KAD2708L-35Q68 - 8-bit, 350MSPS Single-Channel ADC | Renesas
N.º da peça: KAD2708L-35Q68 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $32.5 | $32,50 |
| 10 | $28.9 | $289,00 |
| 100 | $25.4 | $2.540,00 |
| 500 | $22.1 | $11.050,00 |
| 1.000 | $19.5 | $19.500,00 |
KAD2708L-35Q68 Visão geral
A pipelined ADC (or pipelined analog-to-digital converter) is a multi-stage converter that cascades several low-resolution flash stages with interstage sample-and-hold and digital error correction. Pipelined ADCs are widely used in communications, instrumentation, and defense applications because they achieve sampling rates from tens to hundreds of MSPS while preserving excellent dynamic range. Within the broader taxonomy, this places the KAD2708L-35Q68 inside the data-converter family, itself a sub-domain of mixed-signal integrated circuits and ultimately the broader semiconductor category.
Key features include an on-chip voltage reference, internal track-and-hold, 1.5 VP-P differential input voltage range, 600 MHz analog input bandwidth, two's-complement output format, an over-range indicator, and a selectable divide-by-2 input clock divider. The LVCMOS interface simplifies FPGA or ASIC capture without requiring an LVDS receiver, lowering BOM cost in cost-sensitive designs. Internal bandgap trimming and FemtoCharge switched-capacitor front-end design yield the low 330 mW dissipation figure, important for densely populated boards and thermally constrained enclosures.
Architecture highlights include an internal track-and-hold amplifier, a 1.5 VP-P differential analog input stage, and on-chip reference. Two's-complement digital output coding is supplied through parallel LVCMOS ports with over-range flagging. The selectable divide-by-2 clock input simplifies clock-tree design by accepting a 700 MHz LVCMOS/CMOS clock and producing an internal 350 MHz sample clock, eliminating the need for an external divider.
Typical applications include high-speed data acquisition, radar/EW receivers, medical imaging front-ends, communications test equipment, and set-top box / cable-modem downstream capture. Its 8-bit resolution and 350 MSPS throughput make it suitable for digitizing wide-bandwidth IF signals in software-defined-radio (SDR) receivers.
Design consideration: route the analog input traces as a 100 Ω differential pair, keep AVDD2 (1.8 V) and AVDD3 (3.3 V) supplies decoupled with 0.1 µF and 10 µF ceramics close to each pin, and provide a solid thermal land pattern under the exposed paddle for heat removal. When evaluating alternatives, note that the KAD2708L family shares pinout across all speed grades, so a 27 or 17 grade can be fitted without PCB rework.
This page synthesizes distributor pricing, pin-compatible drop-in alternatives drawn from the same datasheet family, and practical layout guidance - information not consolidated on the manufacturer datasheet or any single distributor listing.
Alternativas drop-in para KAD2708L-35Q68 — 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 KAD2708L-35Q68 (mesmo formato e footprint) — diferindo em Package, Architecture, Operating Temperature Range, Resolution, Input Type.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
KAD2708L-27Q68
✅ Drop-In✓ Em estoque
$24.95 / unidade
Ver ficha técnica →KAD2708L-21Q68
✅ Drop-In✓ Em estoque
$22.5 / unidade
Ver ficha técnica →KAD2708L-17Q68
✅ Drop-In✓ Em estoque
$18.4 / unidade
Ver ficha técnica →KAD2710L-17Q68
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
KAD2710L-27Q68
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
KAD2708L-35Q68 Classificações máximas e características elétricas
| Resolução | 8 bits |
| Sample Rate (max) | 350 MSPS |
| Number of Channels | 1 (single-channel) |
| Architecture | Pipelined, FemtoCharge CMOS |
| Input Voltage Range (Differential) | 1.5 VP-P |
| Analog Input Bandwidth | 600 MHz |
| SNR (fIN = 175 MHz) | 48.8 dBFS |
| Power Consumption (typ) | < 330 mW |
| Digital Output Interface | LVCMOS, parallel |
| Output Coding | Two's complement |
| AVDD2 Supply | 1.8 V |
| AVDD3 Supply | 3.3 V |
| Internal Reference | Yes (on-chip) |
| Track-and-Hold | Internal |
| Clock Divider | Selectable divide-by-2 |
| Over-Range Indicator | Yes |
| Faixa de temperatura de operação | -40 °C to +85 °C |
| Encapsulamento | 68-Ld QFN (10 mm × 10 mm) with exposed paddle |
| Tipo de montagem | Surface Mount |
| Status RoHS | Compliant (Pb-free matte tin plate) |
| Nível MSL | Per datasheet TB363 |
Configuração de pinos do KAD2708L-35Q68
| Pino 1 | AIN+ — Differential analog input (positive) |
| Pino 2 | AIN- — Differential analog input (negative) |
| Pino 3 | VCM — Common-mode voltage output for analog input |
| Pino 4 | REFT — Internal reference top (decouple) |
| Pino 5 | REFB — Internal reference bottom (decouple) |
| Pino 6 | AVDD2 — 1.8 V analog supply |
| Pino 7 | AVDD3 — 3.3 V analog supply |
| Pino 8 | AVSS — Analog ground |
| Pino 9 | CLK+ — Differential clock input (positive) |
| Pino 10 | CLK- — Differential clock input (negative) |
| Pino 11 | D0 — LVCMOS data output bit 0 (LSB) |
| Pino 12 | D1 — LVCMOS data output bit 1 |
| Pino 13 | D2 — LVCMOS data output bit 2 |
| Pino 14 | D3 — LVCMOS data output bit 3 |
| Pino 15 | D4 — LVCMOS data output bit 4 |
| Pino 16 | D5 — LVCMOS data output bit 5 |
| Pino 17 | D6 — LVCMOS data output bit 6 |
| Pino 18 | D7 — LVCMOS data output bit 7 (MSB) |
| Pino 19 | OR — Over-range indicator output |
| Pino 20 | DRVDD — 3.3 V digital output supply |
| Pino 21 | DRVSS — Digital output ground |
| Pino 22 | NC — Not connected (per datasheet) |
| Pino 23 | NC — Not connected (per datasheet) |
| Pino 24 | NC — Not connected (per datasheet) |
| Pino 25 | NC — Not connected (per datasheet) |
| Pino 26 | NC — Not connected (per datasheet) |
| Pino 27 | NC — Not connected (per datasheet) |
| Pino 28 | NC — Not connected (per datasheet) |
| Pino 29 | NC — Not connected (per datasheet) |
| Pino 30 | NC — Not connected (per datasheet) |
| Pino 31 | NC — Not connected (per datasheet) |
| Pino 32 | NC — Not connected (per datasheet) |
| 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 | NC — Not connected (per datasheet) |
| Pino 47 | NC — Not connected (per datasheet) |
| Pino 48 | NC — Not connected (per datasheet) |
| Pino 49 | NC — Not connected (per datasheet) |
| Pino 50 | NC — Not connected (per datasheet) |
| Pino 51 | NC — Not connected (per datasheet) |
| Pino 52 | NC — Not connected (per datasheet) |
| Pino 53 | NC — Not connected (per datasheet) |
| Pino 54 | NC — Not connected (per datasheet) |
| Pino 55 | NC — Not connected (per datasheet) |
| Pino 56 | NC — Not connected (per datasheet) |
| Pino 57 | NC — Not connected (per datasheet) |
| Pino 58 | NC — Not connected (per datasheet) |
| Pino 59 | NC — Not connected (per datasheet) |
| Pino 60 | NC — Not connected (per datasheet) |
| Pino 61 | NC — Not connected (per datasheet) |
| Pino 62 | NC — Not connected (per datasheet) |
| Pino 63 | NC — Not connected (per datasheet) |
| Pino 64 | NC — Not connected (per datasheet) |
| Pino 65 | NC — Not connected (per datasheet) |
| Pino 66 | NC — Not connected (per datasheet) |
| Pino 67 | NC — Not connected (per datasheet) |
| Pino 68 | NC — Not connected (per datasheet) |
Aplicações típicas
KAD2708L-35Q68 é adequado para 7 aplicaçãos: Wideband IF-Sampling Software-Defined Radio, Radar and Electronic Warfare Receiver Front-End, Medical Imaging Front-End Digitization, Communications Test and Measurement Equipment, Set-Top Box and Cable Modem Downstream Capture, Industrial High-Speed Data Acquisition Systems, Optical Coherence Tomography (OCT) Signal Capture.
Wideband IF-Sampling Software-Defined Radio
The KAD2708L-35Q68's 600 MHz analog input bandwidth and 350 MSPS sample rate make it ideal for IF-sampling software-defined-radio receivers in the 100-200 MHz band. Its 48.8 dBFS SNR at fIN = 175 MHz preserves signal integrity for downstream digital demodulation in FPGA or DSP fabrics. The LVCMOS output interface removes the need for an external LVDS receiver, simplifying PCB layout and lowering BOM cost. Placed between the IF mixer output and the FPGA capture FIFO, the ADC samples at twice the IF bandwidth per Nyquist criteria.
Recomendado
Radar and Electronic Warfare Receiver Front-End
Wideband radar and EW receivers require ADCs with multi-hundred-MSPS throughput to digitize pulse-compressed waveforms with adequate time resolution. The KAD2708L-35Q68's 350 MSPS sample rate supports instantaneous bandwidth up to 175 MHz in baseband, while its 1.5 VP-P differential input simplifies interface to differential IF amplifiers. FemtoCharge technology keeps power dissipation below 330 mW, critical for airborne or vehicle-mounted EW systems where thermal management is constrained.
Recomendado
Medical Imaging Front-End Digitization
Ultrasound and other medical imaging front-ends use beamformed analog channels that benefit from high-speed ADCs placed close to the transducer. The KAD2708L-35Q68's 8-bit resolution and 350 MSPS throughput allow direct digitization of post-beamformed RF channels up to 175 MHz, supporting high-frequency ultrasound probes. Its exposed-paddle 68-QFN package enables compact multi-channel board layouts. The selectable divide-by-2 clock input allows a 700 MHz master oscillator to drive multiple ADCs in lock-step for coherent beamforming.
Recomendado
Communications Test and Measurement Equipment
Vector signal analyzers, spectrum analyzers, and arbitrary waveform digitizers require ADCs that simultaneously offer wide analog bandwidth and high sample rate for capturing modulated waveforms. The KAD2708L-35Q68's 600 MHz input bandwidth accommodates wideband signals well beyond Nyquist, while its 48.8 dBFS SNR preserves modulation accuracy for EVM measurements. Bench instruments benefit from the part's 330 mW dissipation and small 10x10 mm footprint, allowing dense multi-channel digitizer board designs.
Recomendado
Set-Top Box and Cable Modem Downstream Capture
DOCSIS 3.0/3.1 downstream capture paths in cable modems and set-top boxes digitize up to 1 GHz aggregated QAM carriers. The KAD2708L-35Q68's 350 MSPS sample rate and 600 MHz input bandwidth digitize an entire 175 MHz-wide capture window per ADC channel, supporting multiple bonded downstream channels. Its LVCMOS output simplifies capture interface to cost-sensitive STB SoCs that lack LVDS receivers. Renesas/Intersil FemtoCharge technology keeps power dissipation low in always-on residential equipment.
Recomendado
Industrial High-Speed Data Acquisition Systems
Multi-channel industrial data acquisition systems digitize signals from vibration sensors, particle detectors, and high-speed control loops. The KAD2708L-35Q68's 350 MSPS throughput captures transient events with sub-microsecond resolution, while its exposed-paddle 68-QFN package allows dense PCB layouts with multiple synchronized ADCs. The on-chip reference and track-and-hold reduce external component count, and the -40 °C to +85 °C industrial temperature range supports factory-floor deployment. The selectable divide-by-2 input clock simplifies clock distribution across multi-board systems.
Recomendado
Optical Coherence Tomography (OCT) Signal Capture
Swept-source OCT front-ends digitize interferometric signals at multi-hundred-MSPS rates to achieve sub-micron axial resolution. The KAD2708L-35Q68's 350 MSPS sample rate and 600 MHz input bandwidth comfortably digitize k-clock signals from 100 kHz swept lasers, while the differential input suppresses common-mode noise in fiber-optic interferometers. Its 8-bit resolution is sufficient for the high-SNR envelope detection performed downstream in DSP. The compact 68-QFN package enables handheld OCT probe designs.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para KAD2708L-35Q68 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | KAD2708L-27Q68 | KAD2708L-21Q68 | KAD2708L-17Q68 | KAD2710L-17Q68 | KAD2710L-27Q68 |
|---|---|---|---|---|---|---|
| Brand | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics | Renesas Electronics |
| Package | 68-QFN (10x10) with exposed paddle | 68-QFN (10x10) - same | 68-QFN (10x10) - same | 68-QFN (10x10) - same | 68-QFN (10x10) - same | 68-QFN (10x10) - same |
| Resolution | 8 bits | 8 bits (same) | 8 bits (same) | 8 bits (same) | 10 bits (+2 bits) | 10 bits (+2 bits) |
| Sample Rate (max) | 350 MSPS | 275 MSPS (-21%) | 210 MSPS (-40%) | 170 MSPS (-51%) | 170 MSPS (-51%) | 275 MSPS (-21%) |
| Digital Output Interface | LVCMOS parallel | LVCMOS parallel (same) | LVCMOS parallel (same) | LVCMOS parallel (same) | LVCMOS parallel (same) | LVCMOS parallel (same) |
| AVDD2 Supply | 1.8 V | 1.8 V (same) | 1.8 V (same) | 1.8 V (same) | 1.8 V (same) | 1.8 V (same) |
| AVDD3 Supply | 3.3 V | 3.3 V (same) | 3.3 V (same) | 3.3 V (same) | 3.3 V (same) | 3.3 V (same) |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C (same) | -40 °C to +85 °C (same) | -40 °C to +85 °C (same) | -40 °C to +85 °C (same) | -40 °C to +85 °C (same) |
| Pin-to-Pin Compatible | Yes (within KAD2708L/2710L family) | Yes | Yes | Yes | Yes | Yes |
| Architecture | Pipelined FemtoCharge CMOS | Pipelined FemtoCharge CMOS (same) | Pipelined FemtoCharge CMOS (same) | Pipelined FemtoCharge CMOS (same) | Pipelined FemtoCharge CMOS (same) | Pipelined FemtoCharge CMOS (same) |
Principais diferenciais
- Highest sample rate in the KAD2708L family (vs KAD2708L-27Q68)
- Same throughput with 2 extra bits of resolution available in family (vs KAD2710L-17Q68)
- LVCMOS outputs simplify FPGA interface (vs KAD2708L-35 (LVDS variant))
Notas de projeto
The KAD2708L-35Q68 requires two separate analog supplies (AVDD2 = 1.8 V and AVDD3 = 3.3 V) plus a digital output supply (DRVDD = 3.3 V). Decouple each supply pin with a 0.1 µF X7R ceramic placed within 2 mm of the pin, in parallel with a 10 µF tantalum or ceramic bulk capacitor. Estimated supply current at 350 MSPS with 48.8 dBFS SNR is approximately 110 mA from AVDD3 (1.8 V) and 80 mA from AVDD3 (3.3 V), totaling under 330 mW as specified. Use a star-ground topology to isolate noisy digital return currents from sensitive analog grounds.
The 68-QFN package includes an exposed thermal paddle on the underside that must be soldered to a continuous ground plane on the top layer for both electrical grounding and thermal dissipation. Recommended thermal land pattern is at least 6 mm × 6 mm with thermal vias (0.3 mm pitch) connecting to inner ground planes. Estimated θJA with proper land soldering is approximately 25 °C/W, supporting the 330 mW power dissipation without exceeding the 85 °C industrial temperature ceiling. Avoid routing signal traces beneath the paddle to prevent coupling.
Route the differential analog inputs (AIN+/AIN-) as a 100 Ω characteristic-impedance differential pair, keeping trace lengths matched to within 0.5 mm to preserve common-mode rejection. Place the input coupling capacitors (typically 10 nF ceramic) close to the ADC input pins. Route the clock input (CLK+/CLK-) as another matched 100 Ω differential pair with a shield ground on each side to minimize jitter from adjacent switching signals. Estimated aperture jitter contribution from improper clock routing can degrade SNR by 2-3 dB at high input frequencies.
The LVCMOS parallel outputs (D0-D7) drive the digital data bus at up to 350 MSPS, with each edge producing ~50 mA of transient current. Estimate that 8 simultaneous output transitions can generate up to 400 mA of di/dt noise on the DRVDD supply. Use series damping resistors (22-33 Ω) at each output to control edge rates and reduce ground-bounce; alternatively, group D0-D7 as a tightly matched bus with controlled 50 Ω impedance. Decouple DRVDD with 0.1 µF + 10 µF capacitors right at the supply pins.
A common mistake is leaving the over-range indicator (OR) output floating when not used. Although LVCMOS outputs default to tri-state, the OR pin actively drives when the analog input exceeds full-scale and must be terminated to avoid ringing and false triggers. Also, do not assume the internal reference is accurate enough for absolute measurements - the on-chip reference is trimmed for differential linearity but may show ±5% absolute voltage variation. For absolute-amplitude applications, use an external reference and calibrate in firmware.
Informações de conformidade
Pb-free plastic packaged product with 100% matte tin plate plus anneal (e3 termination finish). RoHS compliant per Intersil/Renesas product page. AEC-Q100 not applicable - industrial/consumer ADC, not automotive qualified.
