Analog Devices Inc. REF198GSZ

Overview

REF198GSZ from Analog Devices is a precision micropower low-dropout voltage reference IC delivering 4.096 V output with ±2 mV initial accuracy, 5 ppm/°C max temperature coefficient, and 45 μA max supply current - designed for high-accuracy ADC/DAC biasing in portable and solar-powered instrumentation.

For engineers reviewing the REF198GSZ datasheet, REF198GSZ pinout, REF198GSZ application, or REF198GSZ equivalent, key selection criteria include dropout voltage (≤0.6 V at 10 mA), sleep-mode current (≤15 μA), load regulation (≤4 ppm/mA), and extended industrial temperature operation (−40°C to +85°C).

Technical Context

The REF198GSZ implements a patented curvature-corrected band gap core with laser-trimmed thin-film resistors to achieve stable 4.096 V output across temperature. Its SLEEP pin enables TTL/CMOS-compatible shutdown, reducing quiescent current to ≤15 μA while disabling output.

It operates with input supply as low as 100 mV above output (i.e., ≥4.196 V), supports 30 mA output current, and requires a 1 μF output bypass capacitor for stability per datasheet specification. Line regulation is specified at 4 ppm/V (E grade) and load regulation at 4 ppm/mA (E grade) at 25°C.

Key Specifications

Pinout & Package

REF198GSZ is packaged in an 8-lead SOIC_N (SOIC-8 narrow-body) with exposed pad option not specified; pin functions are validated per Analog Devices' Figure 1 (Rev. L). Pins 1 and 5 are factory test points (TP) and must remain unconnected in circuit.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision voltage reference applications.

Compared with ADR3440ARJZ-R7 and MAX6126AASA41+T, REF198GSZ uniquely balances SOIC-8 compatibility, 30 mA drive capability, integrated sleep mode, and 5 ppm/°C tempco - making it optimal for portable instrumentation requiring moderate load drive and duty-cycled operation.

Availability

REF198GSZ is available at Aetrix Electronics and suitable for portable instrumentation, high-resolution data acquisition, and solar-powered remote sensing requiring stable component supply and long-lifecycle support.

Supply support for REF198GSZ 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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The REF19x series was developed for micropower, low-dropout precision voltage referencing in battery-operated and energy-constrained systems - emphasizing accuracy, thermal stability, and minimal supply overhead.

FAQ

What is the minimum supply voltage required for stable operation of the REF198GSZ?

The REF198GSZ requires a minimum supply voltage of 4.196 V - i.e., at least 100 mV above its 4.096 V nominal output - to maintain regulation under load. At 10 mA output current, the dropout voltage is specified at 0.60 V, confirming operation down to 4.696 V is fully characterized per datasheet Table 13.

Does the REF198GSZ require an output bypass capacitor, and if so, what value and type?

Yes, the REF198GSZ requires a 1 μF ceramic capacitor connected between the OUTPUT pin and GND, as explicitly mandated in the datasheet's "Applications Information" section. This capacitor ensures stability, reduces noise, and improves transient response; tantalum or electrolytic types are not recommended due to ESR and aging effects.

How does the SLEEP pin function on the REF198GSZ, and what logic levels activate it?

The SLEEP pin on the REF198GSZ is an active-low TTL/CMOS-compatible control input. Applying a logic low ≤0.8 V places the device in sleep mode, disabling the output and reducing supply current to ≤15 μA. A logic high ≥2.4 V enables normal operation with ≤45 μA supply current. Input leakage is ≤−8 μA in either state.

Can the REF198GSZ drive a 30 mA load across the full −40°C to +85°C temperature range?

Yes, the REF198GSZ is rated for 30 mA output current at 25°C (Table 11), and maintains 25 mA capability over −40°C to +85°C per Table 12. At +125°C, the datasheet specifies 20 mA (Table 13), confirming robust load drive within its extended industrial temperature range.

What is the purpose of Pins 1 and 5 on the REF198GSZ, and how should they be handled in PCB layout?

Pins 1 and 5 on the REF198GSZ are factory test points used for in-package Zener zapping during laser trimming. They are not intended for user connection. The datasheet explicitly states these pins must be left unconnected - routing traces, adding vias, or tying them to GND/VS invalidates accuracy and may impair functionality.