Analog Devices ADP1882 Evaluation Board ADP1882-1.0-EVALZ ADP1882-1.0-EVALZ Data Sheet

Product codes
ADP1882-1.0-EVALZ
Page of 40
 
Synchronous Current-Mode with 
Constant On-Time, PWM Buck Controller
  
ADP1882/ADP1883
 
 
Rev. 0 
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Tel: 781.329.4700 
www.analog.com
 
Fax: 781.461.3113 
©2010 Analog Devices, Inc. All rights reserved. 
FEATURES 
Power input voltage as low as 2.75 V to 20 V 
Bias supply voltage range: 2.75 V to 5.5 V 
Minimum output voltage: 0.8 V 
0.8 V reference voltage with ±1.0% accuracy 
Supports all N-channel MOSFET power stages 
Available in 300 kHz, 600 kHz, and 1.0 MHz options 
No current-sense resistor required 
Power saving mode (PSM) for light loads (ADP1883 only) 
Resistor-programmable current-sense gain 
Thermal overload protection 
Short-circuit protection 
Precision enable input 
Integrated bootstrap diode for high-side drive 
140 μA shutdown supply current 
Starts into a precharged load 
Small, 10-lead MSOP package 
APPLICATIONS 
Telecom and networking systems 
Mid to high end servers 
Set-top boxes 
DSP core power supplies 
TYPICAL APPLICATIONS CIRCUIT 
COMP/EN BST
FB
DRVH
GND
SW
VDD
DRVL
PGND
VIN
C
C
C
VDD
V
DD
= 2.75V TO 5.5V
C
VDD2
C
C2
R
C
R
BOT
R
TOP
V
OUT
V
IN
 = 2.75V TO 20V
Q1
Q2
R
RES
L
C
OUT
V
OUT
C
BST
LOAD
C
IN
ADP1882/
ADP1883
08
90
1-
00
1
 
Figure 1.  
 
100
95
90
85
80
75
70
65
60
55
50
45
25
30
35
40
100
1k
10k
100k
EF
F
IC
IEN
C
Y (
%
)
LOAD CURRENT (mA)
V
DD
 = 5.5V, V
IN
 = 13.0V
V
DD
 = 5.5V, V
IN
 = 16.5V
V
DD
 = 5.5V, V
IN
 = 5.5V (PSM)
V
DD
 = 5.5V, V
IN
 = 5.5V
V
DD
 = 3.6V, V
IN
 = 5.5V
T
A
 = 25°C
V
OUT
 = 1.8V
f
SW
 = 300kHz
WURTH INDUCTOR:
744325120, L = 1.2µH, DCR = 1.8m
Ω
INFINEON MOSFETs:
BSC042N03MS G (UPPER/LOWER)
08
90
1-
0
02
 
Figure 2. ADP1882/ADP1883 Efficiency vs. Load Current  
(V
OUT
 = 1.8 V, 300 kHz) 
GENERAL DESCRIPTION 
The ADP1882/ADP1883 are versatile current-mode, synchronous 
step-down controllers that provide superior transient response, 
optimal stability, and current-limit protection by using a constant 
on-time, pseudo-fixed frequency with a programmable current-
limit, current-control scheme. In addition, these devices offer 
optimum performance at low duty cycles by using valley current-
mode control architecture. This allows the ADP1882/ADP1883 
to drive all N-channel power stages to regulate output voltages 
as low as 0.8 V. 
The ADP1883 is the power saving mode (PSM) version of the 
device and is capable of pulse skipping to maintain output 
regulation while achieving improved system efficiency at light 
loads (see the Power Saving Mode (PSM) Version (ADP1883) 
section for more information).  
Available in three frequency options (300 kHz, 600 kHz, and 
1.0 MHz, plus the PSM option), the ADP1882/ADP1883 are 
well suited for a wide range of applications. These ICs not only 
operate from a 2.75 V to 5.5 V bias supply, but they also can 
accept a power input as high as 20 V.  
In addition, an internally fixed soft start period is included to limit 
input in-rush current from the input supply during startup and 
to provide reverse current protection during soft start for a pre-
charged output. The low-side current-sense, current-gain scheme 
and integration of a boost diode, along with the PSM/forced 
pulse-width modulation (PWM) option, reduce the external 
part count and improve efficiency.  
The ADP1882/ADP1883 operate over the −40°C to +125°C 
junction temperature range and are available in a 10-lead MSOP.