Grayhill 61S128-2 Rotary Encoder Optical 128PPR Equivalent & Substitute Parts

Part Overview

The Grayhill 61S128-2 is an optical rotary encoder with 128 pulses per revolution (PPR), delivering quadrature incremental output at 5V supply voltage. This vertical-mount, through-hole component features a 1/4" diameter flatted end actuator with detent positioning and is designed for applications requiring high-resolution angular position feedback. The part maintains Active product status with 698 units in current inventory stock. Substitute parts are identified based on matching electrical specifications, mechanical compatibility, and functional output characteristics within the optical encoder category.

Substiute Parts

61S128-2

Grayhill Inc.In Stock: 75761S128-2 Datasheet

Current PartRFQ

62F22-01-P-L

Grayhill Inc.In Stock: 121062F22-01-P-L Datasheet

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62S11-M0-P

Grayhill Inc.In Stock: 87162S11-M0-P Datasheet

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62S22-M0-P

Grayhill Inc.In Stock: 72162S22-M0-P Datasheet

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HRPG-AD32#13R

Broadcom LimitedIn Stock: 788HRPG-AD32#13R Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 61S128-2 are grouped based on strict parameter matching within the optical rotary encoder category. The primary substitution criteria are:

Mandatory Matching Parameters:

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

Variable Parameters (Resolution Dependent):

• Pulses per Revolution: 16, 32, or 128 PPR
• Rotational Life: 1M or 10M cycles minimum
• RoHS Status: RoHS Compliant or ROHS3 Compliant

The identified substitutes maintain electrical and mechanical compatibility with the 61S128-2 while offering alternative resolution options (16 PPR and 32 PPR) and different manufacturers (Grayhill Inc. and Broadcom Limited). All substitutes operate at 5V, feature identical actuator geometry, and mount identically on PCB through-hole configurations.

Parameter Comparison

Engineering Selection Recommendations

61S128-2 (Primary Selection): Select this part when 128 PPR resolution is required and extended rotational life of 10 million cycles is specified. This part offers the highest resolution among available options and superior mechanical durability. RoHS Compliant status applies.

62S11-M0-P (32 PPR Alternative): Select this Grayhill optical encoder when 32 PPR resolution is acceptable and cost optimization is a consideration. Rotational life is rated at 1 million cycles minimum. ROHS3 Compliant status applies. Suitable for applications with lower resolution requirements.

HRPG-AD32#13R (32 PPR Cross-Manufacturer Alternative): Select this Broadcom optical encoder when 32 PPR resolution is acceptable and cross-manufacturer sourcing is required for supply chain diversification. Rotational life is rated at 1 million cycles minimum. ROHS3 Compliant status applies. Mechanical and electrical compatibility with 61S128-2 is maintained.

62F22-01-P-L and 62S22-M0-P (16 PPR Options): Select either of these Grayhill optical encoders when 16 PPR resolution is acceptable. Both parts are rated for 1 million cycles minimum rotational life and carry ROHS3 Compliant status. These represent the lowest resolution options within the substitute group.

All substitute parts maintain identical 5V supply voltage, 1/4" flatted end actuator geometry, detent positioning, vertical PCB through-hole mounting, and PC pin termination. Selection between substitutes depends on required resolution (PPR), acceptable rotational life rating, and manufacturer preference.

Frequently Asked Questions (FAQ)

Q: Can the 62S11-M0-P (32 PPR) directly replace the 61S128-2 (128 PPR)?

A: The 62S11-M0-P is mechanically and electrically compatible with the 61S128-2 in terms of mounting, voltage, actuator type, and termination. However, the resolution differs significantly: 32 PPR versus 128 PPR. Direct replacement is possible only if the application can tolerate lower angular resolution. The quadrature output format remains identical.

Q: What is the difference between RoHS Compliant and ROHS3 Compliant status?

A: Both designations indicate compliance with Restriction of Hazardous Substances regulations. RoHS Compliant (61S128-2) and ROHS3 Compliant (substitute parts) both meet hazardous substance restrictions. The designation difference reflects the regulatory version under which compliance was certified. Both are acceptable for applications requiring RoHS compliance.

Q: Are the Grayhill and Broadcom optical encoders interchangeable?

A: The Grayhill 62S11-M0-P and Broadcom HRPG-AD32#13R are functionally interchangeable when 32 PPR resolution is acceptable. Both feature identical electrical specifications (5V supply, quadrature output), mechanical dimensions (1/4" flatted end actuator), mounting configuration (PCB through-hole, vertical orientation), and termination style (PC pin). Selection between manufacturers depends on supply availability and procurement requirements.

Q: What does "Pulses per Revolution" mean in encoder selection?

A: Pulses per Revolution (PPR) defines the angular resolution of the encoder. The 61S128-2 generates 128 pulses per complete 360-degree rotation, providing finer angular position discrimination than lower PPR alternatives. The 32 PPR substitutes generate 32 pulses per rotation, and 16 PPR substitutes generate 16 pulses per rotation. Higher PPR values enable more precise position tracking.

Q: Does rotational life rating affect substitute part selection?

A: The 61S128-2 is rated for 10 million cycles minimum rotational life, while all substitute parts are rated for 1 million cycles minimum. If the application specifies extended operational life or high-cycle-count duty, the 61S128-2 is the appropriate selection. For applications with lower cycle requirements, substitute parts with 1 million cycle ratings are acceptable.

Q: Can I use a 16 PPR encoder where a 128 PPR encoder is specified?

A: Substitution from 128 PPR to 16 PPR is possible only if the application firmware or control system can function with reduced angular resolution. The 62F22-01-P-L and 62S22-M0-P (16 PPR) are mechanically and electrically compatible but provide one-eighth the resolution of the 61S128-2. Application-level verification is required before substitution.

Q: Are all substitute parts available in the same packaging format?

A: The 61S128-2 is packaged as individual units. Substitute parts (62F22-01-P-L, 62S11-M0-P, 62S22-M0-P, HRPG-AD32#13R) are supplied in Bulk packaging. Inventory availability: 61S128-2 (698 units), 62F22-01-P-L (1152 units), 62S11-M0-P (772 units), 62S22-M0-P (660 units), HRPG-AD32#13R (760 units).