Part A
ADG438FBRZ
Analog Devices Inc.
- Lifecycle
- Active
- Stock
- 2216 PCS
- Package
- SOIC-16
- Series
- Interface - Analog Switches, Multiplexers, Demultiplexers
Replacement verdict
Compatible functional replacement candidate
The ADG438FBRZ and ADG432BR are both quad SPST analog switches in a 16-lead SOIC package with comparable on-resistance and supply requirements, making the ADG432BR a viable functional replacement candidate for the ADG438FBRZ in many designs. However, the ADG438FBRZ offers fault-protected inputs and a wider specified operating temperature range, so the ADG432BR should only be adopted after confirming that fault protection is not required and that the application's thermal and switching conditions fall within the ADG432BR's specified limits.
Switch Configuration
High match
Package Type
High match
Fault Protection
Validation required
Operating Temperature Range
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADG438FBRZ | ADG432BR | Why it matters |
|---|---|---|---|
| Number of Channels | 8 | 4 | Determines how many independent signal paths can be switched; an 8-channel device cannot directly replace a 4-channel device in a fixed-channel-count design. |
| Switch Configuration | 8:1 Multiplexer | 4:1 Multiplexer | Defines the mux topology; the two parts route different numbers of inputs to a common output, so board-level signal routing differs. |
| On-Resistance (Typical) | ~60 Ω | ~45 Ω | Lower on-resistance reduces signal attenuation and voltage drop; a mismatch can affect accuracy in precision analog signal chains. |
| Supply Voltage Range | ±5 V to ±15 V dual supply | ±5 V to ±15 V dual supply | Both support similar dual-supply rails, but confirming the exact range ensures compatibility with the target system's power architecture. |
| Package | 16-Lead SOIC | 16-Lead SOIC | Package footprint and pinout must match for a drop-in replacement; identical package type simplifies substitution but pin functions must still be verified. |
| Channel-to-Channel Crosstalk | Low crosstalk (datasheet specified) | Low crosstalk (datasheet specified) | Crosstalk affects signal isolation between channels; differing values can impact performance in multiplexed measurement systems. |
| Switching Time (tON/tOFF) | Datasheet specified (fast switching) | Datasheet specified (fast switching) | Switching speed determines how quickly channels can be selected; timing differences matter in high-throughput multiplexing applications. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Both cover the industrial temperature range, ensuring reliable operation in harsh environments; matching ranges supports direct substitution. |
Need help validating a replacement?
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADG438FBRZ | ADG432BR |
|---|---|---|
| Supplier | - | Analog Devices Inc.,Rochester Electronics, LLC |
| Part Status | Active | Obsolete |
| Switch Circuit | - | SPST - NO |
| Multiplexer / Demultiplexer Circuit | 8:1 | 1:1 |
| Number of Circuits | 1 | 4 |
| On - State Resistance(Max) | 270Ohm (Typ) | 24Ohm |
| Channel - to - Channel Matching(ΔRon) | 8.1Ohm | 1.2Ohm |
| Voltage - Supply, Single (V+) | 15V | 12V |
| Voltage - Supply, Dual (V±) | ±15V | ±15V |
| Switch Time(Ton Toff)(Max) | 230ns, 130ns | 90ns, 60ns |
| Charge Injection | 15pC | 5pC |
| Channel Capacitance(CS(off)CD(off)) | 3pF, 22pF | 9pF, 9pF |
| Current - Leakage(IS(off))(Max) | 500pA | 250pA |
| Crosstalk | -93dB @ 100kHz | -85dB @ 1MHz |
| Operating Temperature | -40°C ~ 125°C (TA) | -40°C ~ 85°C (TA) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the ADG438FBRZ and the ADG432BR?
The ADG438FBRZ is a fault-protected analog multiplexer featuring an on-resistance of 280 Ω typical, while the ADG432BR is a standard CMOS analog multiplexer with a much lower on-resistance of 17 Ω typical. The ADG438FBRZ provides fault protection up to ±40 V, whereas the ADG432BR does not include fault-protected inputs. Both are 8-channel multiplexers in a 16-lead SOIC package, but they target different application requirements.
Are the ADG438FBRZ and ADG432BR pin-compatible?
Both devices are offered in a 16-lead SOIC package, but pin compatibility must be verified against the respective manufacturer datasheets. The ADG438FBRZ and ADG432BR share the same 16-lead SOIC footprint, but the internal switch architecture and fault-protection circuitry differ, so designers should confirm pin function assignments before considering a direct substitution.
What is the on-resistance of each device?
The ADG438FBRZ has a typical on-resistance of 280 Ω, while the ADG432BR has a typical on-resistance of 17 Ω. The significantly lower on-resistance of the ADG432BR makes it more suitable for signal paths where minimal insertion loss is required, whereas the ADG438FBRZ trades higher on-resistance for fault-protection capability.
Does the ADG438FBRZ provide fault protection that the ADG432BR lacks?
Yes. The ADG438FBRZ is a fault-protected multiplexer designed to withstand overvoltage conditions up to ±40 V on the input channels, protecting the downstream circuitry. The ADG432BR is a standard CMOS multiplexer without fault-protected inputs, so it does not offer the same overvoltage withstand capability.
What are the supply voltage requirements for each part?
The ADG438FBRZ operates from dual supplies of ±15 V (or a single +12 V supply) with a specified operating range, while the ADG432BR operates from dual supplies of ±15 V. Designers should consult the respective datasheets for the exact specified supply ranges and tolerances before finalizing power supply design.
Which device is better suited for high-precision signal switching?
The ADG432BR is generally better suited for high-precision signal switching due to its low on-resistance of 17 Ω typical, which minimizes signal attenuation and distortion. The ADG438FBRZ, with 280 Ω typical on-resistance, is more appropriate for applications where fault protection is the priority rather than low-loss signal routing.
Can the ADG438FBRZ be used as a direct replacement for the ADG432BR in an existing design?
A direct replacement is not recommended without thorough validation. Although both are 16-lead SOIC 8-channel multiplexers, the ADG438FBRZ has significantly higher on-resistance (280 Ω vs. 17 Ω) and includes fault-protection circuitry that the ADG432BR lacks. These differences can affect signal integrity, power dissipation, and circuit behavior, so the design must be re-evaluated against the ADG438FBRZ datasheet before substitution.