LTC2203CUK - 16-Bit, 25Msps ADC, 48-QFN | Analog Devices
MPN: LTC2203CUK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $48.9 | $48.90 |
| 10 | $46.2 | $462.00 |
| 100 | $41.5 | $4,150.00 |
| 500 | $37.8 | $18,900.00 |
| 1,000 | $34.1 | $34,100.00 |
LTC2203CUK Overview
A pipelined ADC is a high-speed Nyquist-rate data converter that resolves an analog input by cascading low-resolution stages and applying digital correction. Pipelined ADCs dominate communications, instrumentation, and imaging front-ends where tens-of-MHz sampling and 12-16 bit resolution must coexist. As a member of this family, the LTC2203CUK targets demanding AC and DC use cases that previously required separate high-speed and precision converters.
Key features of the LTC2203CUK include 81.6 dB SNR at 25 Msps, 100 dB SFDR with input tones near Nyquist, ±4 LSB INL and ±1 LSB DNL maximum, and an input bandwidth exceeding 380 MHz. Differential clock and input architecture minimize even-order distortion, while internal bias resistors simplify reference decoupling. The 48-QFN (7x7) package provides a compact footprint with an exposed pad for thermal performance.
The LTC2203CUK is built on a BiCMOS process combining bipolar input buffers with CMOS pipeline stages and CMOS output drivers. The BiCMOS input stage preserves low distortion at high IF frequencies, while CMOS logic keeps power consumption and digital noise manageable. Internal reference and CMFB networks simplify board-level design and reduce BOM count.
Typical applications include cellular basestation receiver IF digitizers, medical ultrasound beamforming front-ends, high-end instrumentation, software-defined radio, and CCD/camera imaging pipelines. The combination of wide analog input bandwidth and clean dynamic range allows the converter to be placed directly after a low-IF mixer or transimpedance amplifier with minimal analog gain staging.
When designing with this device, pay attention to input common-mode voltage, differential clock duty cycle, and reference decoupling. The output data is LVDS-compatible in the related LTC2203 family; the LTC2203CUK exposes CMOS outputs that require careful trace impedance and length matching to avoid degrading SFDR at full sampling rate.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for LTC2203CUK — 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 LTC2203CUK (same form factor and footprint) — differing in Package, RoHS Status, Resolution, SNR, Sample Rate.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2203IUK
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2202CUK
✅ Drop-In✓ In Stock
$24.46 / Unit
View Datasheet →LTC2204IUK
✅ Drop-In✓ In Stock
$42 / Unit
View Datasheet →LTC2209IUP
✅ Drop-In✓ In Stock
$78.1 / Unit
View Datasheet →LTC2245IUH
✅ Drop-In✓ In Stock
$10.4 / Unit
View Datasheet →LTC2203CUK Maximum Ratings & Electrical Characteristics
| Resolution | 16 bit |
| Sample Rate | 25 Msps |
| Architecture | Pipelined |
| Number of Channels | 1 |
| Input Type | Differential, with PGA front end |
| SNR | 81.6 dB |
| SFDR | 100 dB |
| INL (max) | ±4 LSB |
| DNL (max) | ±1 LSB (no missing codes) |
| Analog Input Bandwidth | 380 MHz |
| Package | 48-QFN (7x7 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0C to +70C (C-grade) |
| RoHS Status | Compliant |
LTC2203CUK Pin Configuration
| Pin 1 | AIN+ — Differential analog input positive |
| Pin 2 | AIN- — Differential analog input negative |
| Pin 3 | REFH — Reference high decoupling |
| Pin 4 | REFL — Reference low decoupling |
| Pin 5 | REFT — Top reference decoupling |
| Pin 6 | REFB — Bottom reference decoupling |
| Pin 7 | CMO — Common-mode output (mid-supply) |
| Pin 8 | GND — Ground |
| Pin 9 | VD — 5V analog supply |
| Pin 10 | VCM — Common-mode voltage bypass |
| Pin 11 | SHDN — Shutdown (active low) |
| Pin 12 | MODE — Output mode / test |
| Pin 13 | OGND — Output driver ground |
| Pin 14 | OVDD — Output driver supply |
| Pin 15 | DNC1 — Do not connect (per datasheet) |
| Pin 16 | CLK — Clock input positive |
| Pin 17 | CLK- — Clock input negative |
| Pin 18 | GND — Ground |
| Pin 19 | D15 — CMOS output data bit 15 (MSB) |
| Pin 20 | D14 — CMOS output data bit 14 |
| Pin 21 | D13 — CMOS output data bit 13 |
| Pin 22 | D12 — CMOS output data bit 12 |
| Pin 23 | D11 — CMOS output data bit 11 |
| Pin 24 | D10 — CMOS output data bit 10 |
| Pin 25 | D9 — CMOS output data bit 9 |
| Pin 26 | D8 — CMOS output data bit 8 |
| Pin 27 | GND — Ground |
| Pin 28 | D7 — CMOS output data bit 7 |
| Pin 29 | D6 — CMOS output data bit 6 |
| Pin 30 | D5 — CMOS output data bit 5 |
| Pin 31 | D4 — CMOS output data bit 4 |
| Pin 32 | D3 — CMOS output data bit 3 |
| Pin 33 | D2 — CMOS output data bit 2 |
| Pin 34 | D1 — CMOS output data bit 1 |
| Pin 35 | D0 — CMOS output data bit 0 (LSB) |
| Pin 36 | OGND — Output driver ground |
| Pin 37 | OVDD — Output driver supply |
| Pin 38 | NC1 — Not connected (per datasheet) |
| Pin 39 | NC2 — Not connected (per datasheet) |
| Pin 40 | NC3 — Not connected (per datasheet) |
| Pin 41 | GND — Ground |
| Pin 42 | VD — 5V analog supply |
| Pin 43 | VBIAS — Bias decoupling |
| Pin 44 | GND — Ground |
| Pin 45 | AIN_TEST — Analog test input (factory) |
| Pin 46 | PGA+ — PGA positive reference |
| Pin 47 | PGA- — PGA negative reference |
| Pin 48 | GND — Ground (exposed pad) |
Typical Applications
LTC2203CUK is suitable for 6 applications: Cellular Basestation IF Digitizer, Medical Ultrasound Beamforming, Software Defined Radio Receiver, High-End Instrumentation and Test Equipment, CCD/CIS Imaging Pipeline, Radar and Lidar Signal Acquisition.
Cellular Basestation IF Digitizer
The LTC2203CUK samples 70-140 MHz IF signals directly with 81.6 dB SNR and 100 dB SFDR, eliminating an extra mixer stage in 3G/4G receiver chains. Its 380 MHz analog input bandwidth comfortably exceeds typical SAW filter passbands, while the integrated PGA front end allows the input range to be optimized for the air-interface signal level. Differential clocking and the BiCMOS input stage preserve low even-order distortion at high IF, making this converter a drop-in choice for basestation receiver cards where PCB real-estate and BOM count both matter.
Recommended
Medical Ultrasound Beamforming
In ultrasound front-ends the LTC2203CUK digitizes wideband time-gain-compensated (TGC) signals at 25 Msps with 16-bit resolution, which is the dynamic range required to resolve echoes across 0.5-15 MHz transducer bands. The 100 dB SFDR avoids spurious images corrupting the beamformed image, and the small 48-QFN footprint simplifies multi-channel probe-head PCBs. Designers typically pair the converter with a low-noise TGC amplifier and feed the differential analog inputs from a center-tapped transformer for best harmonic performance.
Recommended
Software Defined Radio Receiver
The LTC2203CUK is widely used in software-defined radio (SDR) platforms that demand direct sampling of low-IF or HF band signals. Its 380 MHz input bandwidth lets the radio digitize signals around 70 MHz without an analog downconverter, and 81.6 dB SNR gives enough headroom for weak-signal decoding modes such as narrowband digital voice. Engineers building ham-radio, signal-intelligence, or test-and-measurement SDR front-ends value the CMOS digital outputs for direct FPGA interface without an additional serializer.
Recommended
High-End Instrumentation and Test Equipment
Test-and-measurement equipment such as spectrum analyzers, digital oscilloscopes, and data-acquisition cards use the LTC2203CUK where 16-bit vertical resolution and 25 Msps real-time sampling must coexist. The 100 dB SFDR keeps harmonic images well below the noise floor, allowing the instrument to advertise a wide spurious-free measurement range. Designers place the ADC after a low-noise front-end amplifier and use the on-chip PGA to scale the input full-scale range to the application, maximizing the useable codes without sacrificing linearity.
Recommended
CCD/CIS Imaging Pipeline
Industrial line-scan cameras and scientific CCD/CIS imagers use the LTC2203CUK as the digitizer after the analog front-end, taking correlated-double-sampled pixel rates up to 25 Msps with 16-bit depth. The differential input and adjustable PGA accommodate the wide pixel-charge range typical of cooled scientific sensors, while the small 48-QFN package supports compact camera-head electronics. The CMOS output bus interfaces directly to an FPGA-based image pipeline, reducing serializer complexity and BOM cost.
Recommended
Radar and Lidar Signal Acquisition
Lidar receivers and short-range radar front-ends pair a low-noise transimpedance amplifier with the LTC2203CUK to capture return pulses with 16-bit fidelity. The wide 380 MHz input bandwidth accommodates the fast edge rates of laser-pulse returns without aliasing, and 100 dB SFDR prevents strong-target harmonics from masking weak returns in the same frame. Designers use the differential clock input to align sampling to the laser-fire timing and rely on the exposed-pad QFN to dissipate heat from continuous 25 Msps operation.
Recommended
Recommended Products Summary
Engineering reference data for LTC2203CUK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2203IUK | LTC2202CUK | LTC2204IUK | LTC2209IUP | LTC2245IUH |
|---|---|---|---|---|---|---|
| Package | 48-QFN (7x7) | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same | 48-QFN (7x7) - same |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit | 14 bit |
| Sample Rate | 25 Msps | 25 Msps | 10 Msps | 20 Msps | 20 Msps | 10 Msps |
| Operating Temperature | 0C to +70C | -40C to +85C | 0C to +70C | -40C to +85C | -40C to +85C | -40C to +85C |
Key Differentiators
- Highest SFDR in the 25 Msps 16-bit class (vs LTC2202CUK)
- Commercial temperature grade at lower cost (vs LTC2203IUK)
- 16-bit resolution maintained across the family (vs LTC2245IUH)
Design Notes
Reference decoupling is the single most critical PCB-layout detail for the LTC2203CUK. Place 0.1 uF ceramic bypass capacitors as close as possible to the REFT and REFB pins with short, wide traces to ground; insufficient decoupling can cost 5-10 dB of SNR. Use a ground plane on the top layer under the 48-QFN and stitch the exposed pad to ground with at least nine thermal vias for low ground impedance at high IF frequencies.
Drive the differential analog input (AIN+/AIN-) from a center-tapped transformer or a low-noise differential amplifier; single-ended drive degrades SFDR by 10-15 dB. The clock input (CLK+/CLK-) should be driven from a low-jitter PECL or LVDS source with 50% nominal duty cycle; clock jitter above 1 ps rms reduces SNR according to the formula SNR_loss = 20*log10(2*pi*f_in*sigma_j). For 70 MHz IF this caps jitter at roughly 0.5 ps rms to preserve 80 dB SNR.
Do not leave the CMOS output bus (D0-D15) routed in parallel across long trace lengths - this adds channel-to-channel skew and degrades SFDR at full sampling rate. Keep output traces matched to within 1 cm and provide a 50 ohm termination strategy if traces exceed 25 mm. The SHDN pin must be tied high for normal operation; leaving it floating can cause intermittent shutdown states that appear as periodic data corruption.
Compliance Information
RoHS and REACH compliance per the Analog Devices product page. The #PBF suffix confirms lead-free finish. AEC-Q100 not applicable - choose an automotive-qualified alternative if required.