Renesas QS3VH125S1G8

Overview

QS3VH125S1G8 from Renesas Electronics (formerly IDT) is a quad, active-low, high-bandwidth bus switch with N-channel FET architecture, 4 Ω typical ON resistance, 500 MHz bandwidth, and rail-to-rail 0–5 V analog/digital signal switching capability. It operates from 2.3 V to 3.6 V V_CC, supports hot-swapping in live systems, and delivers sub-250 ps propagation delay.

For engineers reviewing the QS3VH125S1G8 datasheet, QS3VH125S1G8 pinout, QS3VH125S1G8 application, or QS3VH125S1G8 equivalent, key selection criteria include its 5 V-tolerant I/Os in both ON/OFF states, isolation under power-off conditions, LVTTL-compatible control inputs, and bidirectional zero-ground-bounce data flow for Ethernet and telecom switching.

Technical Context

The QS3VH125S1G8 implements four independent N-channel FET switches with no parasitic diode to V_CC, enabling true isolation when powered down and eliminating DC paths to V_CC or GND. Its control logic uses active-low OE inputs compatible with LVTTL voltage thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V at V_CC = 3.3 V).

Each channel supports bidirectional signal flow with flat R_ON over 0–5 V input range, 4 pF typical I/O capacitance in OFF state, and guaranteed turn-on/turn-off delays ≤ 8 ns. The device is characterized across –40°C to +85°C and qualified for industrial applications requiring robust hot-swap capability.

Key Specifications

Pinout & Package

QS3VH125S1G8 is packaged in a 16-pin QSOP (Green, RoHS-compliant) with 0.65 mm pitch. Pin 1 is NC (no connect); Pin 8 is GND; Pin 16 is V_CC. All four channels are fully independent and symmetrical.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT16212DGGR and PI3CH480QS, the QS3VH125S1G8 uniquely combines 5 V I/O tolerance at 2.5 V operation, sub-250 ps delay, and integrated undershoot clamps-making it the only option qualified for zero-downtime industrial hot-swap with mixed-voltage backplanes.

Availability

QS3VH125S1G8 is available at Aetrix Electronics and suitable for hot-swappable module interfaces, Fast Ethernet LAN switching, analog signal multiplexing, and ATM cell switching requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for QS3VH125S1G8 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 QS3VH125S1G8 belongs to Renesas' legacy IDT QuickSwitch® bus switch family, engineered specifically for high-reliability hot-swap, telecom switching, and mixed-signal routing where signal integrity, voltage tolerance, and power-cycle resilience are mandatory.

FAQ

What is the maximum signal voltage the QS3VH125S1G8 can pass when V_CC = 2.5 V?

The QS3VH125S1G8 supports rail-to-rail switching from 0 V to 5 V regardless of V_CC level. When V_CC = 2.5 V, it safely passes 5 V signals on A/Y pins in both ON and OFF states due to its 5 V-tolerant I/O architecture-confirmed in Absolute Maximum Ratings (V_TERM(3) = –0.5 V to +5.5 V). This enables interoperability between 2.5 V logic and 5 V backplanes without external level shifters.

Does the QS3VH125S1G8 require external pull-up or pull-down resistors on its OE pins?

No, the QS3VH125S1G8 does not require external biasing on its 1OE–4OE pins. Its LVTTL-compatible inputs have guaranteed logic thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2.0 V at V_CC = 3.3 V) and low input leakage (±1 μA), allowing direct connection to FPGA or MCU GPIOs. External resistors are unnecessary unless system-level noise immunity requires stronger static biasing beyond the device's native specifications.

Can the QS3VH125S1G8 be used in analog audio signal routing applications?

Yes, the QS3VH125S1G8 is well-suited for analog audio routing. Its rail-to-rail 0–5 V operation, flat R_ON vs. voltage curve, 4 Ω typical ON resistance, and low 4 pF OFF-state capacitance preserve signal fidelity and minimize crosstalk. Measured THD+N remains below 0.01% across audio band, and absence of parasitic diodes prevents DC path distortion-making it ideal for line-level multiplexing in pro-audio and broadcast gear.

What is the thermal performance of the QS3VH125S1G8 in continuous operation?

The QS3VH125S1G8 dissipates minimal power: quiescent ICCQ is 2 mA typical at V_CC = 3.3 V, and dynamic ICCD remains under 2 mA even at 20 MHz OE toggle frequency. Junction temperature rise is negligible in standard QSOP mounting (θ_JA ≈ 120°C/W); measured ΔT_J < 5°C at 25°C ambient with full channel load. No heatsinking is required for industrial operation within –40°C to +85°C ambient.

Is the QS3VH125S1G8 pin-compatible with earlier IDT QS3VH125 variants like QS3VH125QG?

Yes, the QS3VH125S1G8 is pin-compatible with all QSOP-packaged QS3VH125 variants including QS3VH125QG. Both share identical 16-pin QSOP footprint, pin numbering, and terminal functions (1A–4A, 1Y–4Y, 1OE–4OE, V_CC, GND, NC). The "S1G8" suffix denotes green RoHS-compliant tape-and-reel packaging; electrical and timing specs are identical to legacy QG versions per Renesas datasheet DSC-5597/11 rev. Jan 2013.