Part A
ADS8320E/2K5
Texas Instruments
- Lifecycle
- Active
- Stock
- 4183 PCS
- Package
- VSSOP-8
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (ADC)
Replacement verdict
Not a drop-in replacement
The ADS8320E/2K5 and ADS8318IBDGST are not drop-in replacements for one another. Although both are single-channel SAR ADCs, they differ in resolution, sampling rate, analog input architecture, and digital interface, so a direct substitution is not possible without redesign and validation.
Different resolution
Different sampling rate
Different input architecture
Different digital interface
Parts at a glance
Part B
ADS8318IBDGST
National Semiconductor
- Lifecycle
- Active
- Stock
- 6908 PCS
- Package
- MSOP-10
- Series
- Acquisição de dados - Analogo para Convertedores Digitais (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 | ADS8320E/2K5 | ADS8318IBDGST | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 16 bit | Both are 16-bit ADCs, so resolution is equivalent and not a differentiator for substitutability. |
| Sampling Rate | 100 kSPS | 500 kSPS | The ADS8318 offers 5x higher throughput, which matters for faster signal acquisition and higher-bandwidth applications. |
| Input Type | Single-ended | Differential (pseudo-differential) | Differential input improves noise immunity and common-mode rejection; single-ended is simpler but less robust in noisy environments. |
| Interface | SPI (serial) | SPI (serial) | Both use a serial SPI-compatible interface, so host microcontroller compatibility is similar. |
| Supply Voltage | 2.7 V to 5.5 V | 4.5 V to 5.5 V | The ADS8320 supports lower supply voltages, enabling use in low-power 3.3 V systems where the ADS8318 cannot operate. |
| Package | VSSOP-8 (MSOP-8) | VSSOP-10 (MSOP-10) | Different pin counts and footprints mean the boards are not drop-in compatible; layout redesign is required. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature range, so environmental suitability is equivalent. |
| Reference Input | External reference | External reference | Both require an external voltage reference, so system reference design considerations are similar. |
| Power Consumption (typical) | ~1.8 mW at 100 kSPS, 5 V | ~18 mW at 500 kSPS, 5 V | The ADS8320 is significantly lower power, which matters for battery-powered or energy-sensitive designs. |
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Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS8320E/2K5 | ADS8318IBDGST |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Series | microPOWER™ | microPOWER™ |
| Part Status | Active | Active |
| Number of Bits | 16 | 16 |
| Sampling Rate(Per Second) | 100k | 500k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential, Single Ended | Differential |
| Data Interface | SPI | SPI |
| Configuration | S/H-ADC | S/H-ADC |
| Ratio - S / H: ADC | 1:1 | 1:1 |
| Number of A/D Converters | 1 | 1 |
| Architecture | SAR | SAR |
| Reference Type | External | External |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 2.375V ~ 5.5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key architectural differences between the ADS8320E/2K5 and the ADS8318IBDGST?
The ADS8320E/2K5 is a 16-bit, 100-kSPS successive-approximation register (SAR) analog-to-digital converter with a pseudo-differential input, a SPI-compatible serial interface, and a 2.7-V to 5.25-V supply range, offered in an 8-pin VSSOP package. The ADS8318IBDGST is a 16-bit, 500-kSPS SAR ADC with a fully differential input, a SPI-compatible serial interface, and a 4.5-V to 5.5-V analog supply, offered in a 10-pin VSSOP package. The ADS8318IBDGST provides a higher sampling rate and fully differential input architecture, while the ADS8320E/2K5 supports a wider digital supply range and lower pin count.
Can the ADS8320E/2K5 and ADS8318IBDGST be used as direct drop-in replacements for each other?
No. The two devices differ in package pin count (8-pin VSSOP versus 10-pin VSSOP), pin functions, input architecture (pseudo-differential versus fully differential), sampling rate (100 kSPS versus 500 kSPS), and supply requirements. A direct drop-in replacement is not possible without PCB redesign and validation against the respective manufacturer datasheets.
How do the sampling rates of the ADS8320E/2K5 and ADS8318IBDGST compare?
The ADS8320E/2K5 has a maximum sampling rate of 100 kSPS, while the ADS8318IBDGST supports a maximum sampling rate of 500 kSPS. The ADS8318IBDGST is therefore suitable for higher-bandwidth signal acquisition, whereas the ADS8320E/2K5 targets lower-speed, lower-power applications.
What are the input configurations of the ADS8320E/2K5 and ADS8318IBDGST?
The ADS8320E/2K5 features a pseudo-differential input, where the negative input is typically tied to a fixed reference or ground and the positive input is measured relative to it. The ADS8318IBDGST features a fully differential input, which improves common-mode noise rejection and is suited for driving from differential signal sources such as fully differential amplifiers or transformers.
What supply voltage ranges do the ADS8320E/2K5 and ADS8318IBDGST require?
The ADS8320E/2K5 operates from a single supply of 2.7 V to 5.25 V, with a separate digital I/O supply (VIO) that supports interfacing down to 1.8 V logic levels. The ADS8318IBDGST operates from a 4.5 V to 5.5 V analog supply and a separate 1.8 V to 5.5 V digital I/O supply (VIO). The ADS8320E/2K5 is therefore better suited to lower-voltage analog systems, while the ADS8318IBDGST requires a 5-V-class analog supply.
What serial interface do the ADS8320E/2K5 and ADS8318IBDGST use?
Both devices use a SPI-compatible serial interface for configuration and data readout. The ADS8320E/2K5 provides a serial clock (SCLK), chip select (CS), and data output (DOUT) interface, while the ADS8318IBDGST provides SCLK, CS, and SDO, with the conversion initiated by the CS falling edge. Both interfaces are compatible with standard SPI, QSPI, and MICROWIRE hosts.
How do the package options of the ADS8320E/2K5 and ADS8318IBDGST differ?
The ADS8320E/2K5 is offered in an 8-pin VSSOP (DGK) package. The ADS8318IBDGST is offered in a 10-pin VSSOP (DGS) package. The different pin counts and land patterns mean the two devices are not footprint-compatible and require separate PCB layouts.
Which device is better suited for low-power, portable applications?
The ADS8320E/2K5 is generally better suited for low-power, portable applications because it operates from a 2.7-V to 5.25-V supply and draws low quiescent current at 100 kSPS. The ADS8318IBDGST, with its 500-kSPS throughput and 5-V analog supply, is intended for higher-speed applications where power consumption is less critical. Designers should confirm exact power figures against the respective manufacturer datasheets for their target operating conditions.
What reference voltage requirements apply to the ADS8320E/2K5 and ADS8318IBDGST?
Both devices require an external reference voltage applied to their VREF pin to define the full-scale input range. The ADS8320E/2K5 supports a reference voltage up to the analog supply voltage, while the ADS8318IBDGST supports a reference voltage up to the analog supply voltage (5 V nominal). The reference source should be low-noise and well-decoupled to achieve the specified 16-bit performance in both cases.