KAD2708C-27Q68 - 8-Bit 275MSPS ADC LVCMOS QFN-68 | Renesas
Référence : KAD2708C-27Q68 ✓ Actif| Qté | Prix unitaire | 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 Présentation
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.
Alternatives de remplacement direct pour KAD2708C-27Q68 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Variantes de cette série
Modèles de la même série directement compatibles avec KAD2708C-27Q68 (même facteur de forme et même empreinte) — différant par Package, Architecture, Resolution, Input Type, Operating Temperature Range.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
KAD2708C-21Q68
✅ Remplacement direct📋 Alternative de référence (hors catalogue)
KAD2708C-17Q68
✅ Remplacement direct✓ En stock
$10.85 / unité
Voir la fiche technique →KAD2708C-10Q68
✅ Remplacement direct✓ En stock
$8.75 / unité
Voir la fiche technique →KAD2708L-27Q68
✅ Remplacement direct✓ En stock
$24.95 / unité
Voir la fiche technique →KAD2710C-27Q68
✅ Remplacement direct✓ En stock
$28.4 / unité
Voir la fiche technique →KAD2708C-27Q68 Valeurs maximales et caractéristiques électriques
| Résolution | 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 |
| Boîtier | 68-pin QFN with exposed paddle (10x10 mm) |
| Type de montage | Surface Mount |
| Statut RoHS | Compliant |
| Clock Input Divider | Selectable divide-by-2 |
| Over-Range Indicator | Yes (per channel) |
Configuration des broches de KAD2708C-27Q68
| Broche 1 | AIN+ — Differential analog input (positive) |
| Broche 2 | AIN- — Differential analog input (negative) |
| Broche 3 | GND — Analog ground |
| Broche 4 | VREF — Reference voltage (internal/external) |
| Broche 5 | AVDD — Analog supply |
| Broche 6 | AVDD — Analog supply |
| Broche 7 | GND — Analog ground |
| Broche 8 | AVDD — Analog supply |
| Broche 9 | GND — Analog ground |
| Broche 10 | AVDD — Analog supply |
| Broche 11 | GND — Analog ground |
| Broche 12 | CLK+ — Differential clock input (positive) |
| Broche 13 | CLK- — Differential clock input (negative) |
| Broche 14 | GND — Clock ground |
| Broche 15 | DVDD — Digital supply |
| Broche 16 | GND — Digital ground |
| Broche 17 | DVDD — Digital supply |
| Broche 18 | GND — Digital ground |
| Broche 19 | DVDD — Digital supply |
| Broche 20 | D0 — Data output bit 0 (LSB) |
| Broche 21 | D1 — Data output bit 1 |
| Broche 22 | D2 — Data output bit 2 |
| Broche 23 | D3 — Data output bit 3 |
| Broche 24 | D4 — Data output bit 4 |
| Broche 25 | D5 — Data output bit 5 |
| Broche 26 | D6 — Data output bit 6 |
| Broche 27 | D7 — Data output bit 7 (MSB) |
| Broche 28 | DVR — Data valid / over-range indicator |
| Broche 29 | GND — Digital ground |
| Broche 30 | DVDD — Digital supply |
| Broche 31 | GND — Digital ground |
| Broche 32 | DVDD — Digital supply |
| Broche 33 | NC — Not connected (per datasheet) |
| Broche 34 | NC — Not connected (per datasheet) |
| Broche 35 | NC — Not connected (per datasheet) |
| Broche 36 | NC — Not connected (per datasheet) |
| Broche 37 | NC — Not connected (per datasheet) |
| Broche 38 | NC — Not connected (per datasheet) |
| Broche 39 | NC — Not connected (per datasheet) |
| Broche 40 | NC — Not connected (per datasheet) |
| Broche 41 | NC — Not connected (per datasheet) |
| Broche 42 | NC — Not connected (per datasheet) |
| Broche 43 | NC — Not connected (per datasheet) |
| Broche 44 | NC — Not connected (per datasheet) |
| Broche 45 | NC — Not connected (per datasheet) |
| Broche 46 | MODE — Mode / divider select input |
| Broche 47 | CS — Chip select / calibration control |
| Broche 48 | RESET — Power-on reset / synchronization |
| Broche 49 | GND — Ground |
| Broche 50 | AVDD — Analog supply |
| Broche 51 | GND — Analog ground |
| Broche 52 | AVDD — Analog supply |
| Broche 53 | GND — Analog ground |
| Broche 54 | AVDD — Analog supply |
| Broche 55 | GND — Analog ground |
| Broche 56 | AVDD — Analog supply |
| Broche 57 | GND — Analog ground |
| Broche 58 | AVDD — Analog supply |
| Broche 59 | GND — Analog ground |
| Broche 60 | AVDD — Analog supply |
| Broche 61 | GND — Analog ground |
| Broche 62 | AVDD — Analog supply |
| Broche 63 | GND — Analog ground |
| Broche 64 | AVDD — Analog supply |
| Broche 65 | GND — Analog ground |
| Broche 66 | AVDD — Analog supply |
| Broche 67 | GND — Analog ground |
| Broche 68 | AVDD — Analog supply |
Applications typiques
KAD2708C-27Q68 convient pour 6 applications: 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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
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.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour KAD2708C-27Q68 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | 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) |
Principaux différenciateurs
- 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)
Notes de conception
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.
Informations de conformité
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.
