Part A
ADS8509IDW
德州儀器
- Lifecycle
- Active
- Stock
- 2404 件
- Package
- SOIC-20
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The ADS8509IDW and ADS8508IBDWRG4 are both 12-bit successive-approximation ADCs from Texas Instruments sharing the same 24-pin SOIC wide-body footprint and comparable serial interface architecture, making them strong functional replacement candidates. Designers should validate the reference configuration and supply-voltage tolerance against the target application before committing to a drop-in substitution.
Resolution and Architecture
High match
Package Type
High match
Reference Configuration
Validation required
Supply Voltage Range
Validation required
Parts at a glance
Part B
ADS8508IBDWRG4
德州儀器
- Lifecycle
- Active
- Stock
- 8833 件
- Package
- SOIC-20
- Series
- 資料獲取-模數轉換器（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 | ADS8509IDW | ADS8508IBDWRG4 | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest measurable analog step; a 16-bit ADC provides 16x finer quantization than a 12-bit device, so these are not functionally interchangeable where accuracy is critical. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both are single-channel devices, so channel count does not differentiate them, but confirming this ensures neither requires a multiplexer front-end. |
| Sampling Rate | 250 kSPS | 250 kSPS | Throughput must meet the system's signal bandwidth; identical rates mean timing budgets are unaffected by substitution. |
| Input Type | Single-ended | Single-ended | Single-ended inputs simplify front-end design versus differential; matching input topology preserves the analog signal chain. |
| Supply Voltage | 5 V (analog and digital) | 5 V (analog and digital) | Supply compatibility ensures the part can drop into the same rail without level shifting or regulator changes. |
| Interface | SPI / Serial | SPI / Serial | A matching serial interface allows reuse of the same microcontroller pins and firmware protocol. |
| Package | SOIC-28 (DW) | SOIC-28 (DW) | Identical package and footprint enable direct PCB drop-in replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Matching temperature grades confirm both parts suit the same industrial environment. |
| INL (Integral Nonlinearity) | ±1.5 LSB (typ) | ±0.5 LSB (typ) | INL defines linearity error; the 12-bit part's tighter LSB spec reflects its lower resolution, so absolute accuracy differs between the two. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS8509IDW | ADS8508IBDWRG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | 16 | 12 |
| Sampling Rate(Per Second) | 250k | 250k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| 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, Internal | External, Internal |
| Voltage - Supply, Analog | 5V | 5V |
| Voltage - Supply, Digital | 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the ADS8509IDW and ADS8508IBDWRG4?
The ADS8509IDW is a 16-bit successive-approximation ADC in a 28-pin SOIC (DW) package, specified over the industrial temperature range of -40°C to +85°C. The ADS8508IBDWRG4 is a 12-bit SAR ADC in a 28-pin SOIC package, supplied in tape-and-reel form with the G4 lead-free/RoHS-compliant designation, and is specified over the industrial temperature range of -40°C to +85°C. The primary differences are resolution (16-bit vs 12-bit) and the tape-and-reel packaging of the ADS8508IBDWRG4.
Are the ADS8509IDW and ADS8508IBDWRG4 pin-compatible?
Both devices are offered in a 28-pin SOIC (DW) package, and their pinouts are defined in their respective datasheets. Designers should verify pin function assignments against the official datasheets before considering any board-level substitution, since the two devices differ in resolution and internal architecture.
What is the resolution and sampling rate of each device?
The ADS8509IDW provides 16-bit resolution, while the ADS8508IBDWRG4 provides 12-bit resolution. Both are successive-approximation register (SAR) analog-to-digital converters. Sampling-rate specifications should be confirmed from the respective manufacturer datasheets for the exact grade and package.
What analog input range do these ADCs support?
Both the ADS8509 and ADS8508 are designed to accept bipolar analog input ranges, typically ±10 V, with the input configuration set by the device's internal reference and input scaling. The exact specified input range and reference voltage should be confirmed from the official datasheets for each part number.
What does the G4 suffix on the ADS8508IBDWRG4 indicate?
The G4 suffix denotes a lead-free (Pb-free) and RoHS-compliant package variant, and the R suffix indicates tape-and-reel packaging. The ADS8509IDW is supplied in tube form without the G4 designation. Designers should confirm the exact ordering code and environmental compliance from the manufacturer's product page.
Can the ADS8508IBDWRG4 be used as a drop-in replacement for the ADS8509IDW?
No. Although both are 28-pin SOIC SAR ADCs, they differ in resolution (12-bit vs 16-bit), so a direct drop-in replacement would change system accuracy and is not recommended without full validation against the manufacturer datasheets and the target design requirements.
What are the operating temperature ranges for these devices?
Both the ADS8509IDW and ADS8508IBDWRG4 are specified over the industrial temperature range of -40°C to +85°C. The exact temperature grade and limits should be verified from the respective manufacturer datasheets for the specific orderable part number.
What interface do these ADCs use to connect to a host processor?
Both the ADS8509 and ADS8508 provide a parallel digital output interface for connection to a host processor or microcontroller. The exact interface timing, control signals, and data format should be confirmed from the official datasheets for each device.