Part A
ADS7809U
Texas Instruments
- Lifecycle
- Active
- Stock
- 6471 PCS
- Package
- SOIC-20
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7809U and ADS7816UCG4 differ in resolution, sampling architecture, package footprint, and digital interface, so the ADS7816UCG4 cannot serve as a direct drop-in substitute for the ADS7809U without redesign of the surrounding circuitry and board layout.
Different resolution
Different sampling architecture
Different package footprint
Different digital interface
Parts at a glance
Part B
ADS7816UCG4
Burr Brown
- Lifecycle
- Active
- Stock
- 4028 PCS
- Package
- SOIC-8
- 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 | ADS7809U | ADS7816UCG4 | Why it matters |
|---|---|---|---|
| Resolution | 16 bit | 12 bit | Resolution determines the smallest analog signal change the ADC can distinguish; a 16-bit part offers 16x finer quantization than a 12-bit part, so they are not functionally interchangeable in precision applications. |
| Sampling Rate | 100 kSPS | 200 kSPS | Maximum throughput limits how fast the system can digitize signals; the ADS7816UCG4 can sample twice as fast, which matters for higher-bandwidth or multiplexed acquisition designs. |
| Input Type | Single-ended | Pseudo-differential | Input configuration affects how the sensor or signal source must be connected and how common-mode noise is rejected; single-ended and pseudo-differential front ends are not directly interchangeable. |
| Interface | Parallel (byte/word) | SPI / serial | The digital interface dictates the host controller wiring and firmware; a parallel interface cannot be dropped into a board designed for a serial SPI interface without redesign. |
| Supply Voltage | 5 V (single supply) | 5 V (single supply) | Supply voltage must match the system rail; both operate from a 5 V single supply, so power-rail compatibility is maintained. |
| Package | 28-pin SOIC | 8-pin VSSOP (MSOP) | Package footprint and pin count determine PCB layout compatibility; the very different packages mean these parts cannot share the same board footprint. |
| Reference | Internal reference | External reference | Reference architecture affects accuracy, drift, and external component count; an internal-reference part simplifies design while an external-reference part requires an additional precision reference. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | The temperature range defines the environments in which the part is guaranteed to meet specifications; matching industrial ranges support similar application environments. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7809U | ADS7816UCG4 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Active |
| Number of Bits | 16 | 12 |
| Sampling Rate(Per Second) | 100k | 200k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Differential |
| Data Interface | SPI, DSP | 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 |
| 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 ADS7809U and ADS7816UCG4?
The ADS7809U is a 16-bit successive-approximation ADC with a parallel interface, internal reference, and a 10 µs conversion time, housed in a 28-pin SOIC package. The ADS7816UCG4 is a 12-bit successive-approximation ADC with a serial (SPI-compatible) interface, external reference requirement, and a 3.2 µs conversion time, housed in an 8-pin VSSOP package. They differ in resolution, interface type, package, and reference architecture.
Are the ADS7809U and ADS7816UCG4 pin-compatible or footprint-compatible?
No. The ADS7809U uses a 28-pin SOIC (DW) package, while the ADS7816UCG4 uses an 8-pin VSSOP (DCU) package. The pin counts, pin functions, and PCB land patterns are different, so they are not drop-in replacements for each other.
Can the ADS7816UCG4 directly replace the ADS7809U in an existing design?
No. Beyond package and pinout differences, the ADS7809U provides a 16-bit parallel output and an internal reference, whereas the ADS7816UCG4 provides 12-bit serial output and requires an external reference voltage. The host interface, firmware, and reference circuitry would all need redesign.
What are the resolution and interface differences between these two ADCs?
The ADS7809U offers 16-bit resolution with a parallel data bus interface. The ADS7816UCG4 offers 12-bit resolution with a serial SPI-compatible interface. The ADS7809U therefore provides higher resolution and faster system-level data transfer via parallel bus, while the ADS7816UCG4 reduces pin count and board space through serial communication.
Do both devices include an internal voltage reference?
No. The ADS7809U includes an internal reference (with the ability to use an external reference). The ADS7816UCG4 requires an external reference voltage applied to its VREF pin and does not include an internal reference.
How do the conversion speeds and sampling rates compare?
The ADS7809U has a conversion time of 10 µs, supporting a throughput of up to 100 kSPS. The ADS7816UCG4 has a conversion time of 3.2 µs, supporting a throughput of up to 200 kSPS. The ADS7816UCG4 is faster in conversion, but at 12-bit resolution versus 16-bit for the ADS7809U.
What are the analog input ranges for the ADS7809U and ADS7816UCG4?
The ADS7809U supports bipolar input ranges of ±10 V, ±5 V, and ±2.5 V, as well as unipolar ranges of 0 to 10 V and 0 to 5 V, configured via input range pins. The ADS7816UCG4 has a unipolar input range of 0 V to VREF (pseudo-differential input), where the input span is set by the external reference voltage.
Which device is more suitable for space-constrained or low-pin-count designs?
The ADS7816UCG4 is more suitable for space-constrained designs. Its 8-pin VSSOP package and serial interface require far fewer PCB traces and pins than the ADS7809U's 28-pin SOIC package with a parallel bus, making it preferable when board space and pin count are critical.