AD1555BPZRL

Overview

The AD1555BPZRL is a fourth-order sigma-delta modulator with an integrated programmable gain amplifier (PGA), packaged in a 28-lead PLCC. It operates from ±5 V analog supplies and a +5 V digital supply, delivering a sampling rate of 256 kSPS. The device provides a dynamic range of 116 dB minimum at a 1 kHz output word rate with PGA gain of 1. Input ranges are selectable via five gain settings: 1, 2.5, 8.5, 34, and 128. It features low input noise of 80 nV rms at 4 ms with maximum gain and high jitter tolerance, eliminating the need for external antialias filters.

Feature Summary

• Fourth-order sigma-delta modulator with continuous-time analog input architecture
• Programmable gain amplifier with gains of 1, 2.5, 8.5, 34, and 128
• Dynamic range up to 120 dB typical at 1 kHz output word rate
• Low power dissipation of 77 mW typical with standby modes available

Applications

• Seismic data acquisition systems
• Chromatography instrumentation
• Automatic test equipment

Procurement Notes

Verify the AD1555BPZRL ordering suffix indicates tape and reel packaging, distinct from the standard tube-packaged AD1555BPZ. Confirm the B-grade temperature range specification of –55°C to +85°C matches system requirements. Ensure compatibility with the companion AD1556 digital filter/decimator for complete ADC functionality.

Selection Notes

Select the AD1555BPZRL when high-volume production requires reel packaging rather than tubes. The B-grade variant ensures performance across the industrial temperature range of –55°C to +85°C. This component must be paired with the AD1556 FIR filter/decimator to achieve the final 24-bit digital output.

Part Context

The AD1555BPZRL belongs to the AD1555/AD1556 chipset family designed for high-resolution, low-frequency measurement applications. While the AD1555 handles analog modulation and amplification, the AD1556 performs digital filtering and decimation. Together, they form a complete 24-bit sigma-delta ADC solution optimized for precision sensor interfaces.

Replacement Considerations

The AD1555APRL serves as a lower-cost alternative with a restricted 0°C to +85°C temperature range. For full industrial temperature coverage, the AD1555BPZ is the tube-packaged equivalent. No direct single-chip replacements exist; the AD1556 companion remains required.