HCF4051BE and CD4051B 8-Channel Analog Multiplexer Selection Guide
Choose the right 8-channel CMOS analog mux from the 4051 family. Compare HCF4051BE, CD4051BE, CD4051BM, CD4051BPWR, and automotive CD4051BQPWRQ1 by package, RON, supply range, and qualification.
Last updated: June 2026
Bottom Line: When selecting an 8-channel CMOS analog multiplexer/demultiplexer from the 4051 family, the three most important parameters are supply voltage range (3 V to 20 V for standard grade), on-resistance (80–400 Ω depending on VDD), and package form factor (DIP-16 for prototyping, SO-16 or TSSOP-16 for production). The STMicroelectronics HCF4051BE is the classic through-hole benchmark; pin-compatible second sources from Texas Instruments—CD4051BE (DIP-16), CD4051BM (SO-16), and CD4051BPWR (TSSOP-16)—offer identical logic with different packaging and qualification levels, including the automotive-grade CD4051BQPWRQ1 (AEC-Q100 Grade 1).
What Is the 4051 Family?
The 4051 is a classic CMOS 8-channel single-ended analog multiplexer/demultiplexer that has been in continuous production since the 1970s. It connects one of eight analog inputs (CH0–CH7) to a common I/O pin based on a 3-bit binary address (A, B, C) plus an active-low enable pin (INH). The device operates bidirectionally: it can route a signal from the common port to one of eight outputs (demultiplexer mode) or from one of eight inputs to the common port (multiplexer mode). This flexibility makes it a versatile building block in sensor scanning, audio switching, test equipment, and industrial data acquisition systems.
Key specifications that define the 4051 family across all manufacturers:
- 8:1 single-ended channel configuration
- Supply voltage: 3 V to 20 V (VDD−VSS)
- Logic-level translation: digital control pins reference VSS to VDD, allowing 3.3 V or 5 V logic to control rail-to-rail analog signals
- Bandwidth: 20 MHz typical at VDD = 15 V
- ON-resistance: 80–400 Ω depending on VDD and manufacturer
- Pinout: 16-pin package (DIP, SOIC, or TSSOP depending on variant)
The HCF4051BE from STMicroelectronics and the CD4051B series from Texas Instruments are the two most widely stocked implementations, sharing a 16-pin logic pinout defined under JEDEC standard B-series CMOS families. Both manufacturers' datasheets reference the same truth table: three-bit binary address selects one of eight channels (Channel 0 = A=0, B=0, C=0; Channel 7 = A=1, B=1, C=1), and INH=HIGH disables all channels.
Key Selection Parameters
1. Supply Voltage Range
The 4051 family supports a wide supply range, but the exact limits vary by part and intended application. Standard commercial parts operate from 3 V to 20 V (VDD−VSS). If you are running a split supply (e.g., ±5 V for audio), VSS can be negative, allowing analog signals to swing rail-to-rail without exceeding the VDD−VSS window. STMicroelectronics specifies the HCF4051BE at 3 V to 18 V maximum; Texas Instruments CD4051B variants are rated to 20 V maximum.
Recommendation: For 3.3 V single-supply systems, verify the datasheet minimum VDD; some variants are specified down to 3 V but exhibit higher on-resistance below 5 V. For 5 V or 15 V systems, all standard 4051 variants perform within spec. Split supplies are preferred in precision analog and audio applications to avoid signal clipping at the rails.
2. On-Resistance (RON)
On-resistance is the channel resistance when the selected switch is closed. Lower RON reduces signal attenuation and thermal noise, which is critical in audio and precision analog paths. The RON value is strongly VDD-dependent across the entire 4051 family. Typical values from the STMicroelectronics HCF4051BE datasheet (DS006052):
| VDD−VSS | Typical RON | Maximum RON |
|---|---|---|
| 5 V | 250 Ω | 400 Ω |
| 10 V | 120 Ω | 175 Ω |
| 15 V | 80 Ω | 120 Ω |
The HCF4051BE and CD4051BE share essentially the same RON characteristics because both implement the same JEDEC CMOS topology. Slight lot-to-lot variation exists but both parts are interchangeable for any application where RON tolerance of ±10–15% is acceptable.
Recommendation: For high-fidelity audio or sensor conditioning paths, use the highest feasible VDD to minimize RON. For digital signal routing, RON matters less as long as it remains well below the load impedance.
3. Off-State Isolation
Off-state isolation defines how well unselected channels are isolated from the common port. The 4051 family typically achieves −40 dB to −60 dB isolation at 1 MHz and −60 dB to −80 dB at low frequencies. The CD4051BF (ceramic DIP variant) datasheet specifies −58 dB off-state isolation at 1 MHz with VDD = 15 V. Isolation degrades at higher frequencies due to parasitic capacitance between channel and common pins (typically 5–10 pF).
Recommendation: For RF or high-frequency switching (signal bandwidth >1 MHz), consider dedicated RF multiplexers. For audio and DC–1 MHz instrumentation, the 4051 family provides adequate isolation for most measurement and switching tasks. If crosstalk between channels is a concern, place guard traces between channel pins on the PCB.
4. Package Options
Package choice drives PCB footprint, thermal performance, and assembly method. The 4051 family is available in three standard package types across STMicroelectronics and TI:
| Package | Footprint | Lead Pitch | Reel Option | Use Case |
|---|---|---|---|---|
| DIP-16 | Through-hole | 2.54 mm | No | Prototyping, breadboard, hand assembly |
| SO-16 (SOIC) | SMD | 1.27 mm | Yes (T&R) | Standard SMT production |
| TSSOP-16 | SMD | 0.65 mm | Yes (T&R) | High-density PCBs |
The HCF4051YM013TR is the STMicro tape-and-reel SO-16 variant, suited for automated SMT assembly. The CD4051BPWR is TI's TSSOP-16 tape-and-reel option, providing a 50% footprint reduction versus SOIC while remaining hand-solderable with appropriate tooling.
Recommendation: For new designs targeting volume production, prefer TSSOP-16 (smaller, lighter, lower cost per unit at volume) or SO-16 (more solderable, easier to inspect and rework). Reserve DIP-16 for prototyping boards, educational kits, or designs requiring hand-assembly.
5. Temperature Grade and Qualification
Most commercial 4051 variants are rated for −40 °C to +85 °C (industrial) or −40 °C to +125 °C (extended commercial). The automotive-qualified CD4051BQPWRQ1 is AEC-Q100 Grade 1 certified (−40 °C to +125 °C), meaning it has passed the full suite of automotive reliability tests including HTOL, HAST, ESD, and latch-up per AEC-Q100 Rev H. This qualification is mandatory for automotive ECU, body electronics, ADAS sensor conditioning, or any design subject to IATF 16949 quality system requirements.
Recommendation: For automotive or high-reliability industrial designs, specify AEC-Q100 parts explicitly. Commercial-grade parts may pass the temperature range in practice but lack the qualification documentation required by Tier 1 automotive suppliers and OEM AVL processes.
6. Switching Speed
Propagation delay (tPD) from address change to channel selection ranges from 50 ns to 200 ns depending on VDD. The break-before-make transition ensures no two channels are simultaneously connected, with transition time typically 10–30 ns at VDD = 10 V. At VDD = 5 V, tPD can reach 200 ns in worst case.
For applications scanning 8 channels, the minimum scan period is approximately: T_scan = 8 × (tPD + settling time). With tPD = 100 ns and a signal settling time of 500 ns per channel, the maximum scan rate is approximately 160 kScans/second (8 × 600 ns per full cycle).
Recommendation: For scanning multiple sensors at >500 kHz aggregate sample rates, select parts with tPD < 100 ns by operating at VDD ≥ 10 V. For slower DC measurement systems (<100 Hz scan rate), switching speed is not a limiting factor.
7. Logic Compatibility and Level Translation
The 4051 family includes built-in level translation: the digital control pins (A, B, C, INH) reference VDD/VSS, while the analog channel signals can swing from VSS to VDD. This means a 3.3 V microcontroller GPIO (referenced to GND) can directly drive the address pins while the analog signal swings ±5 V on a split supply (VDD = +5 V, VSS = −5 V). No external level shifters are required, as long as the digital control voltages remain within the VDD−VSS window and the logic HIGH threshold is met (typically 0.7 × VDD).
This level-translation feature is particularly valuable in mixed-supply systems: a 3.3 V MCU can address the mux while the analog signal path operates at ±5 V for improved dynamic range.
Recommended Products Comparison Table
| Product | Manufacturer | Package | VDD Range | RON (max, 5 V) | Qualification | Best For |
|---|---|---|---|---|---|---|
| HCF4051BE | STMicroelectronics | DIP-16 | 3–18 V | 400 Ω | Commercial | Prototyping, legacy designs, DIP breadboard |
| HCF4051BEY | STMicroelectronics | DIP-16 | 3–18 V | 400 Ω | Commercial | Small-batch production |
| HCF4051YM013TR | STMicroelectronics | SO-16 T&R | 3–18 V | 400 Ω | Commercial | SMT production, STMicro ecosystem |
| CD4051BE | Texas Instruments | DIP-16 | 3–20 V | 400 Ω | Commercial | Drop-in DIP replacement, wider VDD max |
| CD4051BM | Texas Instruments | SO-16 | 3–20 V | 400 Ω | Commercial | SMT production, TI ecosystem |
| CD4051BPWR | Texas Instruments | TSSOP-16 T&R | 3–20 V | 400 Ω | Commercial | High-density SMT production |
| CD4051BQPWRQ1 | Texas Instruments | TSSOP-16 | 3–20 V | 400 Ω | AEC-Q100 Gr.1 | Automotive, high-reliability industrial |
Selection Decision Flowchart
Use the following decision logic to narrow your choice:
Step 1: Is automotive qualification (AEC-Q100) required?
- Yes → Specify CD4051BQPWRQ1 (TSSOP-16, AEC-Q100 Grade 1). Stop.
- No → Continue to Step 2.
Step 2: Is this a prototype or through-hole assembly?
- Yes → Choose HCF4051BE or CD4051BE (DIP-16, pin-compatible substitutes). Stop.
- No (SMT production) → Continue to Step 3.
Step 3: Is board space constrained (pitch < 1.27 mm needed)?
- Yes → Choose CD4051BPWR (TSSOP-16, 0.65 mm pitch). Stop.
- No → Continue to Step 4.
Step 4: Do you have a preferred supplier ecosystem?
- STMicroelectronics → HCF4051YM013TR (SO-16, tape-and-reel). Stop.
- Texas Instruments → CD4051BM (SO-16). Stop.
Note on maximum VDD: If your design operates between 18 V and 20 V, you must choose a TI CD4051B variant (20 V max) rather than STMicro HCF4051 (18 V max). All DIP-16 variants are pin-compatible; all SO-16 variants share the same SOIC-16 footprint; all TSSOP-16 variants share the TSSOP-16 footprint.
FAQ
Q: Are the HCF4051BE and CD4051BE interchangeable?
Yes. The HCF4051BE (STMicroelectronics) and CD4051BE (Texas Instruments) are pin-for-pin compatible and functionally equivalent in the DIP-16 package. Both implement the same JEDEC CMOS 4051 specification with identical pinout (A/B/C/INH/COM/CH0–CH7/VDD/VSS). The primary difference is maximum supply voltage: STMicro specifies 18 V max (VDD−VSS), while TI specifies 20 V max. For systems running at 15 V or below, either part is a direct drop-in replacement with no BOM change required.
Q: What is the maximum analog signal frequency for the HCF4051BE?
The HCF4051BE supports analog signal bandwidth up to approximately 20 MHz at VDD = 15 V, as specified in the STMicroelectronics datasheet DS006052. At lower supply voltages (5 V), bandwidth is reduced to approximately 8–12 MHz due to higher channel capacitance and on-resistance. For signals above 20 MHz or applications requiring low insertion loss at RF frequencies, consider dedicated RF multiplexers rated for your frequency band.
Q: Can I use the HCF4051BE with a 3.3 V microcontroller and 5 V analog signals?
Yes, using a split-supply configuration. Set VDD = +5 V and VSS = 0 V (or −2.5 V for ±2.5 V swing). The digital address pins (A, B, C, INH) will then accept logic levels from 0 V to 3.5 V (0.7 × 5 V threshold). Your 3.3 V MCU GPIO outputs at 3.3 V HIGH meet this threshold. The analog signal can swing from VSS to VDD on the channel and common pins without issue.
Q: What is the difference between the CD4051BM and CD4051BPWR?
Both are SMT variants of the TI CD4051B with identical electrical specifications. The CD4051BM uses an SO-16 (SOIC) package with 1.27 mm lead pitch—easier to hand-solder and inspect under a loupe. The CD4051BPWR uses a TSSOP-16 package with 0.65 mm lead pitch for approximately 40% smaller PCB footprint. Choose SO-16 for prototyping and small-batch SMT; choose TSSOP-16 for high-density designs or when minimizing board area is a priority.
Q: Which 4051 variant should I specify in an automotive design?
For automotive designs, specify the CD4051BQPWRQ1, which is AEC-Q100 Grade 1 certified for −40 °C to +125 °C operation with documented reliability testing per AEC-Q100 Rev H. Commercial-grade HCF4051BE and CD4051BE parts are not AEC-Q100 qualified and should not be designed into safety-critical automotive ECUs, ADAS sensor interfaces, or body control modules without explicit engineering risk acceptance and supply chain qualification.
Conclusion and Next Steps
The 4051 analog multiplexer family remains one of the most cost-effective and flexible solutions for 8-channel analog signal switching in embedded, industrial, audio, and instrumentation designs. The HCF4051BE (STMicroelectronics, DIP-16) is the best starting point for prototyping and legacy through-hole designs. For volume SMT production, the HCF4051YM013TR (SO-16 T&R) or CD4051BPWR (TSSOP-16 T&R) reduce board area while maintaining full pin and electrical compatibility. Automotive and high-reliability industrial designs must use the CD4051BQPWRQ1 (AEC-Q100 Grade 1, TSSOP-16).
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