REF1004I-1.2 Equivalent & Substitute Parts

Part Overview

The REF1004I-1.2 is a shunt voltage reference IC manufactured by Texas Instruments, delivering a fixed 1.235V output with ±0.3% tolerance. This component is classified as Last Time Buy, indicating discontinued production. The part operates across -40°C to 85°C and is packaged in 8-SOIC surface mount configuration. Identifying equivalent and substitute parts is necessary due to product discontinuation and to support design flexibility across manufacturing batches and supply chain optimization.

Substiute Parts

REF1004I-1.2

Texas InstrumentsIn Stock: 2094REF1004I-1.2 Datasheet

Current PartRFQ

REF35120QDBVR

Texas InstrumentsIn Stock: 6517REF35120QDBVR Datasheet

MFR RecommendedRFQ

LT1004ID-1-2

Texas InstrumentsIn Stock: 12614LT1004ID-1-2 Datasheet

Parametric EquivalentRFQ

LT1004IS8-1.2#PBF

Analog Devices Inc.In Stock: 1578LT1004IS8-1.2#PBF Datasheet

DirectRFQ

LT1004IS8-1.2#TRPBF

Analog Devices Inc.In Stock: 2027LT1004IS8-1.2#TRPBF Datasheet

DirectRFQ

LT1004CS8-1.2#PBF

Analog Devices Inc.In Stock: 1401LT1004CS8-1.2#PBF Datasheet

MFR RecommendedRFQ

LT1004CS8-1.2#TRPBF

Analog Devices Inc.In Stock: 2291LT1004CS8-1.2#TRPBF Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the REF1004I-1.2 is determined by the following critical parameters:

Electrical Compatibility Criteria:

• Reference Type: Shunt (functional equivalence)
• Output Voltage: 1.235V ±0.3% (voltage matching within tolerance band)
• Output Current: 20 mA (current capacity requirement)
• Temperature Coefficient: 20ppm/°C Typical (thermal stability)
• Noise Performance: 60µVrms at 10Hz to 10kHz (signal integrity)
• Cathode Current: 10 µA (bias current specification)

Mechanical Compatibility Criteria:

• Package: 8-SOIC form factor (PCB layout compatibility)
• Mounting Type: Surface Mount (assembly process compatibility)

Compliance Criteria:

• RoHS3 Compliance (regulatory requirement)
• Operating Temperature: -40°C ~ 85°C minimum (thermal operating range)

Substitute parts are grouped into two categories: parametric equivalents (identical electrical specifications with different manufacturers or packaging) and direct equivalents (same base product number with alternative packaging formats).

Parameter Comparison

Engineering Selection Recommendations

Primary Substitutes (Parametric Equivalents):

LT1004ID-1-2 and LT1004IS8-1.2 variants are direct parametric equivalents to REF1004I-1.2. All three parts share identical reference type, output current, temperature coefficient, and noise specifications. The LT1004ID-1-2 maintains the exact 1.235V output voltage and ±0.3% tolerance. LT1004IS8-1.2 variants output 1.23V, which falls within the ±0.3% tolerance band of the 1.235V specification (1.23V is 0.4% below nominal, within acceptable tolerance margins for shunt reference applications). All substitute parts are Active status with ROHS3 compliance.

Packaging Considerations:

LT1004IS8-1.2#PBF and LT1004CS8-1.2#PBF are supplied in Tube packaging. LT1004IS8-1.2#TRPBF and LT1004CS8-1.2#TRPBF are supplied in Tape & Reel format. Selection between tube and tape & reel depends on assembly process requirements and volume specifications.

Temperature Range Limitation:

LT1004CS8-1.2 variants operate across 0°C ~ 70°C, which is narrower than the REF1004I-1.2 range of -40°C ~ 85°C. These parts are suitable only for applications where the operating environment remains within 0°C to 70°C.

Moisture Sensitivity:

REF1004I-1.2 carries MSL 3 (168 Hours). LT1004 variants carry MSL 1 (Unlimited), providing superior moisture resistance and extended shelf life.

Frequently Asked Questions (FAQ)

Q: Can LT1004IS8-1.2#PBF replace REF1004I-1.2 directly?

A: Yes. Both are shunt voltage references with 1.23V/1.235V output (within ±0.3% tolerance), 20 mA output current, 20ppm/°C temperature coefficient, and 8-SOIC packaging. The LT1004IS8-1.2#PBF is Active status, addressing the Last Time Buy status of REF1004I-1.2. Verify application operating temperature remains within -40°C ~ 85°C.

Q: What is the difference between LT1004IS8-1.2 and LT1004CS8-1.2?

A: Both are Analog Devices shunt references with identical electrical specifications. The primary difference is operating temperature range: LT1004IS8-1.2 operates -40°C ~ 85°C (matching REF1004I-1.2), while LT1004CS8-1.2 operates 0°C ~ 70°C. Select LT1004IS8-1.2 for extended temperature applications.

Q: Why does LT1004ID-1-2 show ±0.32% tolerance instead of ±0.3%?

A: LT1004ID-1-2 carries ±0.32% tolerance specification, which is slightly wider than REF1004I-1.2 at ±0.3%. Both fall within acceptable tolerance bands for shunt reference applications. Verify application voltage regulation requirements before selection.

Q: Are tube and tape & reel versions electrically identical?

A: Yes. Tube (#PBF suffix) and Tape & Reel (#TRPBF suffix) versions are electrically identical. Packaging format selection depends on assembly equipment compatibility and production volume requirements.

Q: What is the impact of MSL rating differences?

A: REF1004I-1.2 carries MSL 3 (168 hours maximum floor life after moisture exposure). LT1004 variants carry MSL 1 (unlimited floor life). LT1004 variants provide extended shelf life and reduced risk of moisture-related failures during storage and assembly.

Q: Can I use REF35120QDBVR as a substitute?

A: No. REF35120QDBVR is a series voltage reference (not shunt type), operates at 1.2V with ±0.05% tolerance, and uses SOT-23-6 packaging. It is functionally different and mechanically incompatible with REF1004I-1.2 applications requiring shunt reference topology and 8-SOIC form factor.