AKM (Asahi Kasei Microdevices)

AK4181A - 4-Wire Touch Screen Controller, 12-bit SAR ADC | AKM

부품 번호: AK4181A ✓ 활성
재고 있음 영업일 기준 1~3일 내 발송
2.5 V Vdss TSSOP Package 125 kHz Speed
시작가 $1.38 USD / 개
MOQ: 1 |
가격 업데이트: 2026-10-12
볼륨 가격
수량 단가 합계
1 $2.85 $2.85
10 $2.42 $24.20
100 $1.95 $195.00
500 $1.62 $810.00
1,000 $1.38 $1,380.00
ℹ️ 모든 가격은 USD 기준입니다

AK4181A 개요

The AKM AK4181A is a 4-wire resistive touch screen controller that integrates a 12-bit successive-approximation-register (SAR) analog-to-digital converter with a maximum sampling frequency of 125 kHz. Housed in a compact TSSOP surface-mount package, the AK4181A detects pressed-screen coordinates by performing two successive A/D conversions on the touch-panel analog signals and also measures pen-pressure (Z-axis) touch force.

A touch screen controller is a mixed-signal data-acquisition IC that bridges a 4-wire resistive touch panel and an embedded host MCU. The AK4181A sits in the broader signal-chain hierarchy as: touch-screen controller -> resistive-touch digitizer -> data-acquisition IC -> analog front-end -> semiconductor. By handling the analog measurement locally and presenting digital results to the host, the part removes analog switching and biasing complexity from the host firmware, an essential role in any handheld, HMI, or industrial-control system using legacy resistive panels.

Key features include pen-pressure measurement (Z-axis), an on-chip thermal sensor for system-temperature monitoring, two auxiliary analog input channels for general-purpose ADC use, direct battery-voltage measurement, an on-chip 2.5 V voltage reference, and a 12-bit SAR ADC with integrated sample-and-hold. The low-power architecture supports battery-powered handheld designs, while the direct-battery-measurement channel allows the host to monitor its own supply without extra external dividers.

Typical applications include resistive-touch human-machine interfaces (HMIs), handheld data terminals, industrial control panels, point-of-sale (POS) terminals, consumer electronics with resistive touch, and portable instrumentation. The auxiliary ADC inputs and on-die temperature sensor make the AK4181A useful even in systems that do not require touch input.

Design consideration: the 4-wire resistive interface requires proper PCB routing to keep the X/Y drive signals away from noisy digital traces, and the SAR converter's 125 kHz maximum sampling rate limits touch-report rates to roughly a few hundred Hz. Designers should also account for the part's TSSOP thermal envelope and ESD handling at the panel connector.

This page synthesizes distributor pricing, drop-in alternatives, application examples, and practical design notes not found in the manufacturer datasheet alone - giving engineers a one-stop reference for evaluating the AK4181A in new designs and as a replacement candidate in legacy 4-wire touch systems.

드롭인 대체품: AK4181A — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.

이 시리즈의 변형

다음과 드롭인 호환되는 동일 시리즈 모델: AK4181A (동일 폼 팩터 및 풋프린트) — 차이점: Direct Battery Measurement, Package, RoHS Status.

Analog Devices
Direct Battery Measurement: Up to 6 V
Package: 16-pin QSOP (RQ-16)
RoHS Status: RoHS Compliant
비교 대상: AK4181A →

빠른 비교 도구 — 나란히 비교할 대체 부품을 선택하십시오:

AK4181

✅ 드롭인 ⚠️ 사양 미검증
📦 TSSOP
AKM sibling part in same TSSOP footprint, same 12-bit SAR core, near-identical pinout

📋 참조 대체품 (카탈로그에 없음)

ADS7843

✅ 드롭인
📦 TSSOP-16
TI 12-bit SAR 4-wire touch controller, same 125 kHz sampling rate, SPI interface

📋 참조 대체품 (카탈로그에 없음)

TSC2046

✅ 드롭인
📦 TSSOP-16
TI TSC2046 (Touchstone brother) 12-bit 125 kHz, same TSSOP-16 footprint, PENIRQ + on-chip 2.5V ref

📋 참조 대체품 (카탈로그에 없음)

ADS7845

✅ 드롭인
📦 TSSOP-16
TI 5-wire variant, same TSSOP-16 footprint and SAR core, 5-wire resistive instead of 4-wire

📋 참조 대체품 (카탈로그에 없음)

AD7873ARQZ

✅ 드롭인
Analog Devices
📦 TSSOP-16
12 bits · SAR (Successive Approximation) · 4-Wire Resistive · 2.2 V to 5.25 V · 125 kSPS · 2.5 V · Up to 6 V · Yes, up to +85 C

✓ 재고 있음

$5.49 / 개

데이터시트 보기 →

AK4181A 최대 정격 & 전기적 특성

기능 4-wire resistive touch screen controller
ADC Architecture 12-bit SAR with sample-and-hold
Maximum Sampling Frequency 125 kHz
Touch Panel Interface 4-wire resistive
Pen Pressure (Z-axis) Measurement Yes
On-Chip Voltage Reference 2.5 V
On-Chip Thermal Sensor Yes
Auxiliary Analog Inputs 2 channels
Direct Battery Measurement Yes
패키지 TSSOP
실장 유형 Surface Mount
RoHS 상태 unknown

AK4181A tssop 핀 구성 가이드

AK4181A(tssop 패키지)의 핀 구성입니다. 이 아날로그 부품에는 입력, 출력, 전원 공급 핀이 있습니다. 오프셋 널, 보상, 인에이블 핀 구성은 제조사 데이터시트를 참조하십시오. 신호 컨디셔닝 및 증폭기 회로에 이상적입니다.

AK4181A의 tssop 패키지 핀아웃 다이어그램

다음에 대한 상세 핀아웃 데이터 없음: AK4181A.

다음을 참조하십시오: 데이터시트 전체 핀 구성은 다음을 참조하십시오.

일반적인 애플리케이션

AK4181A 적합 용도: 6 애플리케이션s: Industrial HMI with 4-Wire Resistive Touch, Handheld Data Terminal / Portable Instrumentation, Point-of-Sale (POS) Terminal with Signature Capture, Consumer Electronics with Resistive Touch, Automotive Aftermarket Infotainment / Climate-Control Panels, Medical Monitoring Device Touch UI.

🏭

Industrial HMI with 4-Wire Resistive Touch

The AK4181A's 12-bit SAR ADC at 125 kHz is well-matched to factory-floor HMIs that still rely on legacy 4-wire resistive panels because they tolerate gloved hands, water spray, and cost-sensitive BOMs. The IC converts the X/Y plate voltages into 12-bit coordinates via two successive conversions and reports the Z-axis pen-pressure reading for signature-capture or stylus workflows common in machine-operator terminals. Its on-chip thermal sensor also feeds panel-temperature compensation into the host MCU, which improves touch accuracy in environments that swing from -20C to +70C. Compared with a capacitive-only solution, the AK4181A preserves a known firmware interface and avoids the cost of a projected-capacitive panel.

📱

Handheld Data Terminal / Portable Instrumentation

Battery-powered handheld terminals benefit from the AK4181A's low-power SAR architecture and its direct battery-voltage measurement channel. The on-chip 2.5 V reference lets the host measure its own supply without adding external resistor dividers, simplifying the analog BOM. The 125 kHz maximum sampling rate delivers smooth stylus tracking on signature-capture workflows used in field-service, medical, and logistics devices. Two auxiliary analog inputs can monitor external sensors (e.g. a temperature probe or a current-sense amplifier), reducing part count versus an architecture that needs a separate general-purpose ADC.

🧩

Point-of-Sale (POS) Terminal with Signature Capture

POS terminals in retail and banking still depend on 4-wire resistive panels because they accept pen-based signature capture, which the AK4181A supports natively via its pen-pressure (Z-axis) measurement. The 12-bit resolution is more than enough to capture legible signatures with sub-millimeter coordinate precision, while the 125 kHz sampling rate keeps the on-screen ink trail responsive. The on-chip temperature sensor provides panel-drift compensation that improves touch accuracy in warm retail environments, and the TSSOP package footprint keeps the analog island compact behind the display connector.

🎧

Consumer Electronics with Resistive Touch

Cost-sensitive consumer products such as e-readers, GPS handhelds, portable DVD players, and older-generation smart-home control panels still use 4-wire resistive touch because the panel cost is roughly one-third of an equivalent projected-capacitive stack. The AK4181A's integrated SAR ADC and on-chip reference remove the analog-switch network that an MCU would otherwise need, lowering BOM cost and freeing up GPIO. Its auxiliary ADC inputs can be repurposed as general-purpose ADC channels for buttons, battery monitoring, or external thermistors, increasing the value of every PCB square millimeter.

🚗

Automotive Aftermarket Infotainment / Climate-Control Panels

Aftermarket automotive head units, climate-control panels, and rear-seat entertainment modules continue to use 4-wire resistive touch because it survives wide temperature ranges and gloved-finger operation better than capacitive alternatives. The AK4181A's on-chip thermal sensor plus pen-pressure measurement support stylus-based input for navigation. Engineers planning an automotive design should note that the part is not AEC-Q100 qualified - confirm with AKM for automotive-grade material or select an automotive-qualified alternative such as TI's automotive-graded ADS7843-Q1 variant.

💊

Medical Monitoring Device Touch UI

Bedside patient monitors, infusion pumps, and diagnostic handhelds often pair a 4-wire resistive panel with a dedicated touch controller because medical housings need an easy-to-clean, glove-compatible surface. The AK4181A's 12-bit SAR delivers the coordinate precision required for accurate selection of dosage parameters, while the two auxiliary analog inputs can monitor backup sensors or a battery-management IC voltage rail. The on-chip temperature sensor simplifies the thermal compensation routine, which keeps touch accuracy stable during long patient-monitoring sessions where panel temperature drifts.

추천 제품 요약

ADS7843 Drop-in alternate 4-wire touch controller 사용처: Industrial HMI with 4-Wire Resistive Touch, Point-of-Sale (POS) Terminal with Signature Capture, Automotive Aftermarket Infotainment / Climate-Control Panels AD7873 ADI alternate 4-wire touch controller 사용처: Industrial HMI with 4-Wire Resistive Touch, Consumer Electronics with Resistive Touch TSC2046 TI alternate with PENIRQ for sleep/wake 사용처: Handheld Data Terminal / Portable Instrumentation, Medical Monitoring Device Touch UI
What does the AK4181A do?
The AK4181A is a 4-wire resistive touch screen controller from Asahi Kasei Microdevices (AKM) that integrates a 12-bit SAR A/D converter with a 125 kHz maximum sampling rate. According to the AKM datasheet summary, it captures X/Y touch coordinates via two A/D conversions, measures pen-pressure (Z-axis) force, and exposes two auxiliary analog inputs plus a direct battery-voltage measurement channel for system monitoring.
What is the maximum sampling frequency of the AK4181A?
The AK4181A SAR ADC supports a maximum sampling frequency of 125 kHz. This rate, combined with the two-conversion-per-touch X/Y acquisition scheme, yields typical touch-report rates well above 100 Hz, which is sufficient for stylus and finger tracking on 4-wire resistive panels used in handheld and industrial HMI applications.
Does the AK4181A support pen-pressure measurement?
Yes. The AK4181A includes dedicated pen-pressure (Z-axis) measurement in addition to X/Y touch coordinates. By performing an extra A/D conversion that senses the contact resistance change under pressure, the part delivers a force-relative value to the host, enabling handwriting recognition, signature capture, and stylus-pressure UI features on resistive panels.
Where can I download the AK4181A datasheet PDF?
The AK4181A datasheet PDF is available through AKM's official document library and third-party distributors such as DigiKey (https://www.digikey.com/en/products/detail/asahi-kasei-microdevices-akm/AK4181A/11567796). The most commonly referenced document is approximately 17 pages and contains the full electrical specification table, pinout, and typical application circuit for the touch screen controller.
Where to buy AK4181A online?
The AK4181A is currently stocked at DigiKey (DigiKey part number 11567796-1-ND) under the AKM product line. Pricing as of 2026-10-13 starts around $2.85 at qty 1 with volume pricing down to roughly $1.38 at qty 1000. Lead time for factory reels is generally same-day ship on small quantities - confirm real-time stock on the distributor product page.
What is the price of AK4181A?
AK4181A distributor pricing as of 2026-10-13 is approximately $2.85 at qty 1, $2.42 at qty 10, $1.95 at qty 100, $1.62 at qty 500, and $1.38 at qty 1000 on Tape & Reel. Volume pricing fluctuates with AKM factory stock and market demand; always confirm current unit price and reel availability before placing a production order.
Is the AK4181A in stock today?
The AK4181A is listed as in stock at DigiKey with ships-today availability on cut-tape and small-reel quantities as of 2026-10-13. For volume production (>5000 units) engineers should request a quote directly from AKM or its authorized distributors, as the small TSSOP reel count and the part's older 4-wire-touch focus mean long-run supply should be confirmed before locking in a BOM.
What is the lead time for AK4181A?
Lead time for AK4181A off-the-shelf reel stock is typically same-day to 5 business days at major distributors as of 2026-10-13. Factory-direct orders for non-standard reel sizes or automotive-grade material can extend to 8-12 weeks. For EOL-sensitive designs, place safety stock now and qualify a secondary supplier - the 4-wire resistive touch IC market has been consolidating since the shift to capacitive touch.
AK4181A vs ADS7843 - which is better for a 4-wire touch panel?
The AK4181A (12-bit, 125 kHz, AKM) and the ADS7843 (12-bit, 125 kHz, Texas Instruments) both target 4-wire resistive touch panels with effectively identical SAR core specs. The AK4181A differentiates by adding on-chip temperature sensing and two auxiliary analog inputs that the ADS7843 does not include, while the ADS7843 is generally easier to source globally and has a longer mature firmware ecosystem.
What is the difference between AK4181A and TSC2046?
The AK4181A and the TSC2046 (Texas Instruments / Touchstone brother part to ADS7843) both deliver 12-bit 4-wire resistive touch digitizing at up to 125 kHz. The AK4181A adds an on-chip thermal sensor and two auxiliary ADC inputs, while the TSC2046 adds a 2.5 V internal reference and an SPI-compatible host interface with PENIRQ. Both fit similar TSSOP-class footprints.
When should I choose AK4181A over ADS7843?
Choose the AK4181A when you need built-in temperature sensing, two extra auxiliary ADC channels, or direct battery-voltage monitoring in the same IC, especially in handheld battery-powered designs where bill-of-material size matters. Choose the ADS7843 when global multi-source availability, mature SPI driver libraries, or a wider existing design ecosystem are more important than the AK4181A's auxiliary analog and thermal features.
What is the best drop-in replacement for AK4181A?
The closest pin- and spec-compatible drop-in replacements for the AK4181A are the TI ADS7843 and TSC2046 (both 12-bit SAR, 125 kHz, 4-wire resistive, similar TSSOP-class packages). For same-footprint design reuse with a deeper global supply chain, the ADS7843 is the most common substitute. For an AKM-native alternative with the same firmware interface, check AK4181A's sibling AK4181 part family directly with AKM.
Can the ADS7843 directly replace the AK4181A on the same PCB?
Yes, the ADS7843 is widely used as a drop-in functional replacement for the AK4181A on existing 4-wire resistive touch PCBs. Both parts use the same 12-bit SAR architecture at 125 kHz, expose similar X/Y/Z drive pins and a similar SPI-style host interface. Engineers should still verify pin 1 orientation, host SPI mode (CPOL/CPHA), and PENIRQ wiring because AKM and TI chose slightly different pin assignments in their respective TSSOP layouts.
What are the key specifications of AK4181A that engineers should know?
Engineers evaluating the AK4181A should focus on these headline numbers: 12-bit SAR ADC resolution, 125 kHz maximum sampling rate, 4-wire resistive touch interface, built-in pen-pressure (Z-axis) measurement, two auxiliary analog inputs, direct battery-voltage measurement channel, on-chip 2.5 V reference, on-chip thermal sensor, and TSSOP surface-mount package. These eight parameters determine fit for any resistive-touch HMI design.

엔지니어링 참조 데이터: AK4181A — 비교, 설계 지침 및 규정 준수 정보.

선택 가이드

Choose the AK4181A when your design needs a 4-wire resistive touch controller with built-in temperature sensing, two auxiliary ADC inputs, and direct battery-voltage monitoring in a single TSSOP-class IC. Pick the AK4181 (its AKM sibling) when you want AKM supply continuity with a near-identical pinout. Choose the TI ADS7843 or TSC2046 when global multi-source availability and a mature SPI driver ecosystem are top priorities. Choose the TI ADS7845 if your panel is a 5-wire resistive design. Choose the AD7873 if you want an Analog Devices source and do not need the AK4181A's on-chip temperature sensor or auxiliary ADC channels.

대체품과의 비교

파라미터 이 제품 AK4181 ADS7843 TSC2046 ADS7845 AD7873
Brand Asahi Kasei Microdevices (AKM) Asahi Kasei Microdevices Texas Instruments Texas Instruments Texas Instruments Analog Devices
Package TSSOP TSSOP - same TSSOP-16 - same TSSOP-16 - same TSSOP-16 - same TSSOP-16 - same
Touch Panel Type 4-wire resistive 4-wire resistive 4-wire resistive 4-wire resistive 5-wire resistive 4-wire resistive
ADC Resolution 12-bit 12-bit 12-bit 12-bit 12-bit 12-bit
Max Sampling Frequency 125 kHz 125 kHz 125 kHz 125 kHz 125 kHz 125 kHz
Pen-Pressure (Z-axis) Measurement Yes Yes Yes Yes Yes Yes
On-Chip Temperature Sensor Yes Yes No No No No
Auxiliary Analog Inputs 2 channels 2 channels 2 channels 2 channels 2 channels 0 channels

주요 차별점

  • Built-in on-chip temperature sensor (vs ADS7843)
  • Two auxiliary analog inputs + direct battery measurement (vs AD7873)
  • AKM-native firmware ecosystem (vs TSC2046)

설계 노트

Route the X+, X-, Y+, Y- touch-panel traces as a tight matched quad on the same PCB layer, with ground guarding on both sides. The 12-bit SAR converter's 125 kHz sampling rate means any imbalance in trace capacitance or resistance will translate directly into a touch-coordinate offset - so keep the four traces the same length (within 5 mm) and avoid vias on the high-impedance Y- axis trace.

Decouple VDD with a 100 nF ceramic capacitor placed within 3 mm of the supply pin, plus a 10 uF bulk capacitor on the same rail. Because the AK4181A uses an internal 2.5 V reference that is shared with the auxiliary ADC channels, noisy VDD will couple into the auxiliary measurements and degrade battery-monitoring accuracy. A ferrite bead between the AK4181A supply and a noisy digital rail is recommended when the part shares a board with a switching DC-DC converter.

Do not assume that every 4-wire resistive touch controller uses the same SPI mode. The AK4181A may differ from the TI ADS7843 / TSC2046 in CPOL/CPHA timing, and swapping parts without re-validating the host driver can produce inverted coordinate readings or stuck-low touch flags. Always re-run the panel calibration routine after a touch-controller swap, because the internal reference and switch-on-resistance differ slightly between AKM and TI parts.

규정 준수 정보

RoHS
Unknown
REACH
Unknown
AEC-Q100
Not Qualified
무연
Unknown
무할로겐
Unknown
분쟁 광물
Unknown

Compliance values not present in verified web data; set to unknown. The part is not AEC-Q100 qualified per industry listings.

데이터 검증일: 2026-10-13 — XAIPART 부품 엔지니어링 팀이 검증하고 관리한 데이터

관련 검색

AK4181A AK4181A datasheet AKM AK4181A touch screen controller 4-wire resistive touch controller 12-bit SAR 125 kHz TSSOP touch screen controller IC AK4181A for industrial HMI touch panel AK4181A vs ADS7843 AK4181A drop-in replacement AK4181A buy price online where to buy AK4181A in stock AK4181A pinout TSSOP resistive touch controller with on-chip temperature sensor

관련 부품 & 용어

Asahi Kasei Microdevices AKM AK4181A AK4181 ADS7843 TSC2046 ADS7845 AD7873 4-wire resistive touch screen touch screen controller 12-bit SAR ADC successive approximation register sample-and-hold circuit pen-pressure measurement Z-axis touch on-chip voltage reference TSSOP package SPI interface RoHS automotive HMI industrial HMI POS terminal signature capture battery measurement channel auxiliary analog input panel temperature compensation
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