Functional Description, Application

The IC is designed for use in mobile radio communication devices up to 1100 MHz.

Due to its low power consumption and low phase noise generation it is suitable for the use in battery powered handheld

systems, e.g. GSM, cordless telephone and wireless LANs.

Low supply voltage down to 2.7V.

It can be switched to a low-power standby mode.

Internal current source at the emitter follower output. No external resistor needed in typical applications.

The divide ratio is 1:64/65 or 1:128/129 depending on the external circuit configuration.

The IC is board level compatible to the PMB 2312 prescaler.

Circuit Description

The differential inputs of the IC may be connected either balanced or single ended. In the latter case the unused input must be RF-grounded with a capacitor (about 1.5 nF) with a low serial inductance.

Depending on the logic level at SW input the basic divide ratio of the ECL-stages is fixed to 1:64/65 or 1:128/129. The MOD input determines whether modulus 1:n or 1:n+1 (n=64 or 128 according to SW-level) is active.

The IC can be switched to a low-power standby mode (input STB).

The MOD input is TTL/CMOS compatible.

The emitter follower output is CMOS compatible according to the application circuit on page 11. The minimum logic swing is 0.8 Vpp.