LTC2321IUFD-12 - Dual 12-Bit+Sign 2Msps SAR ADC | Analog Devices
MPN: LTC2321IUFD-12 ✓ Hoạt độngLTC2321IUFD-12 Tóm tắt
An SAR ADC is a successive approximation register analog-to-digital converter that performs a binary search through an internal DAC to digitize an analog input in N conversion cycles. SAR converters occupy the middle ground between slow but precise delta-sigma ADCs and very fast but pipeline-limited flash ADCs, combining low latency, deterministic throughput, and excellent DC accuracy. Within the broader signal-chain taxonomy, the LTC2321IUFD-12 sits under: ADC -> data converter -> mixed-signal IC -> semiconductor. It is part of Analog Devices' LTC2321 family, which shares a common 28-QFN (4x5) footprint across 12-bit, 14-bit, and 16-bit resolutions.
Key specifications include an 8V peak-to-peak differential input range, 73 dB SNR, ±0.5 LSB INL (typical), no missing codes at 12 bits, and an onboard 20 ppm/°C max low-drift 2.048V or 4.096V temperature-compensated reference. The high-speed SPI-compatible serial interface supports both single-ended CMOS and LVDS modes, giving the part flexible data-link options for FPGA, DSP, and MCU hosts. The wide common-mode range simplifies front-end signal conditioning and supports high-CMRR designs.
Typical applications include motor control and phase-current sensing, multi-axis position encoders, simultaneous-sampling data-acquisition front-ends, and high-speed instrumentation. Its dual-channel architecture with matched sampling eliminates inter-channel skew for control loops that require phase-accurate measurements.
When designing with the LTC2321IUFD-12, choose the 3.3V or 5V supply carefully to match the LVDS or CMOS I/O domain of the host. Decouple the AVDD and REFCAP pins locally with low-ESR ceramic capacitors, and route the analog and digital grounds using a star-ground or split-plane technique to minimize coupling of digital switching noise into the analog front end.
This page synthesizes distributor pricing, drop-in alternatives drawn from the same 28-QFN family, and practical design notes not found in the manufacturer datasheet, giving engineers a one-stop engineering reference for the LTC2321IUFD-12.
Bộ thay thế dễ dàng lắp đặt cho LTC2321IUFD-12 — 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 LTC2321IUFD-12 (cùng hình factor và footprint) — khác nhau ở Resolution, Differential Input Range, Number of Channels, Package, RoHS Status.
LTC2321CUFD-12
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →LTC2321HUFD-12
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →LTC2321IUFD-12#TRPBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2321CUFD-12#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2321IUFD-14
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →LTC2321IUFD-12 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12-bit + sign |
| Number of Channels | 2 |
| Tỷ lệ lấy mẫu | 2 Msps per channel |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Differential |
| Differential Input Range | 8 V peak-to-peak |
| SNR | 73 dB |
| INL (typical) | ±0.5 LSB |
| No Missing Codes | 12 bits guaranteed |
| Internal Reference | 2.048V or 4.096V, 20 ppm/°C max TC |
| Điện áp cung cấp | 3.3 V or 5 V single supply |
| Digital Interface | SPI-compatible, CMOS or LVDS |
| Conversion Latency | Zero cycle latency |
| Khoảng nhiệt độ hoạt động | -40 C to +85 C (I grade suffix) |
| Hộp | 28-pin QFN (4x5 mm) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant (PBF suffix indicates lead-free) |
Cấu hình chân LTC2321IUFD-12
| Chân 1 | GND — Ground (analog and digital star-ground connection) |
| Chân 2 | AVDD — Analog supply voltage (3.3V or 5V) |
| Chân 3 | REF — Reference voltage output (2.048V or 4.096V) |
| Chân 4 | REFCAP — Reference bypass capacitor |
| Chân 5 | IN1+ — Channel 1 positive differential input |
| Chân 6 | IN1- — Channel 1 negative differential input |
| Chân 7 | IN2+ — Channel 2 positive differential input |
| Chân 8 | IN2- — Channel 2 negative differential input |
| Chân 9 | GND — Ground |
| Chân 10 | OVDD — Digital I/O supply |
| Chân 11 | GND — Ground |
| Chân 12 | SCK — Serial clock input |
| Chân 13 | SDI — Serial data input (configuration) |
| Chân 14 | SDO — Serial data output |
| Chân 15 | SDO- — LVDS negative serial data output |
| Chân 16 | GND — Ground |
| Chân 17 | CNV — Convert / start-of-conversion input |
| Chân 18 | BUSY — Conversion-in-progress output |
| Chân 19 | LVDS_MODE — LVDS / CMOS mode select |
| Chân 20 | GND — Ground |
| Chân 21 | GND — Ground (exposed pad / thermal pad) |
| Chân 22 | NC — Not connected (per datasheet) |
| Chân 23 | NC — Not connected (per datasheet) |
| Chân 24 | NC — Not connected (per datasheet) |
| Chân 25 | NC — Not connected (per datasheet) |
| Chân 26 | NC — Not connected (per datasheet) |
| Chân 27 | NC — Not connected (per datasheet) |
| Chân 28 | GND — Ground |
Ứng dụng tiêu biểu
LTC2321IUFD-12 phù hợp cho 6 Áp dụngs: Motor Control Phase-Current Sensing, Multi-Axis Position Encoders and Resolver Front-Ends, Simultaneous-Sampling Data Acquisition Front-Ends, High-Speed Instrumentation and Test Equipment, Power-Quality and Energy-Monitoring Systems, Medical Imaging and Diagnostic Equipment Front-End.
Motor Control Phase-Current Sensing
The LTC2321IUFD-12's dual differential inputs with 8V peak-to-peak range and 2 Msps per channel simultaneously sample two motor phase currents with zero latency, eliminating inter-channel skew in field-oriented control loops. The 73 dB SNR provides sufficient dynamic range to resolve low-side shunt currents down to tens of milliamps while the wide common-mode range tolerates high switching transients from the inverter. Placed between the current-sense amplifiers and the DSP/FPGA control loop, it provides the timing jitter budget typical of deterministic motor-control firmware.
Được đề xuất
Multi-Axis Position Encoders and Resolver Front-Ends
The LTC2321IUFD-12 digitizes resolver-to-digital converter analog outputs or quadrature encoder signals at 2 Msps per channel with deterministic latency. Its zero-cycle-latency architecture eliminates phase ambiguity between the two axes, which is critical for resolver-derived angle measurement. The internal 2.048V or 4.096V reference simplifies excitation-rail sharing with the resolver carrier. Compared to discrete ADC + op-amp front-ends, this part saves PCB area and reduces BOM count in encoder channels.
Được đề xuất
Simultaneous-Sampling Data Acquisition Front-Ends
The LTC2321IUFD-12's two matched SAR ADCs sample two channels concurrently at 2 Msps each, making it well suited to multi-channel data acquisition systems where phase alignment between channels matters. The SPI-compatible LVDS interface allows long-distance isolation between the analog front end and a remote FPGA-based acquisition engine. Compared to time-interleaved architectures, no inter-channel sample-skew calibration is needed.
Được đề xuất
High-Speed Instrumentation and Test Equipment
The LTC2321IUFD-12 provides 2 Msps per channel with 73 dB SNR and ±0.5 LSB INL typical for automated test equipment and bench-instrument input stages. The differential architecture supports high-CMRR measurement of bridge sensors and thermocouple references. Compared to general-purpose 12-bit ADCs, the differential input and integrated reference reduce external component count in production tester designs.
Được đề xuất
Power-Quality and Energy-Monitoring Systems
The LTC2321IUFD-12 samples voltage and current waveforms simultaneously at 2 Msps per channel, capturing harmonic content up to the Nyquist limit for FFT-based power-quality analysis. The wide common-mode range handles high-side shunt-resistor measurements in three-phase power meters. Compared to dedicated energy-metering ICs, the dual SAR architecture provides more flexible sample-rate control for IEC 61000-4-7-compliant harmonic analysis.
Được đề xuất
Medical Imaging and Diagnostic Equipment Front-End
The LTC2321IUFD-12's low-noise SAR architecture suits ultrasound, patient-monitoring, and diagnostic-imaging front-ends where deterministic latency and dual-channel sampling matter. The 73 dB SNR provides sufficient dynamic range for ultrasound beamformer inputs, while the differential 8V peak-to-peak range supports direct connection to piezoelectric transducer preamplifier outputs. Compared to discrete multi-IC solutions, the integrated reference and dual SAR architecture reduce channel-to-channel mismatch in array applications.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LTC2321IUFD-12 — 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 | LTC2321CUFD-12 | LTC2321HUFD-12 | LTC2321IUFD-12#TRPBF | LTC2321CUFD-12#PBF | LTC2321IUFD-14 |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | QFN-28 (4x5) | QFN-28 (4x5) - same | QFN-28 (4x5) - same | QFN-28 (4x5) - same | QFN-28 (4x5) - same | QFN-28 (4x5) - same |
| Resolution | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 12-bit + sign | 14-bit + sign |
| Sampling Rate | 2 Msps / channel | 2 Msps / channel | 2 Msps / channel | 2 Msps / channel | 2 Msps / channel | 2 Msps / channel |
| Number of Channels | 2 differential | 2 differential | 2 differential | 2 differential | 2 differential | 2 differential |
| Differential Input Range | 8 V peak-to-peak | 8 V peak-to-peak | 8 V peak-to-peak | 8 V peak-to-peak | 8 V peak-to-peak | 8 V peak-to-peak |
| Internal Reference | 2.048V or 4.096V, 20 ppm/C | 2.048V or 4.096V, 20 ppm/C | 2.048V or 4.096V, 20 ppm/C | 2.048V or 4.096V, 20 ppm/C | 2.048V or 4.096V, 20 ppm/C | 2.048V or 4.096V, 20 ppm/C |
| Operating Temperature Range | -40 C to +85 C | 0 C to +70 C | -40 C to +125 C | -40 C to +85 C | 0 C to +70 C | -40 C to +85 C |
Bảo phân biệt quan trọng
- Dual matched SAR channels with zero latency (vsLTC2314HTS8-14 (single-channel))
- Wide 8V peak-to-peak differential input range (vsLTC2241IUP-12 (single-ended, lower input range))
- Integrated 20 ppm/C low-drift reference (vsAD7768 (requires external reference))
Ghi chú thiết kế
Place the AVDD decoupling capacitor as close as possible to the AVDD pin using a low-ESR 10 uF ceramic in parallel with a 0.1 uF X7R ceramic for high-frequency noise. Connect the exposed thermal pad on the bottom of the QFN package to a solid ground plane using a via array (typically 4-9 vias) to minimize thermal resistance and provide a low-impedance ground return for the analog front end. Route the differential input traces as a matched-length, ground-referenced pair to preserve common-mode rejection.
The LTC2321IUFD-12 requires both AVDD (analog 3.3V or 5V) and OVDD (digital I/O) rails; these may be tied together if the host uses the same supply, or separated to allow level shifting to a different host logic domain. Use a ferrite bead or pi-filter between AVDD and OVDD when they share a rail to prevent digital switching noise from coupling into the analog section. Estimated: a 10 uH ferrite in series with 10 uF + 0.1 uF caps on each side typically provides >40 dB attenuation above 10 MHz.
When using the LVDS interface option, route the SDO+/SDO- pair as a 100 ohm differential microstrip with matched length (±1 mm) and continuous ground reference. Avoid splitting the ground plane beneath the LVDS traces. The CMOS SDO output is more susceptible to noise coupling at high SCK frequencies above 50 MHz; in that regime prefer LVDS for robust data integrity over cable or backplane.
Thông tin tuân thủ
Lead-free finish indicated by #PBF suffix per Analog Devices nomenclature. RoHS and REACH compliance per manufacturer product page.
