General Description

The RTQ8825 is a dual output voltage rail 3+2-phase controller: a 3/2/1/0 phase synchronous buck controller, the rail A and a 2/1/0 phase synchronous buck controller, the rail B. The RTQ8825 adopts G-NAVPTM (Green Native AVP) which is Richtek’s proprietary topology derived from finite DC gain of EA amplifier with current mode control, making it easy to set the droop to support all CPU/Microprocessor requirements of AVP (Adaptive Voltage Positioning). Based on the G-NAVPTM topology, the RTQ8825 features a new generation of quick response mechanism (Adaptive Quick Response, AQR) to optimize AVP performance during load transient and reduce output capacitors. The RTQ8825 supports VID on-the-fly function with four different slew rates via PMBus command setting. The DAC converts the VOUT_COMMAND code ranging from 0.25V to 1.516V with 1.953mV per step. The RTQ8825 integrates a high accuracy ADC for platform and function settings, such as SPS type, PMBus address, boot voltage and load-line. The RTQ8825 provides reset Vout function, Vout to be set to the VBOOT value while RESET# pin is asserted low. The RTQ8825 provides VR_Ready and thermal indicators. It also features complete fault protection functions including over-voltage (OV), under-voltage (UV), slow over-current (SLOW_OC), fast over-current (Fast_OC), over-temperature (OT) and under-voltage lockout (UVLO). The RTQ8825 more supports several functions which can be set by I2C/PMBus interface.

Applications

 Networking system

 Telecom, Datacom and Server system

 Point-of-load power supply (DSP, ASIC, FPGA)

Features

3/2/1/0 Phase (rail A) + 2/1/0 Phase (rail B) PWMController

 G-NAVPTM (Green Native Adaptive VoltagePositioning) Topology

 Each Output Voltage Ranges 0.25V to 1.516V

 Embedded LDO for Dr.MOS 3.3V PWM Level

 Pin Programmable 27 VBOOT Voltages

 Current Sensing by Either Current Type or VoltageType SPS

 Digital Current Balancing With Programmable Gainfor Thermal Balancing

 Differential Output Voltage Sense for HighOutput Accuracy

 Supports Start-Up Into Pre-Bias Voltage

 Pin Selection for Enabling Load-Line Function

 Supports Returning to VBOOT from ExistingVoltage or from 0V

 PMBus v1.3 Compliant Serial Interface

Pin Selectable 16 Addresses

1.8V and 3.3V Logic Level Compliant

SMBALERT#

Internal Non-Volatile Memory (NVM) to StoreCustom Configurations

Programmable Power Up/Down Timing

Monitoring for VOUT, IOUT and Temperature

Selectable Latch or Autonomous RecoveryAfter Shutdown Due to Fault

Extensive Fault Detection and ProtectionCapability

VIN & VCC Input Pins UVLO

Averaged Output SLOW/FAST_OC Protection

Output OV & UV Protection

Output Temperature Warning & Protection

Indicator for VR_Ready & VR_Hot#

 Small 48-Lead WQFN Package