LTC4240IGN#TR Linear Technology, LTC4240IGN#TR Datasheet - Page 23

• Manufacturer Part Number: LTC4240IGN#TR
• Description: IC CTRLR HOT SWAP CPCI 28-SSOP
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC4240IGN#TR

• Applications: CompactPCI™
• Internal Switch(s): No
• Voltage - Supply: 3.3V, 5V, ±12V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP (0.150", 3.95mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
than 2 A, then a 50K resistor can be connected directly
from the 1V bias voltage to the I/O line. However, many ICs
connected to the I/O lines can have leakage currents up to
10 A. For these applications, a 10k resistor is used but
must be disconnected when the board has been seated as
determined by the state of the BD_SEL# signal. Figure 14
shows a precharge circuit that uses a bus switch to
MEDIUM 5V
I/O PIN 128
MEDIUM 5V
I/O PIN 128
BD_SEL#
LONG 5V
GROUND
I/O PIN 1
BD_SEL#
GROUND
LONG 5V
I/O PIN 1
CONNECTOR
BACKPLANE
CompactPCI
CONNECTOR
CompactPCI
BACKPLANE
(MALE)
(MALE)
Figure 14. Precharge Bus Switch Application Circuit for 3.3V and Universal Hot Swap Boards
U
CONNECTOR
CompactPCI
BACKPLANE
U
CONNECTOR
(FEMALE)
CompactPCI
BACKPLANE
(FEMALE)
Figure 13.Precharge Application Circuit for 5V Signaling Systems
2.74
R22
Z4: 1PMT5.0AT3
*ADDITIONAL DETAILS OMITTED FOR CLARITY
2.74
R22
DATA BUS
W
DATA BUS
Z4
Z4
5V
5V
IN
IN
LONG
5V
R17
1.2k
U
5%
1k, 5%
51.1k, 5%
R18
R26
R17
1.2k
5%
R27
28
75k
21
5%
R
R
10
10
5%
I0128
5%
5V
OFF/ON
I01
Q4
MMBT3906
LONG
1k, 5%
IN
R18
GND
5V
connect the individual 10k precharge resistors to the
LTC4240 1V PRECHARGE pin. The electrical connection is
made (bus switches close) when the voltage on the
BD_SEL# pin of the plug-in card is above 4.4V, which
occurs just after the long pins have made contact. The bus
switches are subsequently electrically disconnected when
the board connector makes contact with the BD_SEL# pin
(bus switch OE pin is pulled high by Q4).
18 , 5%
28
21
100
R11
PRECHARGE
R
Z4: 1PMT5.0AT3
*ADDITIONAL DETAILS OMITTED FOR CLARITY
0.1 F
R
10
10
R
5%
I0128
5%
5V
OFF/ON
PRE1
I01
10k
5%
IN
GND
18
10
R
18 , 5%
PRE128
R11
OE
10k
5%
LTC4240*
PRECHARGE
OUT
V
BUS SWITCH
DD
C3, 4.7nF
PRECHARGE OUT
1V 10%
I
R
10k
5%
OUT
18
PRE1
LTC4240*
= 55mA
UP TO 128 I/O LINES
24
OUT
R9
IN
UP TO 128 I/O LINES
R
10k
5%
PRE128
C3, 4.7nF
24
R9
MMBT2222A
PRECHARGE OUT
MMBT2222A
I
DRIVE
OUT
Q3
1V 10%
DRIVE
17
= 55mA
Q3
17
I/O
I/O
12 , 5%
1k, 5%
I/O
I/O
R8
R7
12 , 5%
1k, 5%
LTC4240
R8
R7
BRIDGE
CHIP
PCI
BRIDGE
CHIP
PCI
3V
4240 F13
IN
3V
4240 F14
IN
23
4240f