AD8436ACPZ-R7 - 20MHz True RMS-to-DC Converter | Analog Devices
部品番号: AD8436ACPZ-R7 ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $7.85 | $7.85 |
| 10 | $7.15 | $71.50 |
| 100 | $6.4 | $640.00 |
| 500 | $5.72 | $2,860.00 |
| 1,000 | $5.05 | $5,050.00 |
AD8436ACPZ-R7 概要
A true RMS-to-DC converter is an analog computing block that continuously extracts the root-mean-square energy of an arbitrary AC waveform and presents it as a stable DC voltage proportional to the signal's heating power. Unlike average-responding or peak-responding detectors, true RMS converters correctly measure signals with non-sinusoidal content such as PWM drive outputs, SCR phase-angle waveforms, and switching-converter ripple. The AD8436 belongs to the category hierarchy of RMS-to-DC converter -> AC measurement IC -> data acquisition -> signal chain -> power management specialized IC.
Key features include a 20 MHz bandwidth, sub-100 microsecond settling at high input levels, an on-board output buffer amplifier, and an optional averaging capacitor that lets the user trade ripple versus settling time. The AD8436 also provides a peak-mode/average-mode option, allowing it to deliver average rectified value when required. Operating from a single supply of 4.5 V to 36 V (or dual +/-5 V to +/-18 V), and consuming only 365 microamps of quiescent current, the part is engineered for battery-powered and industrial-grade instrumentation.
Technically, the AD8436 uses a proprietary translinear gain cell and matched monolithic transistor array to compute the implicit square, mean, and square-root functions in a single chip, eliminating the need for an external log-antilog circuit. The on-chip buffer allows direct drive of low-impedance loads, 1 mA or higher, while preserving DC accuracy.
Typical applications include power-line monitoring, switch-mode power supply output sensing, industrial process-control instrumentation, audio amplitude metering, RF transmitter envelope detection, and precision multimeter AC sections. The wide supply range supports 24V industrial bus rails and 48V telecom input monitoring without external regulators.
Designers should note that the on-chip averaging capacitor pin must be paired with the correct external capacitor value to control ripple and settling time. The exposed pad on the LFCSP package must be soldered to a copper pour for thermal dissipation and to achieve the stated bandwidth. This page consolidates distributor pricing, true drop-in alternatives, and design notes that go beyond the manufacturer datasheet to support faster component selection.
ドロップイン代替品: AD8436ACPZ-R7 — 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:
AD8436ACPZ-RL
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AD8436BCPZ-R7
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AD8436ACPZ-R2
✅ ドロップイン ⚠️ 仕様未検証📋 参考代替品（カタログ未掲載）
AD736ACPZ-R7
✅ ドロップイン📋 参考代替品（カタログ未掲載）
LTC1966CMS8#PBF
✅ ドロップイン📋 参考代替品（カタログ未掲載）
AD8436ACPZ-R7 最大定格＆電気的特性
| 機能 | True RMS-to-DC Converter |
| パッケージ | 20-LFCSP (4x4 mm) with Exposed Pad |
| Bandwidth | 20 MHz (1 MHz for 0.25% accuracy) |
| Conversion Accuracy | 0.25% of reading (B grade), 0.5% of reading (A grade) |
| Input Range | 3 mV RMS to 3 V RMS full-scale (larger with external attenuator) |
| Supply Voltage - Single | 4.5 V to 36 V |
| Supply Voltage - Dual | +/-5 V to +/-18 V |
| 静止電流 | 365 microA (typical) |
| Output Buffer Drive | Yes, on-chip op-amp buffer |
| Conversion Modes | True RMS, Average Rectified, Peak Mode (configurable) |
| External Capacitor Required | Single averaging capacitor |
| 動作温度 | -40C to +85C |
| 実装タイプ | Surface Mount |
| MSLレベル | 3 (168 hours) |
| RoHS Compliance | ROHS3 Compliant |
| REACH Compliance | REACH Unaffected |
AD8436ACPZ-R7 ピン構成
| ピン 1 | INHI — High impedance input signal |
| ピン 2 | INLO — Low impedance input signal / reference |
| ピン 3 | COMMON — Common mode reference for differential input |
| ピン 4 | VS+ — Positive supply voltage |
| ピン 5 | VS- — Negative supply voltage / ground |
| ピン 6 | CAV — Averaging capacitor connection |
| ピン 7 | RMSOUT — RMS output voltage (filtered) |
| ピン 8 | BUF OUT — Buffered output from on-chip amplifier |
| ピン 9 | BUF IN — Input to on-chip output buffer |
| ピン 10 | PEAK/AVG — Mode select (peak or average rectified) |
| ピン 11 | NC — Not connected |
| ピン 12 | NC — Not connected |
| ピン 13 | NC — Not connected |
| ピン 14 | NC — Not connected |
| ピン 15 | NC — Not connected |
| ピン 16 | NC — Not connected |
| ピン 17 | NC — Not connected |
| ピン 18 | NC — Not connected |
| ピン 19 | NC — Not connected |
| ピン 20 | NC — Not connected |
| ピン EP | Exposed Pad — Thermal dissipation pad, must be soldered to ground pour |
主な用途
AD8436ACPZ-R7 の用途: 8 件s: Switch-Mode Power Supply Output Sensing, Industrial Power Line Monitoring, Precision Multimeter AC Measurement, Audio Amplitude Metering, RF Transmitter Envelope Detection, Battery Charger Power Quality Monitoring, Process Control Instrumentation, Medical Equipment AC Leakage Detection.
Switch-Mode Power Supply Output Sensing
The AD8436ACPZ-R7 is purpose-built for measuring the AC output of switch-mode power supplies, where the ripple waveform has complex non-sinusoidal content with high-frequency harmonics above 100 kHz. Its 20 MHz bandwidth captures switching transients, while the 0.25% accuracy (B grade) ensures the true heating value is reported even when the duty cycle varies. The on-chip output buffer drives ADC inputs or analog meters directly without external op-amp stages. Placed between the SMPS output filter and a metering ADC, the AD8436 eliminates the need for software RMS calculation and provides a stable DC representation regardless of load transients.
おすすめ
Industrial Power Line Monitoring
The AD8436ACPZ-R7 computes the true RMS value of 50/60 Hz mains and industrial bus voltages, providing accurate measurement regardless of harmonic distortion from variable-frequency drives or SCR rectifiers. Its wide 4.5V to 36V single-supply range operates directly from 24V industrial rails without external regulators. The 365 microA quiescent current makes it suitable for always-on energy meters that must minimize standby power consumption. Used in conjunction with a voltage divider and current-sense amplifier, the part forms the core of a class-0.5 industrial AC power meter.
おすすめ
Precision Multimeter AC Measurement
Handheld and bench multimeters rely on true RMS conversion to maintain accuracy on non-sinusoidal waveforms like dimmer-controlled lamp currents and motor drive outputs. The AD8436ACPZ-R7 delivers the 0.25% accuracy required for CAT III 1000V measurement categories when paired with proper input attenuation. Its single averaging capacitor pin allows designers to tune ripple versus settling, critical for auto-ranging meters. The LFCSP-20 4x4 mm footprint fits dense handheld instrument layouts, and the -40C to +85C operating range covers industrial and field-use environments.
おすすめ
Audio Amplitude Metering
Broadcast and pro-audio equipment use true RMS measurement to display program level on VU meters, ensuring perceived loudness correlates with measured signal. The AD8436ACPZ-R7 20 MHz bandwidth comfortably handles full audio spectrum plus ultrasonic content, while 365 microA quiescent current suits battery-powered portable mixers. The on-chip buffer drives LED meter arrays directly, simplifying analog meter circuits. Its wide supply range operates from single 5V or dual +/-15V analog rails typical in studio environments.
おすすめ
RF Transmitter Envelope Detection
Monitoring RF envelope amplitude requires true RMS conversion to handle amplitude-modulated and noise-like signals accurately. The AD8436ACPZ-R7 20 MHz bandwidth covers AM broadcast and shortwave bands, while its 0.5% of reading accuracy (A grade) provides reliable envelope measurement for transmitter power control loops. The wide supply range accepts 12V or 24V transmitter supply rails. Used after an RF detector diode and DC block, it forms a complete envelope detector for AGC and ALC circuits.
おすすめ
Battery Charger Power Quality Monitoring
EV charging stations and telecom battery systems monitor AC input current and voltage to ensure compliance with power quality standards. The AD8436ACPZ-R7 computes true RMS values across the wide dynamic range required as chargers transition between constant-current and constant-voltage modes. Its low 365 microA quiescent current adds negligible overhead to always-on monitoring circuits. The 20 MHz bandwidth detects switching harmonics from the charger itself, enabling feedback for EMI mitigation and PFC verification.
おすすめ
Process Control Instrumentation
Industrial process loops require accurate AC measurement of variables like motor speed, vibration amplitude, and strain gauge excitation. The AD8436ACPZ-R7 provides true RMS conversion in a compact LFCSP-20 footprint suitable for DIN-rail signal conditioner modules. Its wide -40C to +85C operating range covers harsh factory environments, while the 36V supply tolerance survives industrial transients. The on-chip buffer drives 4-20 mA loop converters and HART modems directly.
おすすめ
Medical Equipment AC Leakage Detection
Medical devices monitor AC leakage current to comply with IEC 60601 patient safety standards. The AD8436ACPZ-R7 measures microamp-level AC leakage currents when paired with appropriate current-sense transformers, providing true RMS regardless of the leakage waveform shape from switching medical power supplies. Its wide input dynamic range handles both normal residual currents and fault conditions. The wide supply range operates from medical-grade 12V or 24V rails with adequate transient margin.
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: AD8436ACPZ-R7 — 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 | AD8436ACPZ-RL | AD8436BCPZ-R7 | AD8436ACPZ-R2 | AD736ACPZ-R7 |
|---|---|---|---|---|---|
| Package | 20-LFCSP (4x4) | 20-LFCSP (4x4) - same | 20-LFCSP (4x4) - same | 20-LFCSP (4x4) - same | 20-LFCSP - same form factor, different pinout |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Accuracy | 0.5% of reading (A grade) | 0.5% of reading (A grade) | 0.25% of reading (B grade) | 0.5% of reading (A grade) | 0.5% of reading |
| Bandwidth | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 460 kHz |
| Quiescent Current | 365 microA | 365 microA | 365 microA | 365 microA | 1 mA |
| Supply Voltage Range | 4.5V to 36V / +/-5V to +/-18V | 4.5V to 36V / +/-5V to +/-18V | 4.5V to 36V / +/-5V to +/-18V | 4.5V to 36V / +/-5V to +/-18V | +/-2.5V to +/-5V dual |
| Output Buffer | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) | Yes (on-chip) |
| Input Range | 3 mV to 3 V RMS | 3 mV to 3 V RMS | 3 mV to 3 V RMS | 3 mV to 3 V RMS | 100 microV to 200 mV RMS |
| Unit Price (1k qty) | $5.05 | $5.05 (estimated) | $5.80 (estimated) | $5.05 (estimated) | $3.50 (estimated) |
主な差別化要因
- Higher bandwidth than legacy RMS-to-DC converters （vs AD736ACPZ-R7)
- Lower quiescent current than competing solutions （vs AD736ACPZ-R7)
- Wide single-supply operation up to 36V （vs LTC1966CMS8#PBF)
設計ノート
The LFCSP-20 package has an exposed thermal pad that must be soldered to a copper pour on the PCB. Estimated: at 365 microA quiescent current and 5V supply, internal dissipation is approximately 1.8 mW - thermal management is not a primary concern, but the exposed pad is still required for electrical ground connection and mechanical reliability. Use at least 100 mm^2 of 1 oz copper on inner/outer layers connected to the EP pin.
Place the CAV averaging capacitor as close as possible to pin 6 to minimize parasitic inductance. Use a ceramic capacitor with X7R or C0G dielectric; values from 0.1 microF (fast settling, higher ripple) to 10 microF (slow settling, lower ripple) trade bandwidth against measurement stability. For general-purpose power metering, 1 microF is a typical starting point. Keep the input signal traces short and shielded to avoid pickup of switching noise from adjacent power stages.
Do not exceed the maximum differential input voltage (typically +/-3V for the AD8436 input pins); use an external resistive divider or current-sense transformer for higher voltages. The INLO pin should be tied to COMMON at the IC, not to remote ground, to avoid ground-loop errors. The exposed pad must be electrically connected to VS- (ground), not left floating. For best accuracy at low input levels (under 10 mV RMS), use a shielded input enclosure and clean ground references.
The AD8436's 20 MHz bandwidth means it will respond to RF interference above the measurement bandwidth. Place 10 nF ceramic bypass capacitors on VS+ and VS- as close to the IC as possible. For industrial applications with high EMI environments, consider a small RC low-pass filter (100 ohm + 100 pF) on the INHI pin to roll off interference above 16 MHz. The on-chip buffer isolates the converter cell from output loading, but the buffer input must still be properly bypassed to avoid oscillation.
コンプライアンス情報
ROHS3 Compliant and REACH Unaffected per manufacturer documentation. Not AEC-Q100 qualified; for automotive applications consult Analog Devices for qualified alternatives. Halogen-free per Analog Devices product policy.
