ISL8484IUZ - Dual SPDT Analog Switch, 0.29 Ohm | Renesas
料号： ISL8484IUZ ✓ 量产中ISL8484IUZ 概述
An analog switch (also called a mux or multiplexer) is an integrated circuit that steers a signal path between multiple sources and destinations under digital control. It belongs to the signal-path hierarchy: analog switch -> multiplexer -> interface IC -> integrated circuit. Unlike a relay or mechanical contactor, it switches in nanoseconds, draws micro-watts of power, and introduces only a small, well-characterized series resistance plus a few picofarads of parasitic capacitance.
Key features of the ISL8484IUZ include very low ON-resistance that stays flat across the signal range, excellent channel-to-channel rON matching of 0.06 ohm, low power consumption below 0.45 microwatts, fast switching of 40 ns tON and 20 ns tOFF at V+ = 4.3 V, guaranteed break-before-make behavior, and an HBM ESD rating of greater than 8 kV. The manufacturer also documents the ISL8484 family as a pin-compatible replacement for the MAX4684 and MAX4685.
Because ON-resistance is only 0.29 ohm and rON flatness across the signal range is 0.03 ohm, the device behaves almost like a shorted trace when closed. This makes it well suited to routing low-frequency analog signals, sensor outputs, reference voltages, and baseband paths where added resistance would degrade accuracy. The very low switching energy keeps the switch usable in battery-powered and portable equipment.
Typical uses include audio and headphone signal routing, portable test equipment, battery-powered sensor interfaces, USB and peripheral routing in low-voltage designs, and general-purpose analog multiplexing in consumer and industrial systems running from 1.8 V to 3.3 V rails.
The key design consideration is supply headroom: the switch operates down to +1.65 V, but ON-resistance rises sharply as V+ falls (0.55 ohm at 1.8 V versus 0.29 ohm at 4.3 V). Budget the signal-path error against the highest rail in your system, and treat the control pins as logic inputs referenced to the same V+ supply.
直接替换替代料： ISL8484IUZ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
ISL8484IUZ-T
✅ 直接替换📋 参考替代料（不在目录中）
ISL8484IU-T
✅ 直接替换📋 参考替代料（不在目录中）
MAX4684
✅ 直接替换📋 参考替代料（不在目录中）
MAX4685
✅ 直接替换📋 参考替代料（不在目录中）
ISL8484IUZ 最大额定值与电气特性
| Device Type | Analog Switch, Dual SPDT (2 Circuit IC Switch 2:1) |
| Number of Switches | 2 |
| Switch Configuration | SPDT (single-pole, double-throw) |
| Supply Voltage Range | +1.65 V to +4.5 V (single supply) |
| ON-Resistance at V+ = 4.3 V | 0.29 ohm |
| ON-Resistance at V+ = 3.0 V | 0.33 ohm |
| ON-Resistance at V+ = 1.8 V | 0.55 ohm |
| rON Matching Between Channels | 0.06 ohm |
| rON Flatness Across Signal Range | 0.03 ohm |
| Power Consumption | < 0.45 uW |
| Turn-On Time (tON) at V+ = 4.3 V | 40 ns |
| Turn-Off Time (tOFF) at V+ = 4.3 V | 20 ns |
| ESD HBM Rating | > 8 kV |
| Break-Before-Make | Guaranteed |
| 封装 | 10-MSOP (10-TFSOP), 3.00 mm width |
| 引脚数量 | 10 pins |
| 安装类型 | Surface Mount |
| Lead-Free / Termination Finish | Pb-free, 100% matte tin e3 termination, RoHS compliant |
| Documented Pin-Compatible Replacement For | MAX4684 and MAX4685 |
ISL8484IUZ 引脚配置
| 引脚 1 | V+ — Positive supply input, +1.65 V to +4.5 V |
| 引脚 2 | GND — Ground reference |
| 引脚 3 | IN1 — Logic select input for switch 1 |
| 引脚 4 | IN2 — Logic select input for switch 2 |
| 引脚 5 | D1 — Switch 1 drain / common node |
| 引脚 6 | S1 — Switch 1 source, throw A |
| 引脚 7 | A1 — Switch 1 source, throw B |
| 引脚 8 | D2 — Switch 2 drain / common node |
| 引脚 9 | S2 — Switch 2 source, throw A |
| 引脚 10 | A2 — Switch 2 source, throw B |
典型应用
ISL8484IUZ 适用于 6 应用s: Portable Audio Signal Routing, Battery-Powered Sensor Signal Multiplexing, Low-Voltage Test and Measurement Equipment, Battery Management and Power-Path Routing, Consumer and Industrial Peripheral Interface Switching, Portable and Wearable Device Interconnect.
Portable Audio Signal Routing
The ISL8484IUZ fits portable audio routing because it offers two independent SPDT paths in a single +1.65 V to +4.5 V supply with 0.29 ohm ON-resistance at 4.3 V. With rON flatness of 0.03 ohm across the signal range, the closed switch adds almost no frequency-dependent insertion loss, so headphone or microphone paths stay spectrally flat instead of showing a low-pass roll-off. Power consumption below 0.45 microwatts keeps the idle cost of standby signal paths negligible in a phone or headset, while the guaranteed break-before-make action avoids momentarily tying the amplifier output to two sources. At a 1.8 V battery rail, budget the higher 0.55 ohm ON-resistance in your insertion-loss calculation.
推荐
Battery-Powered Sensor Signal Multiplexing
For multiplexing low-frequency sensor outputs in battery-powered devices, the ISL8484IUZ combines a very low 0.29 ohm ON-resistance at 4.3 V with power consumption below 0.45 microwatts, so the switch contributes negligible error and near-zero drain. Its 0.06 ohm channel-to-channel rON matching means that the same gain calibration applies whichever throw is selected, which simplifies per-channel error budgets in resistive or bridge sensors. The 20 ns tOFF and 40 ns tON times at 4.3 V allow fast scan rates, and the single-supply operation from +1.65 V to +4.5 V maps directly onto 1.8 V and 3.0 V coin-cell rails. Guard against supply droop: ON-resistance climbs to 0.55 ohm at 1.8 V.
推荐
Low-Voltage Test and Measurement Equipment
Handheld meters and portable instruments benefit from the ISL8484IUZ because ON-resistance flatness of 0.03 ohm across the signal range keeps measurement error nearly independent of input level, and 0.06 ohm channel matching limits probe-switching offsets. The 10-MSOP footprint leaves board area for precision resistors and reference components in a compact handheld enclosure, and the sub-0.45 microwatt consumption avoids loading the low-current shunt in battery-operated meters. Break-before-make operation keeps the input from being connected to two ranges at once during range switching, which protects both the source and the instrument front end. Verify the injection error budget at the lowest supply you use, since rON roughly doubles between 4.3 V and 1.8 V.
推荐
Battery Management and Power-Path Routing
In power-path architectures the ISL8484IUZ can steer a cell or external supply onto a load rail without the quiescent draw of a larger multiplexer, since consumption stays below 0.45 microwatts. The 0.29 ohm ON-resistance at 4.3 V limits conduction loss when routing charger current, and the guaranteed break-before-make behavior avoids the momentary source overlap that a naive MOSFET back-to-back switch can create. Because the part is specified from +1.65 V to +4.5 V single supply, it fits directly across 1-cell Li-ion and 3.0 V rails without level shifting. The trade-off is the 0.55 ohm ON-resistance at 1.8 V, which becomes significant for high-current charging paths and is best reserved for sensing and control routing.
推荐
Consumer and Industrial Peripheral Interface Switching
The ISL8484IUZ suits general-purpose peripheral routing in compact consumer and industrial equipment where two selectable analog paths are needed from a single low-voltage rail. With a 10-MSOP package, dual SPDT function, and 0.29 ohm ON-resistance at 4.3 V, it can replace discrete relays or a larger quad switch in end equipment such as display modules, calibration fixtures, and communication front ends. The very low switching energy supports frequent changeover without measurably affecting the standby budget of an always-connected appliance, and the greater-than-8 kV HBM ESD rating adds margin on lines that reach a connector. Choose it when signal integrity matters more than ultra-low resistance; for very high current paths, use a power FET instead.
推荐
Portable and Wearable Device Interconnect
In wearables and portable devices the ISL8484IUZ lets a designer route one shared analog node to a sensor, a display driver, or a charging interface without duplicating front-end circuitry. The 10-MSOP footprint is small enough for tight wearables boards, the single +1.65 V to +4.5 V supply spans the 1.8 V rails common in wearables, and the sub-0.45 microwatt consumption keeps standby drain from dominating a multi-day battery life. Fast 20 ns tOFF and 40 ns tON transitions at 4.3 V support quick mode switching for duty-cycled sensing, and the guaranteed break-before-make action prevents back-feed between the selected and unselected path. Note that the 0.55 ohm ON-resistance at 1.8 V should be included in divider accuracy calculations.
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推荐产品汇总
工程参考数据： ISL8484IUZ ——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 | ISL8484IUZ-T | ISL8484IU-T | MAX4684 | MAX4685 |
|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Maxim Integrated | Maxim Integrated |
| Package | 10-MSOP (10-TFSOP) | 10-MSOP (10-TFSOP) - same | 10-TFSOP / 10-MSOP (3.00 mm width) - same | 10-MSOP - same footprint | 10-MSOP - same footprint |
| Switch Configuration | Dual SPDT (2 circuits, 2:1) | Dual SPDT (2 circuits, 2:1) | Dual SPDT (2 circuits, 2:1) | Dual SPDT | Dual SPDT |
| Supply Voltage Range | +1.65 V to +4.5 V | +1.65 V to +4.5 V | +1.65 V to +4.5 V | Low-voltage single supply, same family | Low-voltage single supply, same family |
关键差异点
- Ultra-low ON-resistance with excellent flatness for an analog switch in a 10-MSOP package （对比 MAX4684)
- Very low standby power for always-on portable equipment （对比 MAX4685)
- Guaranteed break-before-make plus 20 ns turn-off （对比 ISL8484IU-T)
- HBM ESD margin above 8 kV with Pb-free RoHS-compliant e3 termination （对比 MAX4684)
设计说明
Because ON-resistance is only 0.29 ohm at V+ = 4.3 V and rON flatness across the signal range is 0.03 ohm, the closed switch adds essentially no frequency-dependent attenuation for low-frequency analog signals. Estimated insertion loss for a 50 ohm source into a 0.29 ohm switch is about 0.25 dB, and it stays essentially flat over the audio and sensor bandwidths of interest. The figure to budget is different at 1.8 V, where rON rises to 0.55 ohm, so include the worst-case supply condition in your signal-error budget. Use the pin-description table in the manufacturer datasheet when assigning PCB tracks so the common node and throws land on the correct pins.
The ISL8484IUZ consumes less than 0.45 microwatts, so standby drain in a battery design is dominated by board leakage rather than the switch itself. The practical power concern is conduction loss in the switched path: estimated dissipation is I x V x RON, for example 10 mA at 3.0 V with 0.33 ohm gives roughly 10 microwatts. Keep the switched current modest or accept the voltage drop. Remember that ON-resistance scales with supply, so a 1.8 V rail nearly doubles the path loss compared with 4.3 V, and the control inputs are referenced to the same V+ supply, so no separate level shifting is needed.
Two traps are common when laying out this part. First, guaranteed break-before-make means the common node is never connected to both throws simultaneously, so a design that relies on two throws being briefly tied together for a discharge or charge-share trick will not behave as expected. Second, switching-capacitor and switched-capacitor circuits must account for the charge injection and clock feedthrough associated with any CMOS analog switch; keep the switch control edge rates clean and use the typical characteristics in the manufacturer datasheet. Also verify the MSOP-10 land pattern against your PCB library, since the 10-TFSOP and TDFN-EP-10 options in this family have different footprints.
Place the device close to the signal source and destination so that board trace resistance does not add to the 0.29 ohm switch resistance. Keep the V+ and GND pins on a short, low-impedance path and decouple V+ locally with a high-frequency ceramic capacitor, since supply bounce shows up directly as ON-resistance modulation. Route the logic select inputs away from sensitive analog nodes to limit coupling from the 20 ns turn-off edges. The exposed 10-MSOP body is small, so plan the ground and supply pours to give the device a low-impedance return path directly beneath it.
合规信息
Manufacturer documentation states these Pb-free plastic packaged products employ Pb-free molding compounds, die attach materials, and a 100% matte tin plate plus anneal e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations. The part is not marketed as AEC-Q100 qualified.
