LTC4244IGN Linear Technology, LTC4244IGN Datasheet - Page 21

• Manufacturer Part Number: LTC4244IGN
• Description: IC CTRLR HOT SWAP CPCI 20-SSOP
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC4244IGN

• Applications: CompactPCI™
• Internal Switch(s): No
• Voltage - Supply: 3.3V, 5V, ±12V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SSOP (0.154", 3.91mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
are experimentally determined based on the board’s para-
sitic resonance circuits. As a starting point, the capacitors
in these networks are chosen to be 10 to 100 the power
MOSFET’s C
determined experimentally that ranges from 1 to 50 ,
depending on the parasitic resonance circuit. Note that in
all LTC4244 circuit schematics, both transient voltage
limiters and snubber networks have been added to the
12V
Snubber networks are not necessary on the 3.3V
IN
and V
Z1
Figure 13. Place Transient Protection Devices
Close to LTC4244’s 12V
Z1, Z2: SMAJ12CA
*ADDITIONAL DETAILS OMITTED FOR CLARITY
0.1 F
EEIN
OSS
10
C4
R13
under bias. The series resistor is a value
supply rails and should always be used.
U
Figure 12. Place Transient Protection Devices Close to LTC4244’s 5V
12V
12V
5V
3V
3.3V
Z3, Z4: SMAJ5.0A
*ADDITIONAL DETAILS OMITTED FOR CLARITY
Z3
5V
U
LTC4244*
IN
IN
1
IN
IN
GND
IN
8
–12V
V
and V
EEIN
IN
3.3V
2
W
EEIN
17
IN
0.005
R1
Pins
R14
10
3.3V
C5
0.1 F
4244 F16
SENSE
16
U
IRF7457
IN
GATE
Z2
Q1
or the
15
R3
10
3.3V
LTC4244*
GND PLANE
OUT
18
GND
VIAS TO
8
5V
5V
ratings are 13.5V. Transient voltage limiters, however, are
recommended as these devices provide large-scale tran-
sient protection for the LTC4244 in the event of abrupt
changes in supply current. All protection networks should
be mounted very close to the LTC4244’s supply pins using
short lead lengths to minimize trace resistance and induc-
tance. This is shown schematically in Figures 12 and 13
and a recommended layout of the transient protection
devices around the LTC4244 is shown in Figure 14.
Figure 14. Recommended Layout for Transient Protection
Components
IN
IN
0.007
13
R13
R2
C4
supply lines since their absolute maximum voltage
Z1
5V
*ADDITIONAL DETAILS OMITTED FOR CLARITY
DRAWING IS NOT TO SCALE!
SENSE
R14
C5
14
IRF7457
Q2
Z3
Z1
12V
R4
10
5V
IN
OUT
3
IN
LTC4244/LTC4244-1
R5
1k
and 3.3V
V
4244 F12
5V
5V
3V
3.3V
EEIN
0.047 F
OUT
OUT
C1
3.3V
Z4
IN
IN
LTC4244*
Pins
5V
GND
IN
21
4244 F14
42441f
Z4