Analog Devices Inc. LTC1608CG#PBF

Overview

LTC1608CG#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 500ksps successive-approximation analog-to-digital converter with differential input, internal ±2.5V bipolar full-scale range, 90dB S/(N+D), –100dB THD at 500ksps, and dual shutdown modes (7mW Nap, 10µW Sleep). It serves as a complete, self-contained high-speed ADC in precision data acquisition systems requiring no pipeline delay and guaranteed no missing codes over temperature.

For engineers reviewing the LTC1608CG#PBF datasheet, LTC1608CG#PBF pinout, LTC1608CG#PBF application, or LTC1608CG#PBF equivalent, this page delivers verified specifications, validated 36-pin SSOP pin functions, real-world timing constraints (tACQ = 400ns, tCONV = 1.45µs), and two confirmed alternative parts for high-fidelity signal digitization in telecom and DSP systems.

Technical Context

The LTC1608CG#PBF implements a capacitor-based successive approximation register (SAR) architecture with integrated differential sample-and-hold, achieving 15MHz small-signal input bandwidth and 68dB common-mode rejection. Its internal 2.5V bandgap reference (±15ppm/°C tempco) feeds a 1.75× gain reference amplifier, enabling precise scaling of the 16-bit capacitive DAC.

Digital interface uses µP-compatible parallel output (D15–D0, two's complement) with separate CONVST (active-low conversion trigger), BUSY (data-ready flag), and RD/CS control signals - eliminating pipeline latency and supporting direct FIFO/DSP/microprocessor interfacing without external clocking or alignment logic.

Key Specifications

Pinout & Package

Package: 36-lead plastic SSOP (G package), 0.209" body width, JEDEC MO-153 compliant. Thermal resistance θJA = 95°C/W; max junction temperature 125°C.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed 16-bit ADC applications.

Compared with ADS8588SIPM and AD7606CCPZ, the LTC1608CG#PBF uniquely delivers 500ksps single-channel throughput with no pipeline delay, internal ±2.5V reference, and differential input noise rejection - making it irreplaceable for latency-constrained, high-SINAD signal capture where channel count is secondary to speed and fidelity.

Availability

LTC1608CG#PBF is available at Aetrix Electronics and suitable for telecommunications baseband digitization, digital signal processing front-ends, and multiplexed data acquisition systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LTC1608CG#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 ICs, serving aerospace, industrial, automotive, and communications markets.

The LTC1608CG#PBF belongs to Linear Technology's precision high-speed ADC product line, engineered for applications demanding high dynamic range, low distortion, and deterministic timing - especially in telecom infrastructure and real-time DSP systems.

FAQ

What is the operating temperature range for the LTC1608CG#PBF?

The LTC1608CG#PBF is specified for operation from 0°C to 70°C (Commercial grade). This is indicated by the "C" suffix in the part number. The "G" denotes the 36-lead SSOP package. Full performance specifications - including no missing codes, ±1 LSB INL, and 90dB S/(N+D) - are guaranteed across this entire range, unlike the industrial-grade LTC1608IG which extends to –40°C to 85°C.

Does the LTC1608CG#PBF require an external clock to operate?

No, the LTC1608CG#PBF does not require an external clock. It contains a factory-trimmed internal clock that guarantees a maximum conversion time of 1.8µs and a minimum sampling rate of 500ksps. The internal clock eliminates timing jitter from external sources and simplifies system design - only CONVST, CS, and RD control signals are needed for full operation of the LTC1608CG#PBF.

Can the LTC1608CG#PBF interface directly with a 3.3V microprocessor?

Yes, the LTC1608CG#PBF supports 3.3V digital interfacing via its dedicated OVDD pin (Pin 29). When OVDD is supplied with 3.3V, the D15–D0 data outputs and BUSY signal swing between 0V and 3.3V, while digital inputs (CONVST, CS, RD, SHDN) accept 3.3V logic levels regardless of OVDD setting. This dual-voltage capability ensures safe, reliable communication with 3.3V µPs without level shifters - a key feature of the LTC1608CG#PBF.

What is the purpose of the REFCOMP pin (Pin 4) on the LTC1608CG#PBF?

The REFCOMP pin (Pin 4) on the LTC1608CG#PBF is the compensation node for the internal reference amplifier, not an external reference input. It outputs a nominal 4.375V and must be bypassed to AGND with a minimum 22µF tantalum capacitor (plus 0.1µF ceramic) to ensure stability of the 2.5V VREF output. Using REFCOMP as an external reference is explicitly discouraged in the datasheet due to part-to-part variation and switching glitches - the LTC1608CG#PBF relies solely on its internal reference or externally driven VREF.

How does the Nap and Sleep shutdown modes differ in the LTC1608CG#PBF?

In Nap mode (SHDN low, CS low), the LTC1608CG#PBF reduces power to 7.5mW by disabling the analog front-end while keeping the reference and digital logic active - enabling wake-up in 200ns. In Sleep mode (SHDN low, CS high), all bias currents are shut down, drawing only 10µW; however, wake-up requires ~80ms for the reference to stabilize. These distinct modes let designers optimize for either rapid responsiveness (Nap) or ultra-low standby power (Sleep) - both are fully supported by the LTC1608CG#PBF.