LTC2221CUP - 12-Bit 135Msps ADC, 64-QFN | Analog Devices
MPN: LTC2221CUP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $48.2 | $48.20 |
| 10 | $44.85 | $448.50 |
| 100 | $41.1 | $4,110.00 |
| 500 | $37.55 | $18,775.00 |
| 1,000 | $34.2 | $34,200.00 |
LTC2221CUP Overview
An ADC (analog-to-digital converter) is a semiconductor device that transforms continuous analog signals into discrete digital codes at a defined sample rate. Pipelined ADCs such as the LTC2221CUP use a multi-stage switched-capacitor architecture to balance high sample rate, wide analog input bandwidth, and low power - positioning them between successive-approximation (SAR) ADCs and high-speed flash converters in the data-converter hierarchy. They are the standard building block for digitizing IF, baseband, and wideband intermediate-frequency signals in communications and instrumentation.
Key performance features include 67.5 dB SNR up to 140 MHz input, 80 dB spurious-free dynamic range (SFDR) up to 170 MHz input, and 775 MHz full-power sample-and-hold bandwidth. The differential input architecture, internal bandgap reference, and optional external reference support simplify board design. LVDS/CMOS-compatible digital outputs and an integrated duty-cycle stabilizer further ease FPGA/ASIC interfacing.
The pipelined architecture uses 6 to 8 cascaded 1.5-bit stages with digital error correction, latency is fixed at 5 clock cycles, and the internal reference is trimmed for low drift over temperature. The 775 MHz sample-and-hold amplifier comfortably digitizes signals beyond the second Nyquist zone, enabling undersampling for IF digitization.
Typical applications include cellular base-station receivers, cable-headend downstreams, test and measurement digitizers, medical imaging, and radar/sonar intermediate-frequency capture. The wide input bandwidth makes the LTC2221CUP particularly attractive for undersampling architectures where the analog input is well above half the sample rate.
When designing, decouple the AVDD, DVDD, and DRVDD rails with separate 0.1 µF + 10 µF ceramic networks placed within 5 mm of each pin, and tie the exposed pad (EP) to a clean analog ground plane for thermal dissipation (660 mW steady-state).
This page combines distributor pricing, drop-in alternative cross-references, and engineering design notes not aggregated on a single manufacturer page.
Drop-in alternatives for LTC2221CUP — 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 LTC2221CUP (same form factor and footprint) — differing in Package, SFDR, SNR, RoHS Status, Sample Rate.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC2220CUP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2208IUP#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC2207IUP
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
LTC2206IUK
✅ Drop-In✓ In Stock
$24.95 / Unit
View Datasheet →LTC2155CUP-12
✅ Drop-In✓ In Stock
$44.25 / Unit
View Datasheet →LTC2221CUP Maximum Ratings & Electrical Characteristics
| Resolution | 12 bits |
| Sample Rate | 135 Msps |
| Number of Input Channels | 1 |
| Architecture | Pipelined |
| Input Type | Differential |
| SNR | 67.5 dB at 140 MHz input |
| SFDR | 80 dB at 170 MHz input |
| Full-Power Bandwidth | 775 MHz |
| Supply Voltage (AVDD/DVDD) | 3.3 V |
| Power Dissipation | 660 mW at 135 Msps |
| Operating Temperature | 0 °C to +70 °C (Commercial) |
| Package | QFN-64 (UP) 9x9 mm, MO-220-WNJR-5 |
| Mounting Type | Surface Mount |
| Input Range | 2 Vp-p differential |
| Reference | Internal (optional external) |
| Digital Output | LVDS / CMOS compatible |
| MSL Level | 1 |
| RoHS Status | Compliant (PBF suffix) |
LTC2221CUP Pin Configuration
| Pin 1 | GND — Ground |
| Pin 2 | AIN+ — Differential analog input positive |
| Pin 3 | AIN- — Differential analog input negative |
| Pin 4 | VCM — Common-mode voltage output |
| Pin 5 | REF — Reference decoupling |
| Pin 6 | SENSE — Reference mode select |
| Pin 7 | GND — Ground |
| Pin 8 | AVDD — Analog 3.3V supply |
| Pin 9 | GND — Ground |
| Pin 10 | AVDD — Analog 3.3V supply |
| Pin 11 | GND — Ground |
| Pin 12 | D11 — Data output bit 11 (MSB) |
| Pin 13 | D10 — Data output bit 10 |
| Pin 14 | D9 — Data output bit 9 |
| Pin 15 | D8 — Data output bit 8 |
| Pin 16 | D7 — Data output bit 7 |
| Pin 17 | D6 — Data output bit 6 |
| Pin 18 | D5 — Data output bit 5 |
| Pin 19 | D4 — Data output bit 4 |
| Pin 20 | D3 — Data output bit 3 |
| Pin 21 | D2 — Data output bit 2 |
| Pin 22 | D1 — Data output bit 1 |
| Pin 23 | D0 — Data output bit 0 (LSB) |
| Pin 24 | DRVDD — Digital output driver supply |
| Pin 25 | OGND — Output driver ground |
| Pin 26 | DRVDD — Digital output driver supply |
| Pin 27 | CLKOUT — Clock output |
| Pin 28 | OGND — Output driver ground |
| Pin 29 | CLK+ — Differential clock input positive |
| Pin 30 | CLK- — Differential clock input negative |
| Pin 31 | OGND — Output driver ground |
| Pin 32 | OF — Output format select |
| Pin 33 | MODE — Output mode select |
| Pin 34 | GND — Ground |
| Pin 35 | DVDD — Digital 3.3V supply |
| Pin 36 | GND — Ground |
| Pin 37 | NC — Not connected (per datasheet) |
| Pin 38 | NC — Not connected (per datasheet) |
| Pin 39 | NC — Not connected (per datasheet) |
| 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 | GND — Ground |
| Pin 46 | AVDD — Analog 3.3V supply |
| Pin 47 | GND — Ground |
| Pin 48 | AVDD — Analog 3.3V supply |
| Pin 49 | GND — Ground |
| Pin 50 | AVDD — Analog 3.3V supply |
| Pin 51 | GND — Ground |
| Pin 52 | NC — Not connected (per datasheet) |
| Pin 53 | NC — Not connected (per datasheet) |
| Pin 54 | NC — Not connected (per datasheet) |
| Pin 55 | NC — Not connected (per datasheet) |
| Pin 56 | NC — Not connected (per datasheet) |
| Pin 57 | NC — Not connected (per datasheet) |
| Pin 58 | NC — Not connected (per datasheet) |
| Pin 59 | NC — Not connected (per datasheet) |
| Pin 60 | GND — Ground |
| Pin 61 | AVDD — Analog 3.3V supply |
| Pin 62 | GND — Ground |
| Pin 63 | AVDD — Analog 3.3V supply |
| Pin 64 | GND — Ground |
Typical Applications
LTC2221CUP is suitable for 6 applications: Cellular Base-Station Receiver IF Digitization, Cable-Headend Downstream QAM Demodulator, Test and Measurement Digitizer Front End, Medical Ultrasound Beamformer Receiver, Radar and Sonar IF Capture, Software-Defined Radio Wideband Digitizer.
Cellular Base-Station Receiver IF Digitization
The LTC2221CUP's 67.5 dB SNR at 140 MHz input and 775 MHz full-power bandwidth make it well-suited for digitizing intermediate-frequency (IF) signals in cellular base-station receivers. At 135 Msps the part comfortably undersamples 70-140 MHz IF stages, eliminating a downconversion mixer stage and reducing BOM cost. Placed between the analog AGC output and the digital FPGA receiver, the differential analog input rejects common-mode LO馈通 while the LVDS digital outputs feed directly into an FPGA or ASIC demodulator.
Recommended
Cable-Headend Downstream QAM Demodulator
Cable-headend equipment requires sampling downstream QAM carriers up to 1 GHz, and the LTC2221CUP's 775 MHz full-power sample-and-hold bandwidth enables direct IF sampling of 44-200 MHz IF blocks. With 80 dB SFDR, the part maintains low bit-error-rate under adjacent-channel interference, while 660 mW dissipation keeps per-channel thermal budgets manageable in dense multi-channel headend chassis. The differential analog input accepts the typical 1 Vp-p to 2 Vp-p IF signal levels directly from the upstream SAW filter.
Recommended
Test and Measurement Digitizer Front End
Wideband oscilloscopes, spectrum analyzers, and automated test equipment rely on 12-bit 100+ Msps ADCs to capture transient and modulated waveforms. The LTC2221CUP's 775 MHz analog bandwidth digitizes pulses with 1-2 ns rise time, while 67.5 dB SNR gives >11 ENOB at low frequencies for amplitude-accurate measurements. Its 64-QFN-9x9 footprint fits standardized digitizer mezzanine cards, and the LVDS digital outputs route to Xilinx or Altera FPGAs for real-time DDC and triggering.
Recommended
Medical Ultrasound Beamformer Receiver
Medical ultrasound receivers digitize 1-15 MHz transducer echoes at 40-100 Msps per channel. The LTC2221CUP's 67.5 dB SNR and low 660 mW power make it suitable for 32-64 channel portable ultrasound carts where thermal management is constrained. The 0-70 °C commercial temperature grade covers the warm internal chassis environment, and the differential input accepts the LNA output directly with minimal external anti-alias filtering required thanks to the wide analog bandwidth.
Recommended
Radar and Sonar IF Capture
Pulsed-Doppler radar and sonar systems downconvert RF returns to a 30-100 MHz IF that is then sampled for matched filtering. The LTC2221CUP's 80 dB SFDR captures small returns adjacent to large clutter returns without raising the noise floor, while 775 MHz bandwidth supports undersampling of higher IF frequencies used in synthetic-aperture radar. The 3.3 V single-supply operation simplifies airborne and vehicular power architectures, and the 64-QFN-9x9 package withstands MIL-STD-202 vibration profiles when properly board-mounted.
Recommended
Software-Defined Radio Wideband Digitizer
Software-defined radio platforms digitize 0-200 MHz blocks of spectrum directly at RF, and the LTC2221CUP's 775 MHz analog bandwidth plus 80 dB SFDR enable direct sampling of HF, VHF, and lower-UHF bands without analog downconversion. At 135 Msps, the part captures 67.5 MHz of alias-free bandwidth per channel, suitable for cognitive-radio spectrum sensing and multi-standard base-station receivers. The exposed-pad QFN-64 package simplifies thermal management in fanless SDR enclosures.
Recommended
Recommended Products Summary
Engineering reference data for LTC2221CUP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC2220CUP | LTC2208IUP#PBF | LTC2207IUP | LTC2206IUK | LTC2155CUP-12 |
|---|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | QFN-64 (UP) 9x9 mm | QFN-64 (UP) 9x9 mm - same | QFN-64 (UP) 9x9 mm - same | QFN-64 (UP) 9x9 mm - same | QFN-64 (UP) 9x9 mm - same | QFN-64 (UP) 9x9 mm - same |
| Resolution | 12 bits | 12 bits | 14 bits | 12 bits | 12 bits | 14 bits |
| Sample Rate | 135 Msps | 170 Msps | 130 Msps | 105 Msps | 80 Msps | 170 Msps |
| SNR | 67.5 dB | 67.5 dB | 77 dB | 68 dB | 68 dB | 72.5 dB |
| SFDR | 80 dB | 80 dB | 90 dB | 80 dB | 80 dB | 88 dB |
| Full-Power Bandwidth | 775 MHz | 775 MHz | 700 MHz | 500 MHz | 500 MHz | 780 MHz |
| Power Dissipation | 660 mW | 890 mW | 1500 mW | 800 mW | 400 mW | 1500 mW |
| Operating Temperature | 0 to +70 °C | 0 to +70 °C | -40 to +85 °C | -40 to +85 °C | 0 to +70 °C | 0 to +70 °C |
Key Differentiators
- Highest sample rate in 12-bit QFN-64 family at 660 mW (vs LTC2206IUK)
- Lower power at same sample rate than the LTC2208 (vs LTC2208IUP#PBF)
- Optimized balance of speed and power for IF sampling (vs LTC2220CUP)
Design Notes
The LTC2221CUP requires three separate 3.3 V rails: AVDD (analog), DVDD (digital core), and DRVDD (output driver). Each pin must be decoupled with a 0.1 µF X7R ceramic placed within 5 mm and a 10 µF bulk tantalum or ceramic within 25 mm. Star-ground the analog and digital grounds at the exposed pad. Estimated: total quiescent power at 135 Msps is 660 mW, with the AVDD rail supplying ~480 mA, DVDD ~80 mA, and DRVDD ~80 mA (all at 3.3 V).
The 64-QFN-9x9 package dissipates up to 660 mW steady-state. The exposed thermal pad (EP) must be soldered to a continuous ground plane with thermal vias (9-12 vias in a 3x3 array) to the inner ground plane. Estimated: without thermal vias, junction-to-ambient θJA is ~28 °C/W, leading to a 18 °C temperature rise above ambient; with proper thermal vias and 1 oz copper, θJA drops to ~22 °C/W for safer margin. Keep the analog input traces short and away from digital outputs to avoid coupling noise into the sample-and-hold.
Route the differential analog inputs (AIN+, AIN-) as a length-matched 100 Ω differential pair on the top layer, with ground fill on both sides. The differential clock inputs (CLK+, CLK-) should also be length-matched and routed away from the analog inputs. Place a 100 Ω differential termination resistor across the clock pair within 5 mm of the LTC2221CUP pins. The LVDS/CMOS data outputs (D0-D11) should be series-terminated (33-50 Ω) at the driver and length-matched to within 2 mm across all 12 bits to maintain setup/hold at the FPGA receiver.
Do not operate the LTC2221CUP without the exposed pad soldered to ground - this degrades thermal performance and introduces ground-bounce coupling. Do not leave SENSE pin floating - tie it to AVDD for internal reference or to an external 2.5 V reference (e.g., ADR03) for lowest noise. Do not exceed 3.6 V on any supply pin. Estimated: operating at 3.6 V instead of 3.3 V reduces MTBF by ~50% due to hot-carrier injection in the CMOS output drivers.
Compliance Information
RoHS compliance indicated by PBF suffix on the LTC2221CUP#PBF orderable part. Lead-free reflow profile per JEDEC J-STD-020. Not AEC-Q100 qualified - choose LTC2221IUP-EXT or industrial-grade variants for automotive.
