L4972A
4 Electrical Characteristcs
Table 5. Electrical Characteristcs
Refer to the test circuit, TJ = 25°C, Vi = 35V, R4 = 30KΩ, C9 = 2.7nF, fSW = 100KHz typ, unless otherwise
specified.
Symbol
Parameter
Test Condition
DYNAMIC CHARACTERISTICS
Vi Input Volt. Range (pin 11)
Vo = Vref to 40V Io = 2A (**)
Vo Output Voltage
Vi =15V to 50V Io= 1A;
Vo = Vref
∆Vo Line Regulation
Vi =15V to 50V
Io = 0.5A; Vo= Vref
∆Vo Load Regulation
Vo = Vref Io= 0.5A to 2A
Vd Dropout Voltage between Pin Io = 2A
11 and 20
I20L Max Limiting Current
Vi = 15V to 50V
Vo= Vref to 40V
η Efficiency (*)
Io = 2A, f = 100KHz
Vo = Vref
Vo = 12V
SVR Supply Voltage Ripple Rejection Vi = 2VRMS; Io= 1A
f = 100Hz; Vo= Vref
f Switching Frequency
∆f/∆Vi Voltage Stability of Switching Vi = 15V to 45V
Frequency
∆f/Tj Temperature Stability of
Switching Frequency
Tj = 0 to 125°C
fmax Maximum Operating Switching Vo= Vref R4 = 15KΩ
Frequency
Io = 2A C9= 2.2nF
(*) Only for DIP version (**) Pulse testing with a low duty cycle
Min. Typ. Max. Unit Fig.
15
50
V
8
5
5.1
5.2
V
8
12
30
mV
7
20
mV
0.25 0.4
V
2.5
2.8
3.5
A
75
85
90
56
60
%
%
dB
8
90
100 110 KHz 8
2
6
%
8
1
%
8
200
KHz 8
Vref SECTION (pin 13)
V13 Reference Voltage
∆V13 Line Regulation
∆V13 Load Regulation
∆V13 /∆T Average Temperature
Coefficient Reference Voltage
I13 short Short Circuit Current Limit
VSTART SECTION (pin 15)
V14 Reference Voltage
∆V14 Line Regulation
∆V14 Load Regulation
I14 short Short Circuit Current Limit
DC CHARACTERISTICS
V11on Turn-on Threshold
V11 Hyst Turn-off Hysteresys
I11Q Quiescent Current
I11OQ Operating Supply Current
Vi = 15V to 50V
I13 = 0 to 1mA
Tj = 0°C to 125°C
V13 = 0
Vi = 15 to 50V
I14 = 0 to 1mA
V15 = 0V
V8 = 0; S1 = D
V8 = 0; S1 = B; S2 = B
5
5.1
5.2
V
10
10
25
mV 10
20
40
mV 10
0.4
mV/°C 10
70
mA 10
11.4 12 12.6
V
10
0.6
1.4
V
10
50
200
mV 10
80
mA 10
10
11
12
V
12
1
V
12
13
19
mA 12
16
23
mA 12
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