The **AD7828KP** is a high-speed, 8-bit, 8-channel sampling Analog-to-Digital Converter (ADC) manufactured by Analog Devices. It is built using Linear-Compatible CMOS (LC²MOS) technology, which allows for fast conversion times and low power consumption. --- ### ## Technical Specifications Overview | Feature | Specification | | :--- | :--- | | **Resolution** | 8 Bits | | **Number of Channels** | 8 (Multiplexed) | | **Conversion Time** | 2.5 µs (per channel) | | **Input Range** | 0V to +5V (Single Supply) | | **Interface** | Parallel (Microprocessor Compatible) | | **Package Type** | PLCC-28 (Plastic Leaded Chip Carrier) | | **Supply Voltage** | +5V (Single Supply) | --- ### ### Key Functional Components The internal architecture of the AD7828KP consists of several critical electronic sections: 1. **8-Channel Analog Multiplexer:** This component allows the chip to select one of eight different analog input signals (AIN1 to AIN8) based on a 3-bit address input (A0, A1, A2). 2. **Track-and-Hold (T/H) Circuit:** The built-in track-and-hold circuitry ensures that the input signal remains stable during the conversion process, which is essential for capturing high-frequency signals. 3. **Flash Converter (Half-Flash Architecture):** Instead of a slow successive approximation register (SAR), the AD7828 uses a half-flash technique. This involves two 4-bit flash stages to achieve high speed without the excessive power consumption of a full 8-bit flash converter. 4. **Control Logic and Bus Interface:** The device features easy-to-use control pins (`CS` - Chip Select, `RD` - Read, `WR` - Write) that allow it to interface directly with 8-bit microprocessors like a memory location or I/O port. --- ### ### Pin Configuration (Partial - PLCC 28) | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | Vcc | +5V Power Supply | | 2-9 | AIN1-AIN8 | Analog Inputs | | 14 | DGND | Digital Ground | | 15-22 | DB0-DB7 | Data Output Bits (Tri-state) | | 26 | RD | Read Input (Starts conversion/enables output) | | 28 | Vref(+) | Positive Reference Voltage | --- ### ### Typical Applications * **Data Acquisition Systems:** High-speed gathering of sensor data. * **Digital Signal Processing:** Real-time conversion of analog waveforms. * **Process Control:** Monitoring multiple analog variables in industrial environments. * **Instrumentation:** Portable or battery-powered measuring devices due to low power needs. ---