LTC4314_15 Datasheet, PDF (1/20 Pages) Linear Technology – Pin-Selectable, 4-Channel, 2-Wire Multiplexer with Bus Buffers

FEATURES
n _{1:4 Multiplexer/Switch for 2-Wire Bus}
n _{Bidirectional Buffer for SDA and SCL Lines}
n _{High Noise Margin with VIL = 0.3•VCC}
n _{ENABLE Pins Connect SDA and SCL Lines}
n _{Selectable Rise Time Accelerator Current and}
Activation Voltage
n _{Level Shift 1.5V, 1.8V, 2.5V, 3.3V and 5V Busses}
n _{Prevents SDA and SCL Corruption During Live Board}
Insertion and Removal from Backplane
n _{Stuck Bus Disconnect and Recovery}
n _{Compatible with I}²_{C, I}²_{C Fast Mode and SMBus}
n _{±4kV Human Body Model (HBM) ESD Ruggedness}
n _{20-Lead SSOP and 3mm × 4mm QFN Packages}
APPLICATIONS
n _{Telecommunications Systems Including ATCA}
n _{Address Expansion}
n _{Level Translator}
n _{Capacitance Buffers/Bus Extender}
n _{Live Board Insertion}
n _PMBus
LTC4314
Pin-Selectable, 4-Channel,
2-Wire Multiplexer
with Bus Buffers
DESCRIPTION
The LTC^®4314 is a hot-swappable 4-channel 2-wire bus
multiplexer that allows one upstream bus to connect to
any combination of downstream busses or channels.
An individual enable pin controls each connection. The
LTC4314 provides bidirectional buffering, keeping the up-
stream bus capacitance isolated from the downstream bus
capacitances. The high noise margin allows the LTC4314
to be interoperable with I²C devices that drive a high V_OL
(> 0.4V). The LTC4314 supports level translation between
1.5V, 1.8V, 2.5V, 3.3V and 5V busses. The hot-swappable
nature of the LTC4314 allows I/O card insertion into, and
removal from, a live backplane without corruption of the
data and clock busses.
If both data and clock are not simultaneously high at
least once in 45ms and DISCEN is high, a FAULT signal is
generated indicating a stuck bus low condition, the input
is disconnected from all enabled output channels, and up
to 16 clocks are generated on the enabled downstream
busses. A three state ACC pin enables input and output
side rise time accelerators of varying strengths and sets
the V_IL,RISING voltage.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap
is a trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents, including 6356140, 6650174, 7032051, 7478286.
TYPICAL APPLICATION
3.3V
3.3V
0.01μF
SCLIN
SDAIN
ENABLE1
ENABLE2
ENABLE3
ENABLE4
10k 10k
V_CC
V_CC2
SCLIN
SDAIN
ENABLE1
SCLOUT1
ENABLE2
SDAOUT1
ENABLE3
ENABLE4
3.3V
LTC4314
10k
FAULT
ACC
DISCEN
FAULT
SCLOUT4
SDAOUT4
GND
4314 TA01a
10k 10k
0.01μF
SCLOUT1
SDAOUT1
5V
10k 10k
SCLOUT4
SDAOUT4
Rising Edge from Asserted Low
with Level Translation
6V
C_SCLOUT1 + C_SCLOUT4 = 100pF
C_SCLIN = 50pF
SCLOUT4 _5V
SCLOUT1
3.3V
SCLIN
0V
200ns/DIV
4314 TA01b
4314f
1