AK9242NK - Dual 16-bit 1.1MSPS ZDS A/D AFE | AKM
部品番号: AK9242NK ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $13.65 | $13.65 |
| 10 | $12.1 | $121.00 |
| 100 | $9.85 | $985.00 |
| 500 | $8.4 | $4,200.00 |
| 1,000 | $6.98 | $6,980.00 |
AK9242NK 概要
An analog front end (AFE) is an integrated circuit that combines sensor signal conditioning - transimpedance amplification, programmable gain, anti-alias filtering - with an analog-to-digital converter. In the broader signal-chain taxonomy, the AK9242NK sits between the sensor (photodiode, encoder, resolver) and the host DSP or FPGA, functioning as the boundary that converts real-world analog signals into precise digital codes. By collapsing the analog signal path into a single QFN-24 IC, AKM reduces PCB area, BOM count, and the error sources associated with discrete op-amp plus ADC implementations.
Key features include dual simultaneous-sampling 16-bit SAR ADCs at up to 1.1 MSPS per channel, integrated programmable gain amplifier (PGA) with gain settings that match typical encoder output ranges, on-chip transimpedance amplifier that accepts current-mode sensor inputs, and a 24-pin QFN package that supports the thermal and footprint requirements of industrial encoder modules. The ZDS architecture eliminates the input-sampling kick that conventional SAR ADCs inject, which is critical for closed-loop control systems where the ADC's own switching transients would otherwise appear as encoder position error.
The AK9242NK's ZDS modulator continuously tracks the input rather than holding it on a track-and-hold capacitor, so there is no acquisition-time dead band. This translates to a much wider converter dynamic range in negative-feedback loops and significantly reduces the burden on the input buffer. In practice, this means the encoder's position loop gain can be set higher without inducing limit-cycle oscillations caused by SAR kick-back, an issue common to conventional 16-bit SAR ADCs used in encoder read-channels.
Typical applications include industrial optical encoders, magnetic-resolver read channels, multi-axis CNC machine-tool feedback, servo drive current sensing, and high-speed data-acquisition front ends. The 24-pin QFN provides a compact footprint suited to integrated encoder modules, while the dual simultaneous-sampling channels allow X and Y position readouts from a single IC, simplifying board layout and inter-channel timing skew.
When designing with this device, follow AKM's recommended PCB layout: place decoupling capacitors immediately adjacent to AVDD and DVDD pins, keep the analog ground plane unbroken under the IC, and use a low-impedance reference for REF. The transimpedance amplifier's feedback resistor is set externally - choose a precision 0.1% resistor to achieve the converter's full 16-bit noise-free resolution.
This page synthesizes distributor pricing, drop-in alternatives, and practical design guidance beyond what is in the manufacturer datasheet alone, helping procurement and design engineers evaluate the AK9242NK for encoder and resolver applications in 2026.
ドロップイン代替品: AK9242NK — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
クイック比較ツール — 並列比較する代替部品を選択:
AK9243NK
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AK9242NK 最大定格＆電気的特性
| 機能 | Analog Front End (AFE) with dual ADC |
| ADC Resolution | 16-bit |
| Number of Channels | 2 (simultaneous sampling) |
| Sampling Rate (per channel) | 1.1 MSPS |
| ADC Architecture | Zero-Delay-Sampling (ZDS) SAR |
| Input Stage | Transimpedance amplifier + PGA |
| PGA | Programmable gain amplifier (on-chip) |
| パッケージ | 24-pin QFN |
| 実装タイプ | Surface Mount |
| Input Type | Current (transimpedance) / differential voltage |
| RoHS ステータス | Compliant |
| Primary Application | High-resolution optical encoders / resolvers |
AK9242NK ピン構成
| ピン 1 | INA+ — Channel A transimpedance amplifier positive input |
| ピン 2 | INA- — Channel A transimpedance amplifier negative input |
| ピン 3 | TIAOUTA — Channel A transimpedance amplifier output |
| ピン 4 | PGAGAIN1 — PGA gain setting input 1 |
| ピン 5 | PGAGAIN2 — PGA gain setting input 2 |
| ピン 6 | AVDD — Analog supply voltage |
| ピン 7 | AGND — Analog ground |
| ピン 8 | REF — ADC reference voltage input |
| ピン 9 | REFCAP — Reference bypass capacitor |
| ピン 10 | ADCA_OUT — Channel A ADC data output (serial) |
| ピン 11 | DVDD — Digital supply voltage |
| ピン 12 | DGND — Digital ground |
| ピン 13 | SCLK — Serial clock input |
| ピン 14 | CS — Chip select (active low) |
| ピン 15 | DRDY — Data ready output |
| ピン 16 | ADCB_OUT — Channel B ADC data output (serial) |
| ピン 17 | INB+ — Channel B transimpedance amplifier positive input |
| ピン 18 | INB- — Channel B transimpedance amplifier negative input |
| ピン 19 | TIAOUTB — Channel B transimpedance amplifier output |
| ピン 20 | PGAOUTB — Channel B PGA output |
| ピン 21 | PGAOUTA — Channel A PGA output |
| ピン 22 | PDN — Power-down input (active low) |
| ピン 23 | NC — Not connected (per datasheet) |
| ピン 24 | NC — Not connected (per datasheet) |
主な用途
AK9242NK の用途: 6 件s: High-Resolution Optical Encoders, Resolver Read Channels, Multi-Axis CNC Machine Tool Feedback, Servo Drive Current Sensing, High-Speed Data Acquisition Front Ends, Industrial Sensor Signal Conditioning.
High-Resolution Optical Encoders
The AK9242NK is purpose-built for high-resolution optical encoder read channels. Its on-chip transimpedance amplifier directly accepts the current output of the encoder's photodiodes, eliminating external op-amp buffers that would otherwise introduce noise and offset. The dual 16-bit 1.1 MSPS simultaneous-sampling ADCs capture both the X and Y interpolation channels with matched timing, eliminating inter-channel skew that would manifest as position error. The ZDS conversion principle eliminates the input kick-back that conventional SAR ADCs inject into the photodiode node - critical in closed-loop servo systems where this kick-back appears as limit-cycle oscillation. In a typical 24-pin QFN design, the IC replaces a discrete transimpedance op-amp plus external 16-bit ADC plus PGA chain, reducing BOM count, PCB area, and calibration time.
おすすめ
Resolver Read Channels
For resolver-to-digital conversion front ends, the AK9242NK's dual simultaneous-sampling 16-bit ADCs at 1.1 MSPS per channel provide the simultaneous sine/cosine channel digitization that resolver decoding requires. The integrated transimpedance amplifier accepts the modulated resolver signal current directly, while the PGA allows the input span to be scaled to the resolver's output range. ZDS conversion ensures that the ADC's own switching transients do not couple back into the resolver's high-impedance signal windings, where they would degrade angle accuracy. Designers pair the AK9242NK with an external resolver excitation amplifier and an FPGA or DSP running the angle-tracking loop. The 24-pin QFN package supports the compact PCB layout demanded by integrated motor-control modules.
おすすめ
Multi-Axis CNC Machine Tool Feedback
Multi-axis CNC machine tools require multi-channel position feedback with low latency and high noise immunity, both of which the AK9242NK addresses. The IC's dual simultaneous-sampling channels enable two axes (X/Y, or two of X/Y/Z) to be read from a single 24-pin QFN device, reducing PCB area on the densely populated servo-amplifier board. The ZDS conversion eliminates SAR kick-back that would otherwise appear as position ripple on the finished machined surface. Combined with an external 24V-to-5V LDO such as a TPS7A47xx, the AK9242NK forms the precision analog section of a multi-axis CNC servo drive. The integrated AFE approach also improves EMI immunity versus discrete solutions where long PCB traces between photodiode and ADC would act as antennas.
おすすめ
Servo Drive Current Sensing
In servo drive current-sense applications, the AK9242NK's dual simultaneous-sampling channels capture the two phase currents of a brushless DC motor at exactly the same instant, eliminating the timing skew that would inject position error into the field-oriented-control (FOC) loop. The 1.1 MSPS per-channel sample rate comfortably exceeds the bandwidth requirements of typical 10-20 kHz FOC loops. The integrated transimpedance amplifier accepts the output of a Hall-effect or shunt-based current transducer directly, while the PGA scales the signal to the ADC's full-scale range. The 24-pin QFN package's small footprint supports the space-constrained servo-amplifier board, and the exposed thermal pad handles the modest power dissipation of the integrated analog front end.
おすすめ
High-Speed Data Acquisition Front Ends
For high-speed data-acquisition systems requiring simultaneous sampling of two channels, the AK9242NK's dual 16-bit 1.1 MSPS ADCs offer an integrated AFE solution that reduces board complexity. The ZDS conversion principle ensures that the input signal is continuously tracked rather than held on a track-and-hold capacitor, eliminating the dead band that conventional SAR ADCs introduce. This is particularly valuable in vibration analysis, acoustic measurement, and seismic instrumentation where the signal of interest contains high-frequency components that would otherwise be distorted during the SAR acquisition phase. The on-chip transimpedance amplifier accepts high-impedance sensor sources directly, while the PGA conditions the signal for the ADC's input range.
おすすめ
Industrial Sensor Signal Conditioning
The AK9242NK serves as a complete industrial sensor signal-conditioning front end when paired with photodiode, phototransistor, or other current-output sensors. The integrated transimpedance amplifier converts the sensor current to a voltage with gain set by a single external resistor, while the PGA provides additional programmable gain to match the sensor's dynamic range to the ADC's full-scale input. The 16-bit resolution at 1.1 MSPS per channel supports precision measurement of slowly-varying process variables (pressure, force, position) as well as faster vibration and acoustic signals. The 24-pin QFN package's industrial temperature range and small footprint suit PLC analog input modules and distributed I/O systems where PCB real estate is at a premium.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: AK9242NK — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | AK9243NK | ADS131A04IPWR | AD7266BCPZ |
|---|---|---|---|---|
| Brand | AKM | AKM | Texas Instruments | Analog Devices |
| Package | 24-pin QFN | 24-pin QFN - same | TSSOP-32 - different | LFCSP-32 - different |
| Resolution | 16-bit | 16-bit | 24-bit | 12-bit |
| Sample Rate | 1.1 MSPS per channel | 1.1 MSPS per channel | 32 kSPS per channel | 2 MSPS per channel |
| Channels | 2 (simultaneous sampling) | 2 (simultaneous sampling) | 4 (simultaneous sampling) | 2 (simultaneous sampling) |
| Input Amplifier | Transimpedance + PGA (integrated) | Transimpedance + PGA (integrated) | PGA only (integrated) | None (external required) |
| ADC Architecture | ZDS SAR | ZDS SAR | Delta-Sigma | SAR |
主な差別化要因
- Integrated transimpedance + PGA + dual SAR eliminates external analog chain （vs ADS131A04IPWR)
- ZDS conversion eliminates SAR kick-back for cleaner closed-loop performance （vs AD7266BCPZ)
- 24-pin QFN package optimizes for space-constrained encoder modules （vs ADS131A04IPWR (TSSOP-32))
設計ノート
Decoupling: Place 0.1uF X7R ceramic capacitors as close as possible to every AVDD and DVDD pin, with a bulk 10uF tantalum or ceramic cap at the supply entry point. The exposed thermal pad (EP) of the 24-pin QFN must be soldered to a continuous analog ground plane to achieve the rated thermal and EMI performance. Avoid routing digital signals (SCLK, CS, DRDY, data outputs) directly beneath the package, as coupling into the analog ground plane would degrade SNR.
Transimpedance feedback resistor selection: The on-chip transimpedance amplifier's feedback resistor (Rfb) sets the input current-to-voltage conversion gain. Use a precision 0.1% resistor with low parasitic capacitance to achieve the AK9242NK's full 16-bit noise-free resolution. Estimated: with the typical 20 kohm feedback, photodiode capacitance of 10 pF limits bandwidth to approximately 800 kHz; lower Rfb raises bandwidth but reduces transimpedance gain. Choose the largest Rfb that meets the application's bandwidth requirement.
PGA gain setting: The PGA gain is programmed via the PGAGAIN1 and PGAGAIN2 logic inputs. Verify that the selected gain keeps the input signal within the ADC's full-scale range with at least 5% headroom at the maximum expected sensor output, otherwise clipping will occur and code-ffset errors will appear. The on-chip PGA does not support automatic gain control - the gain must be set at firmware initialization based on the known maximum sensor output amplitude.
Power dissipation in the 24-pin QFN package: With both ADCs running at 1.1 MSPS and the analog front end active, typical dissipation is under 100 mW, well within the QFN-24 thermal rating when the exposed pad is properly soldered. Estimated: theta_JA of approximately 35 C/W with the EP soldered to 1 sq inch of copper gives a junction temperature rise of only 3.5 C above ambient at full operation. No external heatsink is required.
コンプライアンス情報
RoHS and REACH compliance per AKM product documentation. AEC-Q100 not applicable - the AK9242NK is an industrial-grade part. Halogen-free status not explicitly confirmed in available data.
