Diodes Incorporated PI3B3863Q

Overview

PI3B3863Q from Pericom Semiconductor is a 3.3V, 10-bit, 2-port bus switch with SSTL-2-compatible Bus Enable (BE) input, designed for high-speed memory and address/data bus isolation in DDR SDRAM systems. It features 20 Ω typical ON resistance, 3.8 ns max switching time, near-zero propagation delay, and operates across –40°C to +85°C ambient temperature.

For engineers reviewing the PI3B3863Q datasheet, PI3B3863Q pinout, PI3B3863Q application, or PI3B3863Q equivalent, key selection criteria include SSTL-2 BE compatibility, 10-bit bidirectional switching capability, QSOP-24 package footprint, low R_ON (17–36 Ω), and absence of added ground bounce or propagation delay in high-speed digital interfaces.

Technical Context

The PI3B3863Q implements a passive CMOS transmission gate architecture-no internal logic or level-shifting-enabling true bidirectional signal pass-through between A0–A9 and B0–B9 ports. Its BE input accepts SSTL-2 voltage thresholds (V_IL ≤ V_REF − 0.18 V, V_IH ≥ V_REF + 0.18 V) with V_REF = 1.15–1.35 V, ensuring direct interface with DDR memory controllers.

Switching is governed solely by BE state: asserted LOW enables all ten channels simultaneously; HIGH places both ports in high-impedance (Hi-Z) mode. The device draws only 1.8–2.5 mA quiescent current and exhibits 4.5 pF input capacitance and 9.5 pF ON-state capacitance, minimizing signal integrity impact on 100+ MHz buses.

Key Specifications

Pinout & Package

PI3B3863Q is housed in a 24-pin plastic QSOP (150 mil wide), pin-compatible with industry-standard 0.635 mm pitch layouts. Thermal pad not present; JEDEC MS-013 compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit bus switch applications.

Compared with PI3B3245Q and SN74CBT3245APW, the PI3B3863Q uniquely delivers 10-bit width, SSTL-2 BE compatibility, and DDR-optimized R_ON/capacitance trade-offs-making it the only drop-in solution for DDR address/data bus isolation without external level shifters or redesign.

Availability

PI3B3863Q is available at Aetrix Electronics and suitable for DDR SDRAM subsystems, memory controller interconnects, and high-speed test access architectures requiring stable component supply, consistent parametric performance, and long-term industrial temperature support.

Supply support for PI3B3863Q 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 logic portfolio remains widely deployed in memory and computing infrastructure.

The PI3B series targets high-speed digital interconnect applications-including DDR, RDRAM, and AGP-where low-latency, low-noise, and precise voltage-threshold switching are essential for signal integrity.

FAQ

What is the function of the VREF pin on PI3B3863Q?

The VREF pin sets the reference voltage for the SSTL-2-compatible Bus Enable (BE) input. It must be supplied with a stable 1.25 V ±0.1 V (typically from DDR memory controller's VREF net) to ensure correct BE logic interpretation-V_IH ≥ V_REF + 0.18 V and V_IL ≤ V_REF − 0.18 V. No internal regulation is provided; external decoupling is required.

Can PI3B3863Q operate with 2.5 V or 1.8 V supplies?

No. PI3B3863Q is specified exclusively for 3.3 V ±5% operation. Its R_ON, switching speed, and SSTL-2 BE thresholds are characterized only at VCC = 3.3 V. Operation outside this range violates Absolute Maximum Ratings and invalidates all AC/DC specifications-including 17–36 Ω R_ON and 3.8 ns t_PHL.

Is PI3B3863Q pin-compatible with PI3B3863L?

Yes-both share identical pin numbering and signal mapping. The 'Q' (QSOP-24) and 'L' (TSSOP-24) variants differ only in package dimensions and thermal characteristics. PCB layout must match respective land patterns: QSOP uses 150-mil width and 0.635 mm pitch; TSSOP uses 173-mil width and same pitch.

Does PI3B3863Q require external pull-up or pull-down resistors on A/B ports?

No. The device has no internal termination and presents high-impedance (Hi-Z) when disabled. External biasing is determined solely by system topology-e.g., DDR address buses typically use controller-side pull-ups, while data lines rely on SDRAM termination. PI3B3863Q adds no DC loading in either state.