TS87C51RB2-VCB Equivalent & Substitute Parts

Part Overview

The TS87C51RB2-VCB is an 80C51-based 8-bit microcontroller manufactured by Microchip Technology, featuring 16KB OTP program memory and 512 bytes of RAM in a 44-PLCC surface mount package. This device operates at 40/30MHz with integrated UART/USART connectivity and standard peripherals including Power-On Reset, PWM, and Watchdog Timer functionality.

The TS87C51RB2-VCB is classified as obsolete. Identifying equivalent substitute parts is necessary to support legacy system maintenance, design updates, and continued production where original components are no longer readily available or have reached end-of-life status.

Substiute Parts

TS87C51RB2-VCB

Microchip TechnologyIn Stock: 977TS87C51RB2-VCB Datasheet

Current PartRFQ

PIC17C44-25/L

Microchip TechnologyIn Stock: 2960PIC17C44-25/L Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the TS87C51RB2-VCB is determined by the following critical parameters:

• Core Architecture & Memory Configuration: 8-bit microcontroller with 16KB OTP program memory and 512 bytes RAM
• Package Compatibility: 44-PLCC surface mount package with matching pinout and mechanical dimensions
• Electrical Specifications: Operating voltage range 4.5V ~ 5.5V, operating temperature 0°C ~ 70°C
• Peripheral Feature Set: UART/USART connectivity, POR, PWM, and WDT functionality
• I/O Count: Minimum 32 I/O pins required

The PIC17C44-25/L qualifies as a substitute based on matching core memory architecture (16KB OTP), identical package format (44-PLCC), compatible voltage supply range (4.5V ~ 6V), matching operating temperature range (0°C ~ 70°C), equivalent peripheral set (UART/USART, POR, PWM, WDT), and sufficient I/O count (33 pins).

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The TS87C51RB2-VCB is obsolete, while the PIC17C44-25/L is active and in current production. Selection of the active substitute ensures ongoing availability and supply chain continuity.

Compliance & Certification: The PIC17C44-25/L is ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements. The original TS87C51RB2-VCB is RoHS non-compliant, making the substitute preferable for new designs or updated production runs subject to environmental regulations.

Performance Trade-off: The substitute operates at 25MHz versus the original 40/30MHz. Applications requiring the original maximum speed specification must evaluate whether the reduced clock frequency impacts system timing requirements, interrupt response, or throughput.

Memory Consideration: The PIC17C44-25/L provides 454 bytes of RAM compared to 512 bytes in the original. Applications utilizing more than 454 bytes of RAM require design modification or alternative component selection.

Electrical Compatibility: Both devices operate within overlapping voltage ranges (4.5V ~ 5.5V for original; 4.5V ~ 6V for substitute) and identical temperature ranges, supporting direct electrical substitution in most applications.

Frequently Asked Questions (FAQ)

Q: Can the PIC17C44-25/L directly replace the TS87C51RB2-VCB in existing PCB designs?

A: Physical and electrical substitution is possible due to matching 44-PLCC package format, compatible voltage supply range, and identical operating temperature specifications. However, firmware compatibility requires evaluation, as the PIC17C44-25/L uses a different processor architecture (PIC versus 80C51) and instruction set. Existing 80C51 firmware cannot execute on the PIC processor without complete recompilation and validation.

Q: What is the impact of the 25MHz speed limitation on the PIC17C44-25/L?

A: The substitute operates at 25MHz compared to the original 40/30MHz specification. Applications dependent on the original maximum clock frequency for timing-critical operations, high-speed serial communication, or interrupt handling must verify that 25MHz operation meets system requirements. Timing-sensitive code may require adjustment or alternative component selection.

Q: Is the 58-byte RAM reduction in the PIC17C44-25/L significant?

A: The substitute provides 454 bytes of RAM versus 512 bytes in the original. Applications utilizing less than 454 bytes of RAM are unaffected. Designs requiring more than 454 bytes of RAM require code optimization, external memory addition, or alternative component selection.

Q: Are there pinout differences between these devices?

A: Both devices use the 44-PLCC package format with matching mechanical dimensions (16.6x16.6mm and 16.59x16.59mm respectively). However, pinout assignment and function mapping differ due to different processor architectures. Direct pin-for-pin substitution is not guaranteed; detailed datasheet comparison and PCB layout verification are required.

Q: What are the compliance advantages of the PIC17C44-25/L?

A: The PIC17C44-25/L is ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory standards. The original TS87C51RB2-VCB is RoHS non-compliant. For applications subject to environmental regulations or customer requirements, the substitute provides compliance advantages.

Q: Is firmware migration from 80C51 to PIC architecture straightforward?

A: No. The 80C51 and PIC architectures use fundamentally different instruction sets, memory organization, and peripheral interfaces. Firmware migration requires complete recompilation using PIC-compatible development tools and thorough validation. This is not a simple code port but a substantial engineering effort.