±10μA
= V
= 1.5mA
= 25°C. V
IN
IN
IN
IN
REF
FB
C
≤ V
≤ V
≤ V
≤ V
≤ 1.4V
≤ 1mA
The
FB
FB
MAX
MAX
MAX
MAX
= 1V
= 1.5V
l
IN
, V
,
denotes the specifications which apply over the full operating
= 15V, V
C
= 0.6V
Source
Sink
LT1170/LT1171/LT1172
LT1170HV/LT1171HV/LT1172HV
LT1172S8
C
= 0.5V, V
T
T
T
T
T
T
J
J
J
J
J
J
≥ 25°C
< 25°C
≥ 25°C
< 25°C
≥ 25°C
< 25°C
FB
= V
REF
, output pin open, unless otherwise noted.
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
1.224
1.214
3000
2400
1.80
0.25
15.0
14.0
1.25
1.25
1.00
MIN
150
120
500
150
0.8
0.6
0.4
4.5
2.5
2.5
2.0
15
25
65
75
60
88
85
5
5
4
1.244
1.244
4400
0.38
0.45
16.3
0.01
0.15
0.30
0.60
TYP
350
200
800
300
100
2.6
0.9
6.8
32
40
90
90
80
25
6
8
4
2
1.264
1.274
1100
6000
7000
MAX
2.30
0.52
0.03
1.08
1.25
0.54
17.6
18.0
0.03
0.24
0.50
1.00
750
350
400
112
115
650
3.0
5.0
5.5
5.0
3.0
3.5
2.5
70
70
10
11
10
35
9
9
117012fg
UNITS
μmho
μmho
μmho
mA/A
%/V
%/V
A/V
A/V
A/V
kHz
kHz
V/V
mA
mA
mA
nA
nA
μA
μA
Ω
Ω
Ω
V
V
V
V
V
V
V
V
V
V
V
V
V
V
A
A
A
A
A
A
A
A
A