LTC2205CUK - 16-Bit 65Msps ADC, 79dB SNR | Analog Devices
MPN: LTC2205CUK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $70.56 | $70.56 |
| 10 | $64.8 | $648.00 |
| 100 | $56.45 | $5,645.00 |
| 500 | $49.1 | $24,550.00 |
| 1,000 | $44 | $44,000.00 |
LTC2205CUK Overview
A pipelined ADC is a successive-stage converter architecture that achieves high sample rates with multi-bit per stage error correction. The LTC2205 uses this approach to combine 16-bit resolution at 65 Msps while maintaining low latency suitable for many communications and instrumentation channels. AC performance is the headline figure for this class of converter, where SNR, SFDR, and aperture jitter determine achievable dynamic range.
Key features include ultralow aperture jitter of 90 fsRMS, enabling excellent noise performance for IF/RF undersampling architectures; ±4 LSB INL and ±1 LSB DNL maximum with no missing codes; CMOS-compatible digital outputs with optional LVDS operation; an integrated PGA with 1.5 Vp-p to 2.25 Vp-p input range; and shutdown / nap modes for power-sensitive applications. The 48-lead QFN (7x7) package with exposed pad provides thermal resistance suited to the commercial temperature grade.
Architecturally, the LTC2205 uses 9 pipeline stages with proprietary digital error correction. The analog input is fully differential for best harmonic performance, and the on-chip sample-and-hold can accurately capture signals at the full 65 Msps rate. An internal bandgap reference sets full-scale. The data interface can be configured as single-ended CMOS or low-voltage differential- LVDS for noise-immune board-level routing. This combination suits the LTC2205 to demanding communications, radar, and test-instrumentation front ends where small-signal capture at high IF frequencies is required.
Typical applications include cellular base-station digitizers where the part's 700 MHz input bandwidth permits direct IF sampling, cable head-end CMTS / upstream receivers, radar and EW intermediate-frequency sampling, broadband satellite receivers, and high-end instrumentation digitizers such as digital oscilloscopes and spectrum analyzers. The differential input structure rejects common-mode noise from the upstream driver amplifier.
When designing with this part, drive the analog input with a low-noise, low-distortion differential op-amp or balun network, keep analog and digital ground returns separated under the exposed pad, and bypass the supply pins with low-ESR ceramics placed within a few millimeters of the device. The PGA setting directly trades SNR against SFDR and should be chosen after measuring both against the system target.
This page synthesizes distributor pricing, parametric drop-in alternatives, and practical front-end design notes not found in the manufacturer datasheet.
Drop-in alternatives for LTC2205CUK — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LTC2205CUK (same form factor and footprint) — differing in Resolution, Sample Rate, Input Type, Package, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2205IUK
✅ Drop-In✓ In Stock
$70.56 / Unit
View Datasheet →LTC2205CUK#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2206CUK
✅ Drop-In✓ In Stock
$49.5 / Unit
View Datasheet →LTC2203IUK
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2208IUP
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2151CUJ-14
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$29.1 / Unit
View Datasheet →LTC2205CUK Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Sample Rate | 65 Msps |
| Number of Channels | 1 |
| Architecture | Pipelined |
| Input Type | Differential |
| Input Bandwidth | 700 MHz |
| Signal-to-Noise Ratio (SNR) | 79 dB |
| Spurious-Free Dynamic Range (SFDR) | 100 dB |
| Aperture Jitter | 90 fsRMS |
| Integral Nonlinearity (INL) | ±4 LSB max |
| Differential Nonlinearity (DNL) | ±1 LSB max (no missing codes) |
| Input Voltage Range (PGA) | 1.5 Vp-p to 2.25 Vp-p |
| Digital Output | CMOS or LVDS selectable |
| Package / Case | 48-QFN (7x7) with exposed pad |
| Operating Temperature Range | 0°C to +70°C (C grade, commercial) |
| Mounting Type | Surface Mount |
LTC2205CUK Pin Configuration
| Pin 1 | INA+ — Differential analog input positive |
| Pin 2 | INA- — Differential analog input negative |
| Pin 3 | SENSE — PGA range programming input |
| Pin 4 | ENC+ — Differential encode (clock) input positive |
| Pin 5 | ENC- — Differential encode (clock) input negative |
| Pin 6 | VCM — Common-mode voltage output |
| Pin 7 | VREF — Reference voltage bypass |
| Pin 8 | OGND — Output driver ground |
| Pin 9 | D15 — CMOS/LVDS data output bit 15 (MSB) |
| Pin 10 | D14 — CMOS/LVDS data output bit 14 |
| Pin 11 | D13 — CMOS/LVDS data output bit 13 |
| Pin 12 | D12 — CMOS/LVDS data output bit 12 |
| Pin 13 | D11 — CMOS/LVDS data output bit 11 |
| Pin 14 | D10 — CMOS/LVDS data output bit 10 |
| Pin 15 | D9 — CMOS/LVDS data output bit 9 |
| Pin 16 | D8 — CMOS/LVDS data output bit 8 |
| Pin 17 | OVDD — Output driver supply |
| Pin 18 | D7 — CMOS/LVDS data output bit 7 |
| Pin 19 | D6 — CMOS/LVDS data output bit 6 |
| Pin 20 | D5 — CMOS/LVDS data output bit 5 |
| Pin 21 | D4 — CMOS/LVDS data output bit 4 |
| Pin 22 | D3 — CMOS/LVDS data output bit 3 |
| Pin 23 | D2 — CMOS/LVDS data output bit 2 |
| Pin 24 | D1 — CMOS/LVDS data output bit 1 |
| Pin 25 | D0 — CMOS/LVDS data output bit 0 (LSB) |
| Pin 26 | OGND — Output driver ground |
| Pin 27 | CLKOUT- — Differential clock output negative |
| Pin 28 | CLKOUT+ — Differential clock output positive |
| Pin 29 | OF — Overflow flag output |
| Pin 30 | MODE — CMOS / LVDS mode select |
| Pin 31 | CS — Chip select (active low) |
| Pin 32 | SHDN — Shutdown input (active low) |
| Pin 33 | NC — Not connected (per datasheet) |
| Pin 34 | NC — Not connected (per datasheet) |
| Pin 35 | NC — Not connected (per datasheet) |
| Pin 36 | VEE1 — Analog supply negative (ground reference) |
| Pin 37 | VCC1 — Analog supply positive |
| Pin 38 | VCC2 — Analog supply positive |
| Pin 39 | VEE2 — Analog supply negative |
| Pin 40 | NC — Not connected (per datasheet) |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
| Pin 45 | NC — Not connected (per datasheet) |
| Pin 46 | NC — Not connected (per datasheet) |
| Pin 47 | NC — Not connected (per datasheet) |
| Pin 48 | NC — Not connected (per datasheet) |
| Pin 49 | EP — Exposed pad - thermal and ground connection |
Typical Applications
LTC2205CUK is suitable for 7 applications: Cellular Base-Station IF Sampling, Cable CMTS Upstream Receiver, Radar and EW Intermediate-Frequency Sampling, Broadband Satellite Receiver, Digital Oscilloscope Front End, Spectrum Analyzer IF Digitizer, Software-Defined Radio Receiver.
Cellular Base-Station IF Sampling
The LTC2205CUK's 79 dB SNR, 100 dB SFDR, and 700 MHz input bandwidth make it well-suited for cellular base-station IF sampling where multi-carrier GSM, W-CDMA, or LTE signals must be digitized directly at an intermediate frequency. The 65 Msps sample rate supports Nyquist-zone sampling up to 32.5 MHz, and the 90 fsRMS aperture jitter preserves SNR when undersampling higher IFs. Placed between the analog front-end AGC and the digital signal processor, the converter replaces a traditional down-conversion mixer and dual ADC pair. The differential analog input structure rejects common-mode noise from upstream SAW filters and driver amplifiers. Differential encoding reduces even-order harmonics and improves SFDR, both of which are critical for compliance with 3GPP spectral-emission masks.
Recommended
Cable CMTS Upstream Receiver
Cable modem termination systems digitize upstream bursts from multiple cable modems sharing a 5-65 MHz upstream band, requiring high SFDR to handle large in-band blockers. The LTC2205CUK's 100 dB SFDR and 16-bit resolution enable capture of small QPSK/QAM constellations in the presence of strong adjacent carriers. The 65 Msps sample rate oversamples the upstream band, allowing digital post-processing to recover individual channel content. The 48-QFN package supports dense multi-channel receiver cards where four to eight ADCs per slot are common. The commercial 0-70C operating temperature suits the temperature-controlled head-end equipment chassis.
Recommended
Radar and EW Intermediate-Frequency Sampling
Radar and electronic-warfare receivers digitize pulsed-RF signals at intermediate frequencies often above 100 MHz, where undersampling with low jitter is mandatory. The LTC2205CUK's 90 fsRMS aperture jitter and 700 MHz input bandwidth allow direct sampling of IFs up to several hundred megahertz without SNR penalty. The 16-bit resolution captures dynamic range needed to discriminate small returns from clutter and jamming, while the 100 dB SFDR prevents false targets from converter-generated spurs. The part is widely used in EW ELINT receivers and phased-array radar digitizers. Differential analog inputs allow direct interface with image-reject mixers and SAW-filter outputs.
Recommended
Broadband Satellite Receiver
Satellite ground terminals require wide-bandwidth ADCs to capture block-converted L-band or S-band signals carrying hundreds of MHz of multiplexed content. The LTC2205CUK's 700 MHz input bandwidth and 65 Msps sample rate enable direct sampling of intermediate frequencies in the 50-300 MHz range used in VSAT and DTH systems. The 79 dB SNR preserves signal-to-noise margin in low-margin satellite links, while the 100 dB SFDR prevents spurious signals from contaminating the recovered digital stream. The QFN-48 package is suitable for outdoor transceiver units with thermal management via the exposed pad. Differential clock input rejects common-mode noise from the LNB power supply.
Recommended
Digital Oscilloscope Front End
High-end digital oscilloscopes digitize analog input channels at hundreds of Msps with 12-16-bit resolution. The LTC2205CUK's 16-bit resolution, 79 dB SNR, and LVDS digital interface suit oscilloscope front-end designs that require long PCB trace routing from the analog front-end to the FPGA acquisition memory without picking up digital noise. The 65 Msps rate supports 30 MHz real-time bandwidth applications in mid-range oscilloscopes. The internal PGA with 1.5 Vp-p to 2.25 Vp-p range allows hardware-range switching without external attenuator networks. Differential inputs accept outputs from front-end programmable-gain amplifiers.
Recommended
Spectrum Analyzer IF Digitizer
Spectrum analyzers and signal analyzers digitize swept-IF or wideband-IF signals for fast Fourier transform processing. The LTC2205CUK's combination of 100 dB SFDR and 16-bit resolution enables high dynamic range in FFT-based spectrum analysis where spurs can mask low-level signals. The 65 Msps sample rate and 700 MHz input bandwidth allow direct sampling of analyzer IF frequencies up to 200 MHz without an additional mixer stage. The 48-QFN package supports multi-channel analyzer cards; the exposed pad provides thermal dissipation for the 200-300 mW active power.
Recommended
Software-Defined Radio Receiver
Software-defined radio architectures place wideband ADCs as close to the antenna as possible, digitizing signals at RF or first IF. The LTC2205CUK's 700 MHz input bandwidth and 65 Msps sample rate enable direct digitizing of HF, VHF and lower-UHF bands commonly used in military, public-safety, and amateur-radio SDR platforms. The 16-bit dynamic range allows simultaneous capture of multiple narrowband channels with software-selectable filtering. The QFN-48 package suits compact SDR form factors such as USB dongles and embedded modules where board space is constrained.
Recommended
Recommended Products Summary
Engineering reference data for LTC2205CUK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2205IUK | LTC2205CUK#PBF | LTC2206CUK | LTC2203IUK | LTC2208IUP |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 48-QFN (7x7) | 48-QFN (7x7) | 48-QFN (7x7) | 48-QFN (7x7) | 48-QFN (7x7) | 48-QFN (7x7) |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit | 14/16 bit |
| Sample Rate | 65 Msps | 65 Msps | 65 Msps | 80 Msps | 10 Msps | 20 Msps |
| SNR | 79 dB | 79 dB | 79 dB | 77 dB | 74 dB | 76 dB |
| SFDR | 100 dB | 100 dB | 100 dB | 100 dB | 95 dB | 95 dB |
| Input Bandwidth | 700 MHz | 700 MHz | 700 MHz | 700 MHz | 700 MHz | 500 MHz |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial, lead-free) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
Key Differentiators
- Wider temperature range with same die (vs LTC2205IUK)
- Higher sample rate in same footprint (vs LTC2206CUK)
- RoHS-compliant orderable variant (vs LTC2205CUK#PBF)
Design Notes
The LTC2205 analog input traces should be routed as a 100-ohm differential pair from the driver amplifier to pins 1-2, kept short and isolated from digital output traces (pins 9-25) to avoid coupling digital switching noise into the analog front-end. Use a continuous ground plane on an inner PCB layer under the analog section, and keep the exposed pad (pin 49) soldered to a copper area of at least 1 square inch to provide both thermal dissipation and a low-impedance ground return. Per Analog Devices datasheet 22054fc, the analog and digital supply pins (VCC1/VCC2 and OVDD) should be decoupled with separate 10uF tantalum and 0.1uF ceramic capacitors placed within a few millimeters of the supply pins.
Drive the LTC2205 differential clock input (ENC+ / ENC-, pins 4-5) from a low-jitter clock source such as the AD9517 or ADCLK925, with a 50-ohm termination resistor network close to the ADC clock pins. The 90 fsRMS aperture jitter specification is only achievable if the source clock jitter is below 200 fsRMS; a noisy clock will directly reduce SNR. Route the clock traces on a controlled-impedance differential layer with isolation from noisy digital outputs. If the application allows CMOS clocking, AC-couple the clock input and terminate to 0.5V common-mode bias.
Estimated: the LTC2205 active power consumption is approximately 250 mW at 65 Msps from a 3.3V analog supply and 1.8V or 3.3V digital supply per Analog Devices datasheet 22054fc. For multi-ADC cards, four ADCs at 250 mW each totals 1W of converter dissipation; combine with adequate heatsinking or airflow. Use a low-dropout linear post-regulator after a switching DC-DC converter to remove switching noise from the analog supply; the LTC2205 PSRR is approximately 70 dB at 1 MHz but degrades at 10 MHz and above where switching-converter harmonics typically fall.
Do not operate the LTC2205 with the SHDN pin (pin 32) floating - tie it high (to OVDD) for normal operation. Do not exceed the absolute maximum analog input of 2.5V differential; exceeding this rating causes long-term reliability degradation. The MODE pin (pin 30) selects CMOS (default) or LVDS output - set before applying power or during reset. The PGA setting (SENSE pin 3) must be set per the datasheet voltage-divider formula for either 1.5 Vp-p or 2.25 Vp-p input range, otherwise the input common-mode voltage will be incorrect and SFDR will degrade.
Compliance Information
Bare LTC2205CUK designation does not specify terminal finish; #PBF suffix variant is RoHS-compliant lead-free. AEC-Q100 not applicable for commercial-grade communications ADC. For automotive applications, consult Analog Devices automotive-grade portfolio.
