MAX146AEPP+ - 12-Bit 8-Ch 133ksps ADC | Maxim Integrated
MPN: MAX146AEPP+ ✓ Hoạt độngMAX146AEPP+ Tóm tắt
An SAR ADC (Successive-Approximation Register Analog-to-Digital Converter) is a precision data-conversion architecture that resolves each conversion in a fixed number of clock cycles by binary-searching against an internal DAC. SAR ADCs offer a deterministic latency, no pipeline delay, and excellent DC accuracy, making them a workhorse for multiplexed multi-channel data-acquisition systems, sensor readout, and instrumentation front-ends where the input signal bandwidth is below a few hundred kHz.
Key features of the MAX146AEPP+ include an internal 2.5 V reference (with separate REFADJ pin for fine adjustment), a low-noise sampling front-end, hardware-/software-configurable unipolar/bipolar input ranges, and an SPI/QSPI/MICROWIRE-compatible serial interface. Internal autoshutdown between conversions drops the supply current dramatically for battery-powered or duty-cycled applications. The device also provides an analog input clamp that protects the input from over-voltage transients.
Typical applications include portable instrumentation, 4-20 mA industrial loop digitizers, multi-channel sensor data loggers, patient monitoring front-ends, and front-panel meter signal conditioning. The MAX146AEPP+ is pin-compatible with the MAX146BEPP+ (higher-speed variant) and other members of the MAX146 family in the same 20-pin PDIP footprint, simplifying system upgrades and BOM substitutions.
When designing with this device, decouple VDD with a 10 µF and 0.1 µF capacitor pair placed within 5 mm of the supply pins, route the analog and digital grounds separately back to a single star point, and keep the analog inputs away from the serial clock trace. The internal reference is adequate for many applications, but an external low-noise reference (e.g. MAX6126) is recommended for absolute accuracy better than ±2 LSB.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Bộ thay thế dễ dàng lắp đặt cho MAX146AEPP+ — 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 MAX146AEPP+ (cùng hình factor và footprint) — khác nhau ở Input Type, Internal Reference, Mounting Type, Package, Sampling Rate.
MAX146BEPP+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX146ACPP+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX146CEPP+
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MAX147AEPP+
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MAX146AEPP+ Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Number of Channels | 8 single-ended / 4 differential |
| Tỷ lệ lấy mẫu | 133 ksps |
| Architecture | SAR (Successive Approximation) |
| Input Type | Single-Ended / Differential (software configurable) |
| Điện áp cung cấp | +2.7 V to +3.6 V single supply |
| Supply Current (full speed) | 1.2 mA typ |
| Điện áp tắt | < 1 µA typ |
| Internal Reference | 2.5 V (REFADJ pin for trimming) |
| Data Interface | SPI / QSPI / MICROWIRE-compatible serial |
| INL (LSB) | ±1/2 LSB max |
| Nhiệt độ hoạt động | -40 °C to +85 °C |
| Hộp | 20-pin PDIP (EPP suffix) |
| Kiểu lắp đặt | Through-Hole (THT) |
Cấu hình chân MAX146AEPP+
| Chân 1 | AIN0 — Analog input channel 0 |
| Chân 2 | AIN1 — Analog input channel 1 |
| Chân 3 | AIN2 — Analog input channel 2 |
| Chân 4 | AIN3 — Analog input channel 3 |
| Chân 5 | AIN4 — Analog input channel 4 |
| Chân 6 | AIN5 — Analog input channel 5 |
| Chân 7 | AIN6 — Analog input channel 6 |
| Chân 8 | AIN7 — Analog input channel 7 |
| Chân 9 | AGND — Analog ground |
| Chân 10 | REFADJ — Reference adjust (trim 2.5 V reference) |
| Chân 11 | REF — 2.5 V reference output / external reference input |
| Chân 12 | VDD2 — Analog supply voltage (separate from digital VDD) |
| Chân 13 | GND — Digital ground |
| Chân 14 | VDD — Digital supply voltage (+2.7 V to +3.6 V) |
| Chân 15 | DOUT — Serial data output (SPI) |
| Chân 16 | SSTRB — Serial strobe output (conversion complete flag) |
| Chân 17 | DIN — Serial data input (configuration register write) |
| Chân 18 | SCLK — Serial clock input |
| Chân 19 | CS — Chip select (active low) |
| Chân 20 | SHDN — Shutdown input (active low) |
Ứng dụng tiêu biểu
MAX146AEPP+ phù hợp cho 7 Áp dụngs: Portable Multi-Channel Data Acquisition, Industrial 4-20 mA Loop Digitizer, Medical Patient Monitoring Front-End, Front-Panel Analog Signal Conditioning, Battery-Powered Sensor Data Logger, Automotive Sensor Interface Module, Test & Measurement Instrumentation.
Portable Multi-Channel Data Acquisition
The MAX146AEPP+ fits portable multi-channel data acquisition because its 8 single-ended / 4 differential input multiplexer replaces an external analog switch tree, its 1.2 mA active supply current extends battery runtime, and its <1 µA software shutdown between conversions enables duty-cycled sampling at multi-Hz rates from coin cells or Li-ion packs. Placed near the sensor connector with 0.1 µF + 10 µF VDD decoupling, it streams 12-bit conversions over SPI to a microcontroller. Unlike higher-throughput SAR ADCs it does not require an external reference or front-end buffer for moderate-impedance sensors up to ~10 kΩ source impedance, reducing the analog BOM and PCB area.
Được đề xuất
Industrial 4-20 mA Loop Digitizer
The MAX146AEPP+ is suited to digitizing 4-20 mA current loops when paired with a 250 Ω shunt resistor: each differential input pair directly accepts the 1-5 V signal produced across the shunt, while the 12-bit resolution provides 0.1% full-scale conversion. The industrial -40 °C to +85 °C temperature range guarantees operation in factory-floor enclosures. With hardware-configurable bipolar input range and a software-selectable channel sequencer, a single IC replaces multiple dedicated loop digitizers; the SPI interface connects directly to a process controller or PLC front-end module without glue logic.
Được đề xuất
Medical Patient Monitoring Front-End
The MAX146AEPP+ enables compact multi-parameter patient monitors by digitizing thermocouple, thermistor, and bridge-type sensor signals from up to 8 channels in a single IC. The internal 2.5 V reference is trimmed via the REFADJ pin to support ratiometric measurements of strain-gauge bridges with sub-LSB repeatability. Hardware-configurable unipolar/bipolar input ranges accommodate both single-ended bio-potential electrodes and differential bridge outputs. SPI isolation to the host microcontroller can be achieved with a digital isolator (e.g. MAX14850) for patient-safety creepage and clearance requirements.
Được đề xuất
Front-Panel Analog Signal Conditioning
The MAX146AEPP+ integrates eight 0-10 V analog front-panel inputs directly into a microcontroller-based HMI, replacing bulky parallel-input ADC cards. Its 133 ksps throughput supports oversampling for averaging out 50/60 Hz mains noise on multiple knob/slider inputs simultaneously. The internal input clamp protects against ESD and over-voltage transients typical of cable-connected front-panel wiring. The 20-pin PDIP package is breadboard-friendly for prototype front-panel modules and supports hand-soldering or thru-hole wave-soldering on industrial HMIs.
Được đề xuất
Battery-Powered Sensor Data Logger
The MAX146AEPP+ serves battery-powered multi-sensor loggers because its 1.2 mA active supply current and <1 µA shutdown current enable multi-year runtime on two AA cells when sampling at 1 Hz. Its 8 single-ended input channels connect directly to thermistors, photocells, soil-moisture sensors, and other high-impedance transducers without external signal conditioning. The internal 2.5 V reference eliminates the need for a separate reference IC, reducing quiescent draw. The SPI interface is compatible with low-power MCUs such as the MAXQ2000 for sleep-mode-dominated embedded firmware.
Được đề xuất
Automotive Sensor Interface Module
The MAX146AEPP+ can digitize multiple automotive sensors (temperature, pressure, position) when used outside the engine compartment; its industrial -40 °C to +85 °C range covers cabin and body-electronics modules. Eight single-ended channels map directly to multiple sensor outputs, while the SPI bus connects to a body-control MCU. Note that for under-hood applications the MAX146 family is not AEC-Q100 qualified; the automotive AEC-Q100 equivalent is the MAX1149 or similar qualified part. The internal reference supports ratiometric measurements of thermistor networks and resistive dividers in body controllers.
Được đề xuất
Test & Measurement Instrumentation
The MAX146AEPP+ fits bench-top DMMs and low-frequency signal analyzers because its 12-bit resolution and ±1/2 LSB INL deliver 0.025% FS accuracy, sufficient for production test of op-amp PSRR, regulator ripple, and thermocouple simulators. The 4 differential channels allow direct 4-wire resistance measurements with current excitation, while the 8 single-ended channels accommodate voltage-mode measurements up to VREF. Hardware-configurable bipolar input ranges support ±2.5 V full-scale measurements common in instrumentation. The serial interface enables integration with a USB-based test head or a stand-alone front-panel DMM display.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX146AEPP+ — 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 | MAX146BEPP+ | MAX146ACPP+ | MAX146CEPP+ | MAX147AEPP+ |
|---|---|---|---|---|---|
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Package | 20-PDIP (EPP) | 20-PDIP - same | 20-PDIP - same | 20-PDIP - same | 20-PDIP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 133 ksps | Higher (B-grade) | 133 ksps | 133 ksps | 133 ksps |
| Number of Channels | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF |
| Operating Temperature | -40 °C to +85 °C (industrial) | -40 °C to +85 °C | 0 °C to +70 °C (commercial) | -40 °C to +85 °C | -40 °C to +85 °C |
| Supply Voltage | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +2.7 V to +3.6 V | +4.75 V to +5.25 V (single-supply 5 V variant) |
| Internal Reference | 2.5 V with REFADJ | 2.5 V with REFADJ | 2.5 V with REFADJ | 2.5 V with REFADJ | Reference = VDD (5 V) |
| Serial Interface | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE | SPI / QSPI / MICROWIRE |
Bảo phân biệt quan trọng
- Industrial temperature grade (-40 °C to +85 °C) in same footprint (vsMAX146ACPP+)
- Internal 2.5 V reference with REFADJ trim eliminates external reference IC (vsMAX146BEPP+)
- 8 single-ended / 4 differential input multiplexer replaces external switch tree (vsMAX1062 (2-channel 14-bit SAR ADC))
Ghi chú thiết kế
Decouple VDD and VDD2 with a parallel combination of 10 µF tantalum (or ceramic) and 0.1 µF ceramic placed within 5 mm of the supply pins. Route VDD and VDD2 from the same regulator but with separate ferrite beads if additional analog/digital isolation is required. The shutdown pin (SHDN, active-low) must be tied high through a 100 kΩ pull-up if software shutdown is not used, to avoid floating-pin current spikes.
Place the MAX146AEPP+ near the analog sensor connector and keep all analog traces short and direct. Route the AGND and DGND separately back to a single star point under the IC - never run digital return currents through the analog ground plane. Keep the SCLK trace away from the analog inputs and consider a ground trace between SCLK and AIN0-AIN7 if the board is dense. Use a guard trace around high-impedance AIN lines to reduce leakage.
Do not leave the SHDN pin floating - tie it high through a 100 kΩ pull-up if unused, otherwise the device may enter shutdown intermittently. Do not drive the analog inputs beyond VDD + 0.3 V; the internal clamp protects against transients but sustained over-voltage will degrade ESD cells. When using the internal reference, the REF pin must be bypassed to AGND with at least a 1 µF (and ideally a 0.1 µF in parallel) capacitor; insufficient bypass increases noise and INL.
For best noise performance, average 16 or more conversions in firmware when digitizing low-level DC signals. The 133 ksps throughput supports oversampling by 10x at 13.3 ksps effective rate while still exceeding typical sensor bandwidth. If higher resolution is needed, the MAX146BEPP+ (B-grade) and external averaging can yield effective 14-bit noise performance on the same 20-PDIP footprint.
Thông tin tuân thủ
RoHS/REACH status not directly stated in the provided web data; '+' suffix in MPN indicates lead-free / RoHS-compliant Maxim Integrated packaging. MAX146 family is not AEC-Q100 qualified; use MAX1149 for automotive.
