STMicroelectronics ST2189QTR

Overview

ST2189QTR from STMicroelectronics is an 8-bit bidirectional dual-supply level translator IC without direction control pin, operating across independent 1.65 V–3.6 V rails (VCCA and VCCB), supporting up to 92 Mbps data transfer at 46 MHz clock rate with 5 µA quiescent current and ±4 kV HBM ESD protection - used for voltage translation between low-voltage ASICs/PLDs and higher-voltage subsystems in mobile handsets.

For engineers reviewing the ST2189QTR datasheet, ST2189QTR pinout, ST2189QTR application, or ST2189QTR equivalent, key selection criteria include bidirectional operation without direction pin, partial power-down capability (VCCB = GND → automatic high-Z), tri-state enable via OE, and QFN20 (1.8 × 3.2 mm) package compatibility with space-constrained portable designs.

Technical Context

The ST2189 employs a passive, resistor-based bidirectional architecture with integrated one-shot transistors that activate only during signal transitions - eliminating need for direction control while maintaining level integrity across asymmetric voltage domains. Its I/Os are referenced separately to VCCA or VCCB, enabling flexible VCCA ≤ VCCB or VCCA ≥ VCCB configurations.

Tri-state control is implemented via active-high OE pin (VCCA-referenced), and automatic high-impedance mode activates when VCCB is grounded - reducing VCCA supply current to ≤5 µA. Output drive relies on weak 4 kΩ pull-up/down resistors post-transition, requiring external drivers capable of sourcing/sinking ≥1 mA.

Key Specifications

Pinout & Package

ST2189QTR is housed in a thermally enhanced, leadless QFN20 package measuring 1.8 mm × 3.2 mm × 0.5 mm (0.4 mm pitch), with exposed thermal pad for PCB heat dissipation and RoHS-compliant ECOPACK® construction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional level translation applications.

Compared with TXS0108E and SN74AVC8T245, ST2189QTR uniquely combines directionless operation, automatic VCCB-powered shutdown, and ultra-low quiescent current - making it optimal for energy-sensitive, pin-constrained mobile systems where OE control is acceptable.

Availability

ST2189QTR is available at Aetrix Electronics and suitable for mobile phone design, wearable sensor integration, and FPGA-based embedded systems requiring stable component supply with guaranteed long-term availability.

Supply support for ST2189QTR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, sensing, and control solutions for automotive, industrial, and consumer markets.

The ST2189 belongs to ST's level translation IC portfolio designed specifically for low-voltage, high-density portable electronics - emphasizing minimal footprint, zero-direction-pin operation, and sub-µA power-down states.

FAQ

What is the maximum allowable voltage difference between VCCA and VCCB?

VCCA and VCCB may differ by any amount within their respective 1.65 V–3.6 V ranges - the device supports VCCA ≥ VCCB and VCCA ≤ VCCB configurations without restriction. Absolute maximum ratings allow up to 4.6 V on either supply, but recommended operation stays within 1.65–3.6 V for both rails to ensure specified timing and drive performance.

Can ST2189QTR translate between 1.2 V and 3.3 V logic domains?

No - ST2189QTR's minimum valid supply voltage is 1.65 V for both VCCA and VCCB. A 1.2 V source falls outside its operational range and risks undefined behavior or failure to meet DC specifications such as VIH/VIL thresholds. For 1.2 V interfaces, consider ST's TXS series or dedicated ultra-low-voltage translators.

How does the automatic high-impedance mode work when VCCB is grounded?

When VCCB is pulled to GND, internal circuitry detects loss of B-side supply and forces all I/O pins (both A- and B-side) into high-impedance state without requiring OE assertion. Quiescent current on VCCA drops to ≤5 µA, enabling true zero-power isolation of the B-side bus while retaining A-side readiness.

Is the OE pin 5 V tolerant?

No - OE is referenced to VCCA and must remain within –0.3 V to VCCA + 0.3 V. Applying 5 V to OE when VCCA ≤ 3.6 V violates absolute maximum ratings and may damage the input structure. For systems with 5 V control logic, use a resistive divider or level-shifting buffer to limit OE voltage to ≤VCCA + 0.3 V.