MAX1284ACSA+T - 12-Bit 400ksps Serial ADC | Maxim Integrated
MPN: MAX1284ACSA+T ✓ Hoạt độngMAX1284ACSA+T Tóm tắt
An ADC (analog-to-digital converter) is a mixed-signal data-acquisition building block that converts a continuous-time, continuous-amplitude analog input into a discrete-time, discrete-amplitude digital code. Successive-approximation (SAR) ADCs use an internal binary-search algorithm and a comparator to resolve each bit in N clock cycles, giving a strong balance of speed, resolution, and power consumption for multi-channel data acquisition, sensor readout, and process-control loops. SAR ADCs sit between sigma-delta (high resolution, low speed) and flash (very high speed, low resolution) architectures in the converter taxonomy.
The MAX1284/MAX1285 family delivers 400 ksps (MAX1284) or 300 ksps (MAX1285) throughput with a 4.5 V to 5.5 V supply and draws only a few mW during conversion. The MAX1284ACSA+T variant (suffix 'A' = automotive-style 'A' grade, 'C' = commercial temperature range 0 C to +70 C, 'SA' = 8-pin SO, '+T' = tape-and-reel packaging). It is a drop-in, higher-speed upgrade for the MAX1240/MAX1241 family in legacy 8-pin SO layouts.
Typical applications include portable data loggers, remote sensor front ends, 4-20 mA loop-powered transmitters, pen digitizers, and patient-monitoring instruments where the combination of small footprint, low power, and serial output is valuable. The 8-pin SO footprint is convenient for hand-probe rework and for retrofitting older 8-pin ADC sockets.
When designing with the MAX1284ACSA+T, place a 0.1 uF ceramic bypass capacitor within 5 mm of the AVDD pin and a 10 uF bulk capacitor at the supply rail. Use a low-impedance analog input with an RC anti-alias filter; SAR input current transients settle best when source impedance is kept below about 1 kohm.
Bộ thay thế dễ dàng lắp đặt cho MAX1284ACSA+T — 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 MAX1284ACSA+T (cùng hình factor và footprint) — khác nhau ở Package, Internal Reference, Architecture, Input Type, Number of Channels.
MAX1285ACSA+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX1284ACSA+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX1240ACSA+TG069
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MAX1241ACSA+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX1062ACSA+
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MAX1156ACSA+
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
MAX1284ACSA+T Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bits |
| Sampling Rate (MAX1284) | 400 ksps |
| Sampling Rate (MAX1285) | 300 ksps |
| Number of Channels | 1 single-ended |
| Architecture | Successive Approximation (SAR) |
| Input Type | Single-ended analog input |
| Supply Voltage (AVDD) | 4.5 V to 5.5 V (single supply) |
| Internal Reference | Yes (on-chip reference) |
| Digital Interface | SPI/QSPI/MICROWIRE-compatible serial |
| Hộp | 8-pin SO (SOIC-8), 3.9 mm body width |
| Kiểu lắp đặt | Surface Mount |
| Temperature Grade | Commercial (0 C to +70 C) |
| Process Technology | BiCMOS |
| Track/Hold Bandwidth | High-bandwidth input T/H (datasheet figure) |
| Packaging | Tape and Reel (+T suffix) |
| Trạng thái RoHS | Compliant (manufacturer product page) |
Cấu hình chân MAX1284ACSA+T
| Chân 1 | AVDD — Analog supply, 4.5 V to 5.5 V |
| Chân 2 | AIN — Analog input (single-ended) |
| Chân 3 | GND — Analog ground |
| Chân 4 | REF — Reference bypass/decoupling |
| Chân 5 | SCLK — Serial clock input (SPI/QSPI/MICROWIRE) |
| Chân 6 | DOUT — Serial data output |
| Chân 7 | CS — Active-low chip select |
| Chân 8 | DVDD — Digital supply (connect to AVDD or logic rail) |
Ứng dụng tiêu biểu
MAX1284ACSA+T phù hợp cho 6 Áp dụngs: Portable Data Loggers, Remote Sensor Front Ends, Industrial Process Control Inputs, Patient Monitoring Instruments, Pen Digitizer and Touch Tablets, Test & Measurement Instrumentation.
Portable Data Loggers
The MAX1284ACSA+T fits portable data loggers because of its 12-bit 400 ksps throughput, single 4.5-5.5 V supply, and 8-pin SO footprint that fits slim handheld enclosures. Its on-chip reference removes a second IC from the BOM, lowering cost and quiescent current. The SPI-compatible serial output reduces MCU pin count so a small 8-pin MCU can drive the ADC. For a typical 1 ksps logger, the 400 ksps max throughput gives 400x headroom and lets the ADC spend most of its time in power-down mode, dropping average supply current to microamp levels.
Được đề xuất
Remote Sensor Front Ends
The MAX1284ACSA+T is a strong match for 4-20 mA loop-powered and battery-operated remote sensor front ends, where low power and small size matter more than raw speed. Its internal reference avoids the additional quiescent draw of an external reference IC, and the 8-pin SO requires minimal PCB area. With the 400 ksps max throughput, the converter spends most of its cycle in shutdown between conversions, helping 4-20 mA loops meet the 3.5 mA budget. The SPI output also lets the MCU share its bus with other sensors.
Được đề xuất
Industrial Process Control Inputs
The MAX1284ACSA+T serves in industrial process-control input modules that need to digitize a single 0-5 V analog signal at medium speed. Its 4.5-5.5 V supply matches the 5 V analog rail common in PLC analog-input cards, and its 12-bit resolution gives 1.22 mV LSB for a 5 V full-scale input - enough for many thermocouple-amplifier and pressure-transducer front ends. The SOIC-8 footprint simplifies hand-probe rework during field maintenance. Designers can pair it with a small signal-conditioning op-amp on the same 5 V rail.
Được đề xuất
Patient Monitoring Instruments
The MAX1284ACSA+T supports patient-monitoring instruments such as portable pulse oximeters and bedside diagnostic devices where size, low power, and moderate speed are all priorities. The 12-bit resolution is sufficient for pulse-rate and SpO2 trends (typically 1-2 mV per LSB at the front-end amplifier output), and the 8-pin SOIC-8 fits inside a wearable enclosure. Its internal reference reduces calibration drift and component count, important for FDA-cleared medical designs. Pair it with a low-noise op-amp front end for clean ECG-style signals.
Được đề xuất
Pen Digitizer and Touch Tablets
The MAX1284ACSA+T is well suited to pen-digitizer and touch-tablet digitizing circuits where the position sensor output is a 0-5 V analog signal sampled at medium speed. At 400 ksps, the MAX1284 can digitize a 100 Hz stylus movement with 4000x oversampling, well beyond the Nyquist requirement. Its SPI interface lets a single MCU service the ADC plus the touch-screen controller on a shared bus. The small 8-pin SO saves critical board area in the slim pen housing. Designers can calibrate linearity in software from the 12-bit codes.
Được đề xuất
Test & Measurement Instrumentation
The MAX1284ACSA+T is used in bench and handheld test equipment, including digital multimeters, signal-analyzer front ends, and lab-grade data-acquisition front panels. With 12 bits and 400 ksps, the converter supports a 5 V full-scale input with 1.22 mV LSB - good for voltage, current, and temperature front ends. The internal reference eliminates an external reference and its drift, and the 8-pin SO simplifies probe-station rework. The SPI output also lets the instrument MCU share the bus with a display controller and a flash memory.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX1284ACSA+T — 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 | MAX1285ACSA+T | MAX1284ACSA+ | MAX1240ACSA+ | MAX1241ACSA+ |
|---|---|---|---|---|---|
| Package | SOIC-8 (3.9 mm body) | SOIC-8 (3.9 mm body) - same | SOIC-8 (3.9 mm body) - same | SOIC-8 (3.9 mm body) - same | SOIC-8 (3.9 mm body) - same |
| Brand | Maxim Integrated | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same | Maxim Integrated - same |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Sampling Rate | 400 ksps | 300 ksps | 400 ksps | lower (older gen) | lower (older gen) |
| Internal Reference | Yes | Yes | Yes | Yes | Yes |
| Supply Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V |
| Serial Interface | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE | SPI/QSPI/MICROWIRE |
| Channels | 1 single-ended | 1 single-ended | 1 single-ended | 1 single-ended | 1 single-ended |
| Architecture | SAR (BiCMOS) | SAR (BiCMOS) | SAR (BiCMOS) | SAR | SAR |
Bảo phân biệt quan trọng
- 400 ksps vs 300 ksps throughput in the same SOIC-8 footprint (vsMAX1285ACSA+T)
- Higher speed than the legacy MAX1240/MAX1241 family (vsMAX1240ACSA+)
- Single 5 V supply (vs 2.7-5.5 V) for 5 V-rail-only systems (vsMAX1240ACSA+)
Ghi chú thiết kế
Place a 0.1 uF ceramic bypass capacitor within 5 mm of the AVDD pin and a 10 uF bulk capacitor at the supply rail, as called out in the Maxim MAX1284/MAX1285 datasheet. SAR ADCs draw sharp transient currents at the sampling instant; the bypass capacitor keeps the local AVDD noise under 50 mVpp. DVDD may be tied to AVDD for the simplest 5 V-only system, or driven from a separate 3.3 V rail if the MCU is at 3.3 V logic.
Keep the analog input source impedance below ~1 kohm, as recommended in the Maxim datasheet. Higher source impedance interacts with the ADC's switched-capacitor input and introduces gain error and distortion. If a higher-impedance sensor must be used, add a low-output-impedance buffer (e.g., a precision op-amp) right at the AIN pin. Also avoid running the AIN trace parallel to digital SCLK or DOUT for any length to limit digital-to-analog crosstalk.
Use a star-ground topology with the AGND and DGND pins tied at the ADC's GND pin, then run a single trace to the board ground plane. Keep the SOIC-8 ADC's exposed analog ground as close to the device as possible. Place the 0.1 uF and 10 uF capacitors on the AVDD trace within 5 mm of the AVDD pin, and connect their ground ends to the same AGND star. This layout is consistent with the Maxim evaluation-kit reference for the MAX1284/MAX1285 family.
Thông tin tuân thủ
RoHS/lead-free per Maxim Integrated / Analog Devices product page. Not AEC-Q100 qualified - choose an 'AEC-Q100' grade automotive ADC for automotive use. Commercial temperature range 0 C to +70 C.
