LT1737_15 Datasheet, PDF (3/28 Pages) Linear Technology – High Power Isolated Flyback Controller

LT1737
ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = 14V, GATE open, V_C = 1.4V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
Current Amplifier
V_C
Control Pin Threshold
Duty Cycle = Min
0.90
1.12
1.25
● 0.80
1.35
V_ISENSE
Switch Current Limit
Duty Cycle ≤ 30%
Duty Cycle ≤ 30%
Duty Cycle = 80%
220
250
270
● 200
280
220
∆V_ISENSE/∆V_C
0.30
Timing
f
Switching Frequency
C_OSCAP = 100pF
90
● 80
100
115
125
C_OSCAP
t_ON
t_ED
t_EN
R_t
Oscillator Capacitor Value
Minimum Switch On Time
Flyback Enable Delay Time
Minimum Flyback Enable Time
Timing Resistor Value
Maximum Switch Duty Cycle
(Note 2)
R_tON = 50k
R_ENDLY = 50k
R_MENAB = 50k
(Note 2)
33
24
● 85
200
200
200
200
240
90
Load Compensation
Sense Offset Voltage
2
5
Current Gain Factor
0.80
0.95
1.05
UVLO Function
V_UVLO
UVLO Pin Lockout Threshold
UVLO Pin Shutdown Threshold
● 1.21
1.25
1.29
● 0.4
0.75
0.95
I_UVLO
UVLO Pin Bias Current
3V Output Function
V_UVLO = 1.2V
V_UVLO = 1.3V
– 0.25
+ 0.1
+ 0.25
– 4.50
– 3.5
– 2.50
V_REF
Reference Output Voltage
Output Impedance
I_LOAD = 1mA
● 2.8
3.0
3.2
10
Current Limit
●8
15
Note 1: Absolute Maximum Ratings are those values beyond which the life of
a device may be impaired.
Note 2: Component value range guaranteed by design.
UNITS
V
V
mV
mV
mV
mV
kHz
kHz
pF
ns
ns
ns
kΩ
%
mV
mV
V
V
V
µA
µA
V
Ω
mA
1737fa
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