QS3VH253QG8 - 2.5/3.3V Dual 4:1 Mux/Demux Bus Switch | Renesas
料号： QS3VH253QG8 ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.62 | $1.62 |
| 10 | $1.45 | $14.50 |
| 100 | $1.28 | $128.00 |
| 500 | $1.1 | $550.00 |
| 1,000 | $0.95 | $950.00 |
QS3VH253QG8 概述
A bus switch (also called a passive switch or mux/demux) is a digital signal-routing IC that uses MOSFET pass gates to connect a common node to one of several inputs, behaving much like a high-speed analog mux but without the level shifter. In a system hierarchy, the bus switch sits below a multiplexer/demultiplexer and above discrete analog switches; it is part of the interface-IC family used for memory, peripheral, and backplane signal fan-out. QuickSwitch devices leverage the absence of a parasitic body diode to eliminate power-sequencing pitfalls common to conventional FET switches.
Key features include dual-channel 4:1 mux/demux function (two independent 4-to-1 switches per IC), very low ON-resistance (Ron) keeping signal integrity intact at 2.5V or 3.3V nominal rails, propagation delay under 250ps, no DC path to VCC, isolation under power-off conditions, and a wide operating temperature range of -40C to +85C. The 16-pin QSOP Green package makes the part suitable for SMT assembly on standard digital rails.
The architecture relies on N-channel MOSFET pass gates whose sources and drains are symmetric, allowing bidirectional signal flow. The lack of a parasitic diode to VCC eliminates latch-up concerns when signals cross the VCC rail during hot-insertion or partial power-down. The combination of low Ron and sub-250ps delay enables the device to pass DDR, SPI, and other high-speed edges without significant distortion up to several hundred MHz, depending on capacitive loading.
Typical applications include high-speed signal multiplexing on PCBs, DDR memory fan-out in networking and server platforms, SPI/PCIe/peripheral bus demultiplexing, logic isolation between power domains, and clock or GPIO steering in test and measurement systems. The dual 4:1 structure is particularly useful when two independent channels must share one device.
When designing with the QS3VH253QG8, place decoupling capacitors close to VCC and observe the data-sheet-defined enable logic. Unused select inputs should be tied to a defined logic level (VCC or GND) to prevent floating selections that could cause unwanted channel activation.
This page synthesizes distributor pricing, drop-in alternatives sourced from cross-reference data, and practical design notes that are not duplicated in the manufacturer datasheet.
直接替换替代料： QS3VH253QG8 ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
QS3VH257QG8
✅ 直接替换📋 参考替代料（不在目录中）
QS3VH253QG
✅ 直接替换📋 参考替代料（不在目录中）
QS3VH253Q
✅ 直接替换📋 参考替代料（不在目录中）
QS3VH253QG8 最大额定值与电气特性
| 功能 | Dual 4:1 Mux/Demux (Bus Switch) |
| Number of Channels | 2 independent switches |
| Configuration | 2 x 4:1 mux/demux |
| Supply Voltage (VCC) | 2.5 V / 3.3 V nominal |
| Device Type | QuickSwitch high-bandwidth bus switch |
| Switch Technology | N-channel FET pass transistors, no parasitic diode to VCC |
| Propagation Delay | < 250 ps |
| ON Resistance (Ron) | Very low (see datasheet for exact value) |
| Power-Off Isolation | Yes (no DC path to VCC) |
| 工作温度范围 | -40 C to +85 C |
| 封装 | 16-QSOP (Green) |
| 安装类型 | Surface Mount |
| 引脚数量 | 16 |
| RoHS 状态 | Compliant |
| Lead-Free | Yes (Green package) |
QS3VH253QG8 引脚配置
| 引脚 1 | 1A0 — Channel 1, Source/Drain 0 |
| 引脚 2 | 1A1 — Channel 1, Source/Drain 1 |
| 引脚 3 | 1A2 — Channel 1, Source/Drain 2 |
| 引脚 4 | 1A3 — Channel 1, Source/Drain 3 |
| 引脚 5 | 1Y — Channel 1, Common output |
| 引脚 6 | 1S0 — Channel 1, Select bit 0 |
| 引脚 7 | 1S1 — Channel 1, Select bit 1 |
| 引脚 8 | GND — Ground |
| 引脚 9 | 2Y — Channel 2, Common output |
| 引脚 10 | 2S0 — Channel 2, Select bit 0 |
| 引脚 11 | 2S1 — Channel 2, Select bit 1 |
| 引脚 12 | 2A3 — Channel 2, Source/Drain 3 |
| 引脚 13 | 2A2 — Channel 2, Source/Drain 2 |
| 引脚 14 | 2A1 — Channel 2, Source/Drain 1 |
| 引脚 15 | 2A0 — Channel 2, Source/Drain 0 |
| 引脚 16 | VCC — Positive supply voltage |
典型应用
QS3VH253QG8 适用于 6 应用s: DDR Memory Address Fan-Out, SPI/QSPI Peripheral Multiplexing, Clock Routing and Fan-Out, PCB-Level Logic Isolation and Muxing, Test and Measurement Signal Routing, Networking Line-Card Signal Aggregation.
DDR Memory Address Fan-Out
The QS3VH253QG8's under 250ps propagation delay and very low ON-resistance make it well suited for fan-out of DDR memory address and control signals across multiple ranks. In a typical topology, the host memory controller feeds a dual 4:1 mux that selects between memory banks, DIMM slots, or ECC/ECC-off configurations; the QuickSwitch pass-gate preserves edge rates and minimizes added jitter. Because the N-channel FETs have no parasitic diode to VCC, partial power-down of one memory domain does not back-power the controller - a critical safety feature for hot-swap memory subsystems. The 16-QSOP footprint consumes minimal PCB area near the DIMM connector.
推荐
SPI/QSPI Peripheral Multiplexing
The dual 4:1 topology of the QS3VH253QG8 lets a single MCU route two independent SPI or QSPI buses (SCLK, MOSI, MISO, and CS) to four peripheral targets each, sharing the IC across two systems. Sub-250ps propagation delay keeps the IC's added delay well below a half SPI clock period even at 50 MHz bus speeds, so the mux is transparent to the SPI state machine. The low ON-resistance minimizes loading on the SPI driver, allowing standard CMOS push-pull output stages to drive the bus to four peripherals without additional buffering. The QuickSwitch architecture's lack of a parasitic diode to VCC also prevents contention when peripherals are individually powered down.
推荐
Clock Routing and Fan-Out
Clock-distribution networks demand minimal added jitter, which the QS3VH253QG8 supports through its sub-250ps propagation delay and symmetric pass-gate structure. Each of the two 4:1 switches can route a primary clock to four endpoints (PLLs, ADC sample clocks, FPGA clock pins) or multiplex between redundant clock sources; the bidirectional nature of the pass-gate also enables demultiplexing a clock back to its source for diagnostics. Low Ron keeps channel-to-channel skew tight, while the 16-QSOP footprint allows placement close to the clock buffer for short PCB traces and controlled impedance. Designers typically damp the bus with series resistors near the IC to absorb residual mismatch on fast edges.
推荐
PCB-Level Logic Isolation and Muxing
The QS3VH253QG8 is widely used for logic isolation between power domains, allowing a 2.5V controller to share a bus with a 3.3V peripheral via the part's bidirectional pass-gate. Its under 250ps delay avoids the half-period pitfalls of slower isolators, and the no-DC-path-to-VCC feature eliminates back-powering when one domain powers down. Per channel, four sources can be selected, giving the designer two independent isolation paths per 16-QSOP package. Decoupling caps close to VCC and well-defined select-line termination prevent floating-select oscillation during power transitions.
推荐
Test and Measurement Signal Routing
ATE and bench-instrument designs use the QS3VH253QG8 to multiplex test signals between DUTs and instrument channels. The two 4:1 switches let one instrument drive up to eight DUT nodes (two channels times four ports each) without relay trees, providing sub-250ps switching and full DC isolation of unused lines via the no-parasitic-diode topology. Low ON-resistance is critical when routing milliamp-level analog or logic signals because it limits ground shift; the 16-QSOP package supports high-density matrix designs. Designers should add ESD protection at the instrument-facing pins and verify that the IC's bandwidth matches the test signal's highest harmonic.
推荐
Networking Line-Card Signal Aggregation
In networking line cards, the QS3VH253QG8 aggregates low-speed control or status GPIO buses from line-card PHYs into an aggregation FPGA or management controller, supporting two 4-to-1 paths per IC with sub-250ps delay. The QuickSwitch topology ensures that a powered-down line-card PHY cannot back-power the management controller through the bus, a common failure mode in conventional FET switches. The 16-QSOP footprint enables placement behind the connector pin field, keeping stub lengths short on multi-MHz LVCMOS buses; combined with a low-ESR decoupling network, the IC provides transparent switching for housekeeping signals.
推荐
推荐产品汇总
工程参考数据： QS3VH253QG8 ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | QS3VH257QG8 | QS3VH253QG | QS3VH253Q |
|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | 16-QSOP (Green) | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same |
| Function | Dual 4:1 Mux/Demux Bus Switch | Dual 4:1 Mux/Demux Bus Switch | Dual 4:1 Mux/Demux Bus Switch | Dual 4:1 Mux/Demux Bus Switch |
| Supply Voltage | 2.5V / 3.3V nominal | 5V tolerant (3.3V/5V systems) | 2.5V / 3.3V nominal - same | 2.5V / 3.3V nominal - same |
| Propagation Delay | < 250 ps | < 250 ps | < 250 ps | < 250 ps |
| Channel Count | 2 channels x 4:1 | 2 channels x 4:1 | 2 channels x 4:1 | 2 channels x 4:1 |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| RoHS / Lead-Free | Yes (Green) | Yes (Green) | Depends on lot | Depends on lot |
关键差异点
- QuickSwitch topology removes parasitic body diode to VCC （对比 QS3VH257QG8)
- Sub-250ps propagation delay in a passive pass-gate （对比 QS3VH253QG)
- Dual 4:1 in a 16-QSOP footprint （对比 QS3VH253Q)
设计说明
The QS3VH253QG8 features very low ON-resistance and under 250ps propagation delay, but the IC is a passive FET pass-gate and does not buffer - the driver's impedance and the bus capacitance set the actual edge rate. Place the IC close to the driver to minimize stub length, and consider a small series resistor (22-33 ohm) on each Y output to damp reflections when switching into capacitive loads above ~10 pF. With two independent 4:1 channels, route them on orthogonal layers to avoid crosstalk between channels carrying unrelated signals.
Even though the QS3VH253QG8 has no DC path to VCC (no parasitic body diode to the supply rail), it still requires clean VCC rails for predictable performance. Place a 0.1 uF X7R ceramic bypass capacitor within 50 mils of the VCC pin, with a 1 uF bulk capacitor to handle the transient current when the pass gates turn on simultaneously across two channels. Avoid powering VCC before the input signals stabilize to prevent uncontrolled inrush through the FET gates.
Do not exceed the absolute maximum ratings on the pass-gate drain and source pins with respect to VCC - using the QS3VH253QG8 on a 5V signal when VCC is 3.3V can forward-bias and permanently damage the FETs. If 5V tolerance is required, choose the QS3VH257QG8 instead. Also, unused select inputs (S0/S1) must be tied to a defined logic level (VCC or GND); leaving them floating can cause channel-bleed and partial selection, leading to crosstalk and unpredictable switching.
合规信息
RoHS compliant and supplied in Renesas Green (Pb-free, halogen-free) 16-QSOP package; not AEC-Q100 qualified - this part targets commercial/industrial logic-routing, not automotive.
