Texas Instruments CD40147BM96E4

Overview

CD40147BM96E4 from Texas Instruments is a CMOS priority encoder IC that converts ten active-low decimal inputs (0–9) into a four-bit active-low BCD output (8, 4, 2, 1), with input line 9 assigned highest priority. It operates over –55°C to +125°C, features buffered I/O, and drives one TTL low-power Schottky load per output. Used in keyboard encoding and digital control panels where single-line dominance resolution is required.

For engineers reviewing the CD40147BM96E4 datasheet, CD40147BM96E4 pinout, CD40147BM96E4 application, or CD40147BM96E4 equivalent, key selection considerations include priority encoding behavior, active-low BCD output logic, SOIC-16 packaging, wide temperature range, and TTL-load drive capability in legacy industrial control interfaces.

Technical Context

The CD40147BM96E4 implements combinational priority encoding logic with fixed hierarchy: input 9 > 8 > … > 0. Its outputs are active-low and remain high (logic 1 = VSS) only when all inputs are inactive (logic 0). No internal latching or clocking is present - operation is purely asynchronous and level-sensitive.

All inputs and outputs are CMOS-buffered for noise immunity and fanout control. The device is functionally compatible with TTL 74147 when pin 15 (VDD) is tied low, enabling mixed-technology system integration while maintaining CMOS power advantages.

Key Specifications

Pinout & Package

CD40147BM96E4 is housed in a 16-pin small-outline integrated circuit (SOIC) package, 3.9 mm body width, 1.75 mm height, with 1.27 mm lead pitch and gull-wing terminations. RoHS-compliant NIPDAU finish, MSL Level-1, no moisture sensitivity restrictions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar priority encoder applications.

Compared with CD40147BE and 74HC147, the CD40147BM96E4 offers optimal balance of SOIC manufacturability, guaranteed active-low BCD output, and direct 74147 functional equivalence - making it preferred for space-constrained industrial upgrades requiring minimal redesign.

Availability

CD40147BM96E4 is available at Aetrix Electronics and suitable for industrial control panels, automotive diagnostic tools, and legacy system upgrade projects requiring stable component supply and long-term obsolescence management.

Supply support for CD40147BM96E4 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 CD40147BM96E4 belongs to TI's legacy CMOS logic portfolio, designed specifically for robust, low-power encoding in harsh-environment digital systems where reliability and pin-for-pin compatibility with industry-standard TTL encoders are critical.

FAQ

What is the logic polarity of inputs and outputs on the CD40147BM96E4?

The CD40147BM96E4 features active-low inputs (I0–I9) and active-low BCD outputs (O8, O4, O2, O1). When no input is asserted (all high), all outputs default to logic 1 (VSS). This polarity matches TTL 74147 behavior and enables direct connection to common cathode displays or open-collector drivers without inversion.

Does the CD40147BM96E4 require an external clock or enable signal?

No, the CD40147BM96E4 is a purely combinational logic device with no clock, latch, or enable inputs. Its outputs respond asynchronously to input state changes. This eliminates timing constraints and makes the CD40147BM96E4 ideal for simple, deterministic encoding tasks in real-time control paths.

Can the CD40147BM96E4 directly replace a 74147 in an existing design?

Yes - the CD40147BM96E4 is functionally equivalent to the 74147 when VDD is tied to logic high and pin 15 (VDD) is held low per datasheet guidance. Pinout is identical in SOIC-16, and active-low BCD output behavior matches exactly. No PCB changes are needed beyond verifying supply voltage compatibility (3–18 V vs. 5 V only for TTL).

What is the maximum fanout capability of the CD40147BM96E4 outputs?

Each output of the CD40147BM96E4 can drive one TTL low-power Schottky (LPS) load - defined as 0.4 mA sink / 0.02 mA source at VDD = 5 V. At higher supply voltages (e.g., 12 V), output drive strength increases proportionally, supporting direct interface to multiple LSTTL inputs or discrete transistor switches without buffering.

Is the CD40147BM96E4 rated for automotive temperature ranges?

Yes - the CD40147BM96E4 is specified for operation from –55°C to +125°C, exceeding the AEC-Q100 Grade 3 (–40°C to +125°C) requirement. Its SOIC package and CMOS process ensure stable performance across thermal cycling, making the CD40147BM96E4 suitable for under-hood and chassis-mounted automotive diagnostic modules.