9ZXL1232E / 9ZXL1252E Clock Buffers Renesas Electronics 9ZXL1232E / 9ZXL1252E Clock Buffers are the second generation DB1200ZL differential buffers with enhanced performance. These Renesas Electronics clock buffer parts are pin-compatible upgrades to the 9ZXL1232A and 9ZLX1252A that offer a much-improved phase jitter performance. The 9ZXL1232E / 9ZXL1252E Clock Buffers come with an SMBus write lock feature for increased system security. These buffers also offer fixed external feedback that maintains low drift for critical QPI/UPI applications. Applications include servers, storage, networking, and Solid State Drives (SSDs).