Bourns 3309P-1-203 Trimmer Potentiometer: Equivalent & Substitute Parts

Part Overview

The Bourns 3309P-1-203 is a 20 kOhm, 0.5W through-hole trimmer potentiometer with PC pin termination and top adjustment. This component belongs to the Trimpot® 3309 series and features cermet resistive material for reliable performance in precision adjustment applications. The part is currently obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

3309P-1-203

Bourns Inc.In Stock: 9413309P-1-203 Datasheet

Current PartRFQ

37PR20KLF

TT Electronics/BIIn Stock: 103337PR20KLF Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the Bourns 3309P-1-203 is determined by strict equivalence across the following critical parameters:

• Resistance Value: 20 kOhms (exact match required)
• Power Rating: 0.5W / 1/2W (exact match required)
• Adjustment Type: Top Adjustment (exact match required)
• Mounting Type: Through Hole (exact match required)
• Termination Style: PC Pins (exact match required)
• Resistive Material: Cermet (exact match required)
• Number of Turns: 1 Turn (exact match required)
• Temperature Coefficient: ±250ppm/°C (exact match required)

The TT Electronics/BI 37PR20KLF meets all critical substitution criteria. Minor variations in tolerance (±20% vs. ±25%) and face dimensions (11.50mm x 8.80mm vs. 11.50mm x 9.00mm) remain within acceptable mechanical and electrical compatibility ranges for through-hole PC pin applications.

Parameter Comparison

Engineering Selection Recommendations

The TT Electronics/BI 37PR20KLF is a direct functional equivalent for the obsolete Bourns 3309P-1-203. Selection is supported by:

• Exact electrical equivalence across all critical parameters: resistance, power rating, temperature coefficient, and adjustment characteristics
• Active product status of the substitute part ensures ongoing availability and supply chain continuity
• Compliance alignment: Both parts maintain RoHS and REACH compliance, with the substitute meeting current RoHS standards
• Mechanical compatibility: PC pin through-hole termination and top adjustment design enable direct board-level substitution with minimal layout modification
• Tolerance improvement: The ±20% tolerance of the substitute part provides tighter initial accuracy compared to the ±25% tolerance of the original part

Frequently Asked Questions (FAQ)

Q: Can the TT Electronics/BI 37PR20KLF be used as a direct replacement for the Bourns 3309P-1-203 on existing PCBs?

A: Yes. Both parts share identical PC pin through-hole termination, top adjustment mechanism, and face dimensions within 0.2mm variance. Direct board-level substitution is supported without layout changes.

Q: What is the significance of the tolerance difference (±25% vs. ±20%)?

A: The substitute part features tighter tolerance, which is compatible with applications designed for the original ±25% tolerance. This represents an improvement in initial accuracy and does not create compatibility issues.

Q: Are there any compliance or regulatory differences between these parts?

A: Both parts are RoHS and REACH compliant. The original part carries ROHS3 certification, while the substitute meets current RoHS standards. Both are classified under ECCN EAR99 and HTSUS 8533.40.8050.

Q: What is the practical impact of the 0.2mm height difference (9.00mm vs. 8.80mm)?

A: The 0.2mm difference is negligible for through-hole PC pin applications and does not affect mechanical fit, electrical performance, or board assembly processes.

Q: Why is the original Bourns 3309P-1-203 listed as obsolete?

A: Obsolescence reflects the manufacturer's discontinuation of this specific model. The TT Electronics/BI 37PR20KLF provides functional continuity for applications requiring 20 kOhm, 0.5W cermet trimmer potentiometers with top adjustment and PC pin termination.