Analog Devices Inc. LTC2621IDD#TRPBF

Overview

LTC2621IDD#TRPBF from Analog Devices (formerly Linear Technology) is a 12-bit rail-to-rail voltage-output DAC in a 10-lead 3mm × 3mm DFN package, operating from 2.5V to 5.5V supply, delivering ±15mA output drive with ±0.5 LSB DNL and ±0.8 LSB INL over –40°C to +85°C. It features SPI/MICROWIRE-compatible 3-wire serial interface, hardware CLR, asynchronous LDAC update, and power-on reset to zero scale-used in precision industrial process control loops requiring stable, monotonic analog setpoints.

For engineers reviewing the LTC2621IDD#TRPBF datasheet, LTC2621IDD#TRPBF pinout, LTC2621IDD#TRPBF application, or LTC2621IDD#TRPBF equivalent, key selection criteria include guaranteed monotonicity over temperature, 7μs settling time to ±1 LSB, low 300μA active supply current, 1μA max power-down current, and compatibility with daisy-chained multi-DAC systems using SDO/SDI cascading.

Technical Context

The LTC2621IDD#TRPBF implements a segmented R-2R ladder architecture with integrated rail-to-rail output buffer, enabling full-scale output swing from 0V to V_REF while maintaining <0.15 LSB/mA load regulation at 5V. Its 24-bit serial command structure supports write-only, update-only, or combined write-and-update operations, with optional 32-bit framing for daisy-chain synchronization.

It uses double-buffered input and DAC registers to prevent spurious output transitions during data loading, and includes asynchronous LDAC control for synchronized multi-device updates. The hardware CLR pin forces zero-scale output on level assertion, independent of serial interface state.

Key Specifications

Pinout & Package

Package: 10-lead (3mm × 3mm) plastic DFN with exposed pad (Pin 11 = GND), rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-output DAC applications.

Compared with AD5621BRMZ-REEL7 and MCP4822-E/SN, the LTC2621IDD#TRPBF delivers superior monotonicity (±0.5 vs ±1.5/±2 LSB), integrated rail-to-rail buffer eliminating BOM cost, and hardware CLR for deterministic fault recovery-making it optimal for safety-critical industrial control nodes.

Availability

LTC2621IDD#TRPBF is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and automated test equipment requiring stable component supply with guaranteed long-term availability and traceable lot-level documentation.

Supply support for LTC2621IDD#TRPBF 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 LTC2621IDD#TRPBF belongs to Linear's precision DAC product line, engineered for applications demanding monotonicity, low glitch energy, and robust rail-to-rail output drive in compact industrial and instrumentation environments.

FAQ

What is the guaranteed differential nonlinearity specification for the LTC2621IDD#TRPBF over its full operating temperature range?

The LTC2621IDD#TRPBF guarantees ±0.5 LSB differential nonlinearity across its full –40°C to +85°C operating temperature range, ensuring monotonic behavior in all thermal conditions without code-dependent output reversals. This specification is validated per Note 2 in the official datasheet and applies to codes KL to 2^N–1, where N=12 and KL=64 for V_REF=4.096V. The LTC2621IDD#TRPBF maintains this performance without derating.

Does the LTC2621IDD#TRPBF support daisy-chain configuration, and what is required to implement it?

Yes, the LTC2621IDD#TRPBF supports daisy-chain operation using its SDO (Pin 1) and SDI (Pin 2) pins. Implementation requires 32-bit command framing (8 don't-care bits + 4-bit command + 12-bit data + 8 don't-care bits), with SDO of one device connected to SDI of the next. The SCK and CS/LD signals remain common across the chain, and a single CS/LD rising edge executes commands simultaneously. The LTC2621IDD#TRPBF's 32-bit mode is mandatory for daisy chaining.

What happens to the output of the LTC2621IDD#TRPBF during power-up, and how is it controlled?

During power-up, the LTC2621IDD#TRPBF's output rises less than 10 mV above zero scale until a valid write-and-update command is executed. This behavior is enforced by an internal power-on reset circuit that holds the DAC register at zero code. Unlike the -1 variant, the LTC2621IDD#TRPBF does not default to midscale-it remains at zero scale until explicitly updated. The hardware CLR pin provides immediate zero-scale override at any time.

Can the LTC2621IDD#TRPBF drive a 1000 pF capacitive load while maintaining stability and specified settling time?

Yes, the LTC2621IDD#TRPBF is characterized to drive up to 1000 pF capacitive loads while maintaining stability and its specified 7 μs settling time to ±1 LSB. This capability is confirmed in the "Capacitive Load Driving" parameter (1000 pF) and "Typical Performance Characteristics" section of the datasheet, which shows clean step responses with no ringing or overshoot into 1000 pF + 2 kΩ parallel loads. No external compensation is required.

What is the maximum clock frequency supported by the serial interface of the LTC2621IDD#TRPBF, and are there timing restrictions?

The LTC2621IDD#TRPBF supports a maximum SCK frequency of 50 MHz across its full operating temperature range, with minimum pulse widths defined in the Timing Characteristics table: t3/t4 (SCK high/low time) ≥9 ns, t1/t2 (setup/hold) ≥4 ns, and t5 (CS/LD pulse width) ≥10 ns. These specifications apply for V_CC = 2.5V to 5.5V and ensure reliable data capture at microcontroller GPIO speeds up to 50 MHz without external clock division.