LTC4255 Datasheet, PDF (1/16 Pages) Linear Technology – Quad Network Power Controller with I2C Compatible Interface

LTC4255
Quad Network Power
Controller with I²C Compatible Interface
FEATURES
s _{Controls Four Independent –48V Power Channels}
s _{Each Channel has Separate Relay Drivers, ON/OFF}
Control, Short-Circuit Protection with Current
Foldback, Open-Circuit Detection, and Power Good
Indication
s _{Programmed via I}²_C^TM _{Compatible Interface}
s _{Five Bit Programmable Digital Address Allows}
Control of up to 32 LTC4255s (128 Channels)
s _{Interrupt on FAULT Output can be used to Eliminate}
Software Polling
s _{Programmable Current Limit and Open-Circuit}
Duration Periods
s _{Programmable Latchoff or Autoretry after Short-}
Circuit Faults
s _{Programmable Autoretry Duty Cycle}
U
APPLICATIO S
s _{IP Phone Systems}
s _{DTE Power Distribution}
DESCRIPTIO
The LTC^®4255 is a quad –48V network power controller
with independent relay drivers and I²C compatible inter-
face. Each channel can be turned on and off via software
control, while providing short-circuit protection, open-
circuit detection, and power good indication. The short-
circuit protection includes a current foldback feature to
reduce power dissipation in the switch during shorts and
start-up.
The serial interface allows up to 128 channels to be
controlled with only two digital lines. A FAULT output can
be used as an interrupt line to eliminate fault detection by
software polling.
External switches and current sense resistors allow easy
scaling of current and power dissipation levels and pro-
vide the maximum protection against voltage and current
spikes.
The LTC4255 is available in the 28-pin SSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
I²C is a trademark of Philips Electronics N.V.
TYPICAL APPLICATIO
12V
0.1µF
V_CC
SCL
SDA
FAULT
AD0
AD1
AD2
AD3
AD4
LTC4255
RELAY1
RELAY2
RELAY3
RELAY4
DGND AGND V_EE SENSE1 GATE1 OUT1 SENSE2 GATE2 OUT2 SENSE3 GATE3 OUT3 SENSE4 GATE4 OUT4
–48V
R_S1
0.1µF ^0.33Ω
100k
Q1
R_S2
0.33Ω
Q1, Q2, Q3, Q4: FDC3612
RELAYS: V23079 SERIES
100k
Q2
R_S3
0.33Ω
100k
Q3
R_S4
0.33Ω
100k
Q4
4255 TA01
4255f
1