L4978 STMicroelectronics, L4978 Datasheet - Page 9

• Manufacturer Part Number: L4978
• Description: IC REG SW 2A STEP DOWN 8-DIP
• Manufacturer: STMicroelectronics
• Type: Step-Down (Buck)r

Specifications of L4978

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3 ~ 50 V
• Current - Output: 2A
• Frequency - Switching: 100kHz ~ 300kHz
• Voltage - Input: 8 ~ 55 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Through Hole
• Package / Case: 8-DIP (0.300", 7.62mm)
• Power - Output: 1W
• Output Voltage: 50 V
• Output Current: 2 A
• Input Voltage: 8 V to 55 V
• Switching Frequency: 90 KHz to 110 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: Through Hole
• Duty Cycle (max): 97 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6701-5; E-L4978; E-L4978; L4978

Figure 24. Load transient.
.
Figure 25. Line transient.
.
Figure 26. Soft start capacitor selection Vs
inductor and V
V
1
2
(µH)
(V)
400
300
200
100
30
20
10
CC
L
0
15 20 25 30 35 40 45 50 V
1ms/DIV
fsw=100KHz
ccmax
.
680nF
I
f
O
sw
= 1A
= 100KHz
D97IN786
220nF
470nF
100nF
330nF
D97IN745
CCmax
(mV)
-100
100
V
0
(V)
O
Figure 27. Soft start capacitor selection Vs
inductor and V
Figure 28. Open loop frequency and phase of
error amplifier .
GAIN
-100
-150
-200
(dB)
-50
(µH)
50
300
200
100
0
L
0
10
15 20 25 30 35 40 45 50 V
10
2
10
ccmax
3
fsw=200KHz
10
.
4
10
5
10
6
Phase
GAIN
10
7
10
D97IN787
22nF
56nF
D97IN746
47nF
33nF
8
CC
f(Hz)
max(V)
Phase
135
45
90
L4978
0
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