LTC4242IUHF#PBF Linear Technology, LTC4242IUHF#PBF Datasheet - Page 8

• Manufacturer Part Number: LTC4242IUHF#PBF
• Description: IC CTRLR HOTSWAP DUAL-SLOT 38QFN
• Manufacturer: Linear Technology
• Type: Hot-Swap Controllerr

Specifications of LTC4242IUHF#PBF

• Applications: General Purpose, PCI Express
• Internal Switch(s): No
• Voltage - Supply: 2.7 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 38-WFQFN, Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PI FU CTIO S
LTC4242
12V
N-Channel MOSFET. An internal charge pump provides
a 9µA pull-up current to ramp up 12V
off, a 1mA pull-down current source discharges 12V
to ground. 12V
12V
current source between 12V
An external RC network is required at the pin for optimum
current limit response.
12V
Input. A sense resistor is placed in the supply path between
12V
current. The voltage across the sense resistor is monitored
for active current limit and circuit breaker fault detection.
To disable the circuit breaker function for the 12V channel,
connect 12V
12V
circuit disables the 12V and 3.3V supplies when 12V
voltage is less than 9.78V.
12V
pin to the source of the 12V supply external N-channel
MOSFET for gate drive return. PGOOD1/PGOOD2 cannot
pull low until this pin goes above 10.38V. A 700Ω active
pull-down discharges 12V
MOSFET is turned off.
3V
N-Channel MOSFET. An internal charge pump provides
a 9µA pull-up current to ramp up 3V
off, a 1mA pull-down current source discharges 3V
to ground. 3V
3V
current source between 3V
An external RC network is required at the pin for optimum
current limit response.
8
GATE1
OUTn
U
GATE1
OUTn
SENSE1
INn
IN1
OUT1
/12V
. During an overcurrent fault, a 250mA pull-down
and 12V
/3V
. During an overcurrent fault, a 250mA pull-down
/12V
/12V
/12V
U
IN2
GATE2
SENSEn
OUT2
GATE2
: 12V Supply Input. An undervoltage lockout
GATEn
GATEn
SENSE2
SENSEn
: Gate Drive for 3.3V Supply External
: 12V Output Connection. Connect this
: Gate Drive for 12V Supply External
to 12V
is internally clamped to 5.5V above
U
is internally clamped to 5.5V above
: 12V Supply Current Limit Sense
to sense the 12V channel’s load
OUTn
INn
GATEn
GATEn
.
to ground when the external
and 12V
and 3V
GATEn
GATEn
OUTn
OUTn
. During turn
. During turn
is activated.
is activated.
GATEn
GATEn
INn
3V
A sense resistor is placed in the supply path between 3V
and 3V
voltage across the sense resistor is monitored for active
current limit and circuit breaker fault detection. To disable
the circuit breaker function for the 3.3V channel, connect
3V
3V
circuit disables the 3.3V and 12V supplies when 3V
voltage is less than 2.67V.
3V
pin to the source of the 3.3V supply external N-channel
MOSFET for gate drive return. PGOOD1/PGOOD2 cannot
pull low until this pin goes above 2.855V. A 375Ω active
pull-down discharges 3V
MOSFET is turned off.
AUXFAULT1/AUXFAULT2: AUX Supply Fault Status Out-
put. AUXFAULTn is normally pulled high by an internal 9µA
pull-up. It asserts low if the AUX channel shuts off due
to an overcurrent fault or due to the device temperature
rising above 150°C. Indicates switch ON status when
FONn and ENn are high.
AUXON1/AUXON2: AUX Supply On Control Input. A rising
edge turns on the internal FET, while a falling edge turns it
off. Pulling this pin below 0.6V for more than 3.5µs clears
the fault on the AUX channel.
AUXIN1/AUXIN2: AUX Supply Input. An undervoltage
lockout circuit disables the AUX supply when the voltage
at AUXINn is less than 2.67V. AUXINn is the input to the
internal pass FET.
AUXOUT1/AUXOUT2: AUX Supply Output. AUXOUTn
is the output from the internal pass FET. AUXPGOOD1/
AUXPGOOD2 cannot pull low until this pin goes above
2.855V. A 750Ω active pull-down discharges AUXOUTn
to ground when the internal FET is turned off.
SENSE1
SENSEn
IN1
OUT1
/3V
SENSEn
/3V
IN2
/3V
to 3V
OUT2
: 3.3V Supply Input. An undervoltage lockout
SENSE2
to sense 3.3V channel’s load current. The
: 3.3V Output Connection. Connect this
INn
.
: 3.3V Supply Current Limit Sense Input.
OUTn
to ground when the external
4242f
INn
INn