Part A
ADS7955QDBTRQ1
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 7159 個数
- Package
- TSSOP-30
- Series
- データ取得 - アナログ/デジタルコンバータ (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7955QDBTRQ1 and ADS7951SDBTG4 are both 12-bit, 1-MSPS SAR ADCs from the ADS795x family in a 38-pin TSSOP package with an SPI-compatible serial interface, making them strong functional replacement candidates. The primary distinction is channel count: the ADS7955QDBTRQ1 provides 8 single-ended input channels, while the ADS7951SDBTG4 offers 4 single-ended channels. Designers must confirm that the reduced channel count and the automotive-qualified versus industrial-grade qualification differences are acceptable for the target application before substituting.
Resolution and Sample Rate
High match
Package Type
High match
Channel Count
Validation required
Qualification Grade
Validation required
Parts at a glance
Part B
ADS7951SDBTG4
STマイクロエレクトロニクス
- Lifecycle
- Active
- Stock
- 7822 個数
- Package
- TFSOP-30
- Series
- データ取得 - アナログ/デジタルコンバータ (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 | ADS7955QDBTRQ1 | ADS7951SDBTG4 | Why it matters |
|---|---|---|---|
| Resolution | 10 bit | 12 bit | Resolution determines the smallest measurable voltage step; a 12-bit ADC provides four times finer quantization than a 10-bit device, affecting measurement accuracy. |
| Number of Input Channels | 8 single-ended | 8 single-ended | Channel count defines how many analog signals can be multiplexed into the ADC; matching counts supports similar sensor-array topologies. |
| Sampling Rate | 1 MSPS | 1 MSPS | Maximum throughput limits the bandwidth of signals that can be digitized; equal rates mean comparable timing performance for the host interface. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Operating supply range must match the system rail; identical ranges allow drop-in use across the same power architecture. |
| Interface Type | SPI | SPI | The digital interface must be compatible with the host controller; both using SPI simplifies firmware and pin-level substitution. |
| Input Type | Single-ended | Single-ended | Single-ended versus differential input affects signal conditioning circuitry and noise immunity; matching types preserves the analog front end. |
| Package / Pin Count | TSSOP-30 | TSSOP-30 | Package and pin count determine PCB footprint and layout compatibility; identical packages enable board-level interchangeability. |
| Operating Temperature Range | -40 °C to 125 °C | -40 °C to 125 °C | Temperature range must cover the application environment; matching ranges ensure equivalent reliability in harsh conditions. |
| Automotive Qualification | AEC-Q100 qualified | Not AEC-Q100 qualified | AEC-Q100 qualification indicates automotive-grade reliability; the non-qualified part may not be acceptable for automotive designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7955QDBTRQ1 | ADS7951SDBTG4 |
|---|---|---|
| Supplier | - | Texas Instruments |
| Series | Automotive, AEC-Q100 | microPOWER™ |
| Part Status | Active | Discontinued at Digi-Key |
| Number of Bits | 10 | 12 |
| Sampling Rate(Per Second) | 1M | 1M |
| Number of Inputs | 8 | 8 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI | SPI |
| Configuration | MUX-PGA-S/H-ADC | MUX-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 | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Voltage - Supply, Digital | 1.7V ~ 5.25V | 1.7V ~ 5.25V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
| Features | PGA | - |
Frequently asked questions
What are the key differences between the ADS7955QDBTRQ1 and the ADS7951SDBTG4?
The ADS7955QDBTRQ1 is an automotive-qualified (AEC-Q100 Grade 1) 10-bit, 8-channel, 1-MSPS SAR ADC in a 30-pin TSSOP package, while the ADS7951SDBTG4 is a non-automotive 12-bit, 8-channel, 1-MSPS SAR ADC in a 30-pin TSSOP package. The primary differences are resolution (10-bit vs 12-bit) and qualification grade (automotive Q1 vs industrial).
Are the ADS7955QDBTRQ1 and ADS7951SDBTG4 pin-compatible?
Both devices are offered in the same 30-pin TSSOP (DBT) package and share the same pinout family (ADS795x series), so they are pin-compatible at the package level. However, pin-compatibility does not guarantee functional equivalence; the resolution difference and qualification grade must be validated for the target design.
Do both ADCs support the same serial interface?
Yes. Both the ADS7955QDBTRQ1 and ADS7951SDBTG4 use a SPI-compatible serial interface with the same command set and timing structure from the ADS795x family, supporting daisy-chain and multi-device configurations.
What is the resolution and sampling rate of each device?
The ADS7955QDBTRQ1 provides 10-bit resolution at up to 1 MSPS. The ADS7951SDBTG4 provides 12-bit resolution at up to 1 MSPS. Both are 8-channel, single-ended input SAR ADCs.
Which device is suitable for automotive applications?
The ADS7955QDBTRQ1 is AEC-Q100 Grade 1 qualified and specified for automotive use. The ADS7951SDBTG4 is an industrial-grade device and is not automotive-qualified, so it should not be used in automotive designs requiring Q1 qualification.
Can the ADS7951SDBTG4 be used as a drop-in replacement for the ADS7955QDBTRQ1?
Not as a direct drop-in. Although both are 8-channel, 1-MSPS SAR ADCs in the same 30-pin TSSOP package, the ADS7951SDBTG4 offers 12-bit resolution versus 10-bit on the ADS7955QDBTRQ1, and it lacks AEC-Q100 Grade 1 qualification. System firmware, accuracy budgets, and qualification requirements must be re-validated before substitution.
What are the supply voltage and reference requirements for these ADCs?
Both devices operate from a single analog supply in the 2.7 V to 5.25 V range and use an external reference voltage to set the full-scale input range. The reference input range and analog supply must be verified against the respective datasheet for the target design.