max5905 Maxim Integrated Products, Inc., max5905 Datasheet - Page 20

• Manufacturer Part Number: max5905
• Description: Low-voltage, Dual Hot-swap Controllers/power Sequencers
• Manufacturer: Maxim Integrated Products, Inc.

MAX5909 close to the card’s connector. Use a ground
plane to minimize impedance and inductance. Minimize
the current-sense resistor trace length (<10mm), and
ensure accurate current sensing with Kelvin connec-
tions (Figure 14).
When the output is short circuited, the voltage drop
across the external MOSFET becomes large. Hence,
the power dissipation across the switch increases, as
does the die temperature. An efficient way to achieve
Low-Voltage, Dual Hot-Swap Controllers/Power
Sequencers
Figure 11. Power Sequencing: Channel 2 Turns On t
20
______________________________________________________________________________________
V
EN
OFF
GND
ON
V
V
1
2
t
0
t
1
V
ON2, TH
T
V
DELAY
ON1, TH
R
1
C
1
DELAY
t
2
ON
GND
After Channel 1
IN1
IN2
good power dissipation on a surface-mount package is
to lay out two copper pads directly under the MOSFET
package on both sides of the board. Connect the two
pads to the ground plane through vias, and use
enlarged copper mounting pads on the top side of the
board. See MAX5908 EV Kit.
R
R
SENSE2
SENSE1
MAX5904
MAX5905
SENSE1
SENSE2
V
V
V
V
EN
ON
1
2
t
DELAY
t
t
1
2
= -R
= -R
GATE1
GATE2
= -R
Q1
Q2
1
1
C
C
1
1
1
C
ln
ln
1
(
(
ln
V
V
(
EN
EN
V
V
EN
EN
- V
- V
V
V
- V
- V
EN
EN
ON1, TH
ON2, TH
ON1, TH
ON2, TH
C
C
BOARD2
BOARD1
)
)
)
> 20µs
OUT2
OUT1