The ASM3P18S19B is a versatile spread spectrum frequency modulator designed specifically for input clock frequencies from 20 to 40MHz. It reduces electromagnetic interference (EMI) at the clock source, allowing system-wide reduction of EMI of downstream clock and data-dependent signals. The ASM3P18S19B allows significant system cost savings by reducing the number of circuit board layers, ferrite beads, shielding, and other passive components that are traditionally required.
The ASM3P18S19B is a spread‑spectrum frequency modulator designed for input clocks from 20 MHz to 40 MHz. It provides up to 15 dB EMI reduction, low cycle‑to‑cycle jitter, and a power‑down function for mobile applications. The device is optimized for notebook LCD panel and VGA timing controller applications and is available in commercial temperature range packages.
The datasheet includes absolute maximum ratings, DC and AC electrical characteristics, pin descriptions, package dimensions for 8‑pin SOIC and TSSOP options, and ordering information. It also lists the available spread‑deviation selections and compliance details such as RoHS and FCC approval.
| Operating Voltage | 3.3 V |
|---|---|
| EMI Reduction | up to 15 dB |
| Cycle‑to‑Cycle Jitter | ±200 ps |
| Power‑Down Function | Enabled by PDH pin (active low) |
| Package Types | 8‑pin SOIC and 8‑pin TSSOP |
The device operates at a supply voltage of 3.3 V.
It provides up to 15 dB of EMI reduction.
The IC is offered in 8‑pin SOIC and 8‑pin TSSOP packages.