LT1082 Datasheet, PDF (3/12 Pages) Linear Technology – 1A High Voltage, Efficiency Switching Voltage Regulator

LT1082
ELECTRICAL CHARACTERISTICS V_IN = 15V, V_C = 0.5V, V_FB = V_REF, output pin open, unless otherwise specified.
SYMBOL
I_Q
f
BV
V_FB
V_SAT
I_LIM
∆I_IN
∆I_SW
DC_MAX
PARAMETER
Supply Current
Control Pin Threshold
Normal/Flyback Threshold
on Feedback Pin
Switching Frequency
Output Switch Breakdown Voltage
Control Voltage to Switch
Current Transconductance
Flyback Reference Voltage
Change in Flyback Reference Voltage
Flyback Reference Voltage Line Regulation
Flyback Amplifier Transconductance (g_m)
Flyback Amplifier Source
and Sink Current
Output Switch “On” Resistance (Note 1)
Switch Current Limit
(LT1082C)
Switch Current Limit
(LT1082I)
Switch Current Limit
(LT1082M)
Supply Current Increase
During Switch-On Time
Maximum Switch Duty Cycle
Flyback Sense Delay Time
Shutdown Mode Supply Current
Shutdown Mode
Threshold Voltage
CONDITIONS
3V ≤ V_IN ≤ V_MAX, V_C = 0.6V
Duty Cycle = 0
q
q
800µA ≥ I_FB ≥ 450µA
3V ≤ V_IN ≤ V_MAX, I_SW = 1.5mA
q
I_FB = 60µA
q
60µA ≤ I_FB ≤ 200µA
I_FB = 60µA, 3V ≤ V_IN ≤ V_MAX
∆I_C = ±10µA
V_C = 0.6V Source
q
I_FB = 60µA Sink
q
I_SW = 0.7A (LT1082C), I_SW = 0.5A (LT1082M) q
Duty Cycle = 20%
q
Duty Cycle ≤ 50%
q
Duty Cycle = 80% (Note 2)
q
Duty Cycle = 20%
q
Duty Cycle ≤ 50%
q
Duty Cycle = 80% (Note 2)
q
Duty Cycle = 20%
q
Duty Cycle ≤ 50%
q
Duty Cycle = 80% (Note 2)
q
3V ≤ V_IN ≤ V_MAX, V_C = 0.05V
3V ≤ V_IN ≤ V_MAX
q
MIN TYP MAX
4.5 7.0
0.7 0.9 1.1
0.5
1.25
0.58 0.67 0.8
50 60 70
45
75
12
100 115
1.5
17 18.6 20.5
16
21.5
3.5 4.6 6.5
0.01 0.03
150 300 500
15 32
70
30 50
90
0.8 1.2
1.07
2.6
1.0
2.6
0.8
2.4
0.85
2.8
0.8
2.8
0.65
2.6
0.75
3.0
0.7
3.0
0.6
2.8
35
45
85 92
97
1.5
120 350
70 150 250
50
300
UNITS
mA
V
V
V
kHz
kHz
kHz
V
A/V
V
V
V
%/V
µmho
µA
µA
Ω
A
A
A
A
A
A
A
A
A
mA /A
%
µs
µA
mV
mV
The q denotes the specifications which apply over the operating
temperature range.
Note 1: Measured with V_C in hi clamp, V_FB = 0.8V.
Note 2: For duty cycles (DC) between 50% and 80%, minimum
guaranteed switch current decreases linearly.
3