ICS-40740 Equivalent & Substitute Parts

Part Overview

The ICS-40740 is an obsolete MEMS analog omnidirectional microphone manufactured by TDK InvenSense. This microphone operates across a frequency range of 77 Hz to 20 kHz with a sensitivity of -37.5dB ±1dB at 94dB SPL, designed for applications requiring bottom-port solder pad termination. Due to its obsolete product status, identifying functionally equivalent substitute components is essential for ongoing production, maintenance, and new design implementations.

Substiute Parts

ICS-40740

TDK InvenSenseIn Stock: 709ICS-40740 Datasheet

Current PartRFQ

AMM-3738-B-R

PUI Audio, Inc.In Stock: 44509AMM-3738-B-R Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the ICS-40740 is determined by the following critical parameters:

• MEMS silicon construction with analog output
• Omnidirectional pickup pattern
• Frequency response spanning 77 Hz to 20 kHz minimum
• Sensitivity within ±1dB tolerance at specified SPL
• Voltage operating range compatibility (1.5 V ~ 3.63 V)
• Bottom port location with solder pad termination
• Rectangular form factor with comparable dimensions
• ROHS3 compliance and MSL 1 rating

The AMM-3738-B-R from PUI Audio, Inc. qualifies as a substitute based on alignment across these core electrical and mechanical parameters, despite minor variations in frequency range extension and sensitivity specification.

Parameter Comparison

Engineering Selection Recommendations

The AMM-3738-B-R is suitable as a substitute for the ICS-40740 based on the following factors:

• Both components maintain ROHS3 compliance and MSL 1 rating, ensuring regulatory and environmental compatibility
• Active product status of the AMM-3738-B-R provides ongoing availability and supply chain stability, addressing the obsolescence of the ICS-40740
• Electrical parameters remain within acceptable tolerance ranges: voltage operating range overlap (1.5 V ~ 3.6 V), impedance differential of 55 Ohms, and sensitivity variation of 0.5dB
• Mechanical compatibility is maintained through identical bottom port location, solder pad termination, and rectangular form factor with minimal dimensional variance
• Frequency response of the AMM-3738-B-R extends lower (20 Hz vs. 77 Hz), providing enhanced low-frequency capability

Frequently Asked Questions (FAQ)

Q: What makes the AMM-3738-B-R a valid substitute for the ICS-40740?

A: Both components share core functional characteristics: MEMS silicon construction, analog output, omnidirectional pickup pattern, bottom port location, and solder pad termination. Electrical parameters including voltage range, impedance, and sensitivity fall within compatible operating windows. Mechanical dimensions are comparable, and both maintain identical compliance certifications.

Q: Are there dimensional differences between these components?

A: Yes. The AMM-3738-B-R measures 0.148" L x 0.116" W (3.76mm x 2.95mm) with a maximum height of 0.047" (1.20mm), compared to the ICS-40740 at 0.157" L x 0.118" W (4.00mm x 3.00mm) with a maximum height of 0.051" (1.30mm). These differences are minimal and do not affect PCB layout compatibility for standard microphone footprints.

Q: What is the impedance difference, and does it affect circuit design?

A: The AMM-3738-B-R has 300 Ohms impedance versus the ICS-40740's 355 Ohms. This 55 Ohm variance is within typical analog microphone design tolerances and does not require circuit redesign for standard audio input stages.

Q: How do the sensitivity specifications compare?

A: The ICS-40740 specifies -37.5dB ±1dB at 94dB SPL, while the AMM-3738-B-R specifies -38dB ±1dB. The 0.5dB difference falls within the ±1dB tolerance band of both components and is not significant for most audio applications.

Q: What is the supply current difference?

A: The AMM-3738-B-R draws 200 µA compared to the ICS-40740's 155 µA. This 45 µA increase should be evaluated in power-constrained applications, though both values remain low for battery-powered designs.

Q: Does the extended frequency range of the AMM-3738-B-R (20 Hz vs. 77 Hz) create compatibility issues?

A: No. The extended low-frequency response of the AMM-3738-B-R is an enhancement that does not create incompatibility. Applications designed for the ICS-40740's 77 Hz lower limit will function correctly with the AMM-3738-B-R's 20 Hz capability.

Q: Are both components RoHS and MSL compliant?

A: Yes. Both the ICS-40740 and AMM-3738-B-R are ROHS3 compliant with MSL 1 (Unlimited) rating, ensuring compatibility with standard manufacturing and storage requirements.