STMicroelectronics TSX339IQ4T

Overview

TSX339IQ4T from STMicroelectronics is a micropower quad CMOS voltage comparator in QFN16 3×3 package, featuring 5 µA typical supply current per comparator, 1 pA typical input bias current, and open-drain outputs compatible with 2.7–16 V single or ±1.35–±8 V dual supplies. It operates across –40 °C to +125 °C and is qualified for automotive applications.

For engineers reviewing the TSX339IQ4T datasheet, TSX339IQ4T pinout, TSX339IQ4T application, or TSX339IQ4T equivalent, key selection criteria include ultra-low quiescent current, rail-to-rail input common-mode range including ground, fast 2 µs response at 5 mV overdrive, and compatibility with legacy TS339 designs in TSSOP14/SO14 packages.

Technical Context

The TSX339IQ4T integrates four independent high-impedance comparators with CMOS input stages and open-drain NMOS output transistors. Each channel supports input common-mode voltages from ground to (V_CC+ − 1.5 V) and tolerates inputs up to 16 V regardless of supply-enabling direct sensing of overvoltage or battery-monitoring signals without level-shifting.

Its architecture delivers 73 dB typical common-mode rejection and 88 dB typical supply voltage rejection at 5 V, with propagation delay tightly controlled across 3–16 V supply range and temperature. The exposed thermal pad in QFN16 3×3 improves thermal resistance to 39 °C/W, critical for sustained operation in compact automotive ECUs.

Key Specifications

Pinout & Package

TSX339IQ4T uses a 3 mm × 3 mm QFN16 package with 0.5 mm pitch and an exposed thermal pad (not internally connected; may be tied to V_CC− or left floating). Pin 1 is marked by a dot; top-view pin numbering follows standard QFN convention.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad micropower comparator applications.

Compared with TS339IPT, TSX339IQ4T reduces supply current by 50% and adds automotive qualification; versus TSX3704IPT, it trades push-pull convenience for 3× lower quiescent current and open-drain flexibility in shared-bus monitoring.

Availability

TSX339IQ4T is available at Aetrix Electronics and suitable for automotive battery management, industrial motor protection, cabin climate control, and sensor signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TSX339IQ4T 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The TSX339 product line targets ultra-low-power analog signal conditioning in harsh-environment applications, with emphasis on automotive-grade reliability, extended temperature operation, and footprint scalability from SO14 to QFN16.

FAQ

What is the maximum input voltage allowed on TSX339IQ4T pins relative to V_CC+?

The absolute maximum rating allows input voltages up to 16 V regardless of V_CC+ level, and the datasheet confirms one input may be driven above V_CC+ while the other remains within 0 V to (V_CC+ − 1.5 V). This enables direct battery-sensing without clamping diodes in many cases, though external protection is recommended if inputs exceed 16 V or fall below –0.3 V.

Can unused comparators be left floating, or do they require termination?

Unused comparators must not be left floating: the datasheet specifies connecting both inputs to V_CC+ or V_CC− (Figure 18) to prevent oscillation and excess current draw. Floating inputs cause undefined output states and increase supply current beyond the rated 5 µA per active comparator, potentially violating low-power design goals in battery-operated systems.

Is the exposed thermal pad on the QFN16 package electrically connected internally?

No - the exposed pad is not internally connected to any die node and serves only a thermal function. ST's datasheet explicitly states it "can be connected to V_CC− or left floating." Grounding it to V_CC− improves thermal dissipation (R_thJA = 39 °C/W), but leaving it unconnected does not affect electrical performance or reliability under normal operating conditions.

How does the TSX339IQ4T differ from the TS339 in terms of ESD robustness and temperature range?

TSX339IQ4T improves on TS339 with 4 kV HBM ESD tolerance (vs. unspecified/legacy 2 kV for TS339) and full AEC-Q100 qualification for –40 °C to +125 °C operation. The TS339 was specified only for commercial or industrial grades; TSX339IQ4T's automotive qualification includes enhanced latch-up immunity (200 mA) and guaranteed performance across the full automotive temperature range with tighter offset and bias current specs.