LT1103 Datasheet, PDF (4/32 Pages) Linear Technology – Offline Switching Regulator

LT1103/LT1105
ELECTRICAL CHARACTERISTICS
V_IN = 20V, V_C = 0.85V, OVLO = 0V, V_SW Open, T_A = 25°C, unless otherwise noted.
SYMBOL PARAMETER
CONDITONS
DC
Preset Max Switch Duty Cycle
FB = 4V, V_C = Open, f_OSC = 40kHz, I_SW = 25mA,
q
(LT1103)
Note: Maximum Duty Cycle Can Be Altered at OSC Pin
Preset Max Switch Duty Cycle
FB = 4V, V_C = Open, f_OSC = 40kHz, I_SW = 25mA,
q
(LT1105)
Note: Maximum Duty Cycle Can Be Altered at OSC Pin
Industrial Grade
q
OVLO Threshold
Overvoltage Lockout Threshold at Which Switching is Inhibited q
Industrial Grade
q
OVLO Input Bias Current
OVLO = 2V, Measured Out of Pin (Note 2)
q
V_FB
FB Threshold Voltage
I(V_C) = 0mA
q
FB Input Bias Current
FB = V_FB (Note 3)
q
Industrial Grade
q
Change in FB Input
FB = V_FB, V_C = 1V to 4V (Note 3)
Bias Current with Change in V_C
q
Industrial Grade
q
FB Threshold Line Regulation
10V < V_IN < 30V
q
gm
Error Amp Transconductance
∆I(V_C) = ±50µA
q
Industrial Grade
q
A_V
Error Amp Voltage Gain
1V < V_C < 3V
q
Industrial Grade
q
V_C Switching Threshold
Switch Duty Cycle = 0%
q
Shutdown Threshold Voltage
q
Industrial Grade
q
Error Amp Source Current
q
Error Amp Sink Current
q
Industrial Grade
q
Error Amp Clamp Voltage
FB = 4.75V
q
FB = 4.0V
q
Soft-Start Charging Current
SS = 0V
q
Industrial Grade
q
Soft-Start Reset Current
V_IN = 6V, SS = 0.3V
q
Output Switch Leakage
V_SW = 45V
q
(LT1103)
V_SW = 15V
q
BV
Switch Breakdown Voltage
I_SW = 5mA
q
(LT1103)
V_SW Current Limit (LT1103)
Duty Cycle = 25% (Note 4)
q
Output Switch On Resistance
q
(LT1103)
∆I_IN
I_Q Increase During Switch On Time I_SW = 0.5A to 1.5A
q
∆I_SW
(LT1103)
Switch Output High Level
I_SW = 200mA, V_GATE = 15V
q
(LT1105)
I_SW = 750mA, V_GATE = 15V
q
Switch Output High Level
I_SW = 200mA, V_GATE = 15V
q
Industrial Grade
I_SW = 750mA, V_GATE = 15V
q
MIN TYP MAX
58 65 72
56 63 70
55
75
2.3 2.5 2.7
2.2
2.8
1.0 3.0
4.425 4.50 4.575
4.400 4.50 4.600
5 10 20
4
22
8 11 13
7 11 14
6
15
0.025 0.10
9000 12000 17500
6000 12000 20000
5000
24000
500 1250
450
0.85 1.25 1.4
50 150 250
50
300
150 275
1.5 3 4.5
0.7
4.5
0.3 0.7 0.9
4.2 4.4 4.6
25 40 60
20
75
12
500
200
50 70
2.0 2.5 3.0
0.4 0.75
30 50
13.00 13.5
12.50 13.2
12.75
12.25
UNIT
%
%
%
V
V
µA
V
V
µA
µA
µA / V
µA / V
µA / V
%/ V
µmho
µmho
µmho
V/ V
V/ V
V
mV
mV
µA
mA
mA
V
V
µA
µA
mA
µA
µA
V
A
Ω
mA/A
V
V
V
V
4