
September 2005 
rev 1.4
ASM5P2308A
Notice: The information in this document is subject to change without notice. 
Alliance Semiconductor 
2575 Augustine Drive 
 Santa Clara, CA  
 Tel: 408.855.4900 
 Fax: 408.855.4999 
 www.alsc.com
3.3V Zero-Delay Buffer 
General Features 
  
Zero input - output propagation delay, adjustable by 
capacitive load on FBK input. 
  
Multiple configurations - Refer “ASM5P2308A 
Configurations “ Table. 
  
Input frequency range: 15MHz to 133MHz 
  
Multiple low-skew outputs. 
  
Output-output skew less than 200pS. 
  
Device-device skew less than 700pS. 
  
Two banks of four outputs, tri-stateable by two select 
inputs. 
  
Less than 200pS cycle-to-cycle jitter  
       (-1, -1H,-2, -3,  -4, -5H). 
  
Available in 16 pin SOIC and TSSOP packages. 
  
3.3V operation. 
  
Advanced 0.35μ CMOS technology. 
  
Functional Description 
Industrial temperature available. 
ASM5P2308A is a versatile, 3.3V zero-delay buffer 
designed to distribute high-speed clocks. It is available in a 
16 pin package. The part has an on-chip PLL which locks 
to an input clock presented on the REF pin. The PLL 
feedback is required to be driven to FBK pin, and can be 
obtained from one of the outputs. The input-to-output 
propagation delay is guaranteed to be less than 250pS, 
and the output-to-output skew is guaranteed to be less than 
200pS. 
The ASM5P2308A has two banks of four outputs each, 
which can be controlled by the select inputs as shown in 
the Select Input Decoding Table. The select input also 
allows the input clock to be directly applied to the outputs 
for chip and system testing purposes. 
Multiple ASM5P2308A devices can accept the same input 
clock and distribute it. In this case the skew between the 
outputs of the two devices is guaranteed to be less than 
700pS. 
The 
ASM5P2308A 
is 
available 
in 
five 
different 
configurations(Refer “ASM5P2308A Configurations” Table). 
The ASM5P2308A-1 is the base part, where the output 
frequencies equal the reference if there is no counter in the 
feedback path. The ASM5P2308A-1H is the high-drive 
version of the -1 and the rise and fall times on this device 
are much faster. 
The ASM5P2308A-2 allows the user to obtain 2X and 1X 
frequencies on each output bank. The exact configuration 
and output frequencies depends on which output drives the 
feedback pin. The ASM5P2308A-3 allows the user to 
obtain 4X and 2X frequencies on the outputs. 
The ASM5P2308A-4 enables the user to obtain 2X clocks 
on all outputs.  
The ASM5P2308A-5H is a high-drive version with REF/2 
on both banks. Thus, the part is extremely versatile, and 
can be used in a variety of applications.