Analog Devices ADP2139 Evaluation Board ADP2139CB-2.8EVALZ ADP2139CB-2.8EVALZ Data Sheet

Product codes
ADP2139CB-2.8EVALZ
Page of 8
 
Evaluation Board User Guide
UG-249
One
 
Technology
 
Way
 
 
P.O.
 
Box
 
9106
 
 
Norwood,
 
MA
 
02062-9106,
 
U.S.A.
 
 
Tel:
 
781.329.4700
 
 
Fax:
 
781.461.3113
 
 
www.analog.com 
 
Evaluation Board for the 800 mA, 3 MHz Buck Regulator 
 
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT  
WARNING AND LEGAL TERMS AND CONDITIONS.
 
Rev. 0 | Page 1 of 8 
FEATURES  
Full-featured evaluation board for the ADP2138/ADP2139 
Standalone capability 
Simple device measurements, including line and load 
regulation, demonstrable with 
A single voltage supply 
A voltage meter 
A current meter  
Load resistors  
Easy access to external components 
 
 
 
 
 
GENERAL DESCRIPTION 
 are high efficiency, low quiescent 
current, synchronous step-down dc-to-dc converters. The 
ADP2139 has the additional feature of an internal discharge 
switch. The total solution requires only three tiny external 
components.  
When the MODE pin is set high, the buck regulator operates in 
forced PWM mode, which provides low peak-to-peak ripple for 
power supply noise sensitive loads at the expense of light load 
efficiency. When the MODE pin is set low, the buck regulator 
automatically switches operating modes, depending on the load 
current level. At higher output loads, the buck regulator operates 
in PWM mode. When the load current falls below a predefined 
threshold, the regulator operates in power save mode (PSM), 
improving light load efficiency.  
The 3 MHz switching frequency minimizes the size of external 
components. Full details on the ADP2138/ADP2139 are 
provided in the ADP2138/ADP2139 data sheet available from 
Analog Devices, Inc., which should be consulted in conjunction 
with this data sheet. 
DIGITAL PICTURE OF THE EVALUATION BOARD 
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Figure 1.