FAQs > CW Signals > Answers

Q1: How do I divide a 10 MHz-300 MHz sine wave by 2 and output a TTL square wave? 

A1:  The PRL-260ANT is an 8-bit manually programmable frequency divider that provides both NECL and TTL f/n outputs. The NECL input can accept an AC-coupled sinewave using our PRL-SC-104 DC Block.

Q2: How do I convert a sine wave into an ECL/PECL signal? 

A2: For small-amplitude signals (as small as 10 mV p-p) use the PRL-350ECL. This a dual channel comparator with complementary ECL outputs. It is similar to the PRL-350TTL but can be driven beyond 1.8 GHz. A PECL output version is also available via special order.

For larger signals (>200 mV p-p), most of our products with ECL or PECL inputs will also receive an AC-coupled sinewave. For example, to convert a sinewave to NECL, you can AC-couple into our PRL-430N using our PRL-SC-104 DC Block. The following products will receive AC-coupled sinewave inputs:

• PRL-255N and PRL-255P,  ECL and PECL frequency dividers
• PRL-430N and PRL-430P, ECL and PECL line drivers
• PRL-431N and PRL-431P, ECL and PECL 1:2 fanout buffers 
• PRL-434, ECL 1:4 fanout buffer 
• PRL-450ND and PRL-450PD, ECL and PECL to TTL translators
• PRL-460NPD and PRL-460PND, ECL ↔ PECL translators

Q3: How do I convert a 160 MHz sine wave into a pair of 5 V square wave signals for driving 50 Ω loads? 

A3: For small signals, use the complementary outputs of a PRL-350ECL to drive two Variable Output Line Drivers (PRL-470A).  Each PRL-470A can deliver +5 V or -2.5 V into a 50 Ω load. For a 0 to 5 V output, the PRL-470 has a 1 ns rise time and can operate up to 250 MHz. An output polarity switch will reverse the phase error induced by driving the two line drivers with true and complement signals.

If the sinewave is more than 2 V p-p, then the PRL-350 is not necessary; instead use a DC block to AC couple the sine wave into a PRL-812, 6 dB splitter, and from there drive the NECL inputs of the two PRL-470A's.