LTC1646CGN Linear Technology, LTC1646CGN Datasheet - Page 9

• Manufacturer Part Number: LTC1646CGN
• Description: IC CNTRLR HOTSWAP PCIDUAL 16SSOP
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC1646CGN

• Applications: CompactPCI™
• Internal Switch(s): No
• Voltage - Supply: 3.3V, 5V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

BLOCK DIAGRA
APPLICATIO S I FOR ATIO
Hot Circuit Insertion
When a circuit board is inserted into a live CompactPCI
(CPCI) slot, the supply bypass capacitors on the board can
draw huge supply transient currents from the CPCI power
bus as they charge up. The transient currents can cause
glitches on the power bus, causing other boards in the
system to reset.
The LTC1646 is designed to turn a board’s supply voltages
on and off in a controlled manner, allowing the board to be
safely inserted or removed from a live CPCI slot without
glitching the system power supplies. The chip also pro-
tects the supplies from shorts, precharges the bus I/O pins
during insertion and extraction and monitors the supply
voltages.
RESETIN 16
PWRGD 4
OFF/ON 15
TIMER 2
FAULT 3
5V
Q7
Q6
5V
2.5V
UVL
Q5
12
in
IN
5µA
150mV
55mV
+–
+–
5V
SENSE
11
+–
+
–
U
5V
+
–
OUT
W
U
W
GATE
Q1
10
V
GG
U
13µA
GND
LOGIC
200µA
6
The LTC1646 is specifically designed for CPCI applica-
tions where the chip resides on the plug-in board.
LTC1646 Feature Summary
1. Allows safe board insertion and removal from a CPCI
2. Controls 5V and 3.3V CPCI supplies.
3. Current limit during power-up: the supplies are allowed
backplane.
to power up in current limit. This allows the chip to
power up boards with widely varying capacitive loads
without tripping the circuit breaker. The maximum
allowable power-up time is programmable using the
TIMER pin and an external capacitor.
3V
+
–
OUT
–
+
+
–
3V
SENSE
9
150mV
2.5V
55mV
UVL
–
–
+
+
3V
8
IN
C
C
P3
P4
DRIVE
14
+
+
–
–
Q2
REF
REF
3V
7
OUT
LTC1646
PRECHARGE
5V
+
–
OUT
5
13
1V
Q3
Q4
1
1646 BD
RESETOUT
1646fa
9