Using a proprietary digital-phase, locked-loop technique, the LMX243x devices generate very stable, low-noise control signals for RF and IF voltage controlled oscillators. Both the RF and IF synthesizers include a two-level programmable charge pump. Both the RF and IF PLLs have dedicated fastlock circuitry with integrated time-out counters which require only a single word write to power up or change frequencies.
The LMX243x devices are high-performance frequency synthesizers with integrated dual-modulus prescalers. A 32/33 or a 16/17 prescale ratio can be selected for the 5-GHz LMX2434 RF synthesizer. An 8/9 or a 16/17 prescale ratio can be selected for both the LMX2430 and LMX2433 RF synthesizers. The IF circuitry contains an 8/9 or a 16/17 prescaler.
Serial data is transferred to the devices through a three-wire interface (DATA, LE, CLK). A low voltage logic interface allows direct connection to 1.8-V devices. Supply voltages from 2.25 V to 2.75 V are supported.
| Integrated VCO | No |
| Output frequency (min) (MHz) | 250 |
| Output frequency (max) (MHz) | 3000 |
| Normalized PLL phase noise (dBc/Hz) | -218 |
| Current consumption (mA) | 2.8 |
| Features | Fastlock, Programmable charge-pump current, Synchronous and asynchronous power down |
| 1/f noise (10-kHz offset at 1-GHz carrier) (dBc/Hz) | -100 |
| Rating | Catalog |
| Operating temperature range (°C) | -40 to 85 |
| Lock time (µs) (typ) | Loop BW dependent |
| TSSOP (PW) | 20 | 41.6 mm² 6.5 x 6.4 |
| ULGA (NPE) | 20 | 12.25 mm² 3.5 x 3.5 |