LTC4215-1 Datasheet, PDF (1/28 Pages) Linear Technology – Hot Swap Controller with I2C Compatible Monitoring

FEATURES
n _{Allows Safe Insertion into Live Backplane}
n _{8-Bit ADC Monitors Current and Voltage}
n _I²_{C/SMBus Interface}
n _{Wide Operating Voltage Range: 2.9V to 15V}
n _{dI/dt Controlled Soft-Start}
n _{Three General Purpose Outputs}
n _{High Side Drive for External N-channel MOSFET}
n _{No External Gate Capacitor Required}
n _{Input Overvoltage/Undervoltage Protection}
n _{Optional Latchoff or Auto-Retry After Faults}
n _{Alerts Host After Faults}
n _{Inrush Current Limit with Foldback}
n _{Available in 24-Pin (4mm × 5mm) QFN}
APPLICATIONS
n _{Live Board Insertion}
n _{Electronic Circuit Breakers}
n _{Computers, Servers}
n _{Platform Management}
LTC4215-1
Hot Swap Controller with
I²C Compatible Monitoring
DESCRIPTION
The LTC^®4215-1 Hot Swap™ controller allows a board to be
safely inserted and removed from a live backplane. Using
an external N-channel pass transistor, board supply voltage
and inrush current are ramped up at an adjustable rate.
An I²C interface and onboard ADC allow for monitoring
of load current, voltage and fault status.
The device features adjustable foldback current limit and
a soft-start pin that sets the dI/dt of the inrush current.
An I²C interface may configure the part to latch off or
automatically restart after the LTC4215-1 detects a cur-
rent limit fault.
The controller has additional features to interrupt the host
when a fault has occurred, provide three general purpose
outputs, notify when output power is good, detect insertion
of a load card, and power-up either automatically upon
insertion or wait for an I²C command to turn on.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Hot Swap
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patent 7330065.
TYPICAL APPLICATION
12V Application With 5A Circuit Breaker
Start-Up Waveform
12V
SDA
SCL
GND
BACKPLANE PLUG-IN
CARD
0.003Ω
V_OUT
+
12V
34k
C_L 30.1k
10Ω
0.1μF
1.74k
3.57k
2.67k
SMBJ14A
UV V_DD SENSE⁺ SENSE^– GATE SOURCE
OV
FB
SDAI
SDAO
SCL
ADR0
ADR1
LTC4215-1
GPIO1
GPIO2
GPIO3
ADIN
INTV_CC
ON TIMER SS
GND EN
POWERGOOD
RESET
OK LED
MEASURED
VOLTAGE
68nF
0.1μF
4215 TA01a
V_DD
10V/DIV
INRUSH
CURRENT
2.5A/DIV
V_OUT
10V/DIV
CONTACT
BOUNCE
V_GPIO1
10V/DIV
5k PULL-UP TO V_DD
C_L = 12000μF
40ms/DIV
42151 TA01b
42151fa
1