Analog Devices Inc. DC1384A-A

Overview

LTC2452 from Analog Devices (formerly Linear Technology) is a fully differential, 16-bit delta-sigma analog-to-digital converter with SPI interface, operating from 2.7V to 5.5V supply and delivering 60 conversions per second. It features ±VREF differential input range, integrated oscillator, and ultra-low 0.2µA sleep current - ideal for battery-powered sensor monitoring and embedded data acquisition systems.

For engineers reviewing the LTC2452 datasheet, LTC2452 pinout, LTC2452 application, or LTC2452 equivalent, key selection considerations include its no-latency delta-sigma architecture, 2LSB offset error, 4LSB full-scale error, 800µA active supply current, and support for both CPOL = 0 and CPOL = 1 SPI modes in DFN and TSOT-23 packages.

Technical Context

The LTC2452 employs a proprietary delta-sigma modulator core with continuous internal offset and full-scale calibration, eliminating latency in multiplexed applications and ensuring accuracy over temperature without user intervention. Its input sampling scheme reduces average input current to 50nA and minimizes inter-pin leakage.

It operates in three deterministic states - CONVERT (16.6ms nominal), SLEEP (<0.2µA), and DATA OUTPUT - controlled via 3-wire SPI (CS, SCK, SDO). The device supports both idle-high and idle-low clock polarity, allows conversion status monitoring via SDO level, and enables 2-wire operation by hardwiring CS to GND.

Key Specifications

Pinout & Package

The LTC2452 is available in two surface-mount packages: 8-lead 3mm × 2mm DFN (DD8) and 8-lead TSOT-23 (TS8), both with exposed thermal pad (Pin 9) tied to GND. Pin functions are identical across packages.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar delta-sigma ADC applications.

Compared with ADS1115IDGSR and MAX11602AUT+, the LTC2452 delivers superior DC precision (±1 LSB INL, continuous calibration), lowest sleep current (<0.2 µA), and true differential input architecture optimized for low-frequency sensor signals - making it uniquely suited for long-life, high-accuracy embedded measurement.

Availability

LTC2452 is available at Aetrix Electronics and suitable for industrial process control, environmental monitoring, direct temperature measurement, and embedded ADC upgrade applications requiring stable component supply and long-term manufacturability.

Supply support for LTC2452 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 technologies, serving industrial, automotive, communications, and healthcare markets.

The LTC2452 belongs to ADI's precision delta-sigma ADC product line, designed specifically for ultra-low-power, high-accuracy sensor interfacing in space- and energy-constrained embedded systems.

FAQ

What is the conversion time of the LTC2452 and how does it affect system timing?

The LTC2452 has a nominal conversion time of 16.6 ms (max 23 ms), enabling exactly 60 conversions per second. This fixed timing allows deterministic system-level scheduling - no polling or status checking is needed. The LTC2452 automatically transitions from CONVERT to SLEEP state upon completion, and the host can trigger the next conversion precisely using CS or SCK edges, making the LTC2452 ideal for time-critical embedded control loops.

Does the LTC2452 require an external crystal or clock source?

No, the LTC2452 includes a fully integrated oscillator that requires no external components. This eliminates the need for crystals, oscillators, or clock distribution circuitry, reducing bill-of-materials cost and PCB area. The LTC2452's internal clock drives the delta-sigma modulator and SPI interface reliably across its full temperature range (–40°C to 85°C), and its timing is factory-trimmed for accuracy - a key advantage over externally clocked ADCs.

How does the LTC2452 handle input overrange and underrange conditions?

The LTC2452 provides up to 31 LSB total overrange + underrange capability (e.g., 8 LSB below GND and 23 LSB above VREF). When VIN+ – VIN– exceeds ±VREF, the output code clamps at 0 or 65535, but within the ±VREF range, the LTC2452 can accurately digitize signals slightly outside the nominal span. This behavior is intrinsic to its proprietary sampling architecture and is confirmed in Figure 3 of the LTC2452 datasheet - enabling robust operation with imperfect sensor biasing or drift.

Can the LTC2452 operate with a 2.5V reference while powered from a 3.3V supply?

Yes, the LTC2452 supports independent reference and supply voltages: VREF may be set from 2.5 V to VCC, so a 2.5 V reference is fully valid with a 3.3 V VCC supply. This configuration yields a ±2.5 V differential input range and improves SNR for low-voltage sensor signals. The LTC2452's REF pin draws only ±10 nA leakage current, minimizing reference loading - allowing use of low-power references like the LT6654 or even a precision resistor divider from VCC when stability requirements permit.

What SPI modes does the LTC2452 support and how is data formatted?

The LTC2452 supports both CPOL = 0 (SCK idle low) and CPOL = 1 (SCK idle high), with data sampled on the rising edge of SCK. It outputs 16-bit signed binary data MSB-first (D15 to D0) on SDO, where D15 is the sign bit. The output code equals 32768 × (VIN+ – VIN–)/VREF + 32768, producing values from 0 (–VREF) to 65535 (+VREF). This format is directly compatible with standard microcontroller arithmetic units and requires no post-processing - a key feature of the LTC2452 design.