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PMIC with Ultra-Low I Voltage Regulators,
Buck-Boost for Optical Sensing and
MAX20345
Q
Charger for Small Lithium Ion Systems
General Description
Benefits and Features
The MAX20345 is a power management solution featur-
● Extend Battery-Use Time Between Charging
• 3 x Low Buck Regulators ( = 0.9µA typ)
ing ultra-low I voltage regulators, ideal for low-power
I
I
Q
Q
Q
wearable applications. The device includes a linear battery
charger with a smart power selector and several power-
optimized peripherals. The device features three buck
regulators, three low-dropout (LDO) linear regulators, and
a Buck-Boost regulator, providing up to seven regulated
voltages, each with an ultra-low quiescent current. Two
load switches allow disconnecting system peripherals to
minimize the total quiescent load of the system. MAX20345
allows system designers to minimize power consumption
and extend battery life in 24/7 operation devices, such as
those in the wearable market.
• 220mA Output Current
• Noise Mitigation by Flexible Adjustment of
Switching Frequency
• Buck1: 0.700V to 1.330V Output Voltage in
10mV Steps
• Buck2: 0.700V to 2.275V Output Voltage in
25mV Steps
• Buck3: 0.700V to 3.850V Output Voltage in
50mV Steps
• LDO1 (
I = 0.55µA typ)
Q
• 100mA Output
• 2.7V to 5.5V Input Voltage Range
• 0.8V to 3.6V Output Voltage in 100mV Steps
The three synchronous, high-efficiency buck regulators
use a pulse frequency modulated (PFM) control scheme
for increased efficiency during light-load operation. The
output voltage of these regulators can be programmed
• LDO2 (
I = 1µA typ)
Q
2
• 100mA Output
through I C down to voltages as low as 0.7V. Additionally,
• 1.71V to 5.50V Input Voltage Range
• 0.9V to 4.0V Output Voltage in 100mV Steps
the buck regulators support dynamic voltage scaling
(DVS) allowing the system designer to further improve
system power consumption when using devices that can
take advantage of DVS.
• LDO3 (
I = 1µA typ)
Q
• 50mA Output
• 1.00V to 2.00V Input Voltage Range
• 0.50V to 1.95V Output Voltage in 25mV Steps
Each of the three LDO regulators output voltage can be
programmed through I C. For additional flexibility, each
LDO can be configured as a load switch that can be used
to disconnect the quiescent load of the system peripherals.
2
• 2 x Load Switches
• 0.65V to 5.50V Input Voltage Range
The integrated Buck-Boost converter provides a conve-
nient way to power system peripherals that require volt-
ages higher and/or lower than the battery voltage, and
is optimized for optical sensing systems such as optical
• 1Ω R
at SYS = 3.0V
ON
Buck-Boost Regulator (I = 2µA typ)
Q
• Low
I
Q
• 1.5W Output Capability
• 2.6V to 5.5V Output Voltage in 50mV Steps
heart rate (OHR)/PPG and SpO measurements. The
2
● Easy to Implement Li+ Battery Charging
• Linear Li-Ion Battery Charger
• 5mA to 500mA Charge current
• +28V / -5.5V Tolerant Input
output noise of the Buck-Boost is minimized to provide
the least impact possible on sensitive measurements in
such systems. The addition of DVS offers further power
savings during favorable measurement conditions.
• Step Charging (See the Step Charging Section)
• Thermistor Monitor
• Smart Power Selector
The MAX20345 also features a programmable power con-
troller that allows the device to be configured for applications
that require the device be in a true-off, or always-on, state.
The controller provides a delayed reset signal and voltage
sequencing. The MAX20345 is available in a 56-bump,
0.4mm pitch, 3.37mm x 3.05mm wafer-level package (WLP).
● Optimize System Control
• Power On/ Reset Controller
• Push-Button Monitor
• Factory Shipping Mode
• System Interface
Applications
● Wearable Devices
● IoT
• Monitor Multiplexer with Programmable Divider to
Monitor System Voltages and Charging Current
Ordering Information appears at end of data sheet.
19-100366; Rev 11; 9/23
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