LTC4210-4IS6#PBF Linear Technology, LTC4210-4IS6#PBF Datasheet - Page 11

• 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
GATE ramp up. If the R
limit, the GATE ramps at a constant rate of:
where C
The current through R
components; I
(C
The capacitive load typically dominates.
For a successful start-up without current limit, I
I
Due to the voltage follower configuration, the V
rate approximately tracks V
At time point 6, V
up continues until it reaches a maximum voltage. This
maximum voltage is determined either by the charge
pump or the internal clamp.
Start-Up Cycle With Current Limit
If the duration of the current limit is brief during start-up
(Figure 4) and it did not last beyond the circuit breaker
function time out, the GATE behaves the same as in start-
up without current limit except for the time interval be-
tween time point 5A and time point 5B. The servo amplifier
limits I
Equations 7 and 8 are applicable but with a lower GATE and
V
LIMIT
OUT
LOAD
I
I
I
RSENSE
RSENSE
∆
RSENSE
∆
V
V
∆
:
∆
ramp rate.
GATE
OUT
) and I
T
RSENSE
T
GATE
= I
=
=
=
=
LOAD
I
I
is the total capacitance at the GATE pin.
C
CLOAD
⎛
⎝ ⎜
CLOAD
LIMIT
C
I
by decreasing the I
LOAD
GATE
C
CLOAD
GATE
LOAD
OUT
due to the noncapacitive load elements.
=
U
+ I
is approximately V
≈
R
due to the total load capacitance
•
50
LOAD
SENSE
∆
SENSE
∆
SENSE
V
mV
∆
V
∆
U
GATE
OUT
T
T
GATE
< I
current is below the current
LIMIT
⎞
⎠ ⎟
can be divided into two
=
:
+
GATE
C
I
I
GATE
W
LOAD
GATE
current (<10µA).
IN
<
but GATE ramp-
I
LIMIT
U
OUT
RSENSE
ramp
(9)
(6)
(7)
(8)
<
Gate Start-Up Time
The start-up time without current limit is given by:
During current limiting, the second term in Equation 10 is
partly modified from C
V
For successful completion of current limit start-up cycle
there must be a net current to charge C
current limit duration must be less than t
second term in Equation 11 has to fulfill Equation 12.
t
STARTUP
IN
t
t
/I
STARTUP
STARTUP
CLOAD
I
V
RSENSE
V
TIMER
V
GATE
V
OUT
V
ON
IN
=
=
. The start-up time is now given by:
>2.5V
RESET
MODE
C
C
=
=
Figure 4. Operating Sequence with
Current Limiting at Start-Up Cycle
GATE
>1.3V
GA
1
C
C
T T E
GATE
GATE
LTC4210-3/LTC4210-4
2
•
•
INITIAL
5µA
CYCLE
I
I
GATE
GATE
V
V
•
•
TH
TH
I
V
GATE
V
3 4 5
TH
I
T T H
REGULATED AT 50mV/R
GATE
GATE
COMP2
+
+
+
100µA
COMP1
10µA
C
C
START-UP
+
CYCLE
LOAD
V
V
LOAD
TH
IN
5A
C
<10µA
60µA
• V
GATE
5B 6
•
•
IN
10µA
I
2µA
I
CLOAD
NORMAL
RSENSE
/I
•
SENSE
CYCLE
V
GATE
I
IN
GATE
V
IN
7
100µA
LOAD
V
CBDELAY
IN
DISCHARGE
BY LOAD
to C
–
4210 F04
I
LOAD
and the
11
LOAD
421034fa
. The
(10)
(11)
•