HEF4047BT - CMOS Monostable/Astable Multivibrator SOIC-14
N.º da peça: HEF4047BT ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $0.62 | $0,62 |
| 10 | $0.55 | $5,50 |
| 100 | $0.42 | $42,00 |
| 500 | $0.34 | $170,00 |
| 1.000 | $0.28 | $280,00 |
| 2.500 | $0.24 | $600,00 |
HEF4047BT Visão geral
A multivibrator is a fundamental digital timing element that produces pulse waveforms without a stable DC state, or a single controlled-width pulse (monostable) from a trigger event. Within the digital-IC taxonomy, the HEF4047BT sits in the specialty-logic family of CMOS logic ICs, branching from the broader 4000-series CMOS logic line. Its core role in system design is generating precise time delays or square-wave clocks without software overhead, complementing microcontrollers and PLLs in mixed-signal designs.
Key features include wide supply voltage operation from 4.5 V to 15.5 V, low quiescent current of typically 2.4 mA, 50 ns propagation delay, monostable and astable modes in a single device, retriggerable operation, and master reset. The SOIC-14 package provides ease of assembly on standard reflow profiles with MSL Level 1 moisture sensitivity.
Internally the HEF4047BT uses CMOS logic gates combined with an external RC timing network to set the output pulse width or oscillation frequency. Its high noise immunity (typical of 4000-series CMOS) and low power consumption make it well-suited to battery-powered and industrial environments. The retrigger capability allows the output pulse to be extended by repeated triggers within the timing window.
Typical applications include missing-pulse detection, bounce-free switches, frequency discriminators, timing circuits, clock-pulse generation, and monostable multivibrators for digital debounce in industrial controls, instrumentation, and consumer electronics. Engineers often pair it with the CD4013 or CD4093 for cascaded timing chains.
When designing with the HEF4047BT, select Rt and Ct to place the timing well within the part's specified range, keep Rt traces short to avoid stray capacitance pickup, and bypass VCC with a 100 nF ceramic capacitor placed close to pin 14. Note that the HEF4047BT,653 reel-pack variant and HEF4047BT,652 bulk-pack variant share identical silicon and pinout.
This page synthesizes distributor pricing, drop-in SOIC-14 alternatives, and practical design notes not found in the manufacturer datasheet alone, including cross-vendor substitutes such as CD4047BCN from onsemi and HCF4047 from STMicroelectronics.
Alternativas drop-in para HEF4047BT — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
HEF4047BT,653
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
HEF4047BT,652
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
CD4047BM
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
CD4047BMT
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
HCF4047M013TR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
HEF4047BT Classificações máximas e características elétricas
| Função | Monostable/Astable Multivibrator |
| Logic Family | HEF4000 (CMOS) |
| Trigger Type | Positive-edge or Negative-edge (monostable) |
| Retriggerable | Yes |
| Supply Voltage (VCC) | 4.5 V to 15.5 V |
| Corrente de repouso | 2.4 mA (typical) |
| Propagation Delay | 50 ns (typical) |
| Temperatura de operação | -40 C to +85 C |
| Encapsulamento | SOIC-14 (SOT108) |
| Tipo de montagem | Surface Mount |
| Input Clamp Diodes | Yes |
| Status RoHS | Compliant |
| Master Reset | Yes (MR pin) |
| Timing Components | External Rt and Ct |
Configuração de pinos do HEF4047BT
| Pino 1 | C — Timing capacitor connection |
| Pino 2 | R — Timing resistor connection |
| Pino 3 | RC — Common node for R and C |
| Pino 4 | ASTABLE — Astable mode select |
| Pino 5 | ASTABLE — Astable mode select (complement) |
| Pino 6 | +TRIGGER — Positive-edge trigger input |
| Pino 7 | GND — Ground (0 V) |
| Pino 8 | -TRIGGER — Negative-edge trigger input |
| Pino 9 | RETRIGGER — Retrigger input |
| Pino 10 | MR — Master Reset (active high) |
| Pino 11 | Q — True output |
| Pino 12 | Q-bar — Complement output |
| Pino 13 | OSC OUT — Oscillator output |
| Pino 14 | VCC — Positive supply voltage |
Aplicações típicas
HEF4047BT é adequado para 7 aplicaçãos: Missing-Pulse Detector, Bounce-Free Switch / Debounce Circuit, Frequency Discriminator / Tone Decoder, Clock-Pulse Generator (Astable Oscillator), Long-Delay Timing Circuit, Sequential Timer / Multi-Stage Pulse Chain, Automotive Sensor Signal Conditioning.
Missing-Pulse Detector
The HEF4047BT's retriggerable monostable mode makes it well suited to missing-pulse detection in industrial sensor monitoring. With Rt=100 kohm and Ct=1 uF, the timing window extends approximately 248 ms; a stream of retrigger pulses from a tachometer or flow sensor keeps the output Q high, while a missing pulse allows the timer to expire and triggers an alarm. The 4.5-15.5 V supply matches 5 V and 12 V industrial rails directly without level shifters, and the SOIC-14 footprint is compatible with the onsemi CD4047BM cross-reference.
Recomendado
Bounce-Free Switch / Debounce Circuit
In monostable configuration, the HEF4047BT converts mechanical-switch bouncing into a single clean digital pulse. Each switch closure triggers a fixed-width output pulse (set by Rt/Ct) of typically 10-20 ms, suppressing the 1-5 ms contact bounce typical of mechanical switches and tactile buttons. Its 50 ns propagation delay adds negligible latency, and the master-reset (MR) input allows external logic to override the timer, enabling cascaded debounce chains in industrial control panels.
Recomendado
Frequency Discriminator / Tone Decoder
By configuring the HEF4047BT in monostable mode and feeding a periodic input signal, the device discriminates between in-band and out-of-band frequencies. If the period of the input is shorter than the monostable window, retriggering keeps Q high; if the period exceeds the window, Q goes low - effectively an upper-frequency detector. With Rt=10 kohm and Ct=10 nF the timing window is approximately 248 us, allowing detection of audio tones above 4 kHz for DTMF and tone-decoding applications.
Recomendado
Clock-Pulse Generator (Astable Oscillator)
In astable mode the HEF4047BT generates a continuous square-wave clock without software overhead, freeing microcontrollers from timer interrupts for low-power or cost-sensitive designs. With Rt=47 kohm and Ct=1 nF the oscillation frequency is approximately 21 kHz; with Rt=100 kohm and Ct=10 nF it is approximately 1 kHz - covering audio-band clock generation and stepper-motor step-clock needs. Unlike a crystal oscillator, the frequency is RC-adjustable across three decades, and the SOIC-14 footprint enables PCB layout reuse with the CD4047BM cross-reference.
Recomendado
Long-Delay Timing Circuit
The HEF4047BT supports timing from microseconds to tens of seconds when external Rt is increased to the megohm range with low-leakage Ct. A circuit using Rt=1 Mohm and Ct=10 uF generates a pulse width of approximately 24.8 seconds in monostable mode - useful for equipment power-down delays, watchdog reset circuits, and industrial process timers. The wide 4.5-15.5 V supply tolerates unregulated battery rails in portable test equipment, and the SOIC-14 footprint allows direct substitution with the onsemi CD4047BM for supply-chain resilience.
Recomendado
Sequential Timer / Multi-Stage Pulse Chain
Cascading two or more HEF4047BT monostables creates sequential timing stages where the Q-bar output of stage 1 triggers stage 2, generating sequential pulse trains for sequential relay activation, traffic-light controllers, or washing-machine cycle timers. Each stage's pulse width is independently set by its own Rt/Ct, allowing different on-times per stage. The 50 ns propagation delay per stage adds negligible timing error for second-scale pulse widths, and the wide 4.5-15.5 V supply supports battery and industrial 12 V applications.
Recomendado
Automotive Sensor Signal Conditioning
While the HEF4047BT itself is not AEC-Q100 qualified, its automotive-grade equivalent HEF4047BT-Q100 (when ordered through automotive distribution channels) is used to debounce and condition Hall-effect sensor signals in body and chassis ECUs. The 4.5-15.5 V supply accommodates 12 V automotive bus voltages, the input clamp diodes allow 24 V load-dump-tolerant interfacing with current-limiting resistors, and the SOIC-14 footprint matches the onsemi CD4047BM automotive cross-reference for second-sourcing.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para HEF4047BT — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | HEF4047BT,653 | HEF4047BT,652 | CD4047BM | CD4047BMT | HCF4047M013TR |
|---|---|---|---|---|---|---|
| Brand | Nexperia | Nexperia | Nexperia | onsemi | onsemi | STMicroelectronics |
| Package | SOIC-14 (SOT108) | SOIC-14 (SOT108) - same | SOIC-14 (SOT108) - same | SOIC-14 - same | SOIC-14 - same | SOIC-14 - same |
| Supply Voltage Range | 4.5 V to 15.5 V | 4.5 V to 15.5 V | 4.5 V to 15.5 V | 3 V to 18 V (wider) | 3 V to 18 V (wider) | 3 V to 20 V (wider) |
| Propagation Delay (typ) | 50 ns | 50 ns | 50 ns | 50 ns | 50 ns | 55 ns |
| Monostable/Astable Modes | Both | Both | Both | Both | Both | Both |
| Retriggerable | Yes | Yes | Yes | Yes | Yes | Yes |
| Master Reset (MR) | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -55 C to +125 C (wider) | -55 C to +125 C (wider) | -55 C to +125 C (wider) |
Principais diferenciais
- Drop-in SOIC-14 pin compatibility with onsemi CD4047BM cross-reference (vs CD4047BM)
- Monostable + astable modes in a single part (vs MC14538BDR2G)
- Input clamp diodes enable over-voltage interfacing (vs HCF4047M013TR)
Notas de projeto
Bypass VCC (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the supply pin, and add a 10 uF bulk tantalum or aluminum electrolytic capacitor if the HEF4047BT shares a supply rail with switching converters. The 4.5-15.5 V supply range tolerates battery droop but the quiescent current of 2.4 mA means battery-powered designs should consider sleep-mode gating via the MR pin to disable the timer when not in use.
Select Rt within the datasheet's recommended 10 kohm to 1 Mohm range; below 10 kohm the internal timing comparator saturates and the pulse width becomes non-monotonic, while above 1 Mohm leakage currents in Ct distort the timing. Use a low-leakage film or NP0 ceramic capacitor for Ct - electrolytic capacitors have 1-10 uA leakage that corrupts timing at long pulse widths. Keep the traces from pins 1, 2, 3 to Rt/Ct short (<10 mm) to avoid stray capacitance pickup that shifts the timing.
Place the HEF4047BT on the analog/quiet side of the PCB if used in mixed-signal designs, and route the trigger lines (pins 6, 8, 9) away from switching-converter nodes and high-current traces to prevent false triggering. The SOIC-14 (SOT108) package has standard JEDEC land pattern dimensions; use at least 0.25 mm clearance between pins and avoid running signal traces beneath the package to reduce coupling. The exposed pad (if any variant includes it) should be soldered to a grounded copper pour for thermal stability, though the SOIC-14 SOT108 has no exposed pad.
Informações de conformidade
RoHS compliant per Nexperia product page. Not AEC-Q100 qualified in the standard SOIC-14 variant - for automotive, request the HEF4047BT-Q100 variant or use the onsemi CD4047BM automotive cross-reference. Halogen-free status not explicitly stated in the verified data.
