MAX7301AAI+T - 20-Port SPI GPIO Expander 26MHz | Analog Devices
料号： MAX7301AAI+T ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.15 | $3.15 |
| 10 | $2.87 | $28.70 |
| 100 | $2.58 | $258.00 |
| 500 | $2.35 | $1,175.00 |
| 1,000 | $2.12 | $2,120.00 |
MAX7301AAI+T 概述
A GPIO (general-purpose input/output) expander is a peripheral interface IC that gives a microprocessor or microcontroller additional digital I/O lines over a serial bus. In the system hierarchy, it sits between the host processor and the external devices it controls (switches, LEDs, sensors, relays), offloading pin-count-constrained MCUs and reducing board-level wiring. The MAX7301 family belongs to the interface IC > I/O expander category and is the SPI/Microwire sibling of the I2C-interfaced MAX7300.
Key features include 20 user-configurable ports (P12 to P31), each individually programmable as logic input or logic output; a 26 MHz maximum SPI clock for fast port updates; an integrated push-pull interrupt output; and a wide 2.5V to 5.5V operating supply that covers 3.3V and 5V logic systems. Transition detection on inputs allows the INT output to flag port changes without continuous host polling.
Architecturally, the MAX7301 uses a register-based configuration model: each port's direction and output level is set through internal control registers written over the serial interface. Note that on the 28-pin MAX7301AAI variant, eight die ports are unused; the datasheet requires configuring them as outputs on power-up by writing 0x55 to registers 0x09 and 0x0A, otherwise they float as inputs and quiescent supply current rises (no damage occurs).
Typical applications include gaming machines, industrial controllers, system monitoring, and white goods, where multiple discrete digital signals must be read or driven from a single SPI port. It is also a fit for backplane status monitoring and front-panel key scanning.
Design consideration: keep the unused-port initialization routine in your power-up firmware, and account for SSOP thermal and pitch constraints in PCB layout. For higher drive needs, the pin-compatible MAX6957 adds 24mA constant-current LED drive.
This page synthesizes distributor pricing, drop-in alternatives, design notes, and an FAQ not found in the manufacturer datasheet alone.
直接替换替代料： MAX7301AAI+T ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
MAX7300AAI+T
✅ 直接替换📋 参考替代料（不在目录中）
MAX6957AAI+
✅ 直接替换📋 参考替代料（不在目录中）
MAX6956AAI+
✅ 直接替换📋 参考替代料（不在目录中）
MAX7301AAI+
✅ 直接替换📋 参考替代料（不在目录中）
MAX7301AAI
✅ 直接替换📋 参考替代料（不在目录中）
MAX7301AAI+T 规格参数
| Number of I/O Ports | 20 (P12 to P31) |
| 接口类型 | SPI / 4-wire serial (Microwire-compatible) |
| 最大时钟频率 | 26 MHz |
| Supply Voltage Range | 2.5 V to 5.5 V |
| Port Configuration | Each port individually configurable as logic input or logic output |
| Interrupt Output | Yes, push-pull |
| 封装 | 28-pin SSOP |
| 安装类型 | Surface Mount |
| Product Type | I/O Expander (GPIO peripheral) |
| Packing | Tape & Reel (+T suffix) |
| Typical Applications | Gaming machines, industrial controllers, system monitoring, white goods |
MAX7301AAI+T 28-pin ssop 引脚配置指南
MAX7301AAI+T（28-pin ssop 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： MAX7301AAI+T.
请参阅 数据手册 以查看完整引脚配置。
典型应用
MAX7301AAI+T 适用于 6 应用s: Industrial Controllers, System Monitoring, Gaming Machines, White Goods / Home Appliance Control, Front-Panel Key Scanning, Embedded System GPIO Expansion.
Industrial Controllers
The MAX7301AAI+T is explicitly listed by Analog Devices as a target part for industrial controllers. Its 20 individually configurable GPIO ports let a single MCU SPI bus control limit switches, relays, mode jumpers, and status inputs across a machine, while the wide 2.5V to 5.5V supply range supports both 3.3V and legacy 5V industrial logic domains. The 26 MHz serial clock enables near-instant port refresh for time-critical interlocks, and the push-pull interrupt output allows event-driven monitoring of input transitions without continuous polling, reducing bus traffic in noisy factory-floor environments.
推荐
System Monitoring
In system-monitoring subsystems - chassis status boards, backplane health logic, rack-level alarms - the MAX7301AAI+T aggregates dozens of discrete signals onto one 4-wire SPI link. Each of its 20 ports (P12-P31) is independently settable as input or output, so a single device can read fault flags and drive acknowledge LEDs simultaneously. The interrupt output flags input transitions so the host MCU can sleep between events, cutting quiescent system power. Operating from 2.5V to 5.5V, it interfaces directly with both low-voltage FPGA banks and 5V supervisory logic without level shifting.
推荐
Gaming Machines
Gaming and amusement machines require dense digital I/O for button matrices, lamp outputs, door switches, and coin sensors - exactly the workload Analog Devices cites for the MAX7301 family. The MAX7301AAI+T provides 20 ports expandable across multiple devices on one SPI bus with individual chip selects, avoiding I2C address conflicts when cascading. The 26 MHz clock allows full port scans far faster than human interaction timescales, and the 2.5V-5.5V range matches mixed 3.3V/5V cabinet electronics. The SSOP-28 footprint keeps PCB area small in space-constrained control boards.
推荐
White Goods / Home Appliance Control
White goods control boards - washers, refrigerators, ovens - use many discrete inputs (door interlocks, float switches, encoder pulses) and outputs (valve drivers via transistors, buzzer, indicator LEDs). The MAX7301AAI+T consolidates these onto a single SPI port of a low-cost appliance MCU. Its register-based configuration permits firmware-defined port roles across product variants sharing one PCB, cutting SKU proliferation. The push-pull INT output wakes the host only when a user presses a key or a sensor changes state, supporting low standby-power targets required by modern energy regulations.
推荐
Front-Panel Key Scanning
For keypads and rotary/mode switch arrays, the MAX7301AAI+T can dedicate a subset of its 20 ports to a scanned or static key matrix while the remainder drive backlight enables and status LEDs. Input transition detection on configured inputs drives the INT pin, so keypresses are captured without continuous polling even at low host clock rates. The 26 MHz SPI interface permits full matrix scans well within typical debounce windows. Because ports are individually configurable at runtime, the same silicon adapts to 2x4, 3x4, or 4x4 matrices via firmware alone.
推荐
Embedded System GPIO Expansion
When a microcontroller or FPGA runs out of GPIO, the MAX7301AAI+T is a compact serial-to-parallel expansion stage: four MCU pins (DIN, DOUT, SCLK, CS) yield 20 bidirectional I/O lines at logic levels set by its 2.5V-5.5V supply. It suits test fixtures, daughter-card identification, and board-revision strapping. A key datasheet requirement: on the AAI variant, write 0x55 to registers 0x09 and 0x0A at power-up to force the eight unused die ports to outputs, preventing the quiescent-current rise caused by floating inputs. No damage occurs if omitted, but supply current exceeds spec.
推荐
推荐产品汇总
工程参考数据： MAX7301AAI+T ——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 | MAX7300AAI+T | MAX6957AAI+ | MAX6956AAI+ | MAX7301AAI+ |
|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Brand | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) | Analog Devices (Maxim Integrated) |
| Supply Voltage Range | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| LED Drive Capability | No (logic-level I/O only) | No (logic-level I/O only) | Yes, 24mA constant-current per port | Yes, 30mA per cross-reference listing | No (logic-level I/O only) |
关键差异点
- Fast 26 MHz SPI interface （对比 MAX7300AAI+T)
- Lowest-cost pure logic GPIO expansion （对比 MAX6957AAI+)
- Documented unused-port initialization requirement （对比 MAX7301AAX+T)
设计说明
Per the Analog Devices MAX7301 datasheet, the eight unused die ports on the 28-pin MAX7301AAI must be configured as outputs on power-up by writing 0x55 to registers 0x09 and 0x0A. If this initialization is omitted, the unused ports remain floating inputs and quiescent supply current rises - there is no damage to the part, but your power budget will exceed the datasheet figure. Put this two-register write sequence at the very start of firmware initialization, before entering any low-power mode.
The 28-SSOP package has a 0.65 mm pin pitch; use 6-8 mil trace widths into each pin and place a 0.1 uF ceramic decoupling capacitor within 2-3 mm of the V+ pin. Route SCLK and DIN away from the INT output trace to avoid false interrupt edges during bus bursts; a short series resistor (33-100 ohm estimated value) on SCLK can tame ringing at 26 MHz on long traces. Keep the CS line pulled up or driven low-defined during MCU reset so the expander ignores bus noise at boot.
At the 26 MHz maximum SPI clock, treat the serial bus as a moderate-speed digital net: keep total trace length under ~15 cm where practical, maintain a solid ground return under the bus, and verify setup/hold timing with the worst-case host SPI mode supported by the MAX7301 register interface. For multi-drop designs using separate chip selects per expander, star-route CS lines from the host and keep the shared DOUT line loaded lightly; excessive capacitive loading on DOUT will round edges and erode timing margin at full clock rate.
合规信息
Compliance data was not present in the retrieved web data. The '+' suffix on Maxim part numbers historically indicates lead-free/RoHS-enhanced packaging, but this must be confirmed against the official Analog Devices product page before design-in.
