5
LT1070/LT1071
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Supply Current vs Supply Voltage
(Shutdown Mode)Driver Current* vs Switch Current
SWITCH CURRENT (A)
0
DRIVER CURRENT (mA)
160
140
120
100
80
60
40
20
0
4
1070/71 G10
1
*
23 5
T
J
≥ 25°C
AVERAGE LT1070 POWER SUPPLY CURRENT IS
FOUND BY MULTIPLYING DRIVER CURRENT BY
DUTY CYCLE, THEN ADDING QUIESCENT CURRENT
T
J
= –55°C
SUPPLY VOLTAGE (V)
0
SUPPLY CURRENT (µA)
60
80
100
30
50
1070/71 G12
40
20
0
10 20 40
120
140
160
60
T
J
= 25°C
V
C
= 50mV
V
C
= 0V
Supply Current vs Input Voltage*
INPUT VOLTAGE (V)
0
6
INPUT CURRENT (mA)
8
10
12
10
20
30
*
40
1070/71 G11
50
14
UNDER VERY LOW OUTPUT CURRENT
CONDITIONS, DUTY CYCLE FOR MOST
CIRCUITS WILL APPROACH 10% OR LESS
16
7
9
11
13
15
60
T
J
= 25°C
I
SWITCH
≤ 10mA
90% DUTY CYCLE
50% DUTY CYCLE
0% DUTY CYCLE
10% DUTY CYCLE
Feedback Pin Clamp Voltage
Shutdown Thresholds
TEMPERATURE (°C)
–75
V
C
PIN VOLTAGE (mV)
V
C
PIN CURRENT (µA)
300
250
200
150
100
50
0
125
1070/71 G16
–25 25 75–50 1500 50 100
400
350
–300
–250
–200
–150
–100
–50
0
–400
–350
V
C
VOLTAGE IS REDUCED UNTIL
REGULATOR CURRENT DROPS
BELOW 300µA
VOLTAGE
CURRENT
(OUT OF V
C
PIN)
FEEDBACK CURRENT (mA)
0
FEEDBACK VOLTAGE (mV)
300
400
500
0.8
1070/71 G18
200
100
250
350
450
150
50
0
0.2
0.4
0.6
0.1 0.9
0.3
0.5
0.7
1.0
–55°C
25°C
150°C
TEMPERATURE (°C)
–75
IDLE SUPPLY CURRENT (mA)
7
9
11
125
1070/71 G14
5
3
6
8
10
4
2
1
–25
25
75
–50 150
0
50
100
V
C
= 0.6V
V
SUPPLY
= 60V
V
SUPPLY
= 3V
Idle Supply Current
vs Temperature
Normal/Flyback Mode Threshold
on Feedback Pin
TEMPERATURE (°C)
–50
400
FEEDBACK PIN VOLTAGE (mV)
FEEDBACK PIN CURRENT (µA)
410
430
440
450
500
470
0
50
75
1070/71 G13
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)
Error Amplifier Transconductance
TEMPERATURE (°C)
–75
TRANSCONDUCTANCE (µmho)
3000
4000
5000
125
1070/71 G14
2000
1000
2500
3500
4500
1500
500
0
–25
25
75
–50 150
0
50
100
g
m
=
(V
C
PIN)
(FB PIN)
∆I
∆V
Shutdown Mode Supply Current
V
C
PIN VOLTAGE (mV)
0
SUPPLY CURRENT (µA)
120
160
200
80
1070/71 G14
80
40
100
140
180
60
20
0
20
40
60
10 90
30
50
70
100
T
J
= 150°C
–55°C ≤ T
J
≤ 125°C