LTC4221CGN#PBF Linear Technology, LTC4221CGN#PBF Datasheet - Page 18

• Manufacturer Part Number: LTC4221CGN#PBF
• Description: IC CTLR HOT SWAP DUAL 16SSOP
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC4221CGN#PBF

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 1 V ~ 13.5 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
LTC4221
The LTC4221 can also be configured to automatically retry
after a fault condition. As shown in Figure 10, the FAULT
(which has an internal 3.8μA pull-up current source) and
both ON pins are connected together. The timing diagram
in Figure 11 illustrates a simultaneous start-up sequence
where the LTC4221 is powered up into a load overcurrent
condition on channel 1. After the slow comparators are
18
FAULT
U
V
V
ON n , FAULT
CC1
CC2
SENSE1
FILTER
TIMER
GATE1
CONNECTOR
V
BACKPLANE
Q2: 2N7002LT1
Z1: SMAJ10
* ADDITIONAL DETAILS
(FEMALE)
OUT1
U
OMITTED FOR CLARITY
RESET
0.851V
CONNECTOR
PCB EDGE
W
(MALE)
1
Figure 10. Using FAULT to Configure Autoretry
INITIAL TIMING
1.9μA
V
LONG
LONG
SHORT
LONG
Figure 11. Autoretry Timing Waveforms
t
TMR(H)
INITIAL
V
0.47μF
TMR(L)
C
U
ON1
V
1M
R1
SENSE(SC)
2
ELECTRONIC CIRCUIT BREAKER ARMED
3
START-UP
CHANNEL
20μA
C
t
STARTUP
FILTER
16
10
1nF
1
7
ON1
ON2
FAULT
GND
FILTER
4 5
SLOW COMPARATORS ARMED
Z1
LTC4221*
armed at the end of the start-up cycle at time point 4, slow
comparator 1 immediately trips and FILTER ramps up.
FILTER ramps past its high threshold at time point 6 and
trips the circuit breaker. FAULT and both ON pins are
pulled low by an internal N-channel MOSFET and over-
shoots below the 0.4V reset threshold of the ON1 pin.
Once ON1 < 0.4V for more than 15μs, the internal fault
8
20μA
V
9.5μA
FILTER(TH)
V
t
FILTER
RAMP
SENSE1
FILTER
SENSE(FC)
TIMER
GATE1
R
10Ω
V
105μA
X1
C
100nF
FB1
CC1
9
X1
0.4V
C
1μF
TIMER
6 7
RESET
R
0.004Ω
SENSE1
0.4V
8
t
ON
0.851V
IRF7413
OFF
1.8μA
Q1
9
R
56k
R
15k
F1
F2
INITIAL
TIMING
t
+
INITIAL
2μA
4221 F10
4221 F11
C
LOAD1
V
3.3V
5A
V
2.5V
5A
OUT1
OUT2
4221fa