LTC4210-4IS6#PBF Linear Technology, LTC4210-4IS6#PBF Datasheet - Page 7

• Manufacturer Part Number: LTC4210-4IS6#PBF
• Manufacturer: Linear Technology

Specifications of LTC4210-4IS6#PBF

• Linear Misc Type: Positive Low Voltage
• Package Type: TSOT-23
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 7V
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Height (mm): 0.9mm
• Product Length (mm): 2.9mm
• Mounting: Surface Mount
• Pin Count: 6
• Lead Free Status / RoHS Status: Compliant

APPLICATIO S I FOR ATIO
Hot Circuit Insertion
When circuit boards are inserted into live backplanes, the
supply bypass capacitors can draw large transient cur-
rents from the backplane power bus as they charge. Such
transient currents can cause permanent damage to con-
nector pins, glitches on the system supply or reset other
boards in the system.
The LTC4210 is designed to turn a printed circuit board’s
supply voltage ON and OFF in a controlled manner, allow-
ing the circuit board to be safely inserted into or removed
from a live backplane. The LTC4210 can reside either on
the backplane or on the daughter board for hot circuit
insertion applications.
BLOCK DIAGRA
1
2
U
TIMER
GND
U
W
5µA
2µA
0.2V
1.3V
60µA
W
100µA
INITIAL UP/LATCH OFF
INITIAL DOWN/NORMAL
+
–
+
–
CURRENT LIMIT
COMP1
COMP2
COOL OFF
U
LOGIC
1.3V
–
GLITCH
GLITCH
COMP3
FILTER
FILTER
UVLO
6
V
Overview
The LTC4210-3/LTC4210-4 is designed to operate over a
range of supplies from 2.7V to 7V. Upon insertion, an
undervoltage lockout circuit determines if sufficient sup-
ply voltage is present. When the ON pin goes high an initial
timing cycle assures that the board is fully seated in the
backplane before the MOSFET is turned on. A single timer
capacitor sets the periods for all of the timer functions.
After the initial timing cycle the LTC4210 can either start
up in current limit or with a lower load current. Once the
external MOSFET is fully enhanced and the supply has
ramped up, the LTC4210 monitors the load current through
an external sense resistor. Overcurrent faults are actively
limited to 50mV/R
timer limit. The LTC4210-3 will automatically retry after a
current limit fault while the LTC4210-4 latches off. The
LTC4210-3 timer function limits the retry duty cycle to
3.8% for MOSFET cooling.
CC
+
3
ON
+
–
–
SHUTDOWN
50mV
EA
Z1
12V
+
5
SENSE
LTC4210-3/LTC4210-4
CHARGE
SENSE
PUMP
10µA
4k
for a specified circuit breaker
M5
GATE
Z2
26V
4210 BD
4
421034fa
7