XR77128 Datasheet | Exar

Quad Output Digital PWM/PFM Universal PMIC General Description The XR77128 is a quad channel digital Pulse Width Modulated (PWM) step down (buck) controller. A wide 4.75V to 5.5V and 5.5V to 25V input voltage range allows for single supply operation from standard power rails. With integrated FET gate drivers, two LDOs for standby power and a 105k Hz to 1.23MHz independent channel to channel programmable constant operating frequency, the XR77128 reduces overall ponent count, solution footprint and optimizes conversion efficiencies. A selectable digital Pulse Frequency Mode (PFM) capable of better than 80% efficiency at light current load and low operating current allow for portable and Energy Star pliant applications. Each XR77128 channel’s output voltage is individually programmable down to 0.6V with a resolution of 2.5m V, and is configurable for precise soft start and soft stop sequencing, including delay and ramp control. The XR77128 operations are fully controlled via a SMBus-pliant I2C interface allowing for advanced local and/or remote reconfiguration, full performance monitoring and reporting as well as fault handling. Built-in independent output Over-Voltage, Over-Temperature, Over-Current and Under-Voltage Lockout protections insure safe operation under abnormal operating conditions. The XR77128 is offered in a Ro HS pliant, “green”/halogen free 44-pin TQFN package. Typical Application Features - Quad Channel Step-down Controller  Digital PWM 105k Hz-1.23MHz Operation  Individual Channel Frequency Selection  Patented digital PFM with Ultrasonic mode  Patented Over Sampling Feedback  Programmable 5 coefficient PID control  Integrated MOSFET Drivers  Supports Dr MOS devices - 4.75V to 5.5V and 5.5V to 25V Input Voltage - 0.6V to 5.5V Output Voltage (higher with exter- nal feedback resistors) - SMBus pliant I2C Interface - Full Power Monitoring and Reporting - 3 x 15V Capable PSIO + 2 x GPIOs - Full Start/Stop Sequencing Support -...