Grayhill 61K256 Rotary Encoder Optical 256PPR Equivalent & Substitute Parts

Part Overview

The Grayhill 61K256 is an optical rotary encoder with 256 pulses per revolution (PPR), providing quadrature incremental output. This encoder is designed for panel and PCB through-hole mounting in vertical orientation with a 1/4" diameter flatted end actuator. The part is currently active in production with 1108 units in stock.

Substitute parts are identified when equivalent electrical and mechanical parameters are maintained across the same or compatible product categories. Alternative models may be required due to inventory availability, series selection, or specific application constraints while preserving core functional specifications.

Substiute Parts

61K256

Grayhill Inc.In Stock: 112561K256 Datasheet

Current PartRFQ

61K128

Grayhill Inc.In Stock: 113761K128 Datasheet

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61K64

Grayhill Inc.In Stock: 70661K64 Datasheet

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61KS256

Grayhill Inc.In Stock: 104761KS256 Datasheet

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61R128

Grayhill Inc.In Stock: 113161R128 Datasheet

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61R256

Grayhill Inc.In Stock: 130561R256 Datasheet

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61R64

Grayhill Inc.In Stock: 80061R64 Datasheet

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EM14A0D-C24-L032N

Bourns Inc.In Stock: 1184EM14A0D-C24-L032N Datasheet

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EM14A0D-C24-L064N

Bourns Inc.In Stock: 904EM14A0D-C24-L064N Datasheet

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HRPG-ASCA#19F

Broadcom LimitedIn Stock: 1186HRPG-ASCA#19F Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 61K256 is determined by the following critical parameters:

Primary Substitution Criteria:

• Encoder Type: Optical
• Output Type: Quadrature (Incremental)
• Voltage Supply: 5V
• Actuator Type: 1/4" Dia Flatted End
• Mounting Type: Panel, PCB Through Hole
• Orientation: Vertical
• Termination Style: PC Pin

Secondary Substitution Criteria:

• Pulses per Revolution: 256 (exact match for direct substitution)
• Rotational Life: 10M cycles minimum
• RoHS Compliance: ROHS3 Compliant

Substitute parts are grouped into two categories:

Category A - Direct Equivalents (256 PPR): Parts maintaining identical pulse resolution with all primary parameters matched. These include Grayhill 61KS256 and 61R256.

Category B - Resolution Alternatives (64 PPR, 128 PPR): Parts with reduced pulse resolution but identical electrical and mechanical interfaces. These include Grayhill 61K64, 61K128, 61R64, and 61R128. These are suitable when application requirements permit lower resolution operation.

Category C - Cross-Manufacturer Alternatives: Bourns EM14A0D series and Broadcom HRPG series encoders with compatible parameters but differing rotational life specifications and compliance status.

Parameter Comparison

Engineering Selection Recommendations

Direct Substitution (256 PPR, 10M Cycle Life):

The Grayhill 61KS256 and 61R256 are direct functional equivalents to the 61K256. All three parts maintain identical electrical specifications (5V supply, quadrature output), mechanical interfaces (1/4" flatted end actuator, vertical orientation, PC pin termination), and reliability ratings (10M rotational life cycles). Selection between these three parts is based on series availability and inventory status. The 61R256 currently has the highest inventory level at 1244 units.

Resolution-Reduced Substitution (64 PPR or 128 PPR, 10M Cycle Life):

The Grayhill 61K64, 61K128, 61R64, and 61R128 encoders are substitutable when application requirements permit operation at reduced pulse resolution. These parts maintain all electrical and mechanical compatibility with the 61K256 while providing 64 or 128 PPR output instead of 256 PPR. The 10M rotational life specification is preserved across all Grayhill 61K and 61R series parts.

Cross-Manufacturer Alternatives (Reduced Cycle Life):

The Bourns EM14A0D-C24-L064N and EM14A0D-C24-L032N encoders, as well as the Broadcom HRPG-ASCA#19F, maintain compatible electrical and mechanical parameters but specify only 1M rotational life cycles compared to the 10M specification of the 61K256. These parts are suitable for applications with lower duty cycle requirements. The Bourns EM14A0D series is REACH Affected, whereas the Grayhill and Broadcom parts are REACH Unaffected.

Compliance Considerations:

All substitute parts listed are ROHS3 Compliant and suitable for applications requiring RoHS compliance. The Grayhill 61K and 61R series parts maintain MSL 1 (Unlimited) moisture sensitivity rating, while Bourns EM14A0D series parts are rated MSL Not Applicable. Broadcom HRPG series maintains MSL 1 (Unlimited).

Frequently Asked Questions (FAQ)

Q: Can the 61K256 be directly replaced with the 61R256?

A: Yes. The 61R256 is a direct functional equivalent. Both parts share identical electrical specifications (5V supply, quadrature output, 256 PPR), mechanical interfaces (1/4" flatted end actuator, vertical orientation, PC pin termination), and rotational life rating (10M cycles). Selection is based on series preference and inventory availability.

Q: What is the difference between the 61K and 61R series encoders?

A: The 61K and 61R series are distinct product lines from Grayhill Inc. Both series maintain identical electrical and mechanical specifications for equivalent PPR ratings. The primary distinction is series designation. Parts are interchangeable when PPR and all other parameters match.

Q: Can I use a 128 PPR encoder as a substitute for the 256 PPR 61K256?

A: The 61K128 and 61R128 are mechanically and electrically compatible with the 61K256. However, they provide half the pulse resolution (128 PPR versus 256 PPR). Substitution is valid only if the application can operate with reduced resolution. All other parameters—voltage supply, actuator type, mounting, orientation, and rotational life—remain identical.

Q: What is the rotational life difference between Grayhill and Bourns encoders?

A: Grayhill 61K and 61R series encoders are rated for 10M rotational life cycles. Bourns EM14A0D series and Broadcom HRPG series encoders are rated for 1M rotational life cycles. This represents a tenfold difference in specified cycle life. Selection should account for application duty cycle requirements.

Q: Are the Bourns EM14A0D encoders compatible with the 61K256?

A: The Bourns EM14A0D-C24-L064N and EM14A0D-C24-L032N encoders share the same electrical supply voltage (5V), actuator type (1/4" flatted end), mounting configuration (panel, PCB through hole), orientation (vertical), and termination style (PC pin) as the 61K256. However, they provide different pulse resolutions (64 PPR and 32 PPR respectively) and lower rotational life (1M cycles versus 10M cycles). Compatibility depends on application resolution and duty cycle requirements. Additionally, the Bourns parts are REACH Affected, whereas the Grayhill 61K256 is REACH Unaffected.

Q: What does "Quadrature (Incremental)" output mean?

A: Quadrature output is a standard incremental encoder output format that provides two phase-shifted digital signals (A and B channels). This format allows direction detection and is compatible with standard industrial control systems and microcontroller interfaces. All substitute parts listed maintain this output type.

Q: Can I substitute the Broadcom HRPG-ASCA#19F for the 61K256?

A: The Broadcom HRPG-ASCA#19F shares compatible electrical and mechanical specifications with the 61K256 but provides 120 PPR output instead of 256 PPR and is rated for only 1M rotational life cycles versus 10M. Substitution is valid only if the application can operate with 120 PPR resolution and lower cycle life rating.

Q: What is the significance of MSL (Moisture Sensitivity Level) rating?

A: MSL 1 (Unlimited) indicates that the component has no moisture sensitivity restrictions and does not require special handling or storage conditions. The Grayhill 61K256 and Broadcom HRPG-ASCA#19F both carry MSL 1 rating. The Bourns EM14A0D series is rated MSL Not Applicable, indicating different moisture handling requirements.

Q: Are all listed substitute parts currently in stock?

A: Inventory status is provided in the parameter comparison table. The 61R256 has the highest inventory at 1244 units. All listed parts show active production status with available stock quantities ranging from 644 to 1244 units.