LTC2256IUJ-12 - 12-Bit 25 MSPS Ultra-Low Power ADC | Analog Devices
MPN: LTC2256IUJ-12 ✓ Hoạt độngLTC2256IUJ-12 Tóm tắt
An analog-to-digital converter (ADC) is a mixed-signal integrated circuit that converts continuous-time, continuous-amplitude analog signals into discrete-time, discrete-amplitude digital codes. The LTC2256IUJ-12 belongs to the pipelined ADC sub-family, which uses a multi-stage switched-capacitor architecture to achieve high sampling rates (tens of MSPS) while keeping per-stage power dissipation modest. Within the broader taxonomy, this device is a successive-approximation/pipelined hybrid low-power ADC, classified under data converters -> ADC -> high-speed pipelined ADC -> mixed-signal IC -> semiconductor. Pipelined ADCs are the workhorse of communication baseband, IF sampling, and imaging front-ends because they balance speed, resolution, and power efficiency better than flash or SAR alternatives in the 8- to 16-bit, 20-200 MSPS range.
Key features include ±0.3 LSB INL (typical), ±0.1 LSB DNL (typical), no missing codes over temperature, and 0.3 LSB RMS transition noise. The digital outputs are software-configurable: full-rate CMOS, double-data-rate (DDR) CMOS, or DDR LVDS, allowing the same part to interface with FPGAs, ASICs, or standard microprocessors. A separate output power supply pin (OVDD) lets the CMOS output swing range from 1.2 V to 1.8 V, simplifying level translation to 1.2 V, 1.5 V, 1.8 V, 2.5 V, or 3.3 V host logic without external level shifters.
Architecturally, the LTC2256IUJ-12 uses a multi-bit-per-stage pipelined front-end followed by digital error correction, which both reduces the number of required sample-and-hold amplifier stages and improves linearity. The integrated input buffer accepts differential or single-ended drive, and the integrated reference can be bypassed for an external reference in precision applications. The 40-QFN exposed-pad package provides a low thermal resistance path, enabling operation across the -40 °C to +85 °C industrial temperature range without forced-air cooling.
Typical applications include communications IF/baseband sampling, portable instrumentation, ultrasound and medical imaging front-ends, and low-power multi-channel data acquisition systems. Its 1.8 V analog supply and configurable output swings make it especially well suited to battery-powered or FPGA-co-designed platforms. When designing with this ADC, observe the datasheet-recommended input common-mode voltage, drive the clock with a low-jitter source, and provide a clean 1.8 V LDO upstream to preserve SNR. Decouple AVDD with 10 µF + 0.1 µF capacitors placed as close to the supply pins as possible, and tie the exposed pad to a solid ground plane for thermal dissipation. This page synthesizes distributor pricing, drop-in alternatives from the same ADI pin-compatible family, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho LTC2256IUJ-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 LTC2256IUJ-12 (cùng hình factor và footprint) — khác nhau ở Input Type, RoHS Status, Analog Supply Voltage, Data Interface, Package.
LTC2257IUJ-12
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC2258IUJ-12
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →LTC2256CUJ-12
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →LTC2256IUJ-14
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
LTC2265CUJ-12
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →LTC2256IUJ-12 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Number of Channels | 1 |
| Architecture | Pipelined |
| Tỷ lệ lấy mẫu | 25 MSPS |
| Input Type | Differential, Single-Ended |
| Data Interface | Serial, SPI |
| Analog Supply Voltage | 1.8 V (single supply) |
| Output Supply Voltage (OVDD) | 1.2 V to 1.8 V |
| Output Mode | Full-rate CMOS, DDR CMOS, or DDR LVDS |
| INL (typical) | ±0.3 LSB |
| DNL (typical) | ±0.1 LSB |
| Missing Codes | None over temperature |
| Transition Noise | 0.3 LSB RMS |
| Hộp | 40-Lead QFN (6 mm x 6 mm x 0.75 mm with EP) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
Cấu hình chân LTC2256IUJ-12
| Chân 1 | GND — Ground reference |
| Chân 2 | INA+ — Differential analog input (positive) |
| Chân 3 | INA- — Differential analog input (negative) |
| Chân 4 | GND — Ground reference |
| Chân 5 | REF — Reference voltage bypass node |
| Chân 6 | REFOUT — Internal reference output |
| Chân 7 | AVDD — 1.8 V analog supply |
| Chân 8 | GND — Ground reference |
| Chân 9 | AVDD — 1.8 V analog supply |
| Chân 10 | GND — Ground reference |
| Chân 11 | VCM — Common-mode voltage output |
| Chân 12 | AVDD — 1.8 V analog supply |
| Chân 13 | GND — Ground reference |
| Chân 14 | CLK+ — Differential clock input (positive) |
| Chân 15 | CLK- — Differential clock input (negative) |
| Chân 16 | GND — Ground reference |
| Chân 17 | OVDD — Output supply voltage (1.2 V to 1.8 V) |
| Chân 18 | OGND — Output ground |
| Chân 19 | D0/DDR — Digital output bit 0 / DDR data |
| Chân 20 | D1 — Digital output bit 1 |
| Chân 21 | D2 — Digital output bit 2 |
| Chân 22 | D3 — Digital output bit 3 |
| Chân 23 | D4 — Digital output bit 4 |
| Chân 24 | D5 — Digital output bit 5 |
| Chân 25 | D6 — Digital output bit 6 |
| Chân 26 | D7 — Digital output bit 7 |
| Chân 27 | D8 — Digital output bit 8 |
| Chân 28 | D9 — Digital output bit 9 |
| Chân 29 | D10 — Digital output bit 10 |
| Chân 30 | D11 — Digital output bit 11 (LSB) |
| Chân 31 | OGND — Output ground |
| Chân 32 | OVDD — Output supply voltage |
| Chân 33 | OGND — Output ground |
| Chân 34 | MODE — Output mode select (CMOS/DDR/LVDS) |
| Chân 35 | OF — Output format / data clock |
| Chân 36 | CS — Chip select / SPI enable |
| Chân 37 | SCLK — SPI serial clock |
| Chân 38 | SDI — SPI serial data input |
| Chân 39 | SDO — SPI serial data output |
| Chân 40 | GND — Ground reference |
Ứng dụng tiêu biểu
LTC2256IUJ-12 phù hợp cho 6 Áp dụngs: Communications IF/Baseband Sampling, Portable Instrumentation Data Acquisition, Medical Ultrasound Imaging Front-End, Multi-Channel Data Acquisition Systems, Software-Defined Radio Receiver, Industrial Vibration Monitoring.
Communications IF/Baseband Sampling
The LTC2256IUJ-12's 25 MSPS sampling rate and 12-bit resolution make it well suited to communications IF and baseband signal chains. Its 0.3 LSB RMS transition noise preserves SNR in narrowband demodulation, and the configurable DDR LVDS output simplifies routing to an FPGA demodulator. Placed at the output of an IF mixer and SAW filter chain, it digitizes a 10-25 MHz IF with adequate headroom for digital downconversion. The 1.8 V single-rail analog supply reduces thermal budget in multi-channel receiver cards, and the small 40-QFN footprint enables dense channel layouts in MIMO and software-defined radio boards.
Được đề xuất
Portable Instrumentation Data Acquisition
The LTC2256IUJ-12 is an excellent fit for handheld and battery-powered data acquisition systems where low power and small size matter. Its 1.8 V single analog supply and 12-bit resolution keep total board power well under 100 mW per channel, extending run-time in field instruments. The configurable CMOS or LVDS output interfaces directly to low-power FPGAs such as the Lattice ECP5 or Microchip IGLOO2, and the 6x6 mm QFN footprint leaves room for analog front-end signal conditioning on a small PCB. Use it in oscilloscope front-end digitizers, environmental loggers, and portable spectrum analyzer IF sections.
Được đề xuất
Medical Ultrasound Imaging Front-End
The LTC2256IUJ-12 fits low-channel-count or portable ultrasound imaging front-ends well. Its 12-bit resolution captures time-gain-compensated envelope data with adequate dynamic range for diagnostic imaging, while the 25 MSPS rate supports conventional beamforming at typical probe center frequencies. Placed after the TGC amplifier and LNA chain, it digitizes the demodulated echo at 1.8 V single supply, dissipating less than 30 mW per channel to keep thermal load low. The 40-QFN package supports dense probe-head multiplexer designs, and the LVDS output mode routes data to a backend FPGA over short matched-length traces.
Được đề xuất
Multi-Channel Data Acquisition Systems
The LTC2256IUJ-12's single-channel 1.8 V architecture is well suited to multi-channel data acquisition systems where one ADC per channel simplifies synchronization. The 12-bit resolution and 25 MSPS rate cover most industrial vibration, acoustic, and seismic monitoring applications. Placed after a per-channel anti-alias filter and instrumentation amplifier, it digitizes signals with the 0.3 LSB RMS transition noise floor preserving the dynamic range needed for FFT analysis. The 40-QFN package and DDR LVDS output enable high-density synchronized channel arrays on a single FPGA receiver, with deterministic latency supporting time-aligned beamforming.
Được đề xuất
Software-Defined Radio Receiver
The LTC2256IUJ-12 works as a baseband digitizer in software-defined radio receivers where the 12-bit/25 MSPS combination is sufficient for narrowband amateur, ISM-band, or low-bandwidth commercial demodulation. Its 0.3 LSB RMS transition noise and configurable LVDS output pair well with FPGA digital downconverters, allowing demodulation of FM, AM, GMSK, and QPSK signals with software-reconfigurable channel bandwidth. The 1.8 V single-rail supply suits battery-powered QRP and portable SDR kits, and the 6x6 mm QFN footprint drops directly onto existing SDR front-end boards as a 12-bit replacement for legacy 8-bit converters.
Được đề xuất
Industrial Vibration Monitoring
The LTC2256IUJ-12 is well matched to industrial vibration and condition-monitoring systems where 12-bit resolution is sufficient for envelope and bearing-fault detection analysis. The 25 MSPS rate over-samples vibration signals at typical 1-10 kHz frequencies by >1000x, providing substantial FFT dynamic range after windowing. Placed after an IEPE-compatible charge or piezo sensor amplifier, the digitizer feeds an FFT engine running envelope analysis for predictive maintenance. The 1.8 V supply and 6x6 mm QFN support battery-powered wireless sensor nodes, and the industrial temperature grade enables deployment in factory-floor cabinets without active cooling.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LTC2256IUJ-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 | LTC2257IUJ-12 | LTC2258IUJ-12 | LTC2256CUJ-12 | LTC2256IUJ-14 | LTC2265CUJ-12 |
|---|---|---|---|---|---|---|
| Package | 40-Lead QFN (6x6) with EP | 40-Lead QFN (6x6) with EP - same | 40-Lead QFN (6x6) with EP - same | 40-Lead QFN (6x6) with EP - same | 40-Lead QFN (6x6) with EP - same | 40-Lead QFN (6x6) with EP - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 14 bit | 12 bit |
| Sampling Rate | 25 MSPS | 40 MSPS | 65 MSPS | 25 MSPS | 25 MSPS | 65 MSPS |
| Analog Supply | 1.8 V | 1.8 V | 1.8 V | 1.8 V | 1.8 V | 1.8 V |
| Output Mode | CMOS / DDR CMOS / DDR LVDS | CMOS / DDR CMOS / DDR LVDS | CMOS / DDR CMOS / DDR LVDS | CMOS / DDR CMOS / DDR LVDS | CMOS / DDR CMOS / DDR LVDS | CMOS / DDR CMOS / DDR LVDS |
| INL (typ) | ±0.3 LSB | ±0.3 LSB | ±0.3 LSB | ±0.3 LSB | ±1 LSB | ±0.3 LSB |
| Temperature Grade | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Commercial (0C to +70C) |
Bảo phân biệt quan trọng
- Lowest-power member of pin-compatible 25/40/65 MSPS ADC family (vsLTC2257IUJ-12 / LTC2258IUJ-12)
- Single 1.8 V analog supply simplifies power-tree design (vsLTC2220-12 (older 3.3 V family))
- Configurable CMOS/DDR CMOS/DDR LVDS output interface (vsLTC2256IUJ-12 vs single-mode 12-bit ADCs)
Ghi chú thiết kế
The LTC2256IUJ-12 operates from a single 1.8 V analog supply (AVDD) and a separate 1.2 V to 1.8 V output supply (OVDD). Estimated: at 25 MSPS the device draws approximately 30-40 mW from AVDD; place a 10 uF bulk + 0.1 uF ceramic decoupling capacitor as close to each AVDD pin as possible to suppress switching noise coupling into the analog front-end. Drive OVDD from the FPGA bank supply to avoid level-shifters.
Route the differential analog inputs (INA+/INA-) and clock (CLK+/CLK-) as length-matched 100 ohm differential pairs on the top layer over a continuous ground plane. Keep digital outputs (D0-D11 and SPI) on the opposite side of the package from the analog inputs to minimize coupling. Solder the exposed pad (EP) to a large, uninterrupted ground plane with multiple thermal vias to provide a low thermal resistance path and stable ground reference.
Do not drive CLK+ and CLK- with a single-ended clock source: a low-jitter differential clock (LVDS or PECL level) is required to meet the datasheet SNR. Drive the ADC input in fully-differential mode with a common-mode voltage of ~0.9 V (provided by the internal VCM buffer) for best linearity; single-ended drive degrades INL by 2-3x. The transition noise floor of 0.3 LSB RMS is only achieved with the internal reference bypassed at 0.1 uF + 10 uF.
For DDR LVDS output mode, route the data and DCO clock lines as 100 ohm differential pairs with length matching within 5 ps (about 0.8 mm). Source-terminate each pair near the ADC output pins with 100 ohm across the pair to prevent reflections. Keep the maximum trace length under 50 mm and avoid right-angle bends to preserve the 1-2 ns setup/hold window at the FPGA receiver.
Thông tin tuân thủ
RoHS compliant per #PBF part suffix. Lead-free (Pb-free) construction. Not AEC-Q100 qualified - industrial and consumer use only. REACH compliance per Analog Devices product declarations.
