L4978
Table 6. Electrical Characteristcs
(T
j
= 25°C, C
osc
= 2.7nF, R
osc
= 20kΩ, V
CC
= 24V, unless otherwise specified). “
●
"
Specification Referred
to T
j
from 0 to 125°C
Symbol
V
I
V
o
Parameter
Operating input voltage range
Output voltage
Test Condition
V
o
= 3.3 to 50V; I
o
= 2A
I
o
= 0.5A
●
Min.
8
3.33
3.292
●
Typ.
Max.
55
Unit
V
V
V
V
V
V
A
%
KHz
dB
DYNAMIC CHARACTERISTIC
3.36
3.36
3.36
0.58
●
●
3.39
3.427
3.5
0.733
1.173
3.5
110
I
o
= 0.2 to 2A
V
cc
= 8 to 55V
V
d
Dropout voltage
Maximum limiting current
Efficiency
f
s
SVRR
Switching frequency
Supply voltage ripple rejection
Switching Frequency Stability
vs.
V
cc
Temp. stability of switching
frequency
SOFT START
Soft start charge current
Soft start discharge current
INHIBIT
V
LL
I
sLL
I
qop
I
q
I
qst-by
Low level voltage
Isource Low level
Total operating quiescent
current
Quiescent current
Total stand-by quiescent
current
Duty Cycle = 0; VFB= 3.8V
V
inh
< 0.9V
V
cc
= 55V; V
inh
<0.9V
●
●
3.22
V
cc
= 10V; I
o
= 2A
V
cc
= 8 to 55V
V
o
= 3.3V; I
o
= 2A
●
I
l
2.5
90
60
3
87
100
V
i
= V
cc
+2V
RMS
; V
o
= V
ref
;
I
o
= 2.5A; f
ripple
= 100Hz
V
cc
= 8 to 55V
T
j
= 0 to 125°C
3
4
6
%
%
30
6
40
10
50
14
0.9
µA
µA
V
µA
mA
mA
µA
µA
V
mV
mV/°C
V
5
4
2.5
100
150
3.33
3.36
5
0.4
10.3
15
6
3.5
200
300
3.39
10
DC CHARACTERISTICS
ERROR AMPLIFIER
V
FB
R
L
Voltage Feedback Input
Line regulation
Ref. voltage stability vs
temperature
V
oH
V
oL
I
o source
I
o sink
I
b
SVRR E/A
High level output voltage
Low level output voltage
Source output current
Sink output current
Source bias current
Supply voltage ripple rejection
DC open loop gain
g
m
Transconductance
V
comp
= V
FB
; V
cc
= 8 to 55V
R
L
=
∞
I
comp
= -0.1 to 0.1mA
V
comp
= 6V
60
50
V
FB
= 2.5V
V
FB
= 3.8V
V
comp
= 6V; V
FB
= 2.5V
V
comp
= 6V; V
FB
= 3.8V
180
200
220
300
2
80
57
2.5
3
V
cc
= 8 to 55V
●
0.65
V
µA
µA
µA
dB
dB
mS
4/13
STMICROELECTRONICS [ STMICROELECTRONICS ]
