## Overview of the ADCMP607 The **ADCMP607** is a very fast, single-supply comparator designed for high-speed applications. It features a **PECL-compatible** (Positive Emitter-Coupled Logic) output stage and is built using Analog Devices’ proprietary XFCB2 process. --- ### 1. Key Technical Specifications | Parameter | Value | | :--- | :--- | | **Propagation Delay** | 800 ps (typical) | | **Supply Voltage** | 2.5 V to 5.5 V | | **Output Logic** | Differential PECL | | **Input Common-Mode Range** | -0.2 V to $V_{CC}$ + 0.2 V | | **Power Consumption** | ~21 mW (at 2.5 V) | | **Package** | 6-lead SC70 | --- ### 2. Functional Electronic Features #### A. Input Stage * **Rail-to-Rail Capability:** The inputs can handle signals slightly beyond the power supply rails (up to 200 mV beyond), which is critical for low-voltage systems. * **High Sensitivity:** It can resolve very small signal differences with minimal offset voltage. #### B. Output Stage (PECL) * The output is **differential PECL**, designed to drive 50 Ω transmission lines terminated into $V_{CC} - 2.0$ V. * Unlike standard CMOS outputs, PECL provides high-speed switching with minimal EMI (Electromagnetic Interference) and noise. #### C. Latch Function (LE/HYS Pin) The ADCMP607 includes a versatile **Latch** pin: 1. **Latching:** When the Latch Enable (LE) pin is driven high, the output is held at its current state regardless of the inputs. 2. **Hysteresis Control:** If not using the latch, a resistor can be connected to this pin to program the amount of input hysteresis, improving noise immunity. --- ### 3. Pin Configuration | Pin No. | Name | Description | | :--- | :--- | :--- | | 1 | $Q$ | Non-inverting PECL output | | 2 | $\bar{Q}$ | Inverting PECL output | | 3 | $V_{EE}$ | Negative supply (Ground) | | 4 | $V_{P}$ | Non-inverting input | | 5 | $V_{N}$ | Inverting input | | 6 | $V_{CC}$ | Positive supply | --- ### 4. Typical Applications * **Clock and Data Restoration:** Cleaning up jittery signals in telecommunications. * **High-Speed Line Receivers:** Interpreting signals sent over long PCB traces. * **Pulse Width Modulation (PWM):** Generating precise timing signals. * **Threshold Detection:** Fast detection of transient signals in scientific instrumentation. --- ### 5. Design Considerations When designing a PCB for the ADCMP607, keep the following in mind: * **Bypassing:** Use 0.1 µF and 0.001 µF ceramic capacitors close to the $V_{CC}$ pin to handle high-frequency noise. * **Termination:** PECL outputs require specific termination (typically 50 Ω to $V_{CC} - 2.0$ V) to function correctly and avoid signal reflections. * **Ground Plane:** A continuous ground plane is essential to maintain signal integrity at sub-nanosecond speeds.