Diodes Incorporated PI5C3244S

Overview

PI5C3244S 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), and operates at 5 V ±5% over –40°C to +85°C for high-speed digital bus isolation in notebook and embedded systems.

For engineers reviewing the PI5C3244S datasheet, PI5C3244S pinout, PI5C3244S application, or PI5C3244S equivalent, key selection criteria include its bidirectional low-R_ON switching behavior, dual active-low enable control (BE1/BE2), absence of ground bounce or added propagation delay, and compatibility with legacy 74-series logic footprints in SOIC-20 packaging.

Technical Context

The PI5C3244S implements eight independent analog bus switches-four per port-controlled by separate active-low enables (BE1, BE2), enabling selective connection between A-side and B-side buses without directionality constraints. Each switch exhibits a typical on-resistance of 5 Ω at V_CC = 4.75 V and I_ON = 48 mA, with <12 pF on-state capacitance and <6 pF off-state capacitance.

Its logic-level compatible control inputs accept TTL/CMOS thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V), while the A/B terminals support rail-to-rail analog/digital signal pass-through up to 7.0 V, with no internal level-shifting or buffering-ensuring transparent signal integrity for high-speed data paths.

Key Specifications

Pinout & Package

PI5C3244S is housed in a 20-pin 300-mil wide plastic SOIC (Small Outline Integrated Circuit) package with standard 1.27 mm pitch, RoHS-compliant and Pb-free options available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3244DBR and 74LVC244APW, the PI5C3244S delivers superior signal transparency (no added delay, no output loading), lower static power, and true analog bidirectional switching-making it optimal for low-noise, low-latency bus isolation where signal integrity and power efficiency are critical.

Availability

PI5C3244S is available at Aetrix Electronics and suitable for notebook docking interfaces, industrial backplane routing, and PCI Express slot sharing requiring stable component supply and long-term manufacturability.

Supply support for PI5C3244S 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 of high-speed interface and timing solutions, acquired by Diodes Incorporated in 2016; its legacy bus switch portfolio remains widely deployed in industrial and computing platforms.

The PI5C3244S belongs to Pericom's PI5C family of low-R_ON CMOS bus switches, designed specifically for transparent, low-noise, low-power signal routing in 5 V digital systems where compatibility with 74-series logic footprints is essential.

FAQ

What is the maximum signal voltage that can be passed through the PI5C3244S switches?

The PI5C3244S supports rail-to-rail analog/digital signal pass-through up to 7.0 V on A/B terminals, independent of V_CC, as confirmed by absolute maximum ratings. This allows safe handling of 3.3 V, 5 V, and mixed-voltage signals without level shifting, provided V_CC is maintained at 4.75–5.25 V for proper enable logic operation.

Can BE1 and BE2 be tied together for single-enable operation?

Yes - BE1 and BE2 may be connected to a common enable signal to activate both 4-bit ports simultaneously. The truth table confirms identical behavior when both enables are asserted low, resulting in full 8-bit connectivity (1A=1B and 2A=2B). No additional external logic or pull-up resistors are required for this configuration.

Does the PI5C3244S require external decoupling capacitors?

Yes - a 0.1 µF ceramic capacitor placed close to the V_CC (Pin 11) and GND (Pin 20) pins is recommended to suppress high-frequency switching noise and ensure stable enable logic operation. This is consistent with standard practice for CMOS bus switches and is implied by the device's 120 mA output current rating and fast switching characteristics.

Is the PI5C3244S pinout identical to the 74F244 in all package variants?

Yes - the PI5C3244S maintains identical pin numbering and signal mapping to the 74F244 in SOIC-20 (S), QSOP-20 (Q), and TSSOP-20 (L) packages, including BE1/BE2 placement matching OE1/OE2 and A/B terminal ordering. This enables direct PCB footprint reuse without layout modification across all three package types.