Datasheet
5
LT1072
1072fc
Driver Current* vs Switch Current Supply Current vs Input Voltage*
Supply Current vs Supply Voltage
(Shutdown Mode)
Normal/Flyback Mode Threshold
on Feedback Pin Shutdown Mode Supply Current Error Amplifier Transconductance
Shutdown Thresholds
Idle Supply Current vs
Temperature Feedback Pin Clamp Voltage
SWITCH CURRENT (A)
0
*AVERAGE LT1072 POWER SUPPLY CURRENT IS
FOUND BY MULTIPLYING DRIVER CURRENT BY
DUTY CYCLE, THEN ADDING QUIESCENT CURRENT
DRIVER CURRENT (mA)
80
70
60
50
40
30
20
10
0
1.6
LT1072 • TPC10
0.4 0.8 1.2 21.40.2 0.6 1 1.8
*UNDER VERY LOW OUTPUT CURRENT CONDITIONS,
DUTY CYCLE FOR MOST CIRCUITS WILL APPROACH
10% OR LESS
INPUT VOLTAGE (V)
0
5
SUPPLY CURRENT (mA)
7
9
11
10
20
30 40
LT1072 • TPC11
50
13
15
6
8
10
12
14
60
T
J
= 25°C
NOTE THAT THIS CURRENT DOES NOT
INCLUDE DRIVER CURRENT, WHICH IS
A FUNCTION OF LOAD CURRENT AND
DUTY CYCLE.
90% DUTY CYCLE
50% DUTY CYCLE
10% DUTY CYCLE
0% DUTY CYCLE
SUPPLY VOLTAGE (V)
0
SUPPLY CURRENT (µA)
60
80
100
30
50
LT1072 • TPC12
40
20
0
10 20 40
120
140
160
60
T
J
= 25°C
V
C
= 50mV
V
C
= 0V
TEMPERATURE (°C)
–50
400
FEEDBACK PIN VOLTAGE (mV)
FEEDBACK PIN CURRENT (µA)
410
430
440
450
500
470
0
50
75
LT1072 • TPC13
420
480
490
460
–4
–6
–10
–12
–14
–24
–18
–8
–20
–22
–16
–25 25
100
125
150
FEEDBACK PIN VOLTAGE
(AT THRESHOLD)
FEEDBACK PIN CURRENT
(AT THRESHOLD)
V
C
PIN VOLTAGE (mV)
0
SUPPLY CURRENT (µA)
120
160
200
80
LT1072 • TPC14
80
40
100
140
180
60
20
0
2010
4030
60 70 90
50
100
T
J
= 150°C
–55°C ≤ T
J
≤ 125°C
TEMPERATURE (C°)
–75
0
TRANSCONDUCTANCE (µmho)
500
1500
2000
2500
5000
3500
–25
25
50 150
LT1072 • TPC15
1000
4000
4500
3000
–50 0
75
100
125
G
m
=
∆I
∆V
(V
C
PIN)
(FB PIN)
TEMPERATURE (°C)
–75
V
C
PIN VOLTAGE (mV)
V
C
PIN VOLTAGE (µA)
200
250
300
125
LT1072 • TPC16
150
100
0
–25 25 75–50 150050100
50
400
350
–200
–250
–300
–150
–100
0
–50
–400
–350
CURRENT (OUT OF V
C
PIN)
VOLTAGE
V
C
VOLTAGE IS REDUCED UNTIL
REGULATOR CURRENT DROPS
BELOW 300µA
TEMPERATURE (°C)
–75
1
IDLE SUPPLY CURRENT (mA)
2
4
5
6
11
8
–25
25
50 150
LT1072 • TPC17
3
9
10
7
–50 0
75
100
125
V
C
= 0.6V
V
SUPPLY
= 60V
V
SUPPLY
= 3V
FEEDBACK CURRENT (mA)
0
FEEDBACK VOLTAGE (mV)
300
400
500
0.8
LT1072 • TPC18
200
100
250
350
450
150
50
0
0.20.1
0.40.3
0.6 0.7 0.9
0.5
1
–55°C
25°C
150°C
TYPICAL PERFOR A CE CHARACTERISTICS
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