Datasheet

L4973 Electrical characteristics
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Soft-start
Soft-start charge current 30 45 60 μA
Soft-start discharge
current
15 22 30 μA
Inhibit
High level voltage
(2)
3.0 V
Low level voltage
(2)
0.8 V
I
source
high level V
INH
= 3 V
(2)
10 16 50 μA
I
source
low level V
INH
= 0.8 V
(2)
10 15 50 μA
DC characteristics
Total operating
quiescent current
Duty cycle = 50 % 4 6 mA
Quiescent current Duty cycle = 0 2.7 4 mA
Total stand-by quiescent
current
V
CC
= 24 V; V
INH
= 5 V 100 200 μA
V
CC
= 55 V; V
INH
= 5 V 150 300 μA
Error amplifier
High level output voltage 11.0 V
Low level output voltage 0.65 V
Source bias current 1 2 3 μA
Source output current 200 300 600 μA
Sink output current 200 300 μA
Supply voltage ripple
rejection
V
COMP
= VFB
C
REF
= 4.7 μF 1-5 mA load
current
60 80 dB
DC open loop gain R
L
= ∞ 50 60 dB
Transconductance
I
comp
= -0.1 to 0.1 mA;
V
comp
= 6 V
2.5 mS
Oscillator section
Ramp valley 0.78 0.85 0.92 V
Ramp peak
V
CC
= 8 V
V
CC
= 55 V
1.9
9
2.1
9.6
2.3
10.2
V
V
Maximum duty cycle 95 97 %
Table 4. Electrical characteristics (continued)
(Refer to the test circuit,V
CC
= 24 V; T
J
= 25 °C, C
OSC
= 2.7 nF;
R
OSC
= 20 kΩ; unless otherwise specified)
Symbol Parameter Test condition Min Typ Max Unit