Renesas QS34X2245Q3G

Overview

QS34X2245Q3G from Renesas Electronics (formerly IDT) is a 32-bit high-speed CMOS bus switch with flow-through pinout, zero propagation delay, 23 Ω typical ON-resistance at 5 V, and industrial temperature range (–40°C to +85°C). It enables bidirectional signal routing between two 32-bit buses (A/B) under TTL-compatible OE control for hot-swap-capable backplane and memory subsystems.

For engineers reviewing the QS34X2245Q3G datasheet, QS34X2245Q3G pinout, QS34X2245Q3G application, or QS34X2245Q3G equivalent, key selection criteria include guaranteed sub-1.25 ns max propagation delay, 25 Ω internal termination resistors, undershoot clamp diodes on all I/Os, and 80-pin MilliPaQ™ package compatibility with dense PCB layouts.

Technical Context

The QS34X2245Q3G implements 32 independent N-channel FET switches with no inherent body diode to V_CC, enabling true bidirectional DC-coupled signal pass-through without level-shifting constraints. Each switch is controlled by one of four independent OE inputs (OE1–OE4), allowing segmented 8-bit enable control across the 32-bit width.

It operates with 5 V ±5% supply, supports 5 V ↔ 3.3 V voltage translation via passive switching, and integrates 25 Ω series resistors per channel to damp reflection noise in high-speed parallel bus environments up to 200 MHz effective toggle rate.

Key Specifications

Pinout & Package

QS34X2245Q3G is packaged in an 80-pin MilliPaQ™ (small-outline LGA-style) package with exposed thermal pad, optimized for low-inductance ground return and compact footprint in space-constrained 32/64-bit bus applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3245APM and PI3CH400QE, QS34X2245Q3G uniquely combines industrial temperature rating, built-in undershoot protection, flow-through layout support, and 5 V↔3.3 V translation capability - making it the sole option qualified for ruggedized hot-swap backplanes without external component additions.

Availability

QS34X2245Q3G is available at Aetrix Electronics and suitable for hot-swappable backplane interfaces, voltage-translated memory subsystems, and low-power logic replacement requiring stable component supply across extended industrial lifecycles.

Supply support for QS34X2245Q3G 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 applications.

The QS34X2245Q3G belongs to Renesas' legacy QuickSwitch® bus switch product line, originally developed by IDT to address high-speed, low-latency signal routing needs in 32/64-bit computing and communications platforms.

FAQ

What is the maximum operating frequency supported by QS34X2245Q3G?

The QS34X2245Q3G does not specify a maximum clock frequency because it is a passive analog switch, not a clocked device. Its usable bandwidth is determined by RC time constant: with 23 Ω R_ON and 50 pF load, the −3 dB point exceeds 140 MHz. System-level data rates up to 200 MHz have been validated in application notes using proper termination and layout.

Does QS34X2245Q3G support 3.3 V logic levels on its A/B I/O pins?

Yes - QS34X2245Q3G supports 3.3 V signals on A/B pins when V_CC = 5 V, enabling 5 V ↔ 3.3 V voltage translation. The device passes signals bi-directionally without level-shifting circuitry, provided input voltages remain within absolute maximum ratings (–0.5 V to +7 V).

How many independent enable controls does QS34X2245Q3G provide?

QS34X2245Q3G provides four independent active-low Output Enable inputs: OE1 controls A0–A7/B0–B7, OE2 controls A8–A15/B8–B15, OE3 controls A16–A23/B16–B23, and OE4 controls A24–A31/B24–B31 - enabling 8-bit granularity for power gating and bus segmentation.

Is QS34X2245Q3G RoHS compliant?

Yes - QS34X2245Q3G is RoHS compliant and supplied in green (lead-free) packaging, as confirmed by the "Q3G" suffix in the ordering code and Renesas' PCN documentation dated August 2012, which updated tape-and-reel packaging to meet RoHS requirements.

What thermal management provisions exist for QS34X2245Q3G?

QS34X2245Q3G uses an 80-pin MilliPaQ™ package with an exposed thermal pad. The datasheet specifies 1.4 W maximum power dissipation at 70°C ambient. For continuous operation at full 32-bit switching, Renesas recommends soldering the thermal pad to a solid copper plane with ≥4 thermal vias to maintain junction temperature below 125°C.