STMicroelectronics ST2329BQTR

Overview

ST2329BQTR from STMicroelectronics is a 2-bit dual-supply bidirectional level translator with open-drain outputs and no direction control pin, supporting VL from 1.65 V to 3.6 V and VCC up to 5.5 V. It delivers up to 18 Mbps data rate with totem-pole drivers and enables I²C/UART voltage translation between low-voltage ASICs (e.g., 1.8 V) and higher-voltage peripherals (e.g., 5 V) in mobile and embedded systems.

For engineers reviewing the ST2329BQTR datasheet, ST2329BQTR pinout, ST2329BQTR application, or ST2329BQTR equivalent, key selection criteria include bi-directional operation without direction pin, power-down mode behavior when either supply is off, open-drain output compatibility with pull-up networks, and QFN8 package suitability for space-constrained PCB layouts.

Technical Context

The ST2329BQTR uses a transmission-gate-based architecture enabling true bidirectional level shifting across two independent channels, eliminating need for external direction control logic. Its OE pin provides 5.5 V-tolerant enable/disable functionality, and internal high-impedance state activation on power-off ensures bus isolation when VCC or VL is unpowered.

It supports both open-drain and totem-pole input drivers, with distinct AC performance profiles: max 6.8 Mbps with open-drain inputs (due to RC-limited rise time), and up to 18 Mbps with totem-pole inputs. Propagation delays are asymmetric-tPHL exceeds tPLH by up to 28 ns depending on voltage combination-reflecting inherent NMOS pull-down dominance in its open-drain output stage.

Key Specifications

Pinout & Package

ST2329BQTR is housed in an 8-pin QFN package (1.4 mm × 1.2 mm × 0.55 mm, 0.4 mm pitch) with exposed thermal pad. Pin 1 is marked by a dot; the package is RoHS-compliant and ECOPACK® certified.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TXS0102DCUR and PCA9306DCUR, ST2329BQTR uniquely combines 5.5 V-tolerant OE control, full 1.65–3.6 V VL flexibility, and 18 Mbps capability-making it optimal for mixed-voltage UART/I²C systems requiring deterministic enable sequencing and high-speed interoperability.

Availability

ST2329BQTR is available at Aetrix Electronics and suitable for mobile phone interfaces, I²C sensor subsystems, and UART bridge circuits requiring stable component supply across extended temperature ranges (−40 °C to +85 °C).

Supply support for ST2329BQTR 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, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The ST2329BQTR belongs to ST's level translation portfolio targeting low-power, space-constrained portable electronics-designed specifically to simplify multi-rail interconnect in battery-operated devices with aggressive size and energy budgets.

FAQ

Can ST2329BQTR translate between 1.2 V and 5 V logic domains?

No. The ST2329BQTR specifies a minimum VL of 1.65 V per datasheet Table 5. Attempting operation below 1.65 V risks violating VIHL/VILL thresholds and may cause unreliable logic detection or increased static current. For 1.2 V interfaces, consider ST's ST6G3238 or TI's TXS02612.

Is an external pull-up resistor required on both sides of the ST2329BQTR?

Yes. Because ST2329BQTR has open-drain outputs, external pull-up resistors are mandatory on all I/OVL and I/OVCC pins to establish HIGH logic states. Values must be selected per driver sink capability and desired rise time-e.g., 4.7 kΩ for I²C Fast-mode, 10 kΩ for UART at 3 Mbps.

What happens to the I/Os when VCC is powered but VL is disconnected?

When VL is floating or grounded while VCC is active and OE = HIGH, the I/OVL pins enter undefined behavior per datasheet Section 4.3. To ensure safe high-impedance state under partial power loss, OE must be held LOW whenever either supply is absent-this activates the power-down mode and isolates all I/Os.

Does ST2329BQTR support hot-swap or live-insertion scenarios?

Yes-when OE is held LOW during insertion, all I/Os remain in high-impedance regardless of supply ramp order. The device's power-down mode (activated by OE = LOW + missing VL or VCC) prevents back-driving or bus contention, satisfying IEC 61000-4-2 Class B ESD immunity requirements for hot-plug interfaces.