Analog Devices Inc. LTC2156CUP-12#PBF

Overview

LTC2156CUP-12#PBF from Analog Devices (formerly Linear Technology) is a dual-channel, 12-bit, 210Msps analog-to-digital converter optimized for high-frequency undersampling in communications and instrumentation systems. It delivers 68.5dB SNR, 90dB SFDR, and 1.25GHz full-power bandwidth with single 1.8V supply and DDR LVDS outputs. Used in cellular basestations and software-defined radios for wideband IF digitization.

For engineers reviewing the LTC2156CUP-12#PBF datasheet, LTC2156CUP-12#PBF pinout, LTC2156CUP-12#PBF application, or LTC2156CUP-12#PBF equivalent, key selection criteria include sampling rate (210Msps), SNR/SFDR performance at RF input frequencies up to 907MHz, DDR LVDS output current programmability (1.75mA/3.5mA), and support for external reference via SENSE pin.

Technical Context

The LTC2156CUP-12#PBF implements a pipelined ADC architecture with integrated sample-and-hold, correction logic, and DDR LVDS output drivers. Its 1.25GHz input bandwidth enables high-IF sampling with minimal attenuation, while optional clock duty cycle stabilizer maintains performance across non-50% duty cycle clocks.

Dual independent channels share a common encode clock but feature separate analog inputs (AINA±/AINB±) and parallel DDR LVDS data buses (DA0_1±–DA10_11± and DB0_1±–DB10_11±). Configuration is supported via SPI interface (CS/SCK/SDI/SDO) or parallel mode using PAR/SER pin selection.

Key Specifications

Pinout & Package

64-lead (9mm × 9mm) plastic QFN package with exposed thermal pad (Pin 65 = GND). Requires soldering exposed pad to PCB ground plane for thermal and electrical integrity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel, high-speed ADC applications.

Compared with AD9233BCPZ-210 and LTC2155CUP-12#PBF, the LTC2156CUP-12#PBF uniquely delivers dual-channel 210Msps sampling with 68.5dB SNR and DDR LVDS in a pin-compatible QFN, enabling compact, low-latency, high-fidelity digitization without FPGA SerDes overhead or dual-device layout complexity.

Availability

LTC2156CUP-12#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, test equipment, and medical imaging systems requiring stable component supply, long-term lifecycle support, and guaranteed authentic sourcing.

Supply support for LTC2156CUP-12#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors.

The LTC2156CUP-12#PBF belongs to the LTC215x-12 family of ultra-wideband dual ADCs designed specifically for demanding communications and instrumentation applications where high SFDR, low latency, and flexible interface options are critical.

FAQ

What is the maximum sampling rate supported by the LTC2156CUP-12#PBF?

The LTC2156CUP-12#PBF supports a maximum sampling rate of 210Msps. This is confirmed in the datasheet's "Converter Characteristics" table under fS (Sampling Frequency) for the LTC2156-12 variant. Operation at this rate requires proper power supply decoupling, thermal management, and adherence to timing specifications for ENC+/ENC– and LVDS output loading.

Does the LTC2156CUP-12#PBF support external voltage reference?

Yes, the LTC2156CUP-12#PBF supports external reference via the SENSE pin. Applying a voltage between 1.2V and 1.3V to SENSE configures the input range to ±0.6 × VSENSE. The device also provides an internal 1.25V reference (VREF pin) and common-mode bias (VCM pin), both specified with ppm/°C drift and output resistance values in the datasheet.

How many pins does the LTC2156CUP-12#PBF use for DDR LVDS data output?

The LTC2156CUP-12#PBF uses 24 pins for DDR LVDS data output: 12 differential pairs (6 per channel), each carrying two multiplexed bits (e.g., DA0/DA1 on DA0_1±). Specifically, Channel A uses Pins 44–47, 50–57; Channel B uses Pins 26–31, 34–39. All LVDS pairs support programmable 1.75mA or 3.5mA output current and optional 100Ω on-chip termination.

What is the purpose of the PAR/SER pin on the LTC2156CUP-12#PBF?

The PAR/SER pin (Pin 63) selects the programming interface mode: tied to GND enables SPI serial control (CS/SCK/SDI/SDO), while tied to VDD enables parallel mode where CS, SCK, and SDI become dedicated logic inputs for basic functions like sleep mode entry and LVDS current selection. The pin must be hardwired - not driven dynamically - and determines register access capability and feature configurability.

Can the LTC2156CUP-12#PBF operate with a non-50% duty cycle clock?

Yes, the LTC2156CUP-12#PBF includes an optional clock duty cycle stabilizer that maintains full AC performance (SNR/SFDR) across input clock duty cycles from 15% to 85%. When enabled via SPI register, the internal circuitry corrects duty cycle distortion before clock distribution to the sample-and-hold and pipeline stages - eliminating the need for external clock conditioning.