Datasheet

L4971
4/13
Soft Start
Soft start charge current 30 40 50 µA
Soft start discharge current 6 10 14 µA
Inhibit
V
LL
Low level voltage * 0.9 V
I
sLL
Isource Low level * 5 15 µA
DC Characteristics
Iqop
Total operating quiescent
current
46mA
Iq
Quiescent current Duty Cycle = 0; V
FB
= 3.8V 2.5 3.5 mA
Iqst-by
Total stand-by quiescent
current
V
inh
<0.9V 100 200 µA
Vcc = 55V; Vinh<0.9V 150 300 µA
Error Amplifier
V
FB
Voltage Feedback Input 3.33 3.36 3.39 V
R
L
Line regulation Vcc = 8 to 55V 5 10 mV
Ref. voltage stability vs
temperature
* 0.4 mV/°C
V
oH
High level output voltage V
FB
= 2.5V 10.3 V
V
oL
Low level output voltage V
FB
= 3.8V 0.65 V
Io source
Source output current V
comp
= 6V; V
FB
= 2.5V 200 300 µA
Io sink
Sink output current V
comp
= 6V; V
FB
= 3.8V 200 300 µA
I
b
Source bias current 2 3 µA
SVRR E/A Supply voltage ripple rejection V
comp
= V
fb
; V
cc
= 8 to 55V 60 80 dB
DC open loop gain
R
L
= ∞
50 57 dB
gm Transconductance I
comp
= -0.1 to 0.1mA
V
comp
= 6V
2.5 ms
Oscillator Section
Ramp Valley 0.78 0.85 0.92 V
Ramp peak Vcc = 8V 2 2.15 2.3 V
Vcc = 55V 9 9.6 10.2 V
Maximum duty cycle 95 97 %
Maximum Frequency Duty Cycle = 0% ;
R
osc
= 13kΩ, C
osc
= 820pF
300 kHz
Table 5. (T
j
= 25°C, Cosc = 2.7nF, Rosc = 20kΩ, V
CC
= 24V, unless otherwise specified.)
* Specification Refered to T
j
from 0 to 125°C