Overview
The TCA9406YZPR, produced by Texas Instruments, is a 2-bit bidirectional I2C and SMBus voltage-level translator. This device is designed to interface between lower and higher logic signal levels, making it versatile for various voltage supply rails such as 1.8 V, 2.5 V, 3.3 V, and 5 V. It operates from 1.65 V to 3.6 V on the A-side (VCCA) and from 2.3 V to 5.5 V on the B-side (VCCB), allowing seamless communication between different voltage domains without the need for a direction pin. The TCA9406YZPR features an output enable (OE) input that can be tied directly to VCCA or controlled by a GPIO, enabling the device to place all SCL and SDA pins in a high-impedance state when necessary, significantly reducing quiescent current consumption.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | DSBGA (YZP) | - |
| Pins | 8 | - |
| Operating Temperature Range | -40 to 85 | °C |
| VCCA Supply Voltage Range | 1.65 to 3.6 | V |
| VCCB Supply Voltage Range | 2.3 to 5.5 | V |
| Internal Pullup Resistor | 10 kΩ | - |
| I2C/SMBus Speed | Up to 2 Mbps (Standard, Fast, Fast+ modes) | - |
| ESD Protection | A Port: 2500 V HBM, B Port: 8 kV HBM | - |
| Thermal Resistance (Junction to Ambient) | 105.8 | °C/W |
Key Features
- 2-bit bidirectional translator for SDA and SCL lines in I2C applications without a direction pin.
- Provides bidirectional voltage translation between different voltage domains (VCCA ≤ VCCB).
- High-impedance output SCL_A, SDA_A, SCL_B, and SDA_B pins when OE = Low or VCC = 0 V.
- Internal 10-kΩ pullup resistors on all SDA and SCL pins.
- No power-supply sequencing required; either VCCA or VCCB can be ramped first.
- Low Ioff of 2 µA when either VCCA or VCCB = 0 V.
- OE input can be tied directly to VCCA or controlled by GPIO.
- Latch-up performance exceeds 100 mA per JESD 78, Class II, and ESD protection exceeds JESD 22.
Applications
- I2C/SMBus interfaces.
- UART applications.
- GPIO interfaces.
- General-purpose level translation in mixed-voltage systems.
Q & A
- What is the primary function of the TCA9406YZPR?
The TCA9406YZPR is a 2-bit bidirectional I2C and SMBus voltage-level translator, designed to interface between different voltage domains without a direction pin.
- What are the operating voltage ranges for the A and B ports of the TCA9406YZPR?
The A port operates from 1.65 V to 3.6 V, and the B port operates from 2.3 V to 5.5 V.
- What is the purpose of the internal pullup resistors on the TCA9406YZPR?
The internal 10-kΩ pullup resistors on the SDA and SCL pins help to ensure proper signal levels and can be supplemented with external pullup resistors to reduce total pullup resistance and speed up rising edges.
- How does the OE input affect the operation of the TCA9406YZPR?
The OE input can be tied directly to VCCA or controlled by a GPIO. When set to a logic low, it places all SCL and SDA pins in a high-impedance state, significantly reducing quiescent current consumption.
- What are the ESD protection levels for the TCA9406YZPR?
The device offers ESD protection exceeding JESD 22 standards, with 2500 V HBM for the A port and 8 kV HBM for the B port.
- What are the thermal characteristics of the TCA9406YZPR?
The junction-to-ambient thermal resistance (RθJA) for the DSBGA package is 105.8 °C/W.
- Can the TCA9406YZPR be used in applications other than I2C/SMBus?
Yes, it can be used in UART and GPIO applications, as well as for general-purpose level translation in mixed-voltage systems.
- What is the maximum I2C/SMBus speed supported by the TCA9406YZPR?
The device supports up to 2 Mbps for standard I2C speeds and can handle faster speeds up to 24 Mbps when both ports are driven with push-pull devices.
- Is power-supply sequencing required for the TCA9406YZPR?
No, either VCCA or VCCB can be ramped first without any sequencing requirements.
- What is the quiescent current consumption of the TCA9406YZPR when either VCCA or VCCB is at 0 V?
The quiescent current (Ioff) is 2 µA when either VCCA or VCCB is at 0 V.
