LTC4211IS8 Linear Technology, LTC4211IS8 Datasheet - Page 14

• Manufacturer Part Number: LTC4211IS8
• Description: IC CTRLR HOTSWAP CURR CTRL 8SOIC
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC4211IS8

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 2.5 V ~ 16.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

OPERATIO
LTC4211
Table 1. t
14
TIMER
0.0033µF
0.0047µF
0.0068µF
0.0082µF
TIMER
RESET
0.015µF
0.022µF
0.033µF
0.047µF
0.068µF
0.082µF
C
0.01µF
0.15µF
0.22µF
0.33µF
GATE
V
0.1µF
V
TIMER
OUT
ON
CC
vs C
TIMER
1 2
U
CHECK FOR GATE < 0.2V
FIRST TIMING CYCLE
PLUG-IN CYCLE
V
TMR
2µA
= V
REF
3 4 5
CHECK FOR FILTER LOW (<V
CHECK FOR FAULT HIGH (>V
FAST COMPARATOR ARMED
10µA
SECOND TIMING CYCLE
SOFT-START CYCLE
13.6ms
20.4ms
29.0ms
42.0ms
50.7ms
61.8ms
92.7ms
136ms
204ms
t
2.0ms
2.9ms
4.2ms
5.1ms
6.2ms
9.3ms
TIMER
Figure 5. Normal Power-Up Sequence
6
2µA
POWER
GOOD
(V
FB
> V
REF
)
REF
REF
SLOW COMPARATOR ARMED
7 8
+ 50mV)
– 80mV)
The C
reliable operation. A system may not get started if a timing
period is set too short in relation to the time needed for the
output voltage to ramp up from zero to its rated value.
Conversely, this timing period should not be excessive as
an output short can occur at start-up allowing the external
MOSFET to overheat. A good starting point is to set C
= 10nF and adjust its value accordingly to suit the specific
applications.
OPERATING SEQUENCE
Power-Up, Start-Up Check and Plug-In Timing Cycle
The sequence of operations for the LTC4211 is illustrated
in the timing diagram of Figure 5. When a PC board is first
inserted into a live backplane, the LTC4211 first performs
TIMER
value is vital to ensure a proper start-up and
ON GOES LOW
9
10
RESET PULLED LOW DUE TO POWER BAD
POWER BAD
(V
200µA
FB
< V
REF
)
4211 F05
TIMER
4211fa