LTC3801 LINER [Linear Technology], LTC3801 Datasheet - Page 11

• Manufacturer Part Number: LTC3801
• Description: Micropower Constant Frequency Step-Down DC/DC Controllers in ThinSOT
• Manufacturer: LINER [Linear Technology]

PACKAGE DESCRIPTIO
APPLICATIO S I FOR ATIO
Foldback Current Limiting
As described in the Output Diode Selection, the worst-
case dissipation occurs with a short-circuited output
when the diode conducts the current limit value almost
continuously. To prevent excessive heating in the diode,
foldback current limiting can be added to reduce the
current in proportion to the severity of the fault.
Foldback current limiting is implemented by adding di-
odes D
pin as shown in Figure 5. In a hard short (V
current will be reduced to approximately 50% of the
maximum output current.
3.85 MAX
FB1
0.20 BSC
and D
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
2.62 REF
DATUM ‘A’
RECOMMENDED SOLDER PAD LAYOUT
FB2
U
0.62
MAX
between the output and the I
PER IPC CALCULATOR
U
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
0.30 – 0.50 REF
0.95
REF
W
U
1.22 REF
1.4 MIN
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
OUT
(Reference LTC DWG # 05-08-1636)
U
= 0V), the
6-Lead Plastic TSOT-23
TH
0.09 – 0.20
(NOTE 3)
/RUN
2.80 BSC
S6 Package
1.00 MAX
1.50 – 1.75
(NOTE 4)
0.80 – 0.90
0.95 BSC
Figure 5. Foldback Current Limiting
PIN ONE ID
I
TH
LTC3801B
LTC3801/
/RUN
2.90 BSC
LTC3801/LTC3801B
(NOTE 4)
1.90 BSC
V
FB
R2
R1
+
S6 TSOT-23 0302
0.01 – 0.10
0.30 – 0.45
6 PLCS (NOTE 3)
3801 F05
D
D
FB1
FB2
V
OUT
11
3801f