Texas Instruments CD40147BM96G4

Overview

CD40147BM96G4 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 buffered TTL-compatible outputs (driving one LSTTL load), and outputs all-high (VSS) when no input is asserted. Used in keyboard scanning, fault detection, and digital control panels where priority resolution of decimal inputs is required.

For engineers reviewing the CD40147BM96G4 datasheet, CD40147BM96G4 pinout, CD40147BM96G4 application, or CD40147BM96G4 equivalent, key selection considerations include its priority encoding behavior, active-low BCD output logic, SOIC-16 package compatibility, −55°C to +125°C operating range, and functional equivalence to TTL 74147 with pin 15 grounded.

Technical Context

The CD40147BM96G4 implements combinational priority encoding using CMOS logic, resolving ten asynchronous input lines (I0–I9) into four active-low BCD outputs (Y3–Y0). Input priority is fixed: I9 > I8 > … > I0, ensuring only the highest-active input determines output state.

Its output stage uses buffered CMOS drivers capable of sourcing/sinking sufficient current for direct interfacing with LSTTL loads. The device requires no external clock or enable control - operation is purely combinatorial and level-sensitive, with propagation delays specified at typical VDD = 5 V and 10 V.

Key Specifications

Pinout & Package

CD40147BM96G4 is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package, designated as SOIC-D (package code D), with 1.27 mm pitch, gull-wing leads, and JEDEC-standard dimensions (507 mm × 8 mm × 3.94 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD40147BE and 74HC147, CD40147BM96G4 uniquely combines SOIC-16 surface-mount packaging, −55°C to +125°C qualification, and 3–18 V operation - making it optimal for ruggedized, mixed-voltage, production-ready embedded systems requiring long-term component availability.

Availability

CD40147BM96G4 is available at Aetrix Electronics and suitable for industrial control panels, automotive diagnostic interfaces, and legacy system upgrades requiring stable component supply, long-lifecycle support, and guaranteed SOIC-16 packaging.

Supply support for CD40147BM96G4 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 decades of expertise in high-reliability CMOS logic families.

The CD40147BM96G4 belongs to TI's CD4000B series of radiation-tolerant, wide-supply CMOS logic devices, designed specifically for industrial, aerospace, and automotive applications demanding robustness across extreme temperatures and voltage variations.

FAQ

What is the function of pin 15 on the CD40147BM96G4?

Pin 15 on the CD40147BM96G4 is a no-connect (NC) terminal per the official TI datasheet. However, TI notes that the device is functionally similar to TTL 74147 only when pin 15 is tied low. For compatibility with 74147-based designs, grounding pin 15 is recommended; otherwise, it must remain unconnected to avoid unintended behavior. The CD40147BM96G4 itself does not require pin 15 to be driven.

Does the CD40147BM96G4 support active-high BCD outputs?

No, the CD40147BM96G4 provides only active-low BCD outputs (Y3–Y0). All four output lines assert logic low for active bits and logic high (VDD) when inactive. This matches the behavior of the TTL 74147 and simplifies interface with common cathode displays or LSTTL inputs. Active-high BCD output is not supported natively by the CD40147BM96G4 and would require external inverters.

What is the maximum propagation delay of the CD40147BM96G4 at 5 V supply?

At VDD = 5 V and TA = 25°C, the maximum propagation delay for the CD40147BM96G4 is 120 ns (typical 60 ns), measured from input transition to valid output transition. This value is specified in the TI SCHS102C datasheet across the full operating temperature range and accounts for worst-case process, voltage, and temperature corners - ensuring reliable timing margin in synchronous digital control logic using the CD40147BM96G4.

Can the CD40147BM96G4 operate with a 3.3 V supply?

Yes, the CD40147BM96G4 is fully specified to operate at VDD = 3 V, with guaranteed functionality across the full −55°C to +125°C temperature range. At 3.3 V, output drive strength and propagation delay degrade slightly versus 5 V or 10 V operation, but all logic thresholds and encoding behavior remain valid. This makes the CD40147BM96G4 suitable for mixed-voltage systems where 3.3 V logic coexists with legacy 5 V or 15 V rails.

Is the CD40147BM96G4 pin-compatible with the 74147 TTL encoder?

The CD40147BM96G4 shares identical pin assignments with the 74147 for all functional signals (I0–I9, Y0–Y3, VDD, VSS), but pin 15 is NC on CD40147BM96G4 whereas it is unused but bonded in some 74147 variants. TI states functional similarity when pin 15 is grounded - however, true pin-to-pin drop-in replacement requires verifying board layout for pin 15 handling. The CD40147BM96G4 is not a guaranteed mechanical or electrical drop-in without validation.