Texas Instruments CD40147BEE4

Overview

CD40147BEE4 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 highest priority assigned to input line 9; operates over –55°C to +125°C; features TTL-compatible output drive capability; used in keyboard encoding and interrupt prioritization circuits.

For engineers reviewing the CD40147BEE4 datasheet, CD40147BEE4 pinout, CD40147BEE4 application, or CD40147BEE4 equivalent, this page delivers verified functional identity, confirmed PDIP-16 package mapping, validated priority encoding behavior, BCD output polarity, and direct TTL interface compatibility - all grounded in TI's official SCHS102C datasheet and packaging addendum.

Technical Context

The CD40147BEE4 implements a fixed-priority logic architecture where input line 9 dominates all lower-numbered lines (8 through 0); encoding occurs asynchronously with no clock required. All ten inputs are active-high, and all four BCD outputs are active-low open-drain equivalents buffered for TTL interfacing.

It functions as a combinatorial logic device with no internal latching or state retention; output states settle within typical propagation delays of 120 ns at 5 V supply. Input thresholds follow standard CMOS voltage levels (V_IL ≤ 1.5 V, V_IH ≥ 3.5 V at V_DD = 5 V), and outputs sink ≥ 4.2 mA per line under specified conditions.

Key Specifications

Pinout & Package

CD40147BEE4 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.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD40147BM and 74HC147, the CD40147BEE4 provides the widest operating voltage (3–18 V) and full military-grade temperature support in a through-hole PDIP package - making it optimal for ruggedized, field-deployable, or legacy-replacement designs where layout change is prohibited.

Availability

CD40147BEE4 is available at Aetrix Electronics and suitable for industrial HMI panels, legacy test equipment upgrades, embedded interrupt management subsystems, and BCD-based display interfaces requiring stable component supply across long product lifecycles.

Supply support for CD40147BEE4 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 ICs, with decades of heritage in CMOS logic innovation and industrial reliability.

The CD40147BEE4 belongs to TI's CD4000B series of radiation-tolerant, wide-supply CMOS logic devices - engineered for robust operation in harsh environments including aerospace, energy infrastructure, and factory automation.

FAQ

What is the logic polarity of CD40147BEE4 inputs and outputs?

The CD40147BEE4 features active-high inputs (I0–I9) and active-low BCD outputs (O8, O4, O2, O1). When no input is asserted, all outputs remain high (logic 1). Input I9 has highest priority and forces output 1001 (active-low = 0110). This polarity allows direct connection to common-cathode displays and simplifies interface with TTL logic families.

Is CD40147BEE4 pin-compatible with the TTL 74147?

The CD40147BEE4 is functionally similar to the 74147 but requires pin 15 (O8) to be tied low for full compatibility, as noted in TI's SCHS102C datasheet. While pin count and assignment match, electrical characteristics differ: CD40147BEE4 uses CMOS thresholds and wider supply range (3–18 V), whereas 74147 is strictly 5 V TTL. Direct substitution may require level-shifting or pull-down adjustment.

What is the maximum propagation delay of CD40147BEE4 at 5 V?

Per TI's SCHS102C datasheet, the typical propagation delay (t_PD) for CD40147BEE4 is 120 ns at V_DD = 5 V and 25°C. Maximum delay is 300 ns under worst-case conditions (–55°C, V_DD = 3 V). These values reflect worst-case combinatorial path from any input to any output, confirming suitability for sub-3 MHz encoding applications.

Does CD40147BEE4 require a clock signal to operate?

No, the CD40147BEE4 is a purely combinatorial logic device with no internal clock or memory elements. Encoding occurs asynchronously upon input state change. There is no setup/hold time requirement or clock domain dependency - making it ideal for event-driven systems like keyboard scanning or fault prioritization where deterministic latency matters.

Can CD40147BEE4 drive LEDs directly?

The CD40147BEE4 outputs are buffered CMOS with TTL-compatible sink current (≥ 4.2 mA at V_DD = 5 V), sufficient to drive low-current LEDs (e.g., 2 mA @ 1.8 V forward voltage) with appropriate series resistors. However, for higher-brightness or multiplexed displays, a dedicated driver stage (e.g., ULN2003) is recommended to maintain output voltage margin and longevity.