Access Secure Information About Our Products
Sign in to access authorized secure information. Learn more about secure access rights.
Analog Front-End
NXP’s N-AFE analog front-end family of devices for factory automation enables the software-defined factory. With its software configurable analog inputs, where each input can be configured for voltage, current, resistance, or temperature, NXP’s N-AFE enables a new level of flexibility. In addition, with NXP’s N-AFE, enhanced accuracy and precision in the manufacturing floor measurement, product quality is greatly improved. Lastly, NXP’s N-AFE advanced diagnostics and anomaly detection features enable predictive maintenance, making it possible to identify issues before they occur to avoid downtime. All these features and more allow manufacturers to create a highly efficient smart factory.
NXP’s N-AFE integrates all the signal chain building blocks: protections, multiplexer, amplifier, ADC and digital filtering.
Several options are available: low power or high speed, with or without voltage/current excitation, all of them with the same package and pin-to-pin compatibility.
Analog Front-End Portfolio
NAFE33352B40BS new Preproduction
Software Configurable Analog Input and Output Analog Front End.
NAFE11348B40BS
Universal ±25 V 8-Input Low Power AFE.
16 bits.
NAFE13144B40BS
Universal ±25V 4-Input Low Power AFE with Excitation source
16 bits.
NAFE71388B40BS
High Speed Universal ±25 V 8-Input High Speed AFE.
24 bits.
NAFE13388B40BS
Universal ±25 V 8-Input Low Power AFE with excitation sources.
24 bits.
NAFE11388B40BS
Universal ±25 V 8-Input Low Power AFE.
24 bits.
NAFE73388B40BS
Universal ±25 V 8-Input High Speed AFE with excitation sources.
24 bits.
Evaluation Boards and Reference Designs
NXP offers evaluation boards and reference designs that make secure edge solutions connected and efficient with innovative analog technologies. Start today.
Analog Front-End FAQs
Learn more about NXP's N-AFE portfolio of products.
What is the part family nomenclature for the NAFExx388 family?
Below is the nomenclature of the N-AFE family of devices:
| N-AFE | 1 | 3 | 3 | 8 | 8 |
|---|---|---|---|---|---|
| 1: Low power
7: High speed |
1: No VIEX
3: VIEX |
1: No Cal (calibrated) 3: Factory calibrated | 4: 16 bit
8: 24 bit |
4: 4-ch (channel)
8: 8-ch (channel) |
The low-power flavor has a max data rate of 288 ksps while the high-speed version can support up to 576 ksps in Normal Settling mode.
Refer to the data sheet or contact an NXP sales representative for available part numbers.
What are the different input ranges that N-AFE can measure?
The N-AFE has eight selectable PGA gain settings of 0.2 V/V to 16 V/V that provide eight differential input full-scale ranges from ±25 V to ±312.5 mV for a variety of applications. In general, all of the HV input characteristics are specified to the linear (nominal) input ranges for all of the channel gain settings, which is 80 % of the full input range.
| Nominal range values (V) | ||||||||
| Type | PGA gain setting | |||||||
| 0.2 | 0.4 | 0.8 | 1 | 2 | 4 | 8 | 16 | |
| Bipolar DIFF | ±20.00000 | ±10.00000 | ±5.00000 | ±4.00000 | ±2.00000 | ±1.00000 | ±0.50000 | ±0.25000 |
| Bipolar SE | ±10.00000 | ±5.00000 | ±2.50000 | ±2.00000 | ±1.00000 | ±0.50000 | ±0.25000 | ±0.12500 |
| Unipolar DIFF | ±10.00000 | ±5.00000 | ±2.50000 | ±2.00000 | ±1.00000 | ±0.50000 | ±0.25000 | ±0.12500 |
| Unipolar SE | ±10.00000 | ±5.00000 | ±2.50000 | ±2.00000 | ±1.00000 | ±0.50000 | ±0.25000 | ±0.12500 |
| Min and max values (V) | ||||||||
| Type | PGA gain setting | |||||||
| 0.2 | 0.4 | 0.8 | 1 | 2 | 4 | 8 | 16 | |
| Bipolar DIFF | ±25.00000 | ±12.50000 | ±6.25000 | ±5.00000 | ±2.50000 | ±1.25000 | ±0.62500 | ±0.31250 |
| Bipolar SE | ±12.50000 | ±6.25000 | ±3.12500 | ±2.50000 | ±1.25000 | ±0.62500 | ±0.31250 | ±0.15625 |
| Unipolar DIFF | ±12.50000 | ±6.25000 | ±3.12500 | ±2.50000 | ±1.25000 | ±0.62500 | ±0.31250 | ±0.15625 |
| Unipolar SE | ±12.50000 | ±6.25000 | ±3.12500 | ±2.50000 | ±1.25000 | ±0.62500 | ±0.31250 | ±0.15625 |
| Full range scale (V) | ||||||||
| Type | PGA gain setting | |||||||
| 0.2 | 0.4 | 0.8 | 1 | 2 | 4 | 8 | 16 | |
| Bipolar DIFF | 50 | 25 | 12.5 | 10 | 5 | 2.5 | 1.25 | 0.625 |
| Bipolar SE | 25 | 12.5 | 6.25 | 5 | 2.5 | 1.25 | 0.625 | 0.3125 |
| Unipolar DIFF | 25 | 12.5 | 6.25 | 5 | 2.5 | 1.25 | 0.625 | 0.3125 |
| Unipolar SE | 12.5 | 6.25 | 3.125 | 2.5 | 1.25 | 0.625 | 0.3125 | 0.15625 |
| Resolution (V) | ||||||||
| Type | PGA gain setting | |||||||
| 0.2 | 0.4 | 0.8 | 1 | 2 | 4 | 8 | 16 | |
| Bipolar DIFF | 3.0E-6 | 1.5E-6 | 745.1E-9 | 596.0E-9 | 298.0E-9 | 149.0E-9 | 74.5E-9 | 37.3E-9 |
| Bipolar SE | 3.0E-6 | 1.5E-6 | 745.1E-9 | 596.0E-9 | 298.0E-9 | 149.0E-9 | 74.5E-9 | 37.3E-9 |
| Unipolar DIFF | 3.0E-6 | 1.5E-6 | 745.1E-9 | 596.0E-9 | 298.0E-9 | 149.0E-9 | 74.5E-9 | 37.3E-9 |
| Unipolar SE | 3.0E-6 | 1.5E-6 | 745.1E-9 | 596.0E-9 | 298.0E-9 | 149.0E-9 | 74.5E-9 | 37.3E-9 |
What is the difference between user calibration and factory calibration?
The user calibration is the process by which the N-AFE is calibrated when it is already mounted on a PCB. The factory calibration is performed during chip manufacturing at the NXP factory. The user calibration achieves overall better accuracy with a typical TUE of ±0.002 % of full scale at room temperature. This is because all the errors introduced by external components and the soldering process are calibrated too. However, the accuracy guaranteed by the factory calibrated part, which is ±0.06 % of full scale at room, allows our customers to avoid the expensive and time-consuming calibration process if the provided accuracy fits their requirements.
How fast can the N-AFE read in the Single-Channel Conversion mode?
The N-AFE is available in both a low-power (LP) version and a high-speed (HS) version with maximum data rates of 288 ksps and 576 ksps respectively. The single-channel conversion with normal settling provides the fastest readout of 3.472 us for the LP (NAFE1x388) version and 1.738 us for the HS (NAFE7x388) version.
How fast can the N-AFE read in Multichannel conversion mode?
When in Multichannel Conversion mode, the ADC input signal path requires 16.4 us and 8.2 us front-end settling time (defined as Tswitch in the EC table) for NAFE1x388 and NAFE7x388 respectively. The user should use single-cycle settling for multichannel readout to avoid settling errors. The ADC data rate in single-cycle settling mode is a quarter of the data rate in Normal Settling mode, for example, 72 ksps and 144 ksps for LP and HS parts respectively.
Code 17 for channel programmable delay meets the Tswitch requirement in both the low-power and high-speed flavors.
n channel read time = n * (Tcnv + Tch_delay) where n = number of channels in multichannel read mode. Tcnv = 1/DataRate Tch_delay ≥ Tswitch.
The fastest readout for 8 inputs in Multichannel Conversion mode with single-cycle settling is:
NAFE1x388’s fastest eight-channel read time = 8 * (13.88 us + 16.49 us) ≈ 240 us …..30 us/channel
NAFE7x388’s fastest eight-channel read time = 8 * (6.94 us + 8.24 us) ≈ 120 us……….15 us/channel
How well can N-AFE reject 50/60 Hz line frequency?
The NAFE13388 features a digital filter that provides a 50 Hz and 60 Hz Normal mode rejection (NMR) at lower data rates. The figure below shows the SINC4 filter NMR at the date rates of 10 sps, 50 sps, and 60 sps.
What is the 50/60 Hz common-mode rejection (CMRR) at speeds higher than 100 sps?
The N-AFE provides more than 110 dB CMRR at data rates much higher than 60 sps (without 50/60 Hz rejection of notch filter) as shown in the figure below.
What are the NAFExx388’s Crosstalk (CT) specifications and conditions?
Static crosstalk: ±1 µV/V
Dynamic crosstalk (not AC spec): ±1 µV/V
Below are the test conditions for crosstalk parameters:
- Input crosstalk DC (single channel):
- Set the target channel at 0 V and vary the main channel from 0 V to 10 V
- This test uses single-channel conversion to see the impact of the main channel on the target channel
- The above procedure is repeated for the main channel varying from 0 V to -10 V
- Input crosstalk dynamic (multichannel not an AC crosstalk):
- Set the target channel to -10 V and the adjacent main channel from 0 V to 10 V
- This test uses multichannel conversion to see the impact of the main channel on the target channel
- This quantifies the effect of the channel path settling (MUX+PGA) at specified DR0 and CH_delay in condition for a worst-case input swing at the ADC input
- The above procedure is repeated for the target channel at 10 V and the adjacent main channel varying from 0 V to -10 V
How does the N-AFE implement cancelation of the wire resistance in a 3-wire RTD configuration?
Contrary to competitor solutions that implement two matched current generators to cancel the RTD wire resistance, the N-AFE utilizes the integrated current generator (VIEX) with low-temperature drift performance of 4 ppm/°C typical. The N-AFE optimizes the number of RTDs that can be connected to a single chip by using a single-current source allowing four 3-wire RTD measurements with a single chip.
N-AFE: Software Configurable Analog Front End for Smart Factories
A flexible analog front-end architecture with software-configurable universal analog inputs enables manufacturers to reconfigure a smart factory and adjust settings based on shifting market needs.
Design Resources
In this webinar we will discuss the challenges the designers face in developing a software-configurable universal analog input module and how the new NXP's N-AFE device is able to simplify the design.
Fully featured evaluation board for the NAFExx388 highly configurable AFE for industrial applications.
Additional Documents
N-AFE Software-Configurable Analog Front-End Family With Universal Analog Inputs Fact Sheet
N-AFE devices are highly configurable industrial-grade multichannel universal input analog front-end (AFE) with high accuracy and precision for smart factories.
Read the fact sheetAdding Value to a PLC or Remote I/O Applications with the N-AFE Analog Front-End Family
The N-AFE software configurable device adds value to PLC or remote I/O systems with high-precision measurement features. N-AFE analog front-end enables the efficient design and enhanced reliability for industry 4.0 analog input applications.
Read the application noteIndustrial Application Measurements Using NXP AFE
This article discusses systems-level implementation of voltage and current sensing, temperature and weight scale measurements, and system diagnostics using the NAFE13388EVB (evaluation board) and GUI.
Read the application noteNAFE Applications with MCUXpresso
This article introduces the precompiled NAFE software library for NXP proprietary MCUXpresso platform. The library consists of ready-to-use measurement script for the industrial applications (voltage, current, temperature and weight) with NAFE evaluation KIT as discussed in AN14102.
Read the application note