MAX338CSE+ - 8-Channel CMOS Analog Multiplexer | Maxim
MPN: MAX338CSE+ ✓ Hoạt độngMAX338CSE+ Tóm tắt
What is an analog multiplexer? An analog multiplexer (MUX) is a semiconductor switch that selects one of N analog input channels and routes it to a single output line, allowing a microcontroller or ADC to "scan" many sensors or signals through a single high-performance analog front-end. Multiplexers belong to the larger family of analog switches and are foundational building blocks in data acquisition, instrumentation, audio routing, and test equipment. The MAX338 operates from a single +4.5V to +30V supply (or dual ±4.5V to ±20V supplies), giving designers wide headroom for industrial 24V rails and ±15V instrumentation racks.
Key features include low-leakage CMOS construction (typically < 1 nA at room temperature), break-before-make switching action that prevents momentary channel cross-connection, ESD protection on all logic and analog pins, and pin-compatibility with the industry-standard DG508A / DG509A, enabling direct drop-in upgrade to lower leakage. Logic inputs are TTL/CMOS compatible, simplifying interface to 3.3V and 5V microcontrollers.
The MAX338 is fabricated on a low-leakage dielectric-isolation CMOS process that minimizes parasitic capacitance and channel-to-channel charge injection. Internal logic-level translation allows the digital inputs (A0, A1, A2, EN) to be driven directly from modern microcontrollers. The device is specified over the commercial 0C to +70C temperature range, making it well suited for indoor test equipment and laboratory instrumentation rather than industrial or automotive use; for extended temperature ranges see the MAX338E variant.
Typical applications include data-acquisition front-ends scanning multiple thermocouples or analog sensors, audio signal routing in mixing consoles and broadcast equipment, automated test equipment (ATE) pin boards, instrumentation multiplexer and sample-and-hold front ends, industrial process control signal multiplexing, and medical patient-monitoring analog front ends. Designers choose it when they need more analog inputs than their ADC provides and require clean, low-leakage switching.
When designing with this device, place 0.1uF decoupling capacitors close to V+ and V- (or GND for single-supply use) and keep analog traces short to minimize crosstalk. Ensure all unused digital and analog inputs are tied to a defined logic level (not left floating) to prevent channel-to-channel leakage paths.
This page synthesizes distributor pricing, drop-in alternatives, application guidance, and pin-level design notes that complement the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho MAX338CSE+ — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MAX338CSE+ (cùng hình factor và footprint) — khác nhau ở Mounting Type, Number of Channels, Package.
MAX338CSE+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX338ESE+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX338EPE+
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MAX328CSE+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX338CSE+ Thông số kỹ thuật
| Chức năng | 8:1 analog multiplexer (or dual 4:1) |
| Number of Channels | 8 single-ended or 2x4 differential |
| On-State Resistance (RON) | 400 ohm (max 650 ohm over signal) |
| Single Supply Voltage | +4.5 V to +30 V |
| Dual Supply Voltage | +/-4.5 V to +/-20 V |
| Logic Compatibility | TTL/CMOS compatible |
| Channel Leakage | Low-leakage CMOS, ~ nA typical |
| Switching Action | Break-before-make |
| Address Lines | 3-bit binary (A0, A1, A2) |
| Enable Input | Active-low EN |
| Nhiệt độ hoạt động | 0 C to +70 C (commercial) |
| Hộp | 16-pin Narrow SOIC (NSOIC) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant (Pb-free suffix '+') |
| ESD Protection | Yes (per datasheet) |
Cấu hình chân MAX338CSE+
| Chân 1 | A0 — Address bit 0 (LSB) - TTL/CMOS logic input |
| Chân 2 | A1 — Address bit 1 - TTL/CMOS logic input |
| Chân 3 | A2 — Address bit 2 (MSB) - TTL/CMOS logic input |
| Chân 4 | EN — Active-low enable input |
| Chân 5 | S1 — Analog input channel 1 |
| Chân 6 | S2 — Analog input channel 2 |
| Chân 7 | S3 — Analog input channel 3 |
| Chân 8 | S4 — Analog input channel 4 |
| Chân 9 | S5 — Analog input channel 5 |
| Chân 10 | S6 — Analog input channel 6 |
| Chân 11 | S7 — Analog input channel 7 |
| Chân 12 | S8 — Analog input channel 8 |
| Chân 13 | D — Common analog output (drain) |
| Chân 14 | V+ — Positive analog supply |
| Chân 15 | GND — Ground (or V- for dual supply) |
| Chân 16 | NC — Not connected (or V- pin on dual-supply variant) - per datasheet NSOIC pin mapping |
Ứng dụng tiêu biểu
MAX338CSE+ phù hợp cho 6 Áp dụngs: Data Acquisition Front-End, Audio Signal Routing, Automated Test Equipment Pin Boards, Industrial Process Control Signal Routing, Medical Patient-Monitoring Analog Front End, Laboratory Instrumentation Multiplexing.
Data Acquisition Front-End
The MAX338CSE+ fits data-acquisition front-ends because its 8:1 single-ended topology lets a single ADC (such as the AD7606 or MAX1302) sequentially scan up to eight analog channels. Its 400 ohm typical on-resistance produces modest gain error when the source impedance is below ~5 kohm, while low nA-range channel leakage preserves DC accuracy for slow-moving transducer signals. In 4-wire measurement or thermocouple scanning designs the low-leakage CMOS process minimizes thermocouple-lead errors across the wide +4.5V to +30V supply range, eliminating the need for a low-leakage precision discrete alternative. The 16-pin NSOIC footprint matches typical muxer sockets or pick-and-place lines, enabling rapid board bring-up. Unlike mechanical reed-relay muxes, the MAX338CSE+ adds break-before-make switching that protects downstream sample-and-hold capacitors from momentary cross-conduction between channels.
Được đề xuất
Audio Signal Routing
Audio mixing consoles and broadcast routing matrices use the MAX338CSE+ because its low channel-to-channel crosstalk and break-before-make switching preserve audio fidelity during source changes. The 400 ohm on-resistance interacts cleanly with the high-impedance inputs of audio op-amps (such as the OPA2134 or TL072) without audible signal loss. Its wide +4.5V to +30V single-supply operation matches +/-15V studio rails, allowing the same mux to route line-level audio or microphone preamp outputs in 600-ohm balanced systems. Unlike electromechanical audio relays, the MAX338 introduces no click or pop during switching (when paired with proper zero-crossing detection), and its CMOS construction eliminates the coil-drive current that would otherwise require bulky mechanical switching hardware in production consoles.
Được đề xuất
Automated Test Equipment Pin Boards
In automated test equipment (ATE) and bench-instrument pin boards, the MAX338CSE+ provides fast solid-state switching of multiple test points back to a single measurement instrument. With TTL-compatible address inputs (A0, A1, A2), the device can be driven directly from 3.3V or 5V microcontroller GPIO without level shifters, simplifying the test-head controller firmware. Its break-before-make action prevents momentary short circuits between adjacent test points, and the 400 ohm RON adds only modest measurement error that can be calibrated out per channel. The MAX338CSE+ is well suited to production-line functional testers that scan dozens of nodes per board, replacing larger banks of reed relays with a smaller, faster, and more reliable solid-state alternative. Use it when reconfiguring test points faster than 1 ms per channel matters and the channel count is in the 2-16 range.
Được đề xuất
Industrial Process Control Signal Routing
Industrial process control loops use the MAX338ESE+ (the extended-temperature sibling of MAX338CSE+) to multiplex multiple 4-20 mA current-loop or 0-10V analog signals back to a single PLC analog input. When the +24V industrial rail is used to power V+, the MAX338 directly handles ground-referenced process signals from sensors measuring flow, pressure, or temperature. Although the MAX338CSE+ is rated only to 70C, designers should choose the MAX338ESE+ in -40C to +85C cabinets. The low-leakage CMOS construction avoids the calibration drift seen in legacy mechanical relays that can introduce tens of nanoamps of error after long service. In redundant-loop architectures two MAX338 parts can be used to route primary and backup sensor pairs to redundant PLC inputs for fail-safe operation.
Được đề xuất
Medical Patient-Monitoring Analog Front End
Patient monitoring consoles use the MAX338CSE+ to scan ECG, SpO2, respiration, and temperature channels through a single high-resolution ADC, keeping the analog signal chain short and clean. Its low channel-leakage (typically low-nA) preserves the microvolt-level ECG waveform details that mechanical relays would otherwise smear across adjacent leads. The wide supply range allows operation from +5V logic rails in compact portable patient monitors, while the NSOIC-16 footprint fits within the densely populated analog front-end area of FDA-cleared bedside units. When paired with a low-noise instrumentation amp (such as the INA128) and 24-bit sigma-delta ADC, the MAX338 supports the 0.5-150 Hz bandwidth required for diagnostic-quality ECG without contributing meaningful noise of its own.
Được đề xuất
Laboratory Instrumentation Multiplexing
Bench-top laboratory instruments (DMMs, source-measure units, scope add-ons) often use the MAX338CSE+ to multiplex reference voltages, calibration points, or stimulus signals back through a single precision ADC reference path. Its specified maximum +30V single-supply / +/-20V dual-supply operation matches the high-impedance ranges of bench DMMs measuring up to 200V. The 3-bit binary address interface lets a microcontroller or FPGA route any of the 8 inputs to the ADC with deterministic timing. Unlike smaller muxes such as the 74HC4051 (which has wider RON and higher leakage), the MAX338CSE+ preserves the calibration accuracy expected from instruments with 6.5-digit resolution. The NSOIC-16 footprint enables routing it onto the same small PCB module used in handheld multimeter designs.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX338CSE+ — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MAX338CSE+T | MAX338ESE+T | MAX338EPE+ | MAX328CSE+ |
|---|---|---|---|---|---|
| Package | NSOIC-16 (0.154 inch) | NSOIC-16 - same | NSOIC-16 - same | PDIP-16 - different | NSOIC-16 - same |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Channels | 8:1 / dual 4:1 | 8:1 / dual 4:1 | 8:1 / dual 4:1 | 8:1 / dual 4:1 | Differential 4:1 / dual 2:1 |
| On-Resistance (RON) | 400 ohm typ / 650 ohm max | 400 ohm typ / 650 ohm max | 400 ohm typ / 650 ohm max | 400 ohm typ / 650 ohm max | Lower (precision variant) |
| Single Supply Voltage | +4.5V to +30V | +4.5V to +30V | +4.5V to +30V | +4.5V to +30V | +4.5V to +30V |
| Operating Temperature | 0 C to +70 C | 0 C to +70 C | -40 C to +85 C (extended) | -40 C to +85 C (extended) | 0 C to +70 C |
| Package Type | SMD (NSOIC) | SMD (NSOIC) | SMD (NSOIC) | Through-Hole (PDIP) | SMD (NSOIC) |
| Leakage / Charge Injection | Low leakage CMOS | Low leakage CMOS | Low leakage CMOS | Low leakage CMOS | Lower leak / lower charge injection |
Bảo phân biệt quan trọng
- Direct pin-compatible upgrade to legacy DG508A / DG509A (vsIndustry-standard DG508A multiplexer)
- Wide supply voltage headroom (vsMAX398 precision 8:1 mux)
- Direct TTL/CMOS logic interface without level shifters (vsMAX328 precision 4:1 differential mux)
Ghi chú thiết kế
The MAX338 requires a 0.1uF decoupling capacitor close to V+ (pin 14). When used in dual-supply mode, bypass the V- pin to GND with another 0.1uF ceramic. The supply voltage range is +4.5V to +30V single-supply or +/-4.5V to +/-20V dual-supply. Avoid ground loops by tying the MAX338 GND (pin 15) back to the analog ground plane, not to a noisy digital return path. For best low-noise performance, power V+ from a low-impedance linear regulator such as the MAX8881 or LD1117 rather than directly from a switching converter.
Always tie unused digital address inputs (A0, A1, A2) and EN to a defined logic level (HIGH or LOW) rather than leaving them floating. Floating logic inputs can drift into the linear region, causing excessive supply current and potential channel cross-conduction. During power-up, apply logic levels only after V+ has stabilized to prevent partial switch activation. Also avoid exceeding the absolute maximum analog signal range of V+ and GND - signals beyond these rails cause latch-up that can permanently damage the device.
Keep analog input traces short and well-spaced from digital address lines to minimize capacitive crosstalk. Route the address bus (A0, A1, A2, EN) on the opposite PCB layer from the analog input/output, with a GND plane between them for shielding. Place the bypass capacitor directly at pin 14 with the shortest possible trace to the analog GND pin 15. Series resistors (100-470 ohm) on each analog input pin help dampen resonances in high-impedance source connections. Avoid running analog signal traces parallel to high-frequency digital lines for any significant length.
The 400 ohm on-resistance introduces a voltage divider with whatever load impedance you connect to pin D (output). For high-impedance ADC inputs (>1Mohm typical) the gain error is < 0.04%, but for lower-impedance loads (such as 10kohm) the loss is ~3.85% and must be budgeted. Add a unity-gain buffer (such as the MAX4230 or OPA2333) after the mux output when driving low-impedance or low-distortion stages. Channel-to-channel switching time tON/tOFF in tens of nanoseconds requires that downstream sample-and-hold circuits be triggered after the settling time has elapsed; consult the datasheet timing diagram.
Thông tin tuân thủ
Pb-free '+' suffix confirms RoHS compliance per Maxim Integrated datasheet marking convention. Not AEC-Q100 qualified - choose MAX338ESE+ for industrial temperature range. Halogen-free status is not explicitly listed in distributor data.
