CD4543BM LCD Driver 7-Segment 1-Digit 16-SOIC Equivalent & Substitute Parts

Part Overview

The CD4543BM is a discontinued LCD driver integrated circuit manufactured by Texas Instruments, designed to drive 7-segment single-digit displays using BCD (Binary-Coded Decimal) interface. The device operates across a wide supply voltage range of 3V to 18V with minimal supply current of 40 nA, making it suitable for low-power display applications. Due to its discontinued status at DiGi Electronics, identifying functionally equivalent substitute parts is necessary for ongoing design support, production continuity, and component sourcing flexibility.

Substiute Parts

CD4543BM

Texas InstrumentsIn Stock: 1185CD4543BM Datasheet

Current PartRFQ

CD4543BM96

Texas InstrumentsIn Stock: 35461CD4543BM96 Datasheet

DirectRFQ

MC14543BDG

onsemiIn Stock: 1385MC14543BDG Datasheet

DirectRFQ

HEF4543BT,653

Nexperia USA Inc.In Stock: 2921HEF4543BT,653 Datasheet

MFR RecommendedRFQ

ICM7211AMIPLZ

Renesas Electronics CorporationIn Stock: 2235ICM7211AMIPLZ Datasheet

MFR RecommendedRFQ

MC14543BDR2G

onsemiIn Stock: 53140MC14543BDR2G Datasheet

MFR RecommendedRFQ

NLV14543BDR2G

onsemiIn Stock: 3714NLV14543BDR2G Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the CD4543BM is determined by strict alignment with the following critical parameters:

Primary Substitution Criteria:

• Display Type: LCD (required match)
• Configuration: 7 Segment (required match)
• Interface: BCD (required match)
• Package / Case: 16-SOIC form factor (required match for direct PCB compatibility)
• Mounting Type: Surface Mount (required match)
• Voltage - Supply: 3V ~ 18V range (required match or compatible overlap)
• Operating Temperature: -55°C ~ 125°C (required match or compatible range)

Substitute Categories:

Direct Equivalents (Same Package, Same Digit Count): Parts meeting all primary criteria with identical 1-digit configuration and 16-SOIC packaging enable direct board-level substitution without layout modification.

Functional Equivalents (Same Package, Different Supply Current): Parts with matching package, display type, configuration, and interface but differing supply current specifications remain functionally compatible for BCD-driven 7-segment LCD applications.

Manufacturer Variants (Different Package): Parts with matching electrical function but different package types (such as 40-DIP) require PCB redesign and are not recommended for direct substitution in existing designs.

Parameter Comparison

Engineering Selection Recommendations

Recommended Direct Substitutes (16-SOIC Package, No PCB Modification Required):

CD4543BM96 (Texas Instruments) is the primary recommended substitute. It maintains identical electrical specifications, package form factor, and operating parameters as the original CD4543BM. The part is currently in active production status with substantial inventory availability (35,400 units), ensuring long-term supply continuity. Both parts share the same base product number (CD4543) and are ROHS3 compliant with MSL 1 rating.

MC14543BDR2G (onsemi) and MC14543BDG (onsemi) are functionally compatible alternatives. Both maintain the 16-SOIC package, BCD interface, 7-segment LCD configuration, and full -55°C to 125°C operating temperature range. Supply current specification differs (10 µA versus 40 nA), but this represents lower power consumption and does not affect functional compatibility. Both parts are in active production with strong inventory levels.

NLV14543BDR2G (onsemi) is compatible for 16-SOIC package-constrained designs. It maintains the 3V to 18V supply voltage range and -55°C to 125°C operating temperature specification. Limited parameter documentation does not preclude functional equivalence for BCD-driven 7-segment LCD applications.

Conditional Substitutes (Voltage or Temperature Limitations):

HEF4543BT,653 (Nexperia USA Inc.) is compatible for applications within its specified operating envelope. The part supports 7-segment BCD-driven LCD operation in the 16-SOIC package. However, the supply voltage range is limited to 3V to 15V (versus 3V to 18V for CD4543BM) and operating temperature range is restricted to -40°C to 85°C (versus -55°C to 125°C). Use this part only when application requirements fall within these narrower specifications.

Not Recommended for Direct Substitution:

ICM7211AMIPLZ (Renesas Electronics Corporation) is not suitable for direct substitution. Although it provides 7-segment BCD-driven LCD functionality, it is packaged in 40-DIP through-hole format rather than 16-SOIC surface mount. This package incompatibility requires complete PCB redesign. Additionally, the 4-digit configuration and 3V to 6V supply voltage range differ from the 1-digit, 3V to 18V specification of the CD4543BM.

Compliance and Certification:

All recommended substitute parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating, ensuring compatibility with standard manufacturing and storage protocols. REACH status is unaffected across all alternatives.

Frequently Asked Questions (FAQ)

Q: Can CD4543BM96 be used as a direct replacement for CD4543BM without any circuit modifications?

A: Yes. CD4543BM96 is a direct substitute with identical electrical specifications, package form factor, and pin configuration. No circuit modifications are required. Both parts share the same base product number and are functionally interchangeable.

Q: What is the difference between MC14543BDR2G and MC14543BDG?

A: Both parts are functionally identical onsemi LCD drivers with 7-segment BCD interface in 16-SOIC packaging. The primary difference is packaging format: MC14543BDR2G is supplied on Tape & Reel (TR), while MC14543BDG is supplied in Tube format. Electrical specifications and performance are equivalent.

Q: Why is HEF4543BT,653 not recommended as a primary substitute?

A: HEF4543BT,653 has restricted operating specifications compared to CD4543BM. The supply voltage range is limited to 3V to 15V (CD4543BM supports 3V to 18V), and the operating temperature range is -40°C to 85°C (CD4543BM supports -55°C to 125°C). Use this part only if your application operates within these narrower limits.

Q: Can ICM7211AMIPLZ replace CD4543BM in an existing PCB design?

A: No. ICM7211AMIPLZ requires PCB redesign due to package incompatibility (40-DIP through-hole versus 16-SOIC surface mount). Additionally, it is a 4-digit driver, not a 1-digit driver, and has a restricted supply voltage range of 3V to 6V. It is not suitable for direct substitution.

Q: What does BCD interface mean in the context of these LCD drivers?

A: BCD (Binary-Coded Decimal) interface means the driver accepts 4-bit binary input signals that represent decimal digits 0-9. The driver decodes these BCD inputs and generates the appropriate 7-segment display outputs to show the corresponding digit on the LCD.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All recommended substitute parts (CD4543BM96, MC14543BDR2G, MC14543BDG, NLV14543BDR2G, and HEF4543BT,653) are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity rating, meeting standard environmental and manufacturing requirements.

Q: What is the significance of the 40 nA supply current specification?

A: The 40 nA supply current indicates extremely low quiescent power consumption, making the CD4543BM suitable for battery-powered or low-power applications. Some substitutes (such as MC14543BDR2G) specify 10 µA supply current, which is higher but still represents low power consumption and does not affect functional compatibility for most applications.

Q: Can I use NLV14543BDR2G if detailed specifications are not fully documented?

A: NLV14543BDR2G maintains the critical parameters for 7-segment BCD-driven LCD operation: 16-SOIC package, 3V to 18V supply voltage range, and -55°C to 125°C operating temperature. Limited parameter documentation does not preclude functional equivalence. Verify with the manufacturer or distributor if application-specific requirements demand complete specification confirmation.