MAX146BCAP - 12-Bit 8-Ch 133kSPS Serial ADC | Maxim Integrated
MPN: MAX146BCAP ✓ Hoạt độngMAX146BCAP Tóm tắt
An ADC (Analog-to-Digital Converter) is a mixed-signal integrated circuit that quantizes a continuous-time analog input voltage into a discrete digital code. The MAX146 belongs to the successive-approximation register (SAR) ADC family, which trades raw speed for excellent DC accuracy and very low power consumption per conversion. In a typical signal chain (sensor -> amplifier -> ADC -> microcontroller), the ADC digitizes the conditioned analog signal so that a digital controller can process, log, or transmit the reading. MAX146-class devices sit between precision delta-sigma ADCs (slower, higher resolution) and high-speed flash ADCs (faster, lower resolution) on the performance-versus-speed spectrum, and they are widely used in industrial control, instrumentation, and embedded monitoring designs.
Key features of the MAX146BCAP include 133 kSPS maximum sampling rate, an 8-channel single-ended or 4-channel differential input multiplexer, software-configurable unipolar/bipolar input ranges, an internal 2.5V reference with a ±1.5% buffer adjustment range, a hardware SHDN-bar pin plus software power-down that drops supply current to under 10 uA between conversions, and an automatic end-of-conversion shutdown mode for battery-aware applications. Operating supply range spans +2.7V to +3.6V on AVDD and +2.7V to DVDD +0.3V on DVDD, and the device is specified over the 0C to +70C temperature range in this CAP commercial-grade variant.
Typical applications for the MAX146BCAP include portable data loggers, patient-monitoring and medical instruments, battery-powered sensor front ends, factory-automation signal conditioning, and embedded system analog I/O expansion for microcontrollers lacking an internal ADC. Its low-power operation and integrated multiplexer make it well-suited for multi-sensor monitoring in remote or wearable nodes.
When designing with this device, use a clean analog ground plane and keep digital traces away from analog inputs; place the 10uF X7R bypass capacitor on AVDD as close to the pin as possible. The serial-interface SCLK should be kept under 2 MHz to preserve ADC linearity and avoid coupling digital noise into the analog input. Drive SHDN-bar high during normal operation and pull it low only between conversions to enter shutdown.
Bộ thay thế dễ dàng lắp đặt cho MAX146BCAP — 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 MAX146BCAP (cùng hình factor và footprint) — khác nhau ở Operating Temperature Range, Package, Resolution, Sampling Rate.
MAX146BCAP+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX146BEAP+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX1134BCAP+
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →MAX146BCAP Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Number of Input Channels | 8 single-ended / 4 differential |
| Tỷ lệ lấy mẫu | 133 kSPS |
| Converter Architecture | SAR (Successive Approximation Register) |
| Input Signal Type | Single-ended, Differential |
| Supply Voltage AVDD | +2.7 V to +3.6 V |
| Supply Voltage DVDD | +2.7 V to +3.6 V |
| Analog Input Voltage Range | 0 V to AVDD (software configurable bipolar modes) |
| Internal Reference Voltage | 2.5 V (with +/-1.5% buffer adjustment) |
| External Reference Support | Yes (MAX147 variant; this part has internal 2.5V reference) |
| Giao diện | SPI / QSPI / MICROWIRE-compatible serial |
| Điện áp tắt | < 10 uA (typ. software per SHDN-bar) |
| Khoảng nhiệt độ hoạt động | 0 C to +70 C (CAP commercial grade) |
| Hộp | 20-pin SSOP |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 1 (unlimited) |
| Trạng thái RoHS | Compliant |
| Lead-Free Reflow | Yes |
Cấu hình chân MAX146BCAP
| 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 | REF — Reference voltage (internal 2.5V or external input) |
| Chân 11 | AVDD — Analog supply +2.7V to +3.6V |
| Chân 12 | DVDD — Digital supply +2.7V to +3.6V |
| Chân 13 | DGND — Digital ground |
| Chân 14 | SCLK — Serial clock input |
| Chân 15 | DIN — Serial data input (configuration writes) |
| Chân 16 | DOUT — Serial data output (conversion results) |
| Chân 17 | CS-bar — Active-low chip select |
| Chân 18 | SHDN-bar — Active-low shutdown input |
| Chân 19 | NC — Not connected (per datasheet) |
| Chân 20 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
MAX146BCAP phù hợp cho 6 Áp dụngs: Portable Battery-Powered Data Loggers, Patient Monitoring and Medical Instrumentation, Industrial Process Sensor Monitoring, Embedded Microcontroller Analog I/O Expansion, Remote Wireless Sensor Nodes, Test and Measurement Front End.
Portable Battery-Powered Data Loggers
The MAX146BCAP's 133 kSPS sampling rate, 12-bit resolution, and sub-10 uA shutdown current make it ideal for portable battery-powered data loggers. Its integrated 8-channel analog multiplexer lets one ADC digitize eight different sensors (temperature, pressure, voltage, current) without an external mux, while the SHDN-bar pin and automatic end-of-conversion shutdown extend battery life between samples. The internal 2.5 V reference eliminates the need for a separate reference IC in cost-sensitive designs. Place the device on a clean analog ground plane and supply it from a regulated 3.3V rail; it draws only a few mA during active conversion and is fully specified for lithium-cell-powered designs.
Được đề xuất
Patient Monitoring and Medical Instrumentation
The MAX146BCAP's 12-bit resolution and 8-channel input multiplexer suit medical patient-monitoring designs that need to digitize several physiological signals at low power. With 133 kSPS throughput it can sample ECG or pulse-oximeter front-ends while consuming only a few mW from a 3.3 V rail. The SHDN-bar pin enables sleep modes between patient measurements, prolonging battery life in portable monitors. Design tip: dedicate separate analog and digital ground planes joined at a single point near the IC, and add a 10 uF X7R bypass on AVDD placed within 1 cm of the pin to preserve linearity on small high-impedance bio-potential signals.
Được đề xuất
Industrial Process Sensor Monitoring
The MAX146BCAP's differential-input capability, bipolar software-configurable ranges, and 8-channel integration simplify industrial process-control boards that monitor multiple 4-20 mA loops, RTDs, or thermocouples. Its 12-bit resolution provides adequate accuracy for trend monitoring, while the SPI interface lets a single microcontroller poll up to eight field sensors with minimal pin count. For noisy factory environments, choose the MAX146BEAP+ extended-temperature variant. Best practice: insert a unity-gain buffer amplifier and RC anti-aliasing filter in front of each AIN channel, and run SCLK below 2 MHz to keep digital switching noise out of the analog input band.
Được đề xuất
Embedded Microcontroller Analog I/O Expansion
Many low-cost microcontrollers lack an internal ADC, or provide only 10-bit resolution. The MAX146BCAP lets a designer add 8 channels of 12-bit ADC over a 4-wire SPI bus with only a few GPIO pins consumed. With 133 kSPS sampling and software-controllable channels, it can digitize potentiometers, thermistors, light sensors, and current-sense amplifier outputs on a single PCB. Use it as a stand-alone peripheral alongside an 8051, PIC, or ARM Cortex-M0 microcontroller and store calibration coefficients in non-volatile memory to compensate for the +/-1 LSB INL typical of SAR converters in this class.
Được đề xuất
Remote Wireless Sensor Nodes
The MAX146BCAP's 2.7 V minimum supply, sub-10 uA shutdown current, and 8-channel multiplexer suit remote wireless sensor nodes powered by 2xAA cells or coin-cell batteries. It can digitize multiple environmental sensors before sleeping in SHDN-bar mode while a radio module transmits data, then wake on CS-bar assertion for the next sample. Compared to a delta-sigma ADC of similar channel count, the SAR conversion architecture completes in microseconds and lets the radio sleep for longer between bursts, saving system-level power. For best battery life, drive SHDN-bar high only during conversion, then return to shutdown between samples.
Được đề xuất
Test and Measurement Front End
The MAX146BCAP's 12-bit resolution, 133 kSPS throughput, and 8 input channels let bench-test designers build a low-cost multi-channel data-acquisition front end. The internal multiplexer and reference simplify the analog path, while the SPI bus streams conversion results to a host PC over USB. For bench instrumentation that needs guaranteed accuracy at room temperature, the commercial CAP grade is appropriate; for field-deployed test gear, the BEAP extended-temperature grade in the same SSOP-20 footprint is the recommended drop-in. Add an input protection clamp and a unity-gain buffer to drive the AIN pins from external BNC connectors safely.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX146BCAP — 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 | MAX146BCAP+ | MAX146BEAP+ | MAX146BCPP+ | MAX146BEPP+ | MAX1134BCAP+ |
|---|---|---|---|---|---|---|
| Brand | Analog Devices / Maxim Integrated | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | SSOP-20 | SSOP-20 - same | SSOP-20 - same | PDIP-20 - different | PDIP-20 - different | SSOP-20 - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Sampling Rate | 133 kSPS | 133 kSPS | 133 kSPS | 133 kSPS | 133 kSPS | 400 kSPS |
| Serial Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
Bảo phân biệt quan trọng
- Integrated 8-channel multiplexer in SSOP-20 (vsMAX1240 single-channel 8-pin SOIC ADC)
- Internal 2.5V reference vs MAX147 external reference (vsMAX147 external-reference variant)
- Software and hardware shutdown modes (vsMAX1243 with hardware shutdown only)
- 133 kSPS throughput at low supply current (vsMAX1134BCAP+ 400 kSPS upgrade variant)
Ghi chú thiết kế
Provide separate AVDD and DVDD rails or tie them together at a single ferrite bead to keep digital switching noise out of the analog supply. Add a 10uF X7R bypass capacitor as close as possible to the AVDD pin (less than 1 cm trace) and a 0.1uF ceramic in parallel for high-frequency decoupling. Keep the SHDN-bar pin high during normal operation and pull it low only between conversions to enter the sub-10 uA shutdown mode.
Use a star-ground topology with AGND and DGND connected at a single point near the IC. Keep digital interface traces (CS-bar, SCLK, DIN, DOUT) short and routed on a different layer from the analog input traces to minimize coupling. Place the analog input RC anti-aliasing filter components near each AIN pin. Avoid running digital traces directly under the IC or near the analog input channels to preserve 12-bit linearity.
Limit SCLK to 2 MHz maximum to maintain ADC linearity and avoid injecting clock harmonics into the analog input. Drive SCLK with a clean low-jitter source; for slower MCUs use the lowest SPI divider that still exceeds the conversion rate. Source impedance above 1 kohm degrades INL, so add a unity-gain buffer amplifier (such as a MAX4475) on each analog input channel when driving from high-impedance sensors.
Do not apply input voltages to AIN0-AIN7 that exceed AVDD or go below AGND; the absolute maximum input range is AVDD + 0.3V to AGGN - 0.3V. In differential mode, ensure both inputs are within the common-mode range. Avoid leaving unused analog inputs floating - tie them to AGND or a known mid-rail voltage to prevent spurious conversion results from injected noise. Always enter shutdown mode (SHDN-bar low) before changing configuration registers.
Thông tin tuân thủ
RoHS compliant per Maxim Integrated product page (lead-free finish on MAX146BCAP+). Not AEC-Q100 qualified - choose MAX146BEAP+ extended-temperature grade for industrial applications.
