Datasheet
24
LTC4221
4221fa
APPLICATIO S I FOR ATIO
WUUU
Figure 16. Recommended Layout for LTC4221 R
SENSE
, Power MOSFETs and Feedback Networks
G
W
•
•
•
•
•
•
•
•
•
•
POWER MOSFET
SO-8
POWER MOSFET
SO-8
NOTE: DRAWING IS NOT TO SCALE
*ADDITIONAL DETAILS OMITTED FOR CLARITY
R
SENSE2
R
SENSE1
TRACK WIDTH W
CURRENT FLOW
TO LOAD
CHANNEL 2
OUTPUT
S
S
S
R
F3
R
F4
VIAS
BOTTOM LAYER
AND GND TRACE
VIAS
GND
TO
LOAD
D
D
D
D
LTC4221*
G
S
S
S
D
D
D
D
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
ON1
V
CC1
SENSE1
GATE1
FB1
PWRGD1
FAULT
FILTER
ON2
V
CC2
SENSE2
GATE2
FB2
PWRGD2
GND
TIMER
R
F2
R
F1
4221 F16
R4
R3
R1C
X1
R2
Z1
R
X1
R
X2
Z2
C
X2
W
CHANNEL 2
INPUT
CHANNEL 1
OUTPUT
CHANNEL 1
INPUT
GND
CURRENT FLOW
TO LOAD
CURRENT FLOW
TO LOAD
CURRENT FLOW
TO LOAD
W
C
TIMER
C
FILTER
APPE DIX
U
Table 1 lists some current sense resistors that can be used
with the circuit breaker. Table 2 lists some power MOSFETs
that are available. Table 3 lists the web sites of several
manufacturers. Since this information is subject to change,
please verify the part numbers with the manufacturer.
Table 1. Sense Resistor Selection Guide
CURRENT LIMIT VALUE PART NUMBER DESCRIPTION MANUFACTURER
1A LRF120601R020F 0.02
Ω
0.5W 1% Resistor
IRC-TT
2.5A WSL25127L000F 0.007
Ω
1W 1% Resistor
Vishay-Dale
3.3A WSL25126L000F 0.006
Ω
1W 1% Resistor
Vishay-Dale
5A WSL25124L000F 0.004
Ω
1W 1% Resistor
Vishay-Dale
10A WSL25122L000F 0.002
Ω
1W 1% Resistor
Vishay-Dale
2A LRF120601R010F 0.01
Ω
0.5W 1% Resistor
IRC-TT