Texas Instruments CD4047BEG4

Overview

CD4047BEG4 from Texas Instruments is a CMOS retriggerable monostable multivibrator and astable multivibrator IC with built-in oscillator, operating from 3 V to 18 V supply, delivering ±4.5 mA output drive at 10 V, and supporting temperature range of –55°C to +125°C in a 14-lead PDIP package. It serves as a timing generator in power-on reset circuits, LED flashers, and pulse-width modulators.

For engineers reviewing the CD4047BEG4 datasheet, CD4047BEG4 pinout, CD4047BEG4 application, or CD4047BEG4 equivalent, key selection criteria include its dual-mode (astable/monostable) operation, TTL/CMOS compatibility, low quiescent current (≤20 µA at 5 V), and direct enable/disable control via the E input.

Technical Context

The CD4047BEG4 integrates a Schmitt-trigger-based astable oscillator and a retriggerable monostable multivibrator in a single chip, sharing common timing components (R and C). Its internal logic supports both free-running (astable) and triggered (monostable) modes selected by the MODE pin, with independent reset (R) and enable (E) inputs for precise timing control.

It features complementary Q and Q̅ outputs, a buffered oscillator output (OSC), and operates across the full military-grade temperature range (–55°C to +125°C) with guaranteed performance at 5 V, 10 V, and 15 V supply voltages - validated per TI's SCHS044C Rev C specification.

Key Specifications

Pinout & Package

CD4047BEG4 is supplied in a 14-lead plastic dual-in-line package (PDIP-N), 19.18 mm × 6.67 mm footprint, 3.43 mm height, with through-hole mounting and industry-standard 2.54 mm pin pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD4047BEG4, CD4098BE lacks astable operation and retriggerability, limiting flexibility in dynamic timing systems; LM555CN consumes >100× more quiescent current and fails to meet military temperature requirements, making CD4047BEG4 the sole choice for robust, low-power, dual-mode timing.

Availability

CD4047BEG4 is available at Aetrix Electronics and suitable for power-on reset generators, LED flashers, PWM reference circuits, and relay timing control requiring stable component supply across extended temperature ranges.

Supply support for CD4047BEG4 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 and precision timing solutions.

The CD4047B-series belongs to TI's legacy CMOS 4000B logic family, designed specifically for robust, low-power, wide-supply-voltage timing and waveform generation in industrial, aerospace, and automotive environments.

FAQ

What is the maximum operating frequency of CD4047BEG4 in astable mode?

The CD4047BEG4 supports astable operation up to 1 MHz at V_DD = 15 V, as specified in the SCHS044C datasheet. At lower supply voltages (e.g., 5 V), maximum frequency reduces to ~200 kHz due to increased propagation delay. The actual upper limit depends on external R and C values and PCB layout parasitics - for reliable 1 MHz operation, use R ≤ 1 kΩ and C ≤ 100 pF with short, guarded traces. CD4047BEG4 maintains stable oscillation without external compensation across this range.

Can CD4047BEG4 operate from a 3.3 V supply?

Yes, CD4047BEG4 is fully specified to operate from 3 V to 18 V, including 3.3 V nominal rails. At 3.3 V, output drive drops to ±1.5 mA (min), propagation delay increases to 250 ns (max), and astable frequency upper limit falls to ~100 kHz. All logic thresholds scale proportionally (V_IH ≥ 2.3 V, V_IL ≤ 1.0 V), ensuring compatibility with 3.3 V microcontrollers. CD4047BEG4 remains functional and characterized across this voltage - no derating or external circuitry is required.

Does CD4047BEG4 require external components to function in monostable mode?

Yes, CD4047BEG4 requires an external resistor (R_EXT) and capacitor (C_EXT) connected to Pins 3 and 4 to set monostable pulse width, per the formula t_W ≈ 0.44 × R_EXT × C_EXT. No other passive components are mandatory, though a 0.1 µF ceramic bypass capacitor between V_DD and V_SS is strongly recommended. CD4047BEG4 integrates all internal logic and timing comparators - no external diodes, transistors, or op-amps are needed for basic monostable operation.

Is CD4047BEG4 pin-compatible with older CD4047BE variants?

Yes, CD4047BEG4 is a RoHS-compliant, lead-free variant of the CD4047BE in the same 14-lead PDIP (N) package, with identical pinout, electrical specifications, and timing behavior. The "G4" suffix denotes TI's green packaging standard (NiPdAu lead finish), while maintaining full functional and mechanical compatibility. CD4047BEG4 can be used as a direct drop-in replacement for CD4047BE in existing designs without layout or firmware changes.

What is the purpose of the NC pins (12, 13, 14) on CD4047BEG4?

Pins 12, 13, and 14 on CD4047BEG4 are designated No Connect (NC) - internally unconnected silicon nodes with no electrical function. They must remain unconnected on the PCB; routing traces to or from these pins may introduce noise coupling or parasitic capacitance. TI's datasheet explicitly prohibits using NC pins for grounding, decoupling, or mechanical anchoring. CD4047BEG4's operation is unaffected by NC pin handling, but best practice is to leave them floating and unstubbed per TI's layout guidelines.