TLC551CP Equivalent & Substitute Parts

Part Overview

The TLC551CP is a 555-type timer/oscillator IC manufactured by Texas Instruments, designed for single-channel timing and oscillation applications. This through-hole 8-DIP package component operates at 1.8MHz with a supply voltage range of 1V to 15V and is currently in Last Time Buy status. Due to its end-of-life designation, identifying functionally compatible substitute parts is essential for design continuity and procurement planning. Equivalent alternatives are available in both through-hole and surface-mount configurations from multiple manufacturers.

Substiute Parts

TLC551CP

Texas InstrumentsIn Stock: 2366TLC551CP Datasheet

Current PartRFQ

TLC556CDR

Texas InstrumentsIn Stock: 32720TLC556CDR Datasheet

MFR RecommendedRFQ

ICM7555IPA+

Analog Devices Inc./Maxim IntegratedIn Stock: 1191ICM7555IPA+ Datasheet

MFR RecommendedRFQ

ICM7555IPAZ

Renesas Electronics CorporationIn Stock: 28143ICM7555IPAZ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the TLC551CP is determined by the following critical parameters:

Functional Compatibility Criteria:

• IC Type: 555-type timer/oscillator architecture
• Channel Configuration: Single-channel operation
• Frequency Range: Minimum 500kHz to 2.1MHz operational capability
• Supply Voltage Overlap: Minimum 2V to 15V common range
• Operating Temperature: Overlap within specified range
• Package Compatibility: 8-DIP through-hole form factor for direct pin-compatible replacement

Regulatory & Compliance Criteria:

• RoHS3 Compliance: All substitutes must meet ROHS3 requirements
• REACH Status: REACH Unaffected classification maintained

The substitute parts listed below meet these criteria and are classified into two categories: pin-compatible through-hole replacements and functionally equivalent alternatives with different package types.

Parameter Comparison

Engineering Selection Recommendations

Pin-Compatible Through-Hole Replacements (Direct Socket Substitutes):

ICM7555IPAZ and ICM7555IPA+ are both 8-DIP through-hole packages with identical pinouts to the TLC551CP. These parts support the full supply voltage range overlap (2V ~ 15V) required for compatibility. ICM7555IPAZ, manufactured by Renesas Electronics, operates at 1MHz with extended temperature range (-25°C ~ 85°C) and lower supply current (60 µA). ICM7555IPA+, from Analog Devices Inc./Maxim Integrated, operates at 500kHz with the lowest supply current specification (30 µA) and extended temperature range (-20°C ~ 85°C). Both parts maintain ROHS3 compliance and active product status.

Functionally Equivalent Alternative (Different Package):

TLC556CDR is a dual-channel 555-type timer/oscillator in 14-SOIC surface-mount package. While not a direct pin-compatible replacement, it provides equivalent functional capability at 2.1MHz with active product status and ROHS3 compliance. This part is suitable for new designs or PCB redesigns that accommodate surface-mount technology. The dual-channel configuration provides additional functionality beyond the single-channel TLC551CP requirement.

Selection Basis:

All substitute parts are classified as Active products with current manufacturing status, ensuring long-term availability. All parts maintain ROHS3 compliance and REACH Unaffected status, meeting regulatory requirements equivalent to the original TLC551CP. Selection between through-hole and surface-mount alternatives depends on existing PCB design constraints and manufacturing capabilities.

Frequently Asked Questions (FAQ)

Q: Can ICM7555IPAZ or ICM7555IPA+ be used as direct replacements for TLC551CP in existing designs?

A: Yes. Both ICM7555IPAZ and ICM7555IPA+ are pin-compatible 8-DIP through-hole packages with identical pinouts to TLC551CP. They support the required supply voltage range (2V ~ 15V) and can be inserted directly into existing sockets without PCB modification. Frequency differences (1MHz and 500kHz respectively, versus 1.8MHz) must be evaluated against specific application timing requirements.

Q: What is the primary difference between ICM7555IPAZ and ICM7555IPA+?

A: Both are single-channel 555-type timers in 8-DIP packages. ICM7555IPAZ operates at 1MHz with 60 µA supply current and -25°C ~ 85°C temperature range. ICM7555IPA+ operates at 500kHz with 30 µA supply current and -20°C ~ 85°C temperature range. ICM7555IPA+ has lower power consumption; ICM7555IPAZ has lower minimum operating temperature.

Q: Why is TLC556CDR listed as a substitute if it has a different package?

A: TLC556CDR is functionally equivalent as a 555-type timer/oscillator but requires PCB redesign due to its 14-SOIC surface-mount package versus the 8-DIP through-hole package of TLC551CP. It is suitable for new designs or redesigns where surface-mount technology is preferred. The dual-channel configuration provides additional capability.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. ICM7555IPAZ, ICM7555IPA+, and TLC556CDR are all ROHS3 compliant with REACH Unaffected status, matching the regulatory compliance of TLC551CP.

Q: What is the supply current difference between TLC551CP and the substitute parts?

A: TLC551CP specifies 360 µA supply current. ICM7555IPAZ specifies 60 µA, ICM7555IPA+ specifies 30 µA, and TLC556CDR specifies 720 µA. Lower supply current in ICM7555 variants may reduce power consumption in battery-powered applications. Higher current in TLC556CDR reflects dual-channel operation.

Q: Can frequency differences affect circuit operation?

A: Yes. Frequency specifications determine oscillation and timing characteristics. TLC551CP operates at 1.8MHz, while ICM7555IPAZ operates at 1MHz and ICM7555IPA+ at 500kHz. Applications with frequency-dependent timing requirements must verify that substitute part frequency specifications meet design specifications before implementation.