LT4254IGN Linear Technology, LT4254IGN Datasheet - Page 6

• Manufacturer Part Number: LT4254IGN
• Description: IC CTLR HOTSWAP POS 16-SSOP
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LT4254IGN

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 10.8 V ~ 36 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

PI FU CTIO S
LT4254
V
ranges from 10.8V to 36V for normal operation. I
typically 1.9mA. An internal circuit disables the LT4254 for
inputs less than 9.8V (typ).
GND: Device Ground. This pin must be tied to a ground
plane for best performance.
FB: Power Good Comparator Input. FB monitors the
output voltage through an external resistive divider. When
the voltage on the FB pin is lower than the high-to-low
threshold of 4V, the PWRGD pin is pulled low and released
6
TYPICAL PERFOR A CE CHARACTERISTICS
3.65
3.55
3.50
CC
3.70
3.60
U
: Input Supply Voltage. The positive supply input
–50
OV Threshold Voltage (High-to-
Low) vs Temperature
–25
U
0
TEMPERATURE (°C)
25
4.5
3.5
3.0
5.0
4.0
–50
OPEN Pin Threshold Voltage
vs Temperature
U
50
–25
75
W
0
TEMPERATURE (°C)
100
4254 G22
25
U
125
50
75
500
450
300
200
400
350
250
100
–50
OV Hysteresis vs Temperature
4254 G25
125
–25
CC
0
TEMPERATURE (°C)
is
25
when the FB pin is pulled above the 4.45V low-to-high
threshold.
The FB pin also affects foldback current limit (see Figure 7
and related discussion). To disable PWRGD monitoring,
connect FB to the output voltage and float the PWRGD pin.
TIMER: Timing Input. An external timing capacitor from
TIMER to GND programs the maximum time the part is
allowed to remain in current limit. When the part goes into
current limit, a 120µA pull-up current starts to charge the
timing capacitor. When the voltage on the TIMER pin
50
75
6
5
1
0
4
3
2
100
0
PWRGD Output Voltage vs I
T
4254 G23
A
= 25°C
125
2
4
I
LOAD
10
8
6
4
2
0
6
(mA)
OPEN Output Voltage vs I
0
T
A
= 25°C
8
2
LOAD
10
4
4254 G26
I
LOAD
12
6
(mA)
8
LOAD
10
4254 G24
4254fb
12