Analog Devices Inc. LT6600CS8-20#PBF

Overview

LT6600CS8-20#PBF from Analog Devices (acquired Linear Technology) is a fully differential amplifier with integrated 4th-order 20MHz Chebyshev lowpass antialiasing filter, programmable gain via two external resistors, 76dB SNR at 3V/2VP-P, and adjustable output common-mode voltage. It drives high-speed ADCs in base station receivers and test equipment.

For engineers reviewing the LT6600CS8-20#PBF datasheet, LT6600CS8-20#PBF pinout, LT6600CS8-20#PBF application, or LT6600CS8-20#PBF equivalent, key selection criteria include passband ripple (±0.5dB), input-referred noise (118μVRMS), distortion at 20MHz (63dBc 2nd harmonic), and SO-8 pin compatibility with legacy differential amplifiers.

Technical Context

The LT6600CS8-20#PBF integrates a proprietary differential amplifier stage followed by a fixed 20MHz 4th-order lowpass filter with Chebyshev response, eliminating external passive components for cutoff frequency setting. Its dual-stage architecture enables independent control of first-stage common-mode voltage (via VMID) and second-stage output common-mode level (via VOCM).

Gain is set solely by external RIN resistors (G = 402Ω/RIN), while internal precision feedback ensures stable passband flatness (±0.1dB to 2MHz) and temperature-invariant filter characteristics. The device operates from single 3V, 5V, or dual ±5V supplies with rail-to-rail output swing up to 4.75VP-P differential.

Key Specifications

Pinout & Package

LT6600CS8-20#PBF is housed in an 8-lead plastic SOIC (SO-8, narrow 0.150") package with standard pin spacing and thermal pad fused to Pin 6 (V–) for enhanced heat dissipation. Package outline complies with LTC DWG #05-08-1610.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar differential amplifier and antialiasing filter applications.

Compared with AD8138ARZ and THS4521IDR, the LT6600CS8-20#PBF uniquely combines fixed 20MHz filtering, ultra-low 118μVRMS noise, and programmable gain in SO-8-reducing design cycle time for ADC interface circuits requiring guaranteed alias rejection.

Availability

LT6600CS8-20#PBF is available at Aetrix Electronics and suitable for cellular infrastructure, test instrumentation, medical imaging, and industrial data acquisition requiring stable component supply and long-term production continuity.

Supply support for LT6600CS8-20#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. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, acquired Linear Technology in 2017 to expand precision signal chain solutions.

The LT6600 family was designed by Linear Technology specifically for high-fidelity, low-distortion differential signal conditioning in ADC/DAC interfaces-emphasizing integrated filtering, noise optimization, and supply flexibility for communications and instrumentation.

FAQ

What is the maximum differential input voltage supported by the LT6600CS8-20#PBF?

The LT6600CS8-20#PBF begins limiting differential output above 2VP-P and exhibits noticeable compression above 3.5VP-P. This internal protection prevents damage and maintains linearity for typical 2VP-P ADC inputs. For sustained 2VP-P operation, ensure common-mode voltage remains within specified ranges (e.g., 0–1.5V at VS = 3V). The LT6600CS8-20#PBF does not require external clamping diodes under normal use.

Can the LT6600CS8-20#PBF operate from a single 3.3V supply?

Yes, the LT6600CS8-20#PBF is fully specified and characterized for 3V operation, delivering 76dB SNR and 63dBc 20MHz distortion with 2VP-P output. Use VMID (Pin 7) bypassed to V– and VOCM (Pin 2) tied to VMID to set output common-mode at 1.65V-matching most 3.3V ADC references. The LT6600CS8-20#PBF draws 42mA typical supply current at 3V.

How do I configure the LT6600CS8-20#PBF for unity gain?

Set both external RIN resistors to 402Ω to achieve G = 402Ω / 402Ω = 1. Maintain symmetry: use 1% tolerance metal-film resistors, place them adjacent to Pins 1 and 8, and minimize trace length. For best distortion performance at unity gain, keep VOCM = VMID and use 0.01μF ceramic capacitors on Pins 2 and 7. The LT6600CS8-20#PBF achieves ±0.1dB passband flatness to 2MHz in this configuration.

Does the LT6600CS8-20#PBF require external passive components for its 20MHz filter function?

No-the 20MHz 4th-order Chebyshev lowpass filter is fully integrated; no external capacitors or inductors are needed to set cutoff frequency or passband ripple. Only two external RIN resistors are required for gain programming. The LT6600CS8-20#PBF's internal architecture eliminates component matching errors and temperature drift associated with discrete filter implementations.

What thermal considerations apply to the LT6600CS8-20#PBF in high-power operation?

With 53mA max supply current at 5V, the LT6600CS8-20#PBF dissipates up to 265mW. To maintain junction temperature below 150°C at 85°C ambient, use ≥330mm² copper area connected to Pin 6 (V–) on both PCB layers (θJA ≈ 85°C/W). Avoid routing high-current traces near Pin 6. The LT6600CS8-20#PBF's fused V– pin enables effective thermal conduction to internal ground planes.