LT3751EUFD#PBF Linear Technology, LT3751EUFD#PBF Datasheet - Page 17

• Manufacturer Part Number: LT3751EUFD#PBF
• Description: IC CAPACITOR CHRG 20-QFN
• Manufacturer: Linear Technology

Specifications of LT3751EUFD#PBF

• Applications: Photoflash Capacitor Charger
• Current - Supply: 5.5mA
• Voltage - Supply: 4.75 V ~ 24 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 20-QFN
• Primary Input Voltage: 24V
• No. Of Outputs: 1
• No. Of Pins: 20
• Operating Temperature Range: -40°C To +125°C
• Msl: MSL 1 - Unlimited
• Supply Voltage Range: 4.75V To 24V
• Termination Type: SMD
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
Table 1. Recommended Transformers
MANUFACTURER
Coilcraft
www.coilcraft.com
Würth Elektronik/Midcom
www.we-online.com
Sumida
www.sumida.com
TDK
www.tdk.com
*Transformer has three secondaries where the ratio is designated as PRI:SEC1:SEC2:SEC3
Table 2. Suggested RV
V
TRANS
4.75 to 55
4.75 to 60
80 to 200
8 to 80
>200
(V)
10.000
1.000
0.100
0.010
0.001
Range
Figure 9. Maximum Switching Frequency
1
PEAK PRIMARY CURRENT (A)
TRANS
PART NUMBER
DA2033-AL
DA2034-AL
GA3459-BL
GA3460-BL
HA4060-AL
HA3994-AL
750032051
750032052
750310349
750310355
C8117
C8119
PS07-299
PS07-300
DCT15EFD-U44S003
DCT20EFD-U32S003
DCT25EFD-U27S005
Resistor Divider Dependent
, RV
ΔV
10
OUT
2mA • RV
DRAIN
2.5 to 50
8 to 160
, and R
5 to 80
0 to 5
(V)
f
f
f
MAX
MAX
MAX
RANGE
OUT
= 50kHz
= 100kHz
= 200kHz
DCM
3751 F09
Values
17.4 × 24.1 × 10.2
20.6 × 30 × 11.3
32.65 × 26.75 × 14
32.65 × 26.75 × 14
34.29 × 26.75 × 14
34.29 × 28.75 × 14
28.7 × 22 × 11.4
28.7 × 22 × 11.4
36.5 × 42 × 23
36.5 × 42 × 23
23 × 18.6 × 10.8
32.2 × 27 × 14
32.5 × 26.5 × 13.5
32.5 × 26.5 × 13.5
22.5 × 16.5 × 8.5
30 × 22 × 12
27.5 × 33 × 15.5
SIZE L × W × H (mm)
100
Use Resistor Divider
V
TRANS
RV
(kΩ)
5.11
25.5
40.2
80.6
0 25
TRANS
RV
RV
both the DCM comparator and V
RV
voltage range, V
ΔV
The RV
source. Pin current increases as the pin voltage is taken
higher than the internal 60V Zener clamp. The LT3751 can
operate from V
clamps by limiting the RV
Operating V
dividers. Two applications are presented that operate
.
MAXIMUM I
–
DRAIN
TRANS
TRANS
TRANS
55
V
TRANS
10
20
50
10
20
50
10
20
50
10
20
5
2
5
5
5
5
, RV
(V
from Table 2 based on the transformer supply
sets the common-mode reference voltage for
PRI
DRAIN
TRANS
OUT
(A)
pin is connected to an internal 40μA current
TRANS
-V
Use Resistor Divider
TRANS
and R
above 200V requires the use of resistor
TRANS
V
TRANS
greater than the 60V internal Zener
RV
, and the maximum trip voltage,
(kΩ)
5.11
25.5
40.2
80.6
0 25
DCM
L
.
OUT
).
PRI
–
300
2.5
7.5
2.5
2.5
55
10
10
10
10
10
10
10
10
5
5
5
5
TRANS
(μH)
Selection
V
OUT
pin current to 250μA.
comparator. Select
TURNS RATIO (PRI:SEC)
Use Resistor Divider
0.86 • RV
LT3751
2:1:3:3*
R
(kΩ)
2.32
11.5
18.2
36.5
DCM
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:10
1:3
TRANS
17
3751fb