Texas Instruments CD4585BPWG4

Overview

CD4585BPWG4 from Texas Instruments is a CMOS 4-bit magnitude comparator IC used for digital logic-level signal comparison in combinational logic systems. It features A>B, A=B, and A<B outputs, operates over -55°C to +125°C, supports supply voltages from 3 V to 18 V, and delivers propagation delays of 140 ns (max) at 5 V. It is commonly deployed in address decoding, arithmetic unit control, and priority encoding circuits.

For engineers reviewing the CD4585BPWG4 datasheet, CD4585BPWG4 pinout, CD4585BPWG4 application, or CD4585BPWG4 equivalent, key selection considerations include its wide V_DD range, TTL/CMOS compatibility, dual-supply tolerance, and TSSOP-16 packaging optimized for high-density PCB layouts.

Technical Context

The CD4585BPWG4 implements fully static CMOS logic with no internal latches or clocks, enabling asynchronous comparison of two 4-bit binary words (A3–A0 and B3–B0). Its three mutually exclusive outputs are asserted simultaneously upon input stabilization, with no internal feedback or state retention.

All inputs are buffered with Schmitt-trigger action on enable pins (A<B IN, A=B IN, A>B IN), ensuring noise immunity during cascading. The device supports multi-stage comparison via cascaded inputs - A<B IN, A=B IN, and A>B IN accept results from a less-significant comparator stage to generate hierarchical magnitude decisions.

Key Specifications

Pinout & Package

TSSOP-16 package (PW suffix), 4.4 mm × 5.0 mm body, 1.2 mm max height, 0.65 mm lead pitch, exposed pad not present, RoHS-compliant NiPdAu lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit magnitude comparator applications.

Compared with CD4063BE and 74HC85PW, the CD4585BPWG4 uniquely combines extended temperature operation, wide supply tolerance, and integrated cascade inputs-making it the only option qualified for fault-tolerant industrial control and legacy 15 V logic integration without redesign.

Availability

CD4585BPWG4 is available at Aetrix Electronics and suitable for industrial automation, aerospace avionics, and legacy military system upgrades requiring stable component supply across long production lifecycles.

Supply support for CD4585BPWG4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions with emphasis on reliability, longevity, and industrial-grade qualification.

The CD4585B series belongs to TI's legacy CMOS logic portfolio, designed specifically for robust, wide-voltage, extended-temperature digital interfacing in mission-critical systems where modern alternatives lack qualification or supply stability.

FAQ

What is the maximum supply voltage rating for the CD4585BPWG4?

The CD4585BPWG4 supports a maximum supply voltage of 18 V DC, verified per the official Texas Instruments datasheet SCHS091B. This rating applies across the full operating temperature range (-55°C to +125°C) and enables direct use in 12 V and 15 V industrial logic systems without voltage regulation. Exceeding 18 V risks permanent damage to the internal CMOS structure of the CD4585BPWG4.

Does the CD4585BPWG4 require external pull-up resistors on its outputs?

The CD4585BPWG4 outputs (A>B OUT, A=B OUT, A<B OUT) are push-pull CMOS, not open-drain - no external pull-ups are required. Each output actively drives high or low depending on comparison result, with typical VOH = V_DD – 0.1 V and VOL = 0.1 V at I_O = ±4.2 mA. This simplifies interface design and ensures clean logic levels when driving other CMOS or TTL inputs directly.

Can the CD4585BPWG4 be used to compare signed 4-bit numbers?

The CD4585BPWG4 performs unsigned binary magnitude comparison only. To compare signed two's-complement values, external logic must preprocess the MSB (sign bit) and route operands accordingly - for example, inverting A3/B3 and swapping A/B inputs when signs differ. The CD4585BPWG4 itself does not interpret sign bits or perform arithmetic; its function is strictly bitwise unsigned comparison.

Is the CD4585BPWG4 pin-compatible with the CD4585BE in PDIP-16?

Yes - the CD4585BPWG4 (TSSOP-16) and CD4585BE (PDIP-16) share identical pin numbering, signal assignment, and electrical functionality. Both follow the standard 16-pin dual-in-line/SOIC/TSSOP pinout for CD4585B devices. However, PCB layout and thermal management differ significantly due to package geometry and soldering requirements for the CD4585BPWG4.

What is the purpose of the A<B IN, A=B IN, and A>B IN pins on the CD4585BPWG4?

These three cascade inputs allow the CD4585BPWG4 to participate in multi-bit comparisons beyond 4 bits. When cascading two devices, the outputs of a lower-order comparator feed into these inputs to determine overall magnitude - for example, if lower nibbles are equal (A=B IN high), the higher nibble comparison determines final result. This eliminates need for external logic and preserves timing integrity in the CD4585BPWG4-based system.