Part A
ADS8422IBPFBR
Texas Instruments
- Lifecycle
- Active
- Stock
- 1975 PCS
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The ADS8422IBPFBR and ADS8401IPFBR are not drop-in replacements for one another. Although both are 16-bit successive-approximation analog-to-digital converters in a TQFP-48 package, they differ in resolution-critical architecture, sampling rate, analog input configuration, and digital interface, so a direct substitution is not feasible without a full board-level redesign and validation.
Different sampling rate
Different analog input range
Different digital interface
Different reference architecture
Parts at a glance
Part B
ADS8401IPFBR
Texas Instruments
- Lifecycle
- Active
- Stock
- 4893 PCS
- Package
- TQFP-48
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | ADS8422IBPFBR | ADS8401IPFBR | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit SAR ADCs, so nominal resolution is equivalent for substitutability. |
| Sampling Rate | 4 MSPS | 1.25 MSPS | The ADS8422 offers over 3x the throughput, which is critical for high-speed acquisition systems. |
| Input Type | Pseudo-differential (single-ended input with reference) | Pseudo-differential | Input configuration affects how the ADC interfaces with the analog front end and signal conditioning. |
| Supply Voltage (Analog) | 5 V | 5 V | Matching analog supply simplifies power rail design when substituting parts. |
| Interface | Parallel (byte/word) | Parallel | Both use a parallel interface, but timing and bus width details must be checked for drop-in compatibility. |
| Package | 48-pin TQFP (PFB) | 48-pin TQFP (PFB) | Identical package and pin count allow the same PCB footprint, easing substitution. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Equivalent industrial temperature range supports use in the same environments. |
| INL (Integral Nonlinearity) | ±1.5 LSB (typ) | ±1.5 LSB (typ) | Similar linearity performance means comparable accuracy in measurement applications. |
| Power Consumption | ~155 mW (typ) | ~110 mW (typ) | Lower power in the ADS8401 may benefit thermally constrained or battery-powered designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS8422IBPFBR | ADS8401IPFBR |
|---|---|---|
| Supplier | - | Texas Instruments,Rochester Electronics, LLC |
| Series | microPOWER™ | microPOWER™ |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | - | 1.25M |
| Number of Inputs | 1 | 1 |
| Input Type | Differential | Differential |
| Data Interface | Parallel | Parallel |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | - | 1 |
| Architecture | SAR | SAR |
| Reference Type | External, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | 2.95V ~ 5.25V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Base Product Number | ADS8422 | - |
| Sampling Rate (Per Second) | 4M | - |
| Number of A / D Converters | 1 | - |
| Mounting Type | Surface Mount | - |
| Packaging | Tape & Reel (TR) | - |
Frequently asked questions
What are the key differences between the ADS8422IBPFBR and ADS8401IPFBR?
The ADS8422IBPFBR is a 16-bit, 4 MSPS pseudo-differential SAR ADC with a parallel interface, while the ADS8401IPFBR is a 16-bit, 1.25 MSPS fully differential SAR ADC with a parallel interface. The ADS8422 offers a higher sampling rate and pseudo-differential input configuration, whereas the ADS8401 provides a fully differential input architecture at a lower maximum throughput rate.
Are the ADS8422IBPFBR and ADS8401IPFBR pin-compatible?
Both devices are offered in a 48-pin TQFP package (PFB suffix), but pin compatibility cannot be assumed solely from package type. The pin functions and configuration must be verified against the respective manufacturer datasheets, as the input architecture and internal reference options differ between the two devices.
What is the maximum sampling rate of each device?
The ADS8422IBPFBR supports a maximum sampling rate of 4 MSPS. The ADS8401IPFBR supports a maximum sampling rate of 1.25 MSPS. The ADS8422 therefore provides more than three times the throughput of the ADS8401.
What input configuration does each ADC use?
The ADS8422IBPFBR uses a pseudo-differential input configuration, where the negative input is typically tied to a fixed reference level. The ADS8401IPFBR uses a fully differential input configuration, which provides improved common-mode noise rejection and better performance in differential signal chain designs.
Do both devices operate from the same supply voltage?
Both the ADS8422IBPFBR and ADS8401IPFBR operate from a 5 V analog supply with a separate digital supply. Designers should confirm the exact supply rail requirements and tolerances in the respective manufacturer datasheets, as the internal reference and digital I/O configurations may impose additional constraints.
What interface do these ADCs provide to a host processor?
Both the ADS8422IBPFBR and ADS8401IPFBR provide a parallel digital output interface for connection to a host processor or FPGA. The ADS8422, with its higher 4 MSPS throughput, requires a correspondingly higher data bus bandwidth than the ADS8401 at 1.25 MSPS.
Can the ADS8401IPFBR be used as a drop-in replacement for the ADS8422IBPFBR?
No. The two devices differ in maximum sampling rate (1.25 MSPS vs. 4 MSPS) and input architecture (fully differential vs. pseudo-differential). A drop-in replacement would require validation of timing, input drive requirements, and PCB layout against the target design, and the lower throughput of the ADS8401 would not meet applications requiring 4 MSPS.