PCA9571GUX - 8-Bit 1MHz I2C Output Expander | NXP
料号： PCA9571GUX ✓ 量产中PCA9571GUX 概述
An I2C output expander is an interface IC that adds parallel digital outputs to a serial bus. The hierarchy runs from I2C output expander to GPIO expander, interface expander, and semiconductor. It is useful when a processor has too few general-purpose output pins to control multiple discrete loads while the system architecture requires a shared serial control bus.
The PCA9571GUX provides eight general-purpose parallel outputs and supports 1 MHz I2C operation while retaining backward compatibility with 100 kHz Standard-mode and 400 kHz Fast-mode buses. Backward compatibility allows the same device to operate alongside slower peripherals on a shared bus, although total bus capacitance, pull-up selection, and signal-integrity margin remain system-level constraints.
The streamlined output-only architecture distinguishes this device from bidirectional I/O expanders. It does not provide input pins for state readback, so its primary function is command and control rather than monitoring external logic levels. The 2 mm by 1.7 mm XQFN package supports compact designs where board area is important, although the fine-pitch footprint requires careful PCB assembly and inspection.
Typical applications include portable-device control, low-voltage processor systems, battery-powered equipment, and systems that need multiple parallel outputs driven over I2C. Product family members can be useful in portable and mobile equipment, industrial controllers, embedded systems, and peripheral-control designs where eight outputs reduce the number of direct host-controller connections.
Designers should confirm the address configuration, output behavior, voltage limits, and pin mapping in the manufacturer datasheet before finalizing a PCB. The 1 MHz operating rate is intended for a lightly loaded bus below 100 pF; pull-up resistance, cable length, peripheral capacitance, and signal rise time must be evaluated together when the bus includes long traces or additional devices.
This page organizes the PCA9571GUX function, interface characteristics, package constraints, application guidance, comparison points, and replacement criteria so that engineers can assess the device alongside other I2C output-expansion options before committing a board layout.
直接替换替代料： PCA9571GUX ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
该产品暂无直接替换替代料。
请求替代料PCA9571GUX 规格参数
| Device Type | 8-bit general-purpose parallel output expander |
| Number of Output Bits | 8 bits |
| Maximum I2C Bus Frequency | 1 MHz |
| Fast-mode I2C Frequency | 400 kHz |
| Standard-mode I2C Frequency | 100 kHz |
| Maximum Bus Capacitance at 1 MHz | Less than 100 pF |
| Interface Standard | I2C serial bus |
| Process Technology | CMOS |
| Package Type | 12-pin XQFN |
| Package Dimensions | 2 mm x 1.7 mm |
| 安装类型 | Surface mount |
| RoHS 状态 | Unknown |
| REACH Status | Unknown |
| AEC-Q100 Qualification | Not applicable |
PCA9571GUX 2 mm x 1.7 mm 引脚配置指南
PCA9571GUX（2 mm x 1.7 mm 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： PCA9571GUX.
请参阅 数据手册 以查看完整引脚配置。
典型应用
PCA9571GUX 适用于 6 应用s: Portable Device Output Control, Industrial Peripheral Control, Embedded System Output Expansion, Battery-Powered Instrumentation, Communication Equipment Control, LED and Discrete Load Control.
Portable Device Output Control
The PCA9571GUX fits portable equipment that needs several discrete control outputs but has limited host-controller I/O capacity. Its eight parallel outputs can be connected through an I2C bus operating at up to 1 MHz when total bus capacitance remains below 100 pF. The 12-pin XQFN package measures only 2 mm by 1.7 mm, helping preserve board area in compact products. Because the device is output-only, it is best suited to command-and-control tasks rather than reading switch or sensor states; the host should also confirm active and idle current requirements against the system battery budget.
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Industrial Peripheral Control
PCA9571GUX can reduce the number of direct host connections in a compact industrial peripheral controller. Eight general-purpose outputs are controlled over the shared I2C bus, while operation remains compatible with 100 kHz and 400 kHz systems as well as 1 MHz operation on a lightly loaded bus. The fine-pitch 12-pin XQFN package saves board area but requires assembly capability suitable for its 2 mm by 1.7 mm outline. Engineers should account for pull-up values, bus capacitance, output load, and system grounding when laying out a controller intended for industrial equipment.
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Embedded System Output Expansion
The PCA9571GUX is suitable when an embedded processor must control multiple external loads without dedicating eight pins to parallel outputs. Its streamlined eight-bit output architecture fits command, enable, mode, or discrete actuator-control signals while the host communicates through I2C. The device supports 1 MHz operation on a bus below 100 pF and remains compatible with slower bus modes, giving designers flexibility when integrating older peripherals. Verify address availability, output state during reset, supply voltage, and per-pin loading against the manufacturer datasheet before assigning functions in the firmware.
推荐
Battery-Powered Instrumentation
For battery-powered test and measurement equipment, PCA9571GUX can add eight parallel outputs without consuming eight direct host-controller pins. The compact 12-pin XQFN footprint is useful where panel or board space is constrained, and the I2C interface can run up to 1 MHz on a lightly loaded bus below 100 pF. The device is output-only, so state monitoring must be handled by another interface or through the controlled subsystem itself. Power-consumption and output-slew review should use the electrical characteristics in the NXP manufacturer datasheet rather than estimating behavior from the bus interface alone.
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Communication Equipment Control
PCA9571GUX can serve as a compact output-expansion stage in communication equipment where the primary controller manages a shared I2C bus and local modules require additional discrete controls. Its eight outputs provide a straightforward parallel-control surface, while 1 MHz operation on a lightly loaded bus supports faster host-side updates. Compatibility with 400 kHz Fast-mode and 100 kHz Standard-mode permits integration with mixed-speed peripherals. Designers should evaluate bus pull-ups, worst-case capacitance, signal rise time, output loading, and grounding so that the shared serial link remains reliable across the complete board population.
推荐
LED and Discrete Load Control
The PCA9571GUX can provide eight host-controlled outputs for LED groups, reset enables, mode selectors, or other discrete loads in a compact subsystem. Because it is an output-only device, it is appropriate when the host only needs to command the loads and does not need to sample their state. The I2C bus may operate at up to 1 MHz when its capacitance remains below 100 pF, reducing command latency in suitable designs. Confirm the output voltage, sink and source capability, allowable output state, and current limits in the datasheet; those electrical details determine whether additional driver circuitry is required.
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推荐产品汇总
工程参考数据： PCA9571GUX ——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 |
|---|---|
| Package | 12-pin XQFN, 2 mm x 1.7 mm |
| Brand | NXP Semiconductors |
| Device Type | I2C general-purpose parallel output expander |
| Number of Outputs | 8 bits |
| Maximum I2C Frequency | 1 MHz |
| Fast-mode Compatibility | 400 kHz |
| Standard-mode Compatibility | 100 kHz |
| Bus Capacitance at 1 MHz | Less than 100 pF |
| Process Technology | CMOS |
| Mounting Type | Surface mount |
设计说明
Route the I2C clock and data as a short, tightly coupled pair, and place the associated pull-up resistors where the bus is physically divided or where the master resides. The 1 MHz rating applies to a lightly loaded bus below 100 pF. Include margin for input capacitance, connector wiring, PCB contamination, and test-probe loading; otherwise select 400 kHz or 100 kHz operation for a more conservative timing margin.
The PCA9571GUX uses a 12-pin XQFN package measuring 2 mm by 1.7 mm. Confirm the exposed-pad, terminal-pitch, land-pattern, solder-profile, and paste-volume requirements directly from the NXP package drawing. Assign each net by the numbered pin table rather than by physical position alone, and plan inspection access for this fine-pitch assembly before releasing the PCB.
Do not treat the PCA9571GUX as a bidirectional GPIO device. Its eight parallel pins are outputs, so external logic states cannot be read through them. Assign only functions that the host controls. Also verify the device address, reset or power-on output condition, operating voltage, and per-output loading against the manufacturer datasheet before connecting loads or writing firmware.
合规信息
The component listing does not explicitly state RoHS, REACH, lead-free, halogen-free, or conflict-minerals status. Automotive qualification is treated as not applicable because PCA9571GUX is not identified as an AEC-Q100-qualified automotive variant.
