### MX7828LEAI: High-Speed 8-Bit ADC The **MX7828LEAI** is a high-speed, multi-channel 8-bit Analog-to-Digital Converter (ADC) manufactured by Maxim Integrated (now part of Analog Devices). It is designed for easy interfacing with microprocessors and features an on-chip track-and-hold function. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Resolution** | 8-Bit | | **Channels** | 8 Multiplexed Analog Inputs | | **Conversion Time** | 2.5 µs | | **Input Voltage Range** | 0V to V_REF (Unipolar) | | **Supply Voltage** | +5V Single Supply | | **Interface** | Parallel (Microprocessor compatible) | | **Package Type** | SSOP-28 (Shrink Small Outline Package) | --- ### 2. Internal Functional Blocks The device integrates several critical electronic components into a single CMOS chip: * **8-Channel Multiplexer:** Allows the device to select one of eight analog input signals via address lines (A0, A1, A2). * **Track-and-Hold (T/H) Circuitry:** This internal stage captures rapidly changing signals, allowing the ADC to digitize signals with bandwidths up to several hundred kHz. * **Successive Approximation Register (SAR):** The core architecture used to determine the digital value of the analog input through a binary search process. * **Three-State Output Buffers:** Facilitates direct connection to a data bus, allowing the device to remain "High-Z" (high impedance) when not being read. --- ### 3. Pinout and Control Logic The MX7828 operates like a memory-mapped peripheral. The primary control pins include: 1. **$\overline{CS}$ (Chip Select):** Activates the device for communication. 2. **$\overline{RD}$ (Read):** Initiates the conversion process and enables the output drivers. 3. **$\overline{WR}$ (Write):** Used to latch the address of the desired multiplexer channel. 4. **$V_{REF}$:** Sets the full-scale analog input range. --- ### 4. Applications * **High-Speed Data Acquisition:** Monitoring multiple sensors in real-time. * **Process Control:** Converting industrial sensor signals (0-5V) into digital data for PLCs. * **DSP Front-Ends:** Providing digital input for signal processing algorithms. * **Battery Monitoring:** Checking cell voltages in multi-cell packs. --- ### 5. Part Number Decoding (MX7828LEAI) | Suffix | Meaning | | :--- | :--- | | **MX7828** | Base Part Number | | **L** | Relative Accuracy (Grade L = ±1/2 LSB) | | **E** | Operating Temperature (-40°C to +85°C) | | **A** | SSOP Package | | **I** | Industrial Grade |