L4973 STMicroelectronics, L4973 Datasheet - Page 5

• Manufacturer Part Number: L4973
• Description: 3.5A STEP DOWN SWITCHING REGULATOR
• Manufacturer: STMicroelectronics

ELECTRICAL CHARACTERISTICS (continued)
OSCILLATOR SECTION
SYNC FUNCTION
(*) Pulse testing with a low duty cycle.
(**) The maximum power dissipation of the package must be observed.
Figure 1. Evaluation Board Circuit
V
CC
C1=1000 F/63V
C2=220nF/63V
C3=470nF
C4=1 F/50V
C5=220pF
C6=22nF
C7=2.7nF
C8=220nF/63V
C0=100 F/40V(C9,C10,C11)
C12=Optional (220nF)
L1=150 H K
R1=9.1K
R2=20K
D1=GI SB560
Sink Output Current
Supply Voltage Ripple
Rejection
DC Open Loop Gain
Transconductance
Ramp valley
Ramp peak
Maximum Duty Cycle
Maximum Frequency
High Input Voltage
Low Input Voltage
Slave Sink Current
Master Output Amplitude
Output Pulse Width
C1
R2
C2
OOL
77310 - 40 Turns - 0.9mm
C7
C3
C4
C5
V
C
current
R
I
V
V
V
Duty Cycle = 0%; R
13K ; C
V
V
I
no load, V
comp
source
COMP
comp
CC
CC
CC
CC
REF
L
1
17
16
7,8
=
11
= 8V
= 55V
= 8V to 55V
= 8V to 55V
= -0.1 to 0.1mA;
=4.7 F 1-5mA load
= 6V
= 3mA
= VFB
R1
C6
10
OSC
L4973
V
sync
3.3
5.1
(DIP18)
O
12
15
18
24
(V)
13,14,15
= 820pF;
= 4.5V
4,5,6
D97IN515B
L4973 V3.3
R3(K )
OSC
2.7
12
16
20
30
0
L4973V3 - L4973V5 - L4973D3 - L4973D5
2,3
12
9
=
R4(K )
4.7
4.7
4.7
4.7
4.7
C8
D1
L1
3 x
0.78
0.15
0.20
C0
200
1.9
3.5
60
50
95
9
4
V
O
5.1
12
15
18
24
(V)
L4973 V5.1
0.85
0.25
0.35
300
2.5
2.1
9.6
4.5
80
60
97
C12
R3(K )
6.2
9.1
12
18
0
0.92
10.2
0.45
500
2.3
0.9
R4(K )
V
R3
R4
O
4.7
4.7
4.7
4.7
KHz
mS
mA
dB
dB
%
V
V
V
V
V
V
A
s
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