Micro PMU with 1.2 A Buck, Two 300 mA LDOs,
Supervisory, Watchdog, and Manual Reset
Data Sheet
ADP5041
FEATURES
FUNCTIONAL BLOCK DIAGRAM
VOUT1
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
Open-drain processor reset with externally adjustable
threshold monitoring
Guaranteed reset output valid to VAVIN = 1 V
Manual reset input
R
= 30Ω
FILT
AVIN
VIN1
L1
1µH
SW
V
AT
OUT1
1.2A
FB1
R1
BUCK
C6
VBIAS
10µF
R2
V
= 2.3V TO
5.5V
IN1
PGND
MODE
C1
4.7µF
EN_BK
ON
ON
ON
FPWM
R3
EN1
OFF
PSM/PWM
C5
VOUT2
FB2
V
AT
LDO1
(DIGITAL)
OUT2
300mA
VIN2
V
= 1.7V
IN2
TO 5.5V
C2
1µF
EN_LDO1
2.2µF
R4
EN2
MR
OFF
OFF
nRSTO
VBIAS
µP
WDI
VTHR
SUPERVISOR
EN3
R5
R4
Watchdog refresh input
Buck key specifications
Output voltage range: 0.8 V to 3.8 V
Current mode topology for excellent transient response
3 MHz operating frequency
EN_LDO2
VOUT3
FB3
VIN3
V
AT
OUT3
300mA
V
= 1.7V
LDO2
(ANALOG)
IN3
TO 5.5V
C3
1µF
C6
2.2µF
R7
R3
AGND
Figure 1.
Peak efficiency up to 96%
Uses tiny multilayer inductors and capacitors
Mode pin selects forced PWM or auto PWM/PSM mode
100% duty cycle low dropout mode
LDOs key specifications
Output voltage range: 0.8 V to 5.2 V
Low input supply voltage from 1.7 V to 5.5 V
Stable with 2.2 μF ceramic output capacitors
High PSRR
Low output noise
Low dropout voltage
−40°C to +125°C junction temperature range
GENERAL DESCRIPTION
The ADP5041 combines one high performance buck regulator
and two low dropout (LDO) regulators in a small 20-lead
LFCSP to meet demanding performance and board space
requirements.
range of the ADP5041 LDOs extend the battery life of portable
devices. The ADP5041 LDOs maintain a power supply rejection
greater than 60 dB for frequencies as high as 10 kHz while
operating with a low headroom voltage.
The high switching frequency of the buck regulator enables
use of tiny multilayer external components and minimizes
board space.
Each regulator in the ADP5041 is activated by a high level on
the respective enable pin. The output voltages of the regulators
and the reset threshold are programmed through external resistor
dividers to address a variety of applications. The ADP5041
contains supervisory circuits that monitor power supply voltage
levels and code execution integrity in microprocessor-based
systems. They also provide power-on reset signals. An on-chip
watchdog timer can reset the microprocessor if it fails to strobe
within a preset timeout period.
When the MODE pin is set to logic high, the buck regulator
operates in forced 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
Rev. B
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