Part A
ADS7822U
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 7079 PCS
- Package
- SOIC-8
- Series
- Data Acquisition - Analog to Digital Converters (ADC)
Replacement verdict
Not a drop-in replacement
The ADS7822U and ADS7804UE4 are not drop-in replacements for one another. The ADS7822U is a 12-bit micropower SAR ADC in a small SOIC-8 package with a serial SPI interface, while the ADS7804UE4 is a 12-bit sampling ADC in a wide SOIC-28 package with a parallel byte interface and an internal reference. Their package footprints, digital interfaces, supply and reference architectures, and throughput characteristics differ substantially, so a direct board-level substitution is not feasible without redesign.
Different package footprint
Different digital interface
Different reference architecture
Different throughput class
Parts at a glance
Part B
ADS7804UE4
Texas Dụng cụ
- Lifecycle
- Active
- Stock
- 4392 PCS
- Package
- SOIC-28
- 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 | ADS7822U | ADS7804UE4 | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both are 12-bit ADCs, so nominal quantization resolution is equivalent for substitutability. |
| Sampling Rate | 200 kSPS | 100 kSPS | The ADS7822U can sample twice as fast, which matters for higher-bandwidth signal acquisition. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both are single-channel devices, so channel count does not differentiate them. |
| Input Type | Single-ended | Single-ended | Matching input configuration simplifies direct replacement in single-ended measurement circuits. |
| Supply Voltage | 2.7 V to 5.25 V | 5 V (single supply) | The ADS7822U supports lower supply voltages, enabling use in 3.3 V systems where the ADS7804UE4 cannot operate. |
| Interface | SPI / serial | Parallel | Different digital interfaces require different host connections, so they are not pin/interface compatible. |
| Package / Mounting | 8-SOIC (surface mount) | 28-SOIC (surface mount) | Different package sizes and pin counts prevent direct board-level substitution. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical temperature ratings mean both suit the same industrial ambient conditions. |
| Power Consumption | Low power (micropower, ~1.6 mW at 5 V) | Higher power (~100 mW typical) | The ADS7822U is far more power-efficient, which is critical for battery-powered or thermally constrained designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7822U | ADS7804UE4 |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC,Texas Instruments |
| Part Status | Active | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 100k |
| Number of Inputs | 1 | 1 |
| Input Type | Pseudo-Differential | Single Ended |
| Data Interface | SPI | Parallel |
| 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, Internal |
| Voltage - Supply, Analog | 2.7V ~ 3.6V, 5V | 5V |
| Voltage - Supply, Digital | 2.7V ~ 3.6V, 5V | 5V |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Series | microPOWER™ | - |
Frequently asked questions
What are the key differences between the ADS7822U and the ADS7804UE4?
The ADS7822U is a 12-bit, 200-kSPS micropower sampling analog-to-digital converter with a pseudo-differential input and an SPI-compatible serial interface, supplied in an SOIC-8 package. The ADS7804UE4 is a 12-bit, 100-kSPS sampling ADC with a parallel 8-bit/12-bit interface, an internal reference, and a full 12-bit parallel output, supplied in a 28-pin SOIC package. They differ in resolution interface type, throughput, package, and input architecture.
Are the ADS7822U and ADS7804UE4 pin-to-pin or package compatible?
No. The ADS7822U is offered in an 8-pin SOIC (SOIC-8) package, while the ADS7804UE4 is offered in a 28-pin SOIC (SOIC-28) package. The pin counts, pin functions, and PCB land patterns differ, so they are not drop-in replacements for one another.
Do the ADS7822U and ADS7804UE4 use the same digital interface?
No. The ADS7822U uses a serial SPI-compatible interface for data output and control. The ADS7804UE4 provides a parallel interface with selectable 8-bit or 12-bit output modes. System firmware and host interface wiring must be redesigned when migrating between these devices.
How do the sampling rates of the ADS7822U and ADS7804UE4 compare?
The ADS7822U is specified for a 200-kSPS maximum sampling rate. The ADS7804UE4 is specified for a 100-kSPS maximum sampling rate. The ADS7822U therefore offers twice the throughput of the ADS7804UE4 under their published maximum ratings.
Do both devices provide an internal voltage reference?
No. The ADS7804UE4 includes an internal reference and reference buffer, allowing ratiometric or absolute operation without an external reference in many designs. The ADS7822U does not include an internal reference and requires an external reference voltage applied to its VREF pin for conversion.
What are the input configurations of the ADS7822U and ADS7804UE4?
The ADS7822U provides a pseudo-differential input pair (+IN and -IN) and is typically configured for single-ended or pseudo-differential signals. The ADS7804UE4 provides a full 12-bit successive-approximation input with an internal sample-and-hold and is configured for single-channel analog input with a defined input range set by the reference. Input drive and signal conditioning requirements differ between the two parts.
Can the ADS7822U and ADS7804UE4 operate from the same supply voltage?
Both devices are specified for a single +5 V analog supply in their standard grades. However, because the ADS7822U is a micropower device optimized for low power consumption and the ADS7804UE4 integrates an internal reference and parallel interface, overall supply current and power dissipation differ. Designers should verify the exact grade and datasheet limits for the target operating conditions.
Which device is more suitable for low-power, space-constrained designs?
The ADS7822U is generally more suitable for low-power and space-constrained designs because it is a micropower 12-bit ADC in an 8-pin SOIC package with a serial interface, reducing pin count and board area. The ADS7804UE4, with its 28-pin package, parallel interface, and internal reference, is better suited to systems that require parallel data access and an on-chip reference.