PEMI4CSP/RT,135 Equivalent & Substitute Parts

Part Overview

The PEMI4CSP/RT,135 is a 2nd order RC (Pi) EMI filter manufactured by NXP USA Inc., designed for low-pass filtering applications in LAN, PCS, and WAN systems. This component features 4 channels with 100 Ohm resistance and 23pF total capacitance, housed in a 10-UFBGA, WLCSP package. The product is currently obsolete, necessitating identification of functionally equivalent alternatives for ongoing system support and new designs.

Key Parameters

Parameter	Value
Filter Type	RC (Pi) Low Pass, 2nd Order
Number of Channels	4
Resistance per Channel	100 Ohms
Capacitance (Total)	23pF
Cutoff Frequency	128 MHz
Attenuation	30dB @ 800MHz ~ 3GHz
Current Rating	33 mA
ESD Protection	Yes
Operating Temperature	-40°C ~ 85°C
Mounting Type	Surface Mount
Package	10-UFBGA, WLCSP
Size	0.061" L x 0.041" W (1.56mm x 1.05mm)
Height	0.026" (0.65mm)
RoHS Status	ROHS3 Compliant
MSL Rating	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the PEMI4CSP/RT,135 is determined by the following critical parameters:

Filter Architecture: Must be RC (Pi) topology, 2nd order low-pass configuration
Channel Count: Must provide 4 independent filter channels
Resistance Value: Must maintain 100 Ohm per-channel resistance
Capacitance: Must support equivalent or lower total capacitance (23pF baseline)
Frequency Response: Cutoff frequency and attenuation characteristics must be compatible with the original application bandwidth
Package Compatibility: Surface mount BGA package with comparable footprint and height
Environmental Ratings: Operating temperature range and ESD protection must meet or exceed original specifications
Compliance: RoHS3 compliance and MSL rating must be maintained

The TPD4F202YFUR from Texas Instruments meets these substitution criteria with compatible electrical characteristics and package form factor.

Parameter Comparison

Parameter	PEMI4CSP/RT,135 (NXP)	TPD4F202YFUR (TI)	Compatibility
Filter Type	RC (Pi) Low Pass, 2nd Order	RC (Pi) Low Pass, 2nd Order	Match
Number of Channels	4	4	Match
Resistance per Channel	100 Ohms	100 Ohms	Match
Capacitance (Total)	23pF	15pF	Lower capacitance shifts cutoff higher
Cutoff Frequency	128 MHz	108 MHz	Within acceptable range
Attenuation	30dB @ 800MHz ~ 3GHz	40dB @ 1GHz ~ 3GHz	Enhanced attenuation
ESD Protection	Yes	Yes	Match
Operating Temperature	-40°C ~ 85°C	-40°C ~ 85°C	Match
Mounting Type	Surface Mount	Surface Mount	Match
Package	10-UFBGA, WLCSP	10-XFBGA, DSBGA	Different BGA variant, same footprint
Size	0.061" L x 0.041" W (1.56mm x 1.05mm)	0.061" L x 0.041" W (1.56mm x 1.05mm)	Match
Height	0.026" (0.65mm)	0.014" (0.35mm)	Lower profile
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	Match
MSL Rating	1 (Unlimited)	1 (Unlimited)	Match

Engineering Selection Recommendations

The TPD4F202YFUR qualifies as a direct substitute for the obsolete PEMI4CSP/RT,135 based on electrical and mechanical compatibility. Both components maintain ROHS3 compliance and unlimited moisture sensitivity ratings, ensuring regulatory and environmental consistency.

The TPD4F202YFUR exhibits superior attenuation characteristics (40dB vs. 30dB in the 1GHz ~ 3GHz band) and a lower profile (0.35mm vs. 0.65mm), providing potential advantages in space-constrained applications. The 15pF capacitance versus 23pF results in a slightly higher cutoff frequency (108MHz vs. 128MHz), which remains within acceptable operational parameters for most LAN, PCS, and WAN applications.

Package compatibility is maintained through identical footprint dimensions (1.56mm x 1.05mm), though the BGA variant differs (10-XFBGA, DSBGA vs. 10-UFBGA, WLCSP). PCB layout and reflow profile validation is recommended prior to production implementation.

Frequently Asked Questions (FAQ)

Q: Can the TPD4F202YFUR be used as a direct replacement without PCB modifications?

A: The identical footprint (1.56mm x 1.05mm) and pin count (10) enable direct substitution on existing PCB layouts. However, the different BGA variant and lower profile height (0.35mm vs. 0.65mm) require verification of reflow parameters and solder joint formation to ensure reliability.

Q: How does the lower capacitance (15pF vs. 23pF) affect system performance?

A: Lower capacitance results in a higher cutoff frequency (108MHz vs. 128MHz). This shifts the filter response curve upward in frequency, potentially allowing higher frequency signals to pass. System-level frequency response testing is necessary to confirm compatibility with the intended application bandwidth.

Q: Are there any compliance or certification differences between these parts?

A: Both components are ROHS3 compliant with MSL rating 1 (Unlimited). Regulatory compliance is equivalent. The TPD4F202YFUR carries Last Time Buy status, indicating limited future availability.

Q: What is the significance of the different BGA package variants?

A: UFBGA (Ultra Fine Ball Grid Array) and XFBGA (eXtended Fine Ball Grid Array) represent different BGA construction methods. Both maintain the same footprint and electrical connectivity. The DSBGA (Die Size Ball Grid Array) designation for the TPD4F202YFUR indicates a die-size optimized package. Reflow profile compatibility should be verified with the component manufacturer's documentation.

Q: Is the enhanced attenuation (40dB vs. 30dB) beneficial for all applications?

A: Enhanced attenuation provides superior noise rejection in the 1GHz ~ 3GHz band, which is advantageous for high-speed data line filtering. Applications requiring specific attenuation characteristics should validate that the increased filtering does not introduce undesired signal loss or phase distortion.

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