LTC2191IUKG - 16-Bit, 40Msps Dual ADC | Analog Devices
MPN: LTC2191IUKG ✓ Hoạt độngLTC2191IUKG Tóm tắt
What is a dual ADC? A dual ADC integrates two matched analog-to-digital converter channels on a single die, sharing a common reference and clock distribution. This eliminates channel-to-channel skew in multi-antenna or I/Q signal chains, which is critical for diversity receivers, MIMO transceivers, and beamforming arrays where phase and amplitude matching between channels defines system-level SNR.
Key differentiating specifications include 16-bit resolution at 40 Msps per channel, 77 dB SNR, 90 dB SFDR, an integrated DDR LVDS serial digital interface (1-, 2-, or 4-bit-per-sample modes) to minimize board traces, and optional internal LVDS termination with adjustable output levels. Per-channel power dissipation is approximately 40 mW per ADC at 40 Msps, and a low-power sleep mode drops consumption below 1 mW for portable or battery-backed applications.
Architecturally, the LTC2191IUKG uses a multi-stage switched-capacitor pipeline frontend paired with an on-chip bandgap reference and proprietary digital error correction. The device accepts differential or single-ended inputs and supports bipolar input ranges through the common-mode voltage on each channel, simplifying front-end driver amplifier design. Its DDR LVDS outputs and selectable data-rate modes (one-bit, two-bit, or four-bit per sample) significantly reduce parallel bus width and ease FPGA capture.
Typical applications include diversity antenna receivers, multiband, multimode cellular base stations, phased-array radar digitizers, test and measurement equipment, medical imaging, and high-speed instrumentation. Two synchronized channels make the LTC2191IUKG particularly well suited to I/Q direct-conversion receivers where IQ amplitude and phase matching directly determine image rejection.
A key design consideration is preserving the input common-mode voltage with a wideband ADC driver such as the LT1994 or ADA4937; AC coupling at the input must include a DC bias network to keep common-mode within the ADC's input range. LVDS trace length matching is also critical to maintain setup/hold margins at the FPGA.
This page synthesizes distributor pricing, drop-in alternatives within the Linear Technology / Analog Devices pipelined-ADC family, and practical layout guidance beyond what is summarized in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho LTC2191IUKG — 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 LTC2191IUKG (cùng hình factor và footprint) — khác nhau ở Sample Rate, Package, SNR, RoHS Status, Operating Temperature.
LTC2191CUKG
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →LTC2190IUKG
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Xem tài liệu →LTC2191IUKG Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 16 bits |
| Sample Rate | 40 Msps per channel |
| Number of Channels | 2 (simultaneous sampling) |
| Architecture | Pipelined |
| SNR | 77 dB |
| SFDR | 90 dB |
| Digital Output | Serial LVDS (DDR, 1/2/4-bit per sample) |
| Input Type | Differential |
| Điện áp cung cấp | 1.8 V (analog) / 1.8 V (digital) |
| Power Dissipation | approximately 80 mW total at 40 Msps |
| Package Type | 52-pin QFN (7x8 mm) |
| Kiểu lắp đặt | Surface Mount |
| Khoảng nhiệt độ hoạt động | -40C to +85C (I-grade) |
| RoHS Compliance | Yes |
| Lead Free | Yes (#PBF suffix) |
Cấu hình chân LTC2191IUKG
| Chân 1 | GND — Ground reference |
| Chân 2 | AIN1+ — Channel 1 positive differential analog input |
| Chân 3 | AIN1- — Channel 1 negative differential analog input |
| Chân 4 | VCM1 — Channel 1 input common-mode voltage |
| Chân 5 | GND — Ground reference |
| Chân 6 | VREF — Reference voltage bypass |
| Chân 7 | REFT — Reference top decoupling |
| Chân 8 | REFB — Reference bottom decoupling |
| Chân 9 | GND — Ground reference |
| Chân 10 | OVDD — Digital output supply (1.8 V) |
| Chân 11 | OGND — Digital output ground |
| Chân 12 | CLK+ — Differential clock positive input |
| Chân 13 | CLK- — Differential clock negative input |
| Chân 14 | ENC+ — Encode positive input (per family note) |
| Chân 15 | ENC- — Encode negative input (per family note) |
| Chân 16 | CS — Chip select / SPI control |
| Chân 17 | SDI — SPI serial data input |
| Chân 18 | SCK — SPI serial clock |
| Chân 19 | SDO — SPI serial data output |
| Chân 20 | RESET — Hardware reset, active high |
| Chân 21 | NC — Not connected (per datasheet) |
| Chân 22 | OGND — Digital output ground |
| Chân 23 | OVDD — Digital output supply (1.8 V) |
| Chân 24 | D1+ — LVDS data output pair 1 positive |
| Chân 25 | D1- — LVDS data output pair 1 negative |
| Chân 26 | D2+ — LVDS data output pair 2 positive |
| Chân 27 | D2- — LVDS data output pair 2 negative |
| Chân 28 | OGND — Digital output ground |
| Chân 29 | D3+ — LVDS data output pair 3 positive |
| Chân 30 | D3- — LVDS data output pair 3 negative |
| Chân 31 | D4+ — LVDS data output pair 4 positive |
| Chân 32 | D4- — LVDS data output pair 4 negative |
| Chân 33 | OGND — Digital output ground |
| Chân 34 | D5+ — LVDS data output pair 5 positive |
| Chân 35 | D5- — LVDS data output pair 5 negative |
| Chân 36 | D6+ — LVDS data output pair 6 positive |
| Chân 37 | D6- — LVDS data output pair 6 negative |
| Chân 38 | OGND — Digital output ground |
| Chân 39 | NC — Not connected (per datasheet) |
| Chân 40 | GND — Ground reference |
| Chân 41 | VDD — Analog supply (1.8 V) |
| Chân 42 | GND — Ground reference |
| Chân 43 | AIN2- — Channel 2 negative differential analog input |
| Chân 44 | AIN2+ — Channel 2 positive differential analog input |
| Chân 45 | GND — Ground reference |
| Chân 46 | VCM2 — Channel 2 input common-mode voltage |
| Chân 47 | GND — Ground reference |
| Chân 48 | REFT — Reference top decoupling |
| Chân 49 | REFB — Reference bottom decoupling |
| Chân 50 | GND — Ground reference |
| Chân 51 | VDD — Analog supply (1.8 V) |
| Chân 52 | GND — Ground reference (exposed pad) |
Ứng dụng tiêu biểu
LTC2191IUKG phù hợp cho 6 Áp dụngs: Diversity Antenna Receiver, Multiband Cellular Base Station, Phased-Array Radar Digitizer, Test and Measurement Instrumentation, Medical Imaging Systems, I/Q Direct-Conversion Receiver.
Diversity Antenna Receiver
The LTC2191IUKG's two simultaneously-sampling 16-bit channels at 40 Msps pair well with diversity antenna front ends where channel-to-channel amplitude and phase matching set the SINR floor of the combined output. With 77 dB SNR and 90 dB SFDR the device preserves weak-signal dynamic range against interferers, while the DDR LVDS interface keeps board traces minimal even across multiple antennas. The integrated LVDS termination simplifies the FPGA capture stage and reduces BOM count.
Được đề xuất
Multiband Cellular Base Station
Cellular base-station receivers demand simultaneous multiband capture with high SFDR across wide instantaneous bandwidths; the LTC2191IUKG's two matched 16-bit cores at 40 Msps satisfy LTE and early-5G NR digitizer requirements with 90 dB SFDR at IF. The serial LVDS output reduces FPGA pin count, which matters in densely populated multi-sector baseband boards. Low 80 mW power dissipation keeps thermal budgets on track even when multiple ADCs share a board.
Được đề xuất
Phased-Array Radar Digitizer
Phased-array radar modules require precisely time-aligned multi-channel ADC sampling; the LTC2191IUKG delivers two channels sampled on a common clock edge with matched pipeline latency, preserving phase coherence across element channels. The 90 dB SFDR cleanly resolves returns in clutter-heavy environments and the DDR LVDS reduces board trace density, which is critical at the small element pitches of active phased arrays. Power per channel (~40 mW) supports dense tile integration.
Được đề xuất
Test and Measurement Instrumentation
High-end oscilloscopes, spectrum analyzers, and arbitrary waveform digitizers use the LTC2191IUKG to capture two matched channels at 40 Msps with sufficient dynamic range for high-purity signal acquisition. The 77 dB SNR gives bit-accurate amplitude measurements while 90 dB SFDR protects against large-signal-induced spurs when measuring wideband multitone stimuli. DDR LVDS keeps the data backhaul to the FPGA lean and minimizes the instrument's PCB layer count.
Được đề xuất
Medical Imaging Systems
Ultrasound and other medical imaging modalities rely on tightly-matched multi-channel digitizers; the LTC2191IUKG's two matched 16-bit cores at 40 Msps preserve beamformed image dynamic range and harmonic content for diagnostic-grade imaging. Low ADC noise floor at 77 dB SNR supports deep-tissue imaging penetration, while the small 52-pin QFN (7x8 mm) package fits within ultrasound probe-head and cart-mounted electronics where board area is constrained.
Được đề xuất
I/Q Direct-Conversion Receiver
Direct-conversion I/Q receivers demand matched I and Q sampling to maintain image rejection; the LTC2191IUKG samples both channels of a quadrature demodulator at the same instant at 40 Msps, preserving amplitude and phase matching necessary for high image rejection. The 16-bit resolution captures dynamic range from small to large signals simultaneously, and the LVDS digital output simplifies routing into the baseband FPGA that computes the FFT and demodulation.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LTC2191IUKG — 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 | LTC2191CUKG | LTC2190IUKG |
|---|---|---|---|
| Brand | Analog Devices (formerly Linear Technology) | Analog Devices | Analog Devices |
| Package | 52-pin QFN (7x8 mm) | 52-pin QFN (7x8 mm) - same | 52-pin QFN (7x8 mm) - same |
| Resolution | 16 bits | 16 bits | 16 bits |
| Sample Rate | 40 Msps per channel | 40 Msps per channel | 25 Msps per channel (-37.5%) |
| Number of Channels | 2 (simultaneous sampling) | 2 | 2 |
| SNR | 77 dB | 77 dB | 77 dB |
| SFDR | 90 dB | 90 dB | 90 dB |
| Output Interface | Serial LVDS (DDR, 1/2/4-bit modes) | Serial LVDS (DDR, 1/2/4-bit modes) | Serial LVDS (DDR, 1/2/4-bit modes) |
| Operating Temperature | -40C to +85C (I-grade) | 0C to +70C (C-grade) | -40C to +85C (I-grade) |
Bảo phân biệt quan trọng
- Dual simultaneous-sampling channels at 40 Msps in a compact 52-pin QFN (7x8 mm) (vsSingle-channel 16-bit ADCs in similar packages)
- DDR LVDS output with selectable 1-, 2-, or 4-bit-per-sample modes (vsParallel CMOS-output 16-bit ADCs)
- Low power of approximately 80 mW total at full sample rate (vsCompetitive 16-bit dual ADCs in similar packages)
Ghi chú thiết kế
Layout must use a solid ground plane under the LTC2191IUKG with the exposed pad soldered to a low-inductance thermal/ground footprint. Place the 1.8 V analog decoupling (1 uF / 0.1 uF) within 5 mm of each VDD pin and surround each input pin pair with a ground guard ring. Differential input traces should be matched to within 0.5 mm to preserve the 77 dB SNR; any mismatch between AIN+ and AIN- paths converts directly to even-order distortion at the ADC output.
Common pitfalls include driving the analog inputs single-ended without biasing the common-mode voltage through VCM1/VCM2, which pushes the input outside the linear range and destroys SNR. The clock signal must be a clean differential sine or square from a low-jitter source (typical 250 fs RMS) as clock jitter directly limits SNR according to SNR = 6.02*N + 1.76 + 10*log10(FS/(2*pi*jitter)). Source-synchronous LVDS routing also requires matched lengths (within 50 ps) for setup/hold margin at the FPGA.
Enable the LTC2191IUKG's internal LVDS termination (per the 219210f datasheet) only when the FPGA receiver cannot supply 100 ohm termination near the input. For long board traces (>5 cm) leave termination off and place the 100 ohm differential termination at the receiver side. The serial-LVDS data rates in 2-bit and 4-bit modes exceed 1 Gbps, so controlled-impedance routing (100 ohm differential) and length-matched pairs are mandatory to avoid inter-symbol jitter.
Thông tin tuân thủ
RoHS compliance and lead-free termination indicated by #PBF suffix. AEC-Q100 automotive qualification not stated in the provided data. REACH and conflict-minerals status taken from typical Linear Technology / Analog Devices declarations.
