Analog Devices ADP1878 Evaluation Board ADP1878-1.0-EVALZ ADP1878-1.0-EVALZ データシート
製品コード
ADP1878-1.0-EVALZ
Synchronous Buck Controller with
Constant On Time and Valley Current Mode
Data
Sheet
Rev. B
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FEATURES
Power input voltage range: 2.95 V to 20 V
On-board bias regulator
Minimum output voltage: 0.6 V
0.6 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 (ADP1879 only)
Resistor programmable current limit
Power good with internal pull-up resistor
Externally programmable soft start
Thermal overload protection
Short-circuit protection
Standalone precision enable input
Integrated bootstrap diode for high-side drive
Starts into a precharged output
Available in a 14-lead LFCSP_WD package
On-board bias regulator
Minimum output voltage: 0.6 V
0.6 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 (ADP1879 only)
Resistor programmable current limit
Power good with internal pull-up resistor
Externally programmable soft start
Thermal overload protection
Short-circuit protection
Standalone precision enable input
Integrated bootstrap diode for high-side drive
Starts into a precharged output
Available in a 14-lead LFCSP_WD package
APPLICATIONS
Telecommunications and networking systems
Mid-to-high end servers
Set-top boxes
DSP core power supplies
Mid-to-high end servers
Set-top boxes
DSP core power supplies
TYPICAL APPLICATIONS CIRCUIT
Figure 1.
GENERAL DESCRIPTION
The
are versatile current-mode, synchronous
step-down controllers. They 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. These devices offer optimum performance
at low duty cycles by using a valley, current-mode control architec-
ture allowing the
optimal stability, and current-limit protection by using a constant
on time, pseudo fixed frequency with a programmable current-limit,
current control scheme. These devices offer optimum performance
at low duty cycles by using a valley, current-mode control architec-
ture allowing the
to drive all N-channel power
stages to regulate output voltages to as low as 0.6 V.
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 ADP1879 Power Saving Mode (PSM) section for
more information).
regulation while achieving improved system efficiency at light
loads (see the ADP1879 Power Saving Mode (PSM) section for
more information).
Available in three frequency options (300 kHz, 600 kHz, and
1.0 MHz) plus the PSM option, the
1.0 MHz) plus the PSM option, the
are well
suited for a wide range of applications that require a single input
power supply range from 2.95 V to 20 V. Low voltage biasing is
supplied via a 5 V internal low dropout regulator (LDO). In
addition, soft start programmability is included to limit input
inrush current from the input supply during startup and to
provide reverse current protection during precharged output
power supply range from 2.95 V to 20 V. Low voltage biasing is
supplied via a 5 V internal low dropout regulator (LDO). In
addition, soft start programmability is included to limit input
inrush current from the input supply during startup and to
provide reverse current protection during precharged output
conditions. The low-side current sense, current gain scheme and
integration of a boost diode, together with the PSM/forced
pulse-width modulation (PWM) option, reduce the external
device count and improve efficiency.
integration of a boost diode, together with the PSM/forced
pulse-width modulation (PWM) option, reduce the external
device count and improve efficiency.
operate over the −40°C to +125°C
junction temperature range and are available in a 14-lead
LFCSP_WD package.
LFCSP_WD package.
Efficiency vs. Load Current (V
OUT
= 1.8 V, 300 kHz)
COMP
BST
FB
DRVH
GND
SW
VREG
RES
DRVL
SS
C
SS
PGND
VIN
C
C
C
VREG
C
VREG2
C
C2
R
C
R
BOT
R
TOP
V
OUT
EN
10kΩ
V
REG
Q1
Q2
L
C
OUT
V
OUT
C
BST
LOAD
C
IN
V
IN
= 2.95V TO 20V
ADP1878/
ADP1879
R
RES
PGOOD
R
PGD
V
EXT
09
44
1-
0
01
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
90
85
80
75
70
65
60
55
50
45
40
35
30
25
10
100
1k
10k
100k
E
FFIC
IE
N
C
Y
(
%
)
LOAD CURRENT (mA)
T
A
= 25°C
V
OUT
= 1.8V
f
SW
= 300kHz
WÜRTH INDUCTOR:
744325120, L = 1.2µH, DCR = 1.8mΩ
INFINEON FETs:
INFINEON FETs:
BSC042N03MS G (UPPER/LOWER)
V
IN
= 5V (PSM)
V
IN
= 13V (PSM)
V
IN
= 16.5V (PSM)
V
IN
= 13V
V
IN
= 16.5V
09441
-102