General description
The PF1550 is a power management integrated circuit (PMIC) designed specifically for
use with i.MX processors on low-power portable, smart wearable and Internet-of-Things
(IoT) applications. It is also capable of providing full power solution to i.MX 7ULP, i.MX
6SL, 6UL, 6ULL, and 6SX processors.
With three high-efficiency buck converter, three linear regulators, RTC supply, and battery
linear charger, the PF1550 can provide power for a complete battery-powered system,
including application processors, memory, and system peripherals.

1.1 Features and benefits
This section summarizes the PF1550 features:
• Input voltage range to PMIC VBUSIN pin via USB bus or AC adapter: 4.1 V to 6.0 V
• Buck converters:
– SW1, 1.0 A; 0.6 V to 1.3875 V in 12.5 mV steps, or 1.1 V to 3.3 V in variable steps
– SW2, 1.0 A; 0.6 V to 1.3875 V in 12.5 mV steps, or 1.1 V to 3.3 V in variable steps
– SW3, 1.0 A; 1.8 V to 3.3 V in 100 mV steps
– Soft start
– Quiescent current 1.0 μA in ULP mode with light load
– Peak efficiency > 90 %
– Dynamic voltage scaling on SW1 and SW2
– Modes: forced PWM quasi-fixed frequency mode, adaptive variable-frequency mode
– Programmable output voltage, current limit, and soft start
• LDO regulators
– LDO1, 0.75 V to 1.5 V/1.8 to 3.3 V, 300 mA with load switch mode
– LDO2, 1.8 V to 3.3 V, 400 mA
– LDO3, 0.75 V to 1.5 V/1.8 V to 3.3 V, 300 mA with load switch mode
– Quiescent current < 1.5 μA in Low-power mode
– Programmable output voltage
– Soft start and ramp
– Current limit protection
• Battery charger
– Supports single-cell Lithium Ion/Lithium Polymer batteries
– Linear charging (10 mA to 1500 mA input limit)
– Up to 6.5 V input operating range
– VSYS regulator can withstand transient and DC inputs from 0 V up to +22 V
– Programmable charge voltage (3.5 V to 4.44 V)
– Programmable charge current (100 mA to 1000 mA)
– Programmable charge termination current (5.0 mA to 50 mA)
– Integrated 50 mΩ battery isolation MOSFET for operation with no/low battery
– Battery supplement mode
– Battery discharge overcurrent protection, up to 3.0 A
– USB_PHY low dropout linear regulator
– Programmable LED driver (status indicator)
– JEITA-compliant battery temp sensing and charger control
– Key charging parameters can be configured and permanently stored in OTP
– I2C Control Interface permitting processor control and event detection
• LDO/switch supply
– RTC supply VSNVS 3.0 V, 2.0 mA
– Battery backed memory including coin cell charger
• DDR memory reference voltage, VREFDDR, 0.5 V to 0.9 V, 10 mA
• OTP (One time programmable) memory for device configuration
– User programmable start-up sequence, timing, soft-start, and power-down sequence
– Programmable regulator output voltages and charger parameters
• I2C interface
• User programmable Standby, Sleep/Low-power, and Off (REGS_DISABLE) modes
• Ambient temperature range −40 °C to 105 °C

Applications
• Smart mobile/wearable devices
• Low-power IoT applications
• Wireless game controllers
• Embedded monitoring systems
• Home automation
• POS
• E-Read