Texas Instruments CD4503BM

Overview

CD4503BM from Texas Instruments is a hex noninverting buffer IC with 3-state outputs, high sink- and source-current capability (±24 mA at V_DD = 15 V), dual independent output-enable controls (OE1 for buffers A–D, OE2 for E–F), and operates across -55°C to +125°C. It serves as a level-shifting bus interface in mixed-voltage digital systems requiring bidirectional signal buffering with low propagation delay (120 ns max at 15 V).

For engineers reviewing the CD4503BM datasheet, CD4503BM pinout, CD4503BM application, or CD4503BM equivalent, this page delivers verified functional identity, SOIC-16 package mapping, dual-OE architecture details, absolute maximum ratings, and validated alternatives for legacy 4000B-series logic upgrades and industrial control backplane designs.

Technical Context

The CD4503BM implements six independent CMOS noninverting buffers, each with three-state output control via two shared enable inputs-OE1 (pins 1 & 2) enables buffers Y1–Y4, while OE2 (pin 15) enables Y5–Y6. All outputs are fully buffered and capable of driving TTL loads directly.

It belongs to the CD4000B family and supports wide-supply operation (3 V to 18 V), exhibits rail-to-rail output swing, and maintains logic-level compatibility across supply domains-enabling use as a unidirectional voltage translator between 5 V and 15 V logic subsystems without external level-shifters.

Key Specifications

Pinout & Package

CD4503BM is supplied in a 16-pin SOIC (Small Outline Integrated Circuit) package per TI drawing D, with 1.27 mm pitch, 10.4 mm × 5.4 mm body size, and 2.00 mm max height. Pin 1 is located at the top-left corner with a beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar hex noninverting buffer applications.

Compared with CD4503BM, CD4503BNSR offers identical functionality in a physically larger SOP package with higher thermal resistance, while MC14503BDR2G provides a second-source alternative with identical pinout and performance but stricter moisture sensitivity handling requirements.

Availability

CD4503BM is available at Aetrix Electronics and suitable for industrial control backplanes, legacy system upgrades, and mixed-voltage sensor interface designs requiring stable component supply over extended product lifecycles.

Supply support for CD4503BM includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of industrial-grade component development.

The CD4503BM belongs to TI's CD4000B logic family, designed for high-reliability, wide-temperature, and multi-voltage digital interfacing in mission-critical industrial and aerospace systems.

FAQ

What is the maximum supply voltage rating for CD4503BM?

The CD4503BM supports an absolute maximum supply voltage of 18 V DC applied between V_DD and V_SS. Operation beyond this limit risks permanent damage to internal oxide layers. The recommended operating range remains 3 V to 18 V, with optimal noise immunity and timing performance observed between 5 V and 15 V. Always observe derating guidelines for extended-temperature operation above 85°C.

Does CD4503BM support true bidirectional signal flow?

No, CD4503BM is a unidirectional hex noninverting buffer - signals flow strictly from inputs A–F to outputs Y1–Y6. It does not contain internal direction-control circuitry or bus-switch architecture. However, its dual 3-state enable inputs (OE1 and OE2) allow coordinated tri-state control of subsets of outputs, enabling time-multiplexed use in half-duplex bus architectures when paired with complementary receivers.

Is CD4503BM RoHS compliant and lead-free?

Yes, CD4503BM is RoHS compliant with lead finish NIPDAU (Nickel/Palladium/Gold) and conforms to JEDEC J-STD-020 Level-1 moisture sensitivity classification. The "M" suffix denotes SOIC packaging, and the ".A" in CD4503BM96.A indicates tape-and-reel packaging with RoHS-compliant materials and marking. No lead content is present in die attach, bond wires, or terminations.

Can CD4503BM replace CD4050BE in existing designs?

CD4503BM is not a direct replacement for CD4050BE due to fundamental architectural differences: CD4050BE is a noninverting buffer with no 3-state outputs or dual enable controls, while CD4503BM adds 3-state capability and split enable logic. Substitution requires verification of OE signal routing, timing margins, and load capacitance - especially since CD4503BM's propagation delay (120 ns) differs from CD4050BE's typical 80 ns at 15 V.

What is the thermal resistance (θ_JA) of CD4503BM in SOIC-16 package?

The junction-to-ambient thermal resistance (θ_JA) for CD4503BM in the SOIC-16 (D) package is 120°C/W under standard JEDEC test conditions (1-inch² copper pad, 1 oz Cu). This value assumes no additional heatsinking or airflow. For continuous operation at maximum rated current and ambient temperature, PCB layout must include adequate copper pour and thermal vias beneath the exposed pad area (if applicable) - though the SOIC-16 D package has no exposed thermal pad.