Part A
ADS7955QDBTRQ1
Texas Instruments
- Lifecycle
- Active
- Stock
- 7159 Stückzahl
- Package
- TSSOP-30
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADS7955QDBTRQ1 is a functionally compatible replacement candidate for the ADS7953QDBTRQ1, sharing the same package, pinout, interface, and automotive qualification, with the primary distinction being a reduced channel count (8 versus 16). Designers must confirm that the lower channel count satisfies system requirements before substituting.
Package Type
High match
Resolution
High match
Channel Count
Not compatible
Interface Type
High match
Parts at a glance
Part B
ADS7953QDBTRQ1
National Semiconductor
- Lifecycle
- Active
- Stock
- 1543 Stückzahl
- Package
- TSSOP-38
- Series
- Datenerfassung mit 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 | ADS7953QDBTRQ1 | ADS7955QDBTRQ1 | Why it matters |
|---|---|---|---|
| Number of Input Channels | 16 | 8 | Channel count determines how many analog signals can be sampled; a 16-channel device cannot be directly substituted where 8 channels suffice, and vice versa the 8-channel part cannot cover 16 signals. |
| Resolution | 12 bit | 12 bit | Resolution sets the quantization step and achievable accuracy; matching 12-bit resolution preserves measurement precision when substituting. |
| Sampling Rate | 1 MSPS | 1 MSPS | Maximum throughput must meet the system's signal bandwidth and timing requirements; identical 1 MSPS rates allow equivalent acquisition speed. |
| Supply Voltage | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Operating supply range must match the board's available rails; identical ranges ensure the substitute works in the same power environment. |
| Interface Type | SPI | SPI | The digital interface must be compatible with the host controller; matching SPI interfaces allow reuse of existing firmware and wiring. |
| Input Type | Single-ended | Single-ended | Single-ended versus differential input topology affects signal conditioning and grounding; matching topology simplifies substitution. |
| Package | TSSOP-38 | TSSOP-38 | Package and pinout must be footprint-compatible for a drop-in replacement; identical TSSOP-38 packages allow the same PCB land pattern. |
| Operating Temperature Range | -40 °C to 125 °C | -40 °C to 125 °C | The temperature range must cover the application's environment; matching automotive-grade ranges ensure equivalent reliability. |
| Qualification | AEC-Q100 | AEC-Q100 | Automotive qualification indicates the part meets stringent reliability standards; matching AEC-Q100 status preserves qualification compliance. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADS7955QDBTRQ1 | ADS7953QDBTRQ1 |
|---|---|---|
| Series | Automotive, AEC-Q100 | Automotive, AEC-Q100 |
| Part Status | Active | Active |
| Number of Bits | 10 | 12 |
| Sampling Rate(Per Second) | 1M | 1M |
| Number of Inputs | 8 | 16 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI | SPI |
| Configuration | MUX-PGA-S/H-ADC | MUX-PGA-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 |
| Features | PGA | PGA |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 125°C |
Frequently asked questions
What are the key differences between the ADS7953QDBTRQ1 and ADS7955QDBTRQ1?
The primary difference is channel count and resolution. The ADS7953QDBTRQ1 is a 12-bit, 16-channel successive-approximation register (SAR) analog-to-digital converter (ADC), while the ADS7955QDBTRQ1 is a 10-bit, 8-channel SAR ADC. Both are automotive-qualified (AEC-Q100) devices from Texas Instruments in a 38-pin TSSOP (DBT) package and share the same SPI-compatible serial interface family.
Are the ADS7953QDBTRQ1 and ADS7955QDBTRQ1 pin-compatible?
No. The ADS7953QDBTRQ1 uses a 38-pin TSSOP (DBT) package with 16 analog inputs, while the ADS7955QDBTRQ1 is offered in a smaller package with 8 analog inputs. The pin counts and analog input assignments differ, so they are not drop-in replacements for one another.
What is the resolution and channel count of each device?
The ADS7953QDBTRQ1 provides 12-bit resolution across 16 single-ended input channels (configurable in pairs for pseudo-differential operation). The ADS7955QDBTRQ1 provides 10-bit resolution across 8 single-ended input channels. Both devices support a programmable auto-sequencing mode for scanning channels.
Do both devices support the same serial interface and supply voltage?
Yes. Both the ADS7953QDBTRQ1 and ADS7955QDBTRQ1 use an SPI-compatible serial interface and operate from a single analog supply of 2.7 V to 5.25 V, with a separate digital I/O supply (VBD) of 1.7 V to 5.25 V. This allows direct interfacing to 1.8 V, 3.3 V, or 5 V logic without level shifting.
What are the maximum sampling rates of these ADCs?
Both the ADS7953QDBTRQ1 and ADS7955QDBTRQ1 support a maximum throughput of 1 MSPS (1 megasample per second). The achievable per-channel rate depends on the number of channels being sequenced in auto-scan mode.
Are both parts AEC-Q100 qualified for automotive applications?
Yes. Both the ADS7953QDBTRQ1 and ADS7955QDBTRQ1 carry the "Q1" suffix, indicating they are AEC-Q100 qualified automotive-grade devices from Texas Instruments, suitable for use in automotive and other harsh-environment applications.
Can the ADS7955QDBTRQ1 replace the ADS7953QDBTRQ1 in an existing design?
Not directly. Because the ADS7955QDBTRQ1 has fewer channels (8 vs. 16), lower resolution (10-bit vs. 12-bit), and a different package/pinout, a redesign of the analog front end, PCB layout, and firmware channel-sequencing logic would be required. The replacement is only appropriate if the reduced channel count and resolution meet the system requirements.
What input voltage range do these ADCs support?
Both devices support a unipolar analog input range of 0 V to VREF, where VREF is the external reference voltage (typically up to the analog supply). The input range is therefore set by the applied reference, allowing flexible scaling of the measurement span.