Part A
ADC121S101CIMF
Texas Instruments
- Lifecycle
- Active
- Stock
- 3205 Stückzahl
- Package
- SOT-23-6
- Series
- Datenerfassung mit Analog to Digital Converters (ADC)
Replacement verdict
Compatible functional replacement candidate
The ADC121S021CIMFX is a functional replacement candidate for the ADC121S101CIMF, sharing the same 12-bit SAR architecture, SPI interface, and SOT-23-6 footprint, but it requires validation of the reduced 50 kSPS to 200 kSPS sampling rate against system timing requirements before substitution.
Resolution and Architecture
High match
Package and Pinout
High match
Sampling Rate
Validation required
Supply Voltage and Interface
High match
Parts at a glance
Part B
ADC121S021CIMFX
Texas Instruments
- Lifecycle
- Active
- Stock
- 7767 Stückzahl
- Package
- SOT-23-6
- 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 | ADC121S101CIMF | ADC121S021CIMFX | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both converters provide the same 12-bit resolution, so measurement granularity is equivalent. |
| Sampling Rate | 1 MSPS | 200 kSPS | The higher sampling rate of the ADC121S101 allows capture of faster-changing signals; the ADC121S021 is limited to slower waveforms. |
| Number of Input Channels | 1 (single-ended) | 1 (single-ended) | Both are single-channel devices, so channel count does not differentiate them for substitution. |
| Supply Voltage Range | 2.7 V to 5.25 V | 2.7 V to 5.25 V | Identical supply range means both can operate from the same system rails without level shifting. |
| Interface Type | SPI / QSPI / MICROWIRE compatible | SPI / QSPI / MICROWIRE compatible | Same serial interface allows drop-in compatibility with existing digital host connections. |
| Package | SOT-23-6 | SOT-23-6 | Identical package footprint enables direct PCB replacement without layout changes. |
| Power Consumption (Typical) | Approx. 2 mW at 3 V (1 MSPS) | Approx. 0.5 mW at 3 V (200 kSPS) | The lower sampling rate of the ADC121S021 yields lower power draw, which matters for battery-powered designs. |
| Signal-to-Noise Ratio (SNR) | 72 dB (typ) | 72 dB (typ) | Equivalent SNR indicates comparable noise performance for both converters. |
| Operating Temperature Range | -40 °C to +125 °C | -40 °C to +85 °C | The wider temperature range of the ADC121S101 suits harsher environments, while the ADC121S021 is limited to standard industrial conditions. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADC121S101CIMF | ADC121S021CIMFX |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Obsolete | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 1M | 200k |
| Number of Inputs | 1 | 1 |
| Input Type | Single Ended | Single Ended |
| Data Interface | SPI, DSP | SPI, DSP |
| 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 | Supply | Supply |
| Voltage - Supply, Analog | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Voltage - Supply, Digital | 2.7V ~ 5.25V | 2.7V ~ 5.25V |
| Operating Temperature | -40°C ~ 125°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the ADC121S101CIMF and ADC121S021CIMFX?
The ADC121S101CIMF is a 12-bit, 1 MSPS successive-approximation ADC with a single-ended input, while the ADC121S021CIMFX is a 12-bit, 200 kSPS ADC with a single-ended input. Both are pin-compatible in the SOT-23-6 package and share the same SPI-compatible serial interface, but they differ in maximum throughput rate and power consumption.
Are the ADC121S101CIMF and ADC121S021CIMFX pin-compatible?
Yes. Both devices are offered in the 6-pin SOT-23 package with the same pinout (VIN, GND, CS, SCLK, DOUT, and VA). This allows the ADC121S021CIMFX to be used as a lower-speed drop-in alternative to the ADC121S101CIMF, provided the system timing and throughput requirements are met.
What is the maximum sampling rate of each device?
The ADC121S101CIMF supports a maximum conversion rate of 1 MSPS. The ADC121S021CIMFX supports a maximum conversion rate of 200 kSPS. Designs requiring sample rates above 200 kSPS must use the ADC121S101CIMF.
Do both ADCs use the same serial interface?
Yes. Both devices use a SPI-compatible serial interface with CS, SCLK, and DOUT signals. The ADC121S021CIMFX requires a minimum of 13 SCLK cycles per conversion, while the ADC121S101CIMF requires 16 SCLK cycles per conversion. Firmware timing must account for this difference when interchanging the parts.
How do the power consumption figures compare?
The ADC121S101CIMF typically consumes about 2.5 mW at 1 MSPS with a 3.3 V supply. The ADC121S021CIMFX typically consumes about 0.5 mW at 200 kSPS with a 3.3 V supply. Both devices offer a power-down mode that reduces supply current to the microampere range when not converting.
What is the resolution and input type of these ADCs?
Both the ADC121S101CIMF and ADC121S021CIMFX are 12-bit successive-approximation ADCs with a single-ended, unipolar analog input. They operate from a single supply of 2.7 V to 5.25 V and provide a full-scale input range equal to the supply voltage.
Can the ADC121S021CIMFX replace the ADC121S101CIMF in an existing design?
It can be a drop-in replacement only if the system's maximum required sample rate is 200 kSPS or less and the firmware is adjusted for the 13-clock versus 16-clock frame length. For applications requiring throughput above 200 kSPS, the ADC121S101CIMF must be retained.
What are the operating temperature ranges for these devices?
Both the ADC121S101CIMF and ADC121S021CIMFX are specified over the industrial temperature range of −40 °C to +85 °C, making them suitable for industrial and embedded applications.