General description
The NCA9306 is a 2 channel bidirectional I²C and SMBus multi-voltage level translator with an
enable (EN) pin input. It allows voltage translation between 0.95 V and 5 V without the use of a
direction pin. It supports up to 100 MHz up translation and >100 MHz down translation at ≤ 30 pF
capacitive load. There is no need for a direction pin which minimizes the system effort. The
NCA9306 supports 5 V tolerant I/O pins to support mixed mode signal operation. The ability to set
up different voltage translation levels on each channel makes the device very flexible and suitable
for a lot of different applications.
The low ON-state resistance RON of the switch allows connections to be made with minimal
propagation delay. When EN is HIGH, the translator switch is on, and the SCLA and SDAA I/O are
connected to the SCLB and SDAB I/O respectively, allowing bidirectional data flow between ports.
When EN is LOW, the translator switch is off, and a high-impedance state exists between ports. As
with the standard I²C bus-system, pull-up resistors are required to provide the logic HIGH levels on
the translators bus. The NCA9306 has a standard open-drain configuration of the I²C-bus. The size
of these pull-up resistors depend on the system. Each side of the translator must have a pull-up
resistors. NCA9306 is designed to work with Standard-mode, Fast-mode and Fast-mode plus
I²C bus devices in addition to the SMBus devices.
When the SDAA or SDAB pin is LOW, the clamp is in the ON-state and a low resistance
connections exists between the SDAA and SDAB ports. Assuming the higher voltage is on the
SDAB port when the SDAB port is HIGH, the voltage on the SDAA port is limited to the voltage set
by refA. When the SDAA port is HIGH, the SDAB port is pulled to the refB supply voltage by the
pull-up resistors. The SCLA or SCLB pins also follows the same behavior as described for SDAA or
SDAB pins.
Features and benefits
• 2-channel bidirectional voltage translator for SDA and SCL lines in mixed mode I²C bus
applications
• Open-drain I²C-bus I/O ports (SCLA, SDAA, SCLB and SDAB)
• Provides bidirectional voltage translation with no direction pin
• High-impedance SCLA, SDAA, SCLB and SDAB for EN = LOW
• Up translation
• < 100 MHz; CL = 30 pF
• < 40 MHz; CL = 50 pF
• Down translation
• > 100 MHz; CL = 30 pF
• < 40 MHz; CL = 50 pF
• Hot insertion
• Bidirectional voltage level translation between:
• 0.95 V and 1.8 V, 2.5 V, 3.3 V and 5.0 V
• 1.2 V and 1.8 V, 2.5 V, 3.3 V and 5.0 V
• 1.8 V and 2.5 V, 3.3 V and 5.0 V
• 2.5 V and 3.3 V and 5.0 V
• 3.3 V and 5.0 V
• Low standby current
• 5 V tolerant I²C-bus I/O pins to support mixed mode signal operation
Low RON provides less signal distortion
Latch-up performance exceeds 100 mA per JESD78 class II level A
ESD protection:
• HBM ANSI/ESDA/JEDEC JS-001 Class 2 exceeds 2000 V
• CDM ANSI/ESDA/JEDEC JS-002 Class C3 exceeds 1000 V
Specified from -40 °C to +125 °C
Applications
• GPIO, MDIO, PMBus, SMBus, SDIO, UART, I²C, and other interfaces in Telecom infrastructure
• Industrial
• Personal computing
• Router and Industrial Automation