Analog Devices Inc. AD8436BCPZ-RL

Overview

AD8436BCPZ-RL from Analog Devices is a precision true RMS-to-DC converter IC designed for accurate ac signal measurement in instrumentation, power monitoring, and test equipment. It delivers ±10 μV ±0.25% reading accuracy (B grade), supports 100 μV–3 V rms input range, operates from ±2.4 V to ±18 V dual supplies, and features integrated FET input and precision DC output buffers.

For engineers reviewing the AD8436BCPZ-RL datasheet, AD8436BCPZ-RL pinout, AD8436BCPZ-RL application, or AD8436BCPZ-RL equivalent, key selection criteria include crest factor error <0.5% (CF=1–10), 65 kHz bandwidth at 1% error, 1 MHz −3 dB bandwidth, low 300 µA supply current, and compatibility with single-supply (4.8 V–36 V) or dual-supply operation.

Technical Context

The AD8436BCPZ-RL implements a translinear RMS core using a precision voltage-to-current converter, full-wave rectifier, and log-antilog transistor array for squaring/square-rooting-enabling true heating-value computation without digital processing. Its architecture avoids switching artifacts and delivers stable dc output even at sub-millivolt inputs.

It integrates two independent, separately powered amplifiers: a high-Z (≥10¹² Ω) JFET input buffer with 2.1 MHz bandwidth and <50 pA bias current, and a laser-trimmed bipolar output buffer with <150 μV offset and 16 kΩ internal I-to-V resistor-supporting both voltage and current output configurations.

Key Specifications

Pinout & Package

AD8436BCPZ-RL is housed in a 4 mm × 4 mm, 20-lead LFCSP (CP-20-8) package with exposed thermal pad (optional ground connection). Pin functions are validated per Analog Devices Rev. E datasheet Figure 3 and Table 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar true RMS-to-DC conversion applications.

Compared with AD8436BCPZ-RL, the AD8436ACPZ-RL trades 0.25% reading accuracy for broader temperature coverage, while the AD737JRZ-REEL7 lacks integrated buffering and crest factor correction-making it unsuitable for distorted waveform measurement without added circuitry.

Availability

AD8436BCPZ-RL is available at Aetrix Electronics and suitable for power quality analyzers, portable multimeters, industrial motor drive feedback systems, and utility energy meters requiring stable component supply and long-term production continuity.

Supply support for AD8436BCPZ-RL includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD8436 belongs to Analog Devices' precision RMS-to-DC converter product line, engineered specifically for metrology-grade ac signal conditioning in test & measurement, energy monitoring, and industrial automation applications.

FAQ

What is the maximum input frequency supported by the AD8436BCPZ-RL with ≤1% additional error?

The AD8436BCPZ-RL supports up to 65 kHz input frequency with ≤1% additional error, as specified in the Rev. E datasheet Table 1 under "Response" for 300 mV rms input. This bandwidth enables accurate RMS measurement of switch-mode power supply noise, triac-dimmed lighting, and variable-frequency drive outputs without waveform distortion-induced inaccuracies.

Does the AD8436BCPZ-RL require external components to operate as a basic RMS converter?

Yes-the AD8436BCPZ-RL requires only one external component for basic operation: a 10 μF capacitor connected to the CAVG pin. This capacitor sets the averaging time constant for RMS computation. No external op amps, resistors, or diodes are needed, as the FET input buffer, RMS core, and output buffer are fully integrated on-die.

Can the AD8436BCPZ-RL be used with a single supply, and what is the minimum voltage?

Yes, the AD8436BCPZ-RL supports single-supply operation from 4.8 V to 36 V. The IGND pin provides an internal half-supply reference, allowing rail-to-rail input and output swing when used with an external resistive divider to generate a virtual ground-enabling compatibility with 5 V or 12 V system rails.

How does the CCF pin improve performance of the AD8436BCPZ-RL?

The CCF pin connects a 0.1 μF capacitor to reduce crest factor error to <0.5% for waveforms with crest factors from 1 to 10. This is critical for accurately measuring pulsed, clipped, or phase-controlled waveforms (e.g., SCR outputs or PWM motor currents) where average-responding converters fail-ensuring the AD8436BCPZ-RL maintains metrology-grade fidelity.

Is the AD8436BCPZ-RL pin-compatible with other packages of the AD8436 family?

No-the AD8436BCPZ-RL uses the 20-lead CP-20-8 LFCSP package, while the QSOP variant (e.g., AD8436BRQZ) uses the RQ-20 package with different pin numbering and layout. Although both share identical functionality and electrical specs, PCB layout and routing must be redesigned when switching between packages due to mechanical and pinout differences.