Diodes Incorporated PI5C3244QE

Overview

PI5C3244QE from Pericom Semiconductor is an 8-bit, dual-port bus switch IC with two independent 4-bit bidirectional switch banks (1A/1B and 2A/2B), pinout- and function-compatible with 74FCT244T, 74F244, and 74ALS/AS/LS244 logic drivers. It features near-zero propagation delay (0.25 ns), 5 Ω typical on-resistance, ultra-low quiescent current (0.2 µA typical), and operates at 5 V ±5% over –40°C to +85°C for notebook and low-power embedded bus isolation.

For engineers reviewing the PI5C3244QE datasheet, PI5C3244QE pinout, PI5C3244QE application, or PI5C3244QE equivalent, key selection criteria include its dual active-low enable control (BE1/BE2), direct analog bus connection without added ground bounce, 50 pF load-compatible switching, and Pb-free QSOP-20 packaging for space-constrained PCB layouts.

Technical Context

The PI5C3244QE implements eight independent transmission-gate-based bus switches organized as two 4-bit ports, each controlled by a dedicated active-low enable (BE1 for Port 1, BE2 for Port 2). Its architecture eliminates propagation delay beyond RC time constant (RON × CL), delivering transparent signal path behavior when enabled.

Each switch exhibits rail-to-rail analog conduction with no level-shifting or logic interpretation - inputs and outputs are directly connected via low-resistance MOSFET paths. Control pins feature TTL-compatible thresholds (VIH = 2.0 V, VIL = 0.8 V) and 150 mV hysteresis to suppress noise-induced toggling.

Key Specifications

Pinout & Package

PI5C3244QE is packaged in a Pb-free & Green 20-pin QSOP (Quad Small Outline Package), 150-mil wide, with 0.65 mm lead pitch and gull-wing leads. The package meets JEDEC MO-137 standards and supports reflow soldering per IPC/JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit dual-port bus switch applications.

Compared with SN74CBTD244PW and PI5C3245QE, the PI5C3244QE delivers the lowest quiescent current and tightest RON tolerance - making it optimal for portable, thermally constrained, or high-density bus-isolation designs where power and signal fidelity are co-prioritized.

Availability

PI5C3244QE is available at Aetrix Electronics and suitable for high-speed notebook memory expansion, industrial PLC I/O module isolation, and PCIe slot multiplexing requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for PI5C3244QE 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

Pericom Semiconductor was a fabless provider specializing in high-speed interface, timing, and signal-integrity solutions before its acquisition by Diodes Incorporated in 2016. Its products targeted data center, communications, and portable electronics markets.

The PI5C3244QE belongs to Pericom's PI5C family of low-voltage, low-power bus switches designed specifically for transparent, zero-delay signal routing in space- and power-constrained embedded systems.

FAQ

What is the maximum capacitive load the PI5C3244QE can drive while maintaining specified propagation delay?

The PI5C3244QE is characterized for CL = 50 pF in switching specifications, with tPLH/tPHL guaranteed at 0.25 ns. Its RON–CL time constant remains <0.3 ns up to 100 pF, but system-level rise/fall times may degrade above 50 pF due to driver capability limitations - verify with actual source impedance and load in target application.

Can PI5C3244QE operate reliably with 3.3 V logic levels on its A/B ports while powered at 5 V?

Yes. The PI5C3244QE supports input/output voltages from –0.5 V to +7.0 V independent of VCC, enabling safe 3.3 V signal pass-through on A/B pins when VCC = 5 V. No level shifting is needed, and RON remains stable across this range per datasheet characterization.

Is thermal derating required when operating at 85°C ambient with full 20-pin I/O loading?

No thermal derating is required. At TA = +85°C and VCC = 5.25 V, total power dissipation remains below 0.5 W (max rating) - worst-case ICC × VCC + IOUT² × RON sums to <12 mW. The QSOP package's θJA of ~120°C/W ensures junction temperature stays within safe limits.

Does PI5C3244QE require external pull-up or pull-down resistors on BE1/BE2 enable pins?

No. BE1 and BE2 have CMOS-compatible input structure with ±1 µA leakage (IIH/IIL) and defined VIH/VIL thresholds. They may be driven directly from microcontroller GPIO or logic gates. Pull resistors are unnecessary unless floating-state prevention is required during power-up sequencing.