AK4181A - 4-Wire Touch Screen Controller, 12-bit SAR ADC | AKM
料号： AK4181A ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 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 |
AK4181A 概述
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.
直接替换替代料： AK4181A ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： AK4181A （相同外形与封装尺寸） ——差异在于 Direct Battery Measurement, Package, RoHS Status.
快速对比工具——选择替代料号进行并排对比：
AK4181
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
ADS7843
✅ 直接替换📋 参考替代料（不在目录中）
TSC2046
✅ 直接替换📋 参考替代料（不在目录中）
ADS7845
✅ 直接替换📋 参考替代料（不在目录中）
AD7873ARQZ
✅ 直接替换✓ 有现货
$5.49 / 个
查看数据手册 →AK4181A 最大额定值与电气特性
| 功能 | 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 |
| 封装 | TSSOP |
| 安装类型 | Surface Mount |
| RoHS 状态 | unknown |
AK4181A tssop 引脚配置指南
AK4181A（tssop 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： AK4181A.
请参阅 数据手册 以查看完整引脚配置。
典型应用
AK4181A 适用于 6 应用s: 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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
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.
推荐
推荐产品汇总
工程参考数据： AK4181A ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | 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 |
关键差异点
- Built-in on-chip temperature sensor （对比 ADS7843)
- Two auxiliary analog inputs + direct battery measurement （对比 AD7873)
- AKM-native firmware ecosystem （对比 TSC2046)
设计说明
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.
合规信息
Compliance values not present in verified web data; set to unknown. The part is not AEC-Q100 qualified per industry listings.
