LTC1647 LINER [Linear Technology], LTC1647 Datasheet - Page 25

• Manufacturer Part Number: LTC1647
• Description: Hot Swap Controller
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
A more elaborate connection sense scheme is shown in
Figure 16. The bases of Q1 and Q2 are wired to short pins
located on opposite ends of the edge connector because
the installation/removal of printed circuit cards gener-
ally requires rocking the card back and forth. When V
makes connection, the bases of transistors Q1 and Q2
are pulled high, biasing them ON. When either one of
them is ON, the LTC4211’s ON pin is held low, keeping
the LTC4211 OFF. When both the short base connector
V
5V
IN
Z1 = 1SMA10A OR SMAJ10A
* OPTIONAL
RESET
V
5V
CC
Z1*
CONNECTION
CONNECTOR
BACKPLANE
(FEMALE)
R
10Ω
Figure 13. Hot Swap Controller On Daughter Board (Staggered Pin Connections)
X
C
0.1μF
SENSE
X
Figure 14. Hot Swap Controller on Backplane (Staggered Pin Connections)
PCB
CONNECTOR
PCB EDGE
(MALE)
R5
10k
Q2
R4
10k
LONG
SHORT
SHORT
LONG
Z1 = 1SMA10A OR SMAJ10A
* OPTIONAL
2
4
V
5V
ON
GND
IN
V
10k
R2
CC
Z1*
LTC4211
8
0.007Ω
R
TIMER
SENSE
3
RESET
SENSE
R1
10Ω
GATE
C
10nF
C1
0.1μF
TIMER
FB
7
CC
Si4410DY
6
1
5
R6
10k
1
2
4
Q1
R7
15k
RESET
ON
GND
pins of Q1 and Q2 finally mate to the backplane, their
bases are grounded, biasing the transistors OFF. The
ON pin voltage is then pulled high by R3 enabling the
LTC4211 and a power-up cycle begins.
A software-initiated power-down cycle can be started by
momentarily driving transistor M1 with a logic high signal.
This in turn will drive the LTC4211’s ON pin low. If the ON
pin is held low for more than 8μs, the LTC4211’s GATE
pin is switched to ground.
LTC4211
TIMER
R3
10k
3
SENSE
GATE
C
10nF
CONNECTOR
BACKPLANE
V
TIMER
(FEMALE)
FB
CC
8
7
6
5
R
0.007Ω
SENSE
CONNECTOR
PCB EDGE
(MALE)
Si4410DY
LONG
LONG
SHORT
SHORT
SHORT
Q1
+
R2
100k
C
RESET
R4
36k
R5
15k
OUT
4211 F14
+
4211 F13
LTC4211
C
R1
36k
V
5V
5A
OUT
OUT
V
5V
5A
OUT
25
4211fb