Renesas QS32245PAG

Overview

QS32245PAG from Renesas Electronics is an 8-bit bidirectional CMOS bus switch with TTL-compatible control inputs, 25Ω series resistors for ground bounce suppression, 18–35Ω on-resistance, and operation from –40°C to +85°C. It serves as a zero-delay, low-noise data path isolator in hot-swap interfaces and voltage-level translation between 5V and 3.3V domains.

For engineers reviewing the QS32245PAG datasheet, QS32245PAG pinout, QS32245PAG application, or QS32245PAG equivalent, key selection criteria include its bidirectional switching capability, guaranteed 1.25ns max propagation delay, industrial temperature rating, TSSOP-20 package, and compatibility with legacy 74F/74FCT245 transceiver layouts.

Technical Context

The QS32245PAG implements eight independent N-channel FET switches with no inherent body diode to V_CC, enabling true bidirectional signal flow without forward-bias constraints. Its OE-controlled switching operates with zero intrinsic propagation delay-delay arises solely from RC time constant of R_ON (≤35Ω) and load capacitance.

Each channel integrates undershoot clamp diodes on all A/B and control pins, supports DC input voltages from –0.5V to +7V, and features 25Ω integrated series resistors per I/O to dampen ground bounce during high-speed switching transitions.

Key Specifications

Pinout & Package

TSSOP-20 package (Order Code PGG20), 4.4mm × 6.5mm body, 0.65mm lead pitch, exposed pad not present. Pin 1 marked by notch or dot; pin 10 is V_CC, pin 11 is GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus switch applications.

Compared with SN74CBT3245APWR and 74FCT245CTSO20, the QS32245PAG uniquely combines pin-compatible drop-in replacement, integrated noise-damping resistors, undershoot protection, and ultra-low quiescent current-making it optimal for industrial hot-swap and low-power isolation where signal integrity and reliability are non-negotiable.

Availability

QS32245PAG is available at Aetrix Electronics and suitable for hot-swapping interfaces, voltage translation (5V ↔ 3.3V), and bus isolation applications requiring stable component supply across extended industrial temperature ranges and long production lifecycles.

Supply support for QS32245PAG 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and connectivity solutions for automotive, industrial, infrastructure, and IoT markets.

The QS32245PAG belongs to Renesas' QuickSwitch® bus switch product line, engineered specifically for high-speed, low-noise, zero-delay data path isolation in industrial and computing systems requiring hot-plug capability and voltage domain bridging.

FAQ

What is the maximum operating voltage for QS32245PAG?

The QS32245PAG supports a maximum supply voltage (V_CC) of +5.25V (5.0V ±5%). Absolute maximum ratings allow V_CC up to +7V, but functional operation is only specified within the 4.75V–5.25V range. Exceeding this range may cause parametric shift or reliability degradation. Always operate QS32245PAG within its characterized V_CC window for guaranteed timing, R_ON, and noise performance.

Does QS32245PAG support bidirectional signal flow without external direction control?

Yes, QS32245PAG provides true bidirectional signal conduction between A and B ports with no direction pin required. When OE is active low, each A_n–B_n pair functions as a passive, symmetric conductive path-enabling data flow in either direction based solely on source/sink behavior. This eliminates the need for DIR logic, simplifying design in applications like voltage translation and hot-swap isolation where direction is dynamic or undefined.

What is the purpose of the 25Ω series resistors in QS32245PAG?

The 25Ω series resistors integrated into each A and B I/O line of QS32245PAG serve to suppress ground bounce noise during simultaneous switching of multiple bits. By limiting di/dt and damping ringing caused by PCB trace inductance, they reduce voltage spikes on shared ground planes-critical in dense, high-speed digital systems. These resistors are part of the device's silicon structure and require no external components, making QS32245PAG especially suited for industrial hot-swap applications where EMI and signal integrity are tightly constrained.

Is QS32245PAG pin-compatible with standard 74-series transceivers?

Yes, QS32245PAG is pin-compatible with 74F245, 74FCT245, and 74FCT245T 8-bit transceivers in TSSOP-20 (PGG20) packaging. Its pinout matches these legacy devices exactly-including OE, A0–A7, B0–B7, V_CC, and GND locations-allowing direct substitution without PCB modification. However, unlike those transceivers, QS32245PAG lacks a DIR pin and operates as a bidirectional switch rather than a directional transceiver.

What is the guaranteed maximum propagation delay for QS32245PAG?

The guaranteed maximum propagation delay (t_PLH/t_PHL) for QS32245PAG is 1.25ns under industrial conditions (T_A = –40°C to +85°C, V_CC = 5.0V ±5%, C_LOAD = 50pF). This value represents the worst-case timing contribution of the switch itself-excluding driver and load effects. Because QS32245PAG adds no intrinsic logic delay, total system delay remains dominated by external factors, making it ideal for timing-critical isolation in high-speed buses and clock distribution networks.