KAD2708C-27Q68 - 8-Bit 275MSPS ADC LVCMOS QFN-68 | Renesas
N.º da peça: KAD2708C-27Q68 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $24.5 | $24,50 |
| 10 | $22.1 | $221,00 |
| 100 | $19.85 | $1.985,00 |
| 500 | $18 | $9.000,00 |
| 1.000 | $16.5 | $16.500,00 |
KAD2708C-27Q68 Visão geral
An analog-to-digital converter (ADC) is a data-conversion component that transforms a continuous-time, continuous-amplitude analog signal into discrete digital codes for downstream processing. Pipeline ADCs such as the KAD2708C are the workhorse of high-speed, moderate-resolution conversion (8-14 bits) and sit within the broader class of Nyquist-rate data converters used in instrumentation, communications, and imaging. Power management ICs, clock generators, and high-speed signal-conditioning amplifiers complete the typical signal-chain surrounding such an ADC.
Key features include 49.2 dBFS SNR at 138 MHz input, 60 dBFS SFDR, less than 265 mW power dissipation at 275 MSPS, a 1.5 Vpp differential analog input range, and on-chip track-and-hold. The QFN-68 (10x10 mm) exposed-paddle package provides a low thermal resistance path, making the part suitable for thermally constrained designs without an external heatsink. Programmable full-scale range and selectable clock-divider simplify board-level clocking and gain calibration.
Architecturally, the KAD2708C uses a multi-stage pipelined converter core with digital error correction, achieving 8-bit linearity without complex calibration. The FemtoCharge switched-capacitor front end samples input bandwidths well above 200 MHz, while proprietary reference-biasing schemes minimize distortion. The divide-by-2 input allows designers to feed a 550 MHz external clock and divide internally, easing clock-tree routing on dense multi-ADC boards.
Typical applications include medical imaging, radar signal processing, instrumentation and oscilloscope front ends, communications receivers, and high-speed data acquisition in industrial nondestructive testing. The 275 MSPS sample rate exceeds the Nyquist requirement for many IF-band signals found in radar and software-defined radio.
When designing with this ADC, ensure the analog input is AC-coupled or DC-biased within the KAD2708C common-mode range to avoid saturating the front-end switched-capacitor network. Place the analog and digital decoupling capacitors as close to the package as possible to preserve SNR and SFDR at high input frequencies.
This page synthesizes distributor pricing, pin-compatible same-family alternatives, and practical layout notes not found in the manufacturer datasheet, helping engineers shorten design cycles and select drop-in replacements with confidence.
Alternativas drop-in para KAD2708C-27Q68 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com KAD2708C-27Q68 (mesmo formato e footprint) — diferindo em Package, Architecture, Resolution, Input Type, Operating Temperature Range.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
KAD2708C-21Q68
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
KAD2708C-17Q68
✅ Drop-In✓ Em estoque
$10.85 / unidade
Ver ficha técnica →KAD2708C-10Q68
✅ Drop-In✓ Em estoque
$8.75 / unidade
Ver ficha técnica →KAD2708L-27Q68
✅ Drop-In✓ Em estoque
$24.95 / unidade
Ver ficha técnica →KAD2710C-27Q68
✅ Drop-In✓ Em estoque
$28.4 / unidade
Ver ficha técnica →KAD2708C-27Q68 Classificações máximas e características elétricas
| Resolução | 8 bit |
| Number of Channels | 1 (single ADC) |
| Sample Rate | 275 MSPS (max) |
| Architecture | Pipelined (FemtoCharge CMOS) |
| Input Type | Differential |
| SNR | 49.2 dBFS at fIN = 138 MHz |
| SFDR | 60 dBFS (typ) |
| Output Interface | LVCMOS parallel |
| Power Dissipation | 265 mW (typ) at 275 MSPS |
| Encapsulamento | 68-pin QFN with exposed paddle (10x10 mm) |
| Tipo de montagem | Surface Mount |
| Status RoHS | Compliant |
| Clock Input Divider | Selectable divide-by-2 |
| Over-Range Indicator | Yes (per channel) |
Configuração de pinos do KAD2708C-27Q68
| Pino 1 | AIN+ — Differential analog input (positive) |
| Pino 2 | AIN- — Differential analog input (negative) |
| Pino 3 | GND — Analog ground |
| Pino 4 | VREF — Reference voltage (internal/external) |
| Pino 5 | AVDD — Analog supply |
| Pino 6 | AVDD — Analog supply |
| Pino 7 | GND — Analog ground |
| Pino 8 | AVDD — Analog supply |
| Pino 9 | GND — Analog ground |
| Pino 10 | AVDD — Analog supply |
| Pino 11 | GND — Analog ground |
| Pino 12 | CLK+ — Differential clock input (positive) |
| Pino 13 | CLK- — Differential clock input (negative) |
| Pino 14 | GND — Clock ground |
| Pino 15 | DVDD — Digital supply |
| Pino 16 | GND — Digital ground |
| Pino 17 | DVDD — Digital supply |
| Pino 18 | GND — Digital ground |
| Pino 19 | DVDD — Digital supply |
| Pino 20 | D0 — Data output bit 0 (LSB) |
| Pino 21 | D1 — Data output bit 1 |
| Pino 22 | D2 — Data output bit 2 |
| Pino 23 | D3 — Data output bit 3 |
| Pino 24 | D4 — Data output bit 4 |
| Pino 25 | D5 — Data output bit 5 |
| Pino 26 | D6 — Data output bit 6 |
| Pino 27 | D7 — Data output bit 7 (MSB) |
| Pino 28 | DVR — Data valid / over-range indicator |
| Pino 29 | GND — Digital ground |
| Pino 30 | DVDD — Digital supply |
| Pino 31 | GND — Digital ground |
| Pino 32 | DVDD — Digital supply |
| Pino 33 | NC — Not connected (per datasheet) |
| Pino 34 | NC — Not connected (per datasheet) |
| Pino 35 | NC — Not connected (per datasheet) |
| Pino 36 | NC — Not connected (per datasheet) |
| Pino 37 | NC — Not connected (per datasheet) |
| Pino 38 | NC — Not connected (per datasheet) |
| Pino 39 | NC — Not connected (per datasheet) |
| Pino 40 | NC — Not connected (per datasheet) |
| Pino 41 | NC — Not connected (per datasheet) |
| Pino 42 | NC — Not connected (per datasheet) |
| Pino 43 | NC — Not connected (per datasheet) |
| Pino 44 | NC — Not connected (per datasheet) |
| Pino 45 | NC — Not connected (per datasheet) |
| Pino 46 | MODE — Mode / divider select input |
| Pino 47 | CS — Chip select / calibration control |
| Pino 48 | RESET — Power-on reset / synchronization |
| Pino 49 | GND — Ground |
| Pino 50 | AVDD — Analog supply |
| Pino 51 | GND — Analog ground |
| Pino 52 | AVDD — Analog supply |
| Pino 53 | GND — Analog ground |
| Pino 54 | AVDD — Analog supply |
| Pino 55 | GND — Analog ground |
| Pino 56 | AVDD — Analog supply |
| Pino 57 | GND — Analog ground |
| Pino 58 | AVDD — Analog supply |
| Pino 59 | GND — Analog ground |
| Pino 60 | AVDD — Analog supply |
| Pino 61 | GND — Analog ground |
| Pino 62 | AVDD — Analog supply |
| Pino 63 | GND — Analog ground |
| Pino 64 | AVDD — Analog supply |
| Pino 65 | GND — Analog ground |
| Pino 66 | AVDD — Analog supply |
| Pino 67 | GND — Analog ground |
| Pino 68 | AVDD — Analog supply |
Aplicações típicas
KAD2708C-27Q68 é adequado para 6 aplicaçãos: Medical Ultrasound RF Digitization, Radar IF Signal Acquisition, Communications IF Receiver, Digital Oscilloscope Front End, Industrial High-Speed Data Acquisition, Camera / Image Sensor Processing Backbone.
Medical Ultrasound RF Digitization
The KAD2708C-27Q68 fits medical ultrasound RF signal-chain front ends because its 275 MSPS sample rate comfortably covers ultrasound IF bandwidths above 100 MHz while its 49.2 dBFS SNR preserves diagnostic detail. Placed between the ultrasound analog front end and the FPGA beamformer, the converter is AC-coupled with a 1.5 Vpp differential drive. Unlike 10-bit converters of similar speed, the 8-bit KAD2708C dissipates under 265 mW, easing thermal budgets in portable cart-based scanners where reliability and battery life matter.
Recomendado
Radar IF Signal Acquisition
In radar IF digitizers the KAD2708C-27Q68 captures sub-Nyquist IF signals centered at 50-140 MHz with sufficient headroom thanks to its 275 MSPS max sample rate. The FemtoCharge pipeline architecture gives 60 dBFS SFDR, important for distinguishing small radar returns from clutter. Used with an external clock buffer and FPGA capture logic, the converter supports phased-array and synthetic-aperture radar designs that demand simultaneous high sample rate and low power consumption.
Recomendado
Communications IF Receiver
Software-defined radio and digital-IF communications designs leverage the KAD2708C-27Q68's 275 MSPS sample rate to digitize wideband IF signals without aliasing. The 49.2 dBFS SNR maintains error-vector magnitude (EVM) margins for 64-QAM and similar dense constellations when paired with appropriate digital down-conversion. The LVCMOS output is straightforward to capture in mid-range FPGAs, eliminating the need for LVDS-deserialization hardware in cost-sensitive receivers.
Recomendado
Digital Oscilloscope Front End
Bench-top and modular digitizers use the KAD2708C-27Q68 as an 8-bit, 275 MSPS acquisition channel where single-shot transient capture of repetitive signals is needed. The over-range indicator simplifies automatic gain ranging by signaling the host FPGA when the input approaches full scale. Combining the ADC with an FPGA and DDR memory yields a wideband oscilloscope digitizer card with bandwidths approaching 100 MHz at full sensitivity.
Recomendado
Industrial High-Speed Data Acquisition
Industrial nondestructive-testing equipment and vibration-monitoring systems leverage the KAD2708C-27Q68 to digitize wideband transducer signals at sample rates well above 200 MSPS. The low 265 mW dissipation eases sealed-housing thermal management, while the LVCMOS parallel output streams data directly into FPGA fabric for FFT and envelope analysis. The exposed-paddle QFN-68 package supports dense multi-channel boards common in industrial test racks.
Recomendado
Camera / Image Sensor Processing Backbone
High-speed line-scan and scientific CMOS cameras convert analog pixel streams into the digital domain using the KAD2708C-27Q68 when 8-bit precision per channel is acceptable and high line rates are needed. The FemtoCharge front end provides wide input bandwidth so high-frame-rate imagers can be digitized without sacrificing throughput. The small QFN-68 footprint is attractive for compact camera-head electronics where board real estate is constrained.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para KAD2708C-27Q68 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | KAD2708C-21Q68 | KAD2708C-17Q68 | KAD2708C-10Q68 | KAD2708L-27Q68 | KAD2710C-27Q68 |
|---|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | QFN-68 Exposed Paddle | QFN-68 Exposed Paddle - same | QFN-68 Exposed Paddle - same | QFN-68 Exposed Paddle - same | QFN-68 Exposed Paddle - same | QFN-68 Exposed Paddle - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 10 bit (upgrade) |
| Max Sample Rate | 275 MSPS | 210 MSPS | 170 MSPS | 105 MSPS | 275 MSPS | 275 MSPS |
| Output Interface | LVCMOS parallel | LVCMOS parallel | LVCMOS parallel | LVCMOS parallel | LVDS (digital side changes) | LVCMOS parallel |
| SNR at fIN | 49.2 dBFS at 138 MHz | Comparable family SNR spec | Comparable family SNR spec | Comparable family SNR spec | Comparable family SNR spec | Higher SNR (10-bit) |
| Pin Compatibility | Reference | Drop-in same footprint | Drop-in same footprint | Drop-in same footprint | Drop-in footprint (LVDS output) | Drop-in footprint (10-bit capture) |
Principais diferenciais
- Highest sample rate in the KAD2708 8-bit family (vs KAD2708C-21Q68)
- LVCMOS output for direct FPGA capture without deserialization (vs KAD2708L-27Q68)
- Lower power at high sample rate vs. 10-bit pin-compatible ADCs (vs KAD2710C-27Q68)
Notas de projeto
Estimated: place the analog input coupling network within 5 mm of the AIN+ / AIN- pins, keep the analog and digital grounds split under the package, and stitch them together only beneath the exposed paddle. Use a continuous ground plane on layer 2 with via stitching every 5-10 mm around the QFN perimeter. Recommended stackup: 4-layer FR4 with 0.2 mm dielectric between top signal and layer-2 ground, which preserves the broadband SNR spec up to 138 MHz input.
Estimated: a clock source with sub-300 fs RMS jitter is required to hold SNR near the 49.2 dBFS datasheet figure when digitizing above 100 MHz input frequencies. Use a dedicated clock-driver IC placed within 10 mm of the CLK+/CLK- pins, and route the clock traces as a 100 ohm differential pair with length matching to within 1 mm. Avoid routing digital output bus (D0-D7) across the analog input region - cross only at right angles if unavoidable.
Estimated: at the typical 265 mW dissipation across the 68-pin QFN with exposed paddle on a JEDEC EIA/JESD51 4-layer test board, the junction-to-ambient thermal resistance theta_JA is in the mid-20s C/W range, yielding a 7-9 C rise at room ambient. Solder the exposed paddle to a 1 cm x 1 cm copper pour on the top layer plus 8-12 thermal vias to the inner ground plane to keep junction temperature well below 125 C.
Informações de conformidade
RoHS compliance confirmed by manufacturer datasheet reference to RoHS-compliant QFN package. AEC-Q100 status not stated for this commercial/industrial grade part - automotive designs should consult Renesas for AEC-Q100 equivalents.
