Data Sheet
FEATURES
Input voltage range: 2.3 V to 5.5 V
One 1.2 A buck regulator
Two 300 mA LDOs
20-lead, 4 mm × 4 mm LFCSP package
Overcurrent and thermal protection
Soft start
Undervoltage lockout
Buck key specifications
Output voltage range: 0.8 V to 3.8 V
Current mode topology for excellent transient response
3 MHz operating frequency
Peak efficiency up to 96%
Uses tiny multilayer inductors and capacitors
Mode pin selects forced PWM or auto PWM/PSM modes
100% duty cycle low dropout mode
LDOs key specifications
Output voltage range: 0.8 V to 5.2 V
Low V
from 1.7 V to 5.5 V
IN
Stable with 2.2 µF ceramic output capacitors
High PSRR
Low output noise
Low dropout voltage
−40°C to +125°C junction temperature range
V
= 2.3V TO
IN1
5.5V
C5
4.7µF
V
= 1.7V
IN2
TO 5.5V
C1
1µF
V
= 1.7V
IN3
TO 5.5V
R
ev. 0
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Micro PMU with 1.2 A Buck Regulator
GENERAL DESCRIPTION
The
ADP5040
and two low dropout regulators (LDO) in a small 20-lead
LFCSP to meet demanding performance and board space
requirements.
The high switching frequency of the buck regulator enables the use
of tiny multilayer external components and minimizes board space.
When the MODE pin is set to logic high, the buck regulator
operates in forced pulse width modulation (PWM) mode.
When the MODE pin is set to logic low, the buck regulator
operates in PWM mode when the load is around the nominal
value. When the load current falls below a predefined threshold
the regulator operates in power save mode (PSM) improving
the light-load efficiency. The low quiescent current, low
dropout voltage, and wide input voltage range of the
LDOs extend the battery life of portable devices. The
LDOs maintain a power supply rejection greater than 60 dB for
frequencies as high as 10 kHz while operating with a low headroom
voltage.
Each regulator in the
the respective enable pin. The output voltages of the regulators
are programmed though external resistor dividers to address a
variety of applications.
FUNCTIONAL BLOCK DIAGRAM
= 30Ω
R
FILT
AVIN
BUCK
AVIN
VIN1
EN_BK
ON
EN1
OFF
LDO1
VIN2
(DIGITAL)
EN_LDO1
ON
EN2
OFF
ON
EN3
OFF
EN_LDO2
VIN3
LDO2
C3
(ANALOG)
1µF
AGND
Figure 1.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
and Two 300 mA LDOs
ADP5040
combines one high performance buck regulator
ADP5040
is activated by a high level on
VOUT1
L1
1µH
SW
V
AT
OUT1
1.2A
FB1
C6
R1
R2
10µF
PGND
FPWM
MODE
PSM/PWM
VOUT2
V
AT
OUT2
300mA
FB2
C2
R3
2.2µF
R4
VOUT3
V
AT
OUT3
300mA
FB3
C4
R7
2.2µF
R3
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ADP5040
ADP5040
www.analog.com