Part A
ADC121S021CIMF
德州儀器
- Lifecycle
- Active
- Stock
- 6879 件
- Package
- SOT-23-6
- Series
- 資料獲取-模數轉換器（ADC）
Replacement verdict
Compatible functional replacement candidate
The ADC121S051CIMFX is a higher-resolution variant within the same ADC121S0xx family and shares the identical SOT-23-6 footprint, pinout, and single-channel SAR architecture as the ADC121S021CIMF, making it a viable functional upgrade candidate. The primary distinction is resolution (12-bit versus 10-bit), which requires firmware or configuration validation to confirm the host interface tolerates the increased conversion word length. Designers should verify SPI frame handling and timing before adopting the ADC121S051CIMFX as a direct substitute.
Package Type
High match
Pin Configuration
High match
Resolution
Validation required
Interface Type
High match
Parts at a glance
Part B
ADC121S051CIMFX
德州儀器
- Lifecycle
- Active
- Stock
- 3257 件
- Package
- SOT-23-6
- Series
- 資料獲取-模數轉換器（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 | ADC121S021CIMF | ADC121S051CIMFX | Why it matters |
|---|---|---|---|
| Resolution | 12 bit | 12 bit | Both converters provide 12-bit resolution, so quantization step size is equivalent for a given reference voltage. |
| Sampling Rate | 200 kSPS | 500 kSPS | The higher throughput of the ADC121S051 allows faster signal acquisition and supports wider input bandwidth applications. |
| Number of Input Channels | 1 single-ended | 1 single-ended | Both are single-channel devices, so channel count does not differentiate them for multiplexed system designs. |
| 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 3.3 V or 5 V rails without level shifting. |
| Interface Type | SPI / QSPI / MICROWIRE compatible | SPI / QSPI / MICROWIRE compatible | Matching serial interfaces allow either part to connect to the same host controller without protocol changes. |
| Package / Mounting | SOT-23-6, surface mount | SOT-23-6, surface mount | Same package and footprint enables drop-in board replacement without layout modification. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Equivalent temperature ratings ensure both parts suit the same industrial and commercial environments. |
| Power Consumption (Typical) | Lower (200 kSPS throughput) | Higher (500 kSPS throughput) | The faster device generally draws more supply current, which affects power budget in battery-powered designs. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | ADC121S021CIMF | ADC121S051CIMFX |
|---|---|---|
| Supplier | - | Texas Instruments |
| Part Status | Not For New Designs | Obsolete |
| Number of Bits | 12 | 12 |
| Sampling Rate(Per Second) | 200k | 500k |
| 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 ~ 85°C | -40°C ~ 85°C |
Frequently asked questions
What are the key differences between the ADC121S021CIMF and ADC121S051CIMFX?
The ADC121S021CIMF is a 12-bit, 200 kSPS successive-approximation ADC with a single-ended input, while the ADC121S051CIMFX is a 12-bit, 500 kSPS SAR ADC with a single-ended input. The primary differences are the maximum sampling rate (200 kSPS vs 500 kSPS) and the supply current consumption, which is typically lower for the 200 kSPS device. Both are offered in a 6-pin SOT-23 package and operate over the -40°C to +85°C temperature range.
Are the ADC121S021CIMF and ADC121S051CIMFX pin-compatible?
Yes. Both devices are supplied in the same 6-pin SOT-23 (CIMF package) and share an identical pinout: VIN, GND, VREF, CS, SCLK, and SDATA. This allows the ADC121S051CIMFX to be used as a drop-in replacement for the ADC121S021CIMF on an existing PCB layout, provided the higher sampling rate and associated timing requirements are accommodated by the host interface.
Can the ADC121S051CIMFX directly replace the ADC121S021CIMF in an existing design?
In most cases yes, because both parts share the same package, pinout, 12-bit resolution, single-ended input, and SPI-compatible serial interface. However, the ADC121S051CIMFX supports a higher throughput of 500 kSPS versus 200 kSPS for the ADC121S021CIMF, so the system clock (SCLK) timing and the host's ability to service conversions at the higher rate must be verified. The reference voltage range and analog input range should also be confirmed against the target design requirements.
What is the maximum sampling rate of each device?
The ADC121S021CIMF has a maximum conversion rate of 200 kSPS. The ADC121S051CIMFX has a maximum conversion rate of 500 kSPS. Both are 12-bit successive-approximation register (SAR) ADCs, so the higher rate of the ADC121S051CIMFX comes with correspondingly tighter SCLK timing and shorter acquisition time requirements.
Do both parts use the same serial interface and reference configuration?
Yes. Both devices use a 3-wire or 4-wire SPI-compatible serial interface with CS, SCLK, and SDATA pins, and both require an external reference voltage applied to the VREF pin. The analog input is single-ended and referenced to VREF. Because the interface protocol and reference architecture are the same, firmware written for one device is generally portable to the other, subject to the timing differences imposed by the higher SCLK rate of the ADC121S051CIMFX.
What are the power supply and current consumption specifications for these ADCs?
Both devices operate from a single supply in the 2.7 V to 5.25 V range. The ADC121S021CIMF typically draws a lower supply current than the ADC121S051CIMFX because of its lower 200 kSPS throughput, while the ADC121S051CIMFX consumes more current to support 500 kSPS operation. For exact quiescent and active current figures, consult the respective manufacturer datasheets, as values vary with supply voltage and sampling rate.
In which package and temperature grade are these ADCs available?
Both the ADC121S021CIMF and ADC121S051CIMFX are offered in the 6-pin SOT-23 package, denoted by the CIMF suffix. Both are specified over the industrial temperature range of -40°C to +85°C. The "X" suffix on the ADC121S051CIMFX indicates a tape-and-reel packing option; it does not change the electrical or thermal specifications of the device.
Which device should be selected for a higher-throughput application?
For applications requiring sampling rates above 200 kSPS, the ADC121S051CIMFX should be selected because it supports up to 500 kSPS while maintaining 12-bit resolution. For lower-speed, power-sensitive designs, the ADC121S021CIMF is the more appropriate choice due to its lower throughput and correspondingly lower current consumption. Both share the same footprint, interface, and reference architecture, simplifying migration between the two.