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Contents

README

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AFE881H1RRUR

Texas Instruments · Analog Front End (AFE) · UQFN-24(4x4)

AFE881H1RRUR from Texas Instruments, in a UQFN-24(4x4). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 UARTIN input UART data input for the HART modem; connect to IOVDD or logic high if not used, and do not leave it floating.
2 UARTOUT output UART data output that can be configured to function as the IRQ pin in SPI-only mode.
3 CD output Carrier-detect output; a logic high indicates a valid HART carrier is present.
4 RTS input Request-to-send input; logic high enables the demodulator and disables the modulator, and it must not be left floating.
5 REF_EN input Internal VREF enable; logic high enables the internal reference (VREFIO outputs 1.25 V), and logic low requires an external 1.25-V reference at VREFIO.
6 RESET input Reset input; logic low places the device in power-down mode and resets it, and logic high returns it to normal operation; must not be left floating.
7 SCLK input SPI serial clock input (Schmitt-trigger) supporting rates up to 12.5 MHz; connect to GND or logic low if not used.
8 SDI input SPI data input (Schmitt-trigger) clocked into the 24-bit input shift register on the falling SCLK edge; must not be left floating.
9 SDO output SPI data output driven on the rising SCLK edge while CS is low; also the IRQ pin in UART break mode, Hi-Z at power-up until enabled in the CONFIG register.
10 CS input SPI chip select; data is clocked in while CS is low, and when CS is high SDO is Hi-Z and SDI is ignored; must not be left floating.
11 CLK_OUT output Clock output that can be configured to output the 1.2288-MHz internal clock.
12 IOVDD power_in Interface supply for digital input and output circuitry, specified 1.71 V to 5.5 V, which sets the logic thresholds of the digital interfaces.
13 VDD power_out Internal supply node; with 2.7 V to 5.5 V on PVDD the internal LDO drives it (connect a 1-µF to 10-µF capacitor), and with 1.71 V to 1.89 V on PVDD an external supply must be applied here.
14 GND power_in Digital and analog ground, the ground reference point for all circuitry on the device.
15 AIN0 input ADC input voltage with a range of 0 V to VREF if PVDD = VDD, or 0 V to 2 × VREF if PVDD > 2.7 V.
16 POL_SEL/AIN1 input ADC input AIN1 (0 V to VREF if PVDD = VDD, or 0 V to 2 × VREF if PVDD > 2.7 V) when SPECIAL_CFG.AIN1_ENB = 1; otherwise it sets the polarity of the VOUT alarm voltage (ALMV_POL).
17 PVDD power_in Supply for the internal LDO, ADC input and VOUT DAC; 2.7 V to 5.5 V enables the internal LDO, while 1.71 V to 1.89 V disables it.
18 VOUT output DAC output voltage; the device is specified for 0.15 V to 1.25 V or 0.2 V to 1.0 V output ranges at 1.8-V PVDD and 0.3 V to 2.5 V or 0.4 V to 2.0 V at 5-V PVDD.
19 VREFIO bidirectional Outputs the internal 1.25-V reference when REF_EN is high (requires a 70-nF to 130-nF load capacitance for stability), and accepts an external 1.2 V to 1.3 V reference when REF_EN is low.
20 REF_GND power_in Ground reference for the VREFIO pin.
21 RX_IN input HART FSK input when no external filter is used; do not connect any signal to this pin when an external band-pass filter is used.
22 RX_INF input HART FSK input for an external band-pass filter; when the internal band-pass filter is used by driving RX_IN, connect a 680-pF capacitor to this pin.
23 MOD_OUT output FSK output sinusoid; maximum supported parallel load capacitance is 2 nF.
24 ALARM output Open-drain alarm notification; held low when an alarm condition is asserted, otherwise high-impedance (Hi-Z).
25 EP passive Exposed pad (from the footprint; not named in the datasheet pin table).

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package UQFN-24(4x4)
Category Data Acquisition
Pins 25

CAD (KiCad official)

  • Symbol: AFE881H1RRUR
  • Footprint: Package_DFN_QFN:QFN-24-1EP_4x4mm_P0.5mm_EP2.7x2.7mm
  • 3D model: UQFN-24(4x4) (KiCad packages3D, STEP)
  • 3D model files: afe881h1rrur-etched.step / afe881h1rrur-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); afe881h1rrur.step / afe881h1rrur.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Texas Instruments datasheet (112 pp, sha256 8ab7592274e79b3b, retrieved 2026-10-08, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF