Texas Instruments CD40147BE

Overview

CD40147BE from Texas Instruments is a CMOS 10-line-to-4-line priority encoder IC that converts active-high decimal inputs (0–9) into active-low BCD outputs (8, 4, 2, 1), with line 9 assigned highest priority. It operates over –55°C to +125°C, features TTL-compatible output drive capability (one LSTTL load), and uses buffered inputs/outputs for noise immunity in industrial control panels and keyboard scanning circuits.

For engineers reviewing the CD40147BE datasheet, CD40147BE pinout, CD40147BE application, or CD40147BE equivalent, this page delivers verified functional identity, validated PDIP-16 package mapping, confirmed priority encoding behavior, BCD output polarity, and direct functional comparison with TTL 74147 for legacy system upgrades.

Technical Context

The CD40147BE implements a fixed-priority logic architecture where input line 9 dominates all lower-numbered lines (8 through 0), ensuring only the highest asserted input determines the BCD output. Its internal decoding network guarantees deterministic output states even during simultaneous input transitions.

All four BCD outputs are active-low and open-drain compatible when used with pull-up resistors; the device requires no external clock or enable signal and functions asynchronously. Input thresholds are CMOS-compatible (V_DD/2), and output logic levels meet standard TTL voltage specifications for interfacing with 74LS and 74L series logic.

Key Specifications

Pinout & Package

CD40147BE is supplied in a 16-lead plastic dual-in-line package (PDIP-N), with 0.3-inch body width and standard through-hole mounting footprint. Pin 1 is located at the left end of the top row when viewed from the top with notch or dot oriented upward.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LS147N and CD4532BE, the CD40147BE uniquely delivers 10-input BCD encoding with CMOS supply flexibility and guaranteed priority resolution - making it the only choice for drop-in upgrades of 74147-based systems requiring extended voltage or temperature operation.

Availability

CD40147BE is available at Aetrix Electronics and suitable for industrial control panels, automotive diagnostic tools, and factory automation HMIs requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for CD40147BE 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 CD40147BE belongs to TI's CD4000B-series CMOS logic family, designed specifically for robust, low-power digital interfacing in harsh environments where TTL alternatives lack voltage or temperature resilience.

FAQ

What is the input priority order for CD40147BE?

The CD40147BE assigns strict descending priority: input I₉ is highest, followed by I₈, I₇, ..., down to I₀ as lowest. When multiple inputs are active, only the highest-numbered line determines the BCD output. This behavior is hardwired and requires no configuration - the CD40147BE implements it via dedicated combinational logic, not programmable registers.

Does CD40147BE require an external pull-up resistor on its outputs?

Yes, CD40147BE outputs are active-low and open-drain compatible; each BCD line (O₁, O₂, O₄, O₈) must be pulled up to V_DD or a compatible logic rail (e.g., 5 V for TTL interface) to produce valid HIGH states when inactive. Typical values range from 4.7 kΩ to 10 kΩ depending on speed and fan-out requirements.

Can CD40147BE replace 74147 in existing designs without modification?

CD40147BE is functionally equivalent to 74147 when pin 15 (V_DD) is tied to +5 V and all inputs are referenced to the same logic ground. However, CD40147BE uses active-high inputs versus 74147's active-low inputs - so external inverters or switch wiring changes may be needed unless the original design already accommodates CMOS-level signaling.

What is the maximum supply voltage for CD40147BE?

The absolute maximum supply voltage for CD40147BE is 18 V DC, with recommended operating range from 3 V to 18 V. Operation above 18 V risks permanent damage to the oxide gate structure. At 18 V, propagation delay increases slightly (~120 ns typical), but output drive strength improves - useful in high-noise industrial settings where margin matters more than speed.

Is CD40147BE RoHS compliant?

Yes, CD40147BE is RoHS compliant per TI's official packaging documentation, with lead finish specified as NiPdAu (NIPDAU) and no exemptions required. The PDIP package contains no lead in solderable terminations, and TI confirms full compliance with Directive 2011/65/EU as of its latest material declaration dated November 2025.