Multi-Phase PWM Controller with PWM-VID Reference
The RT8845A is a 4/3/2/1 phase synchronous Buck PWM
controller which is optimized for high performance graphic
microprocessor and computer applications. The RT8845A
adopts G-NAVPTM (Green Native AVP) which is Richtek's
proprietary topology derived from finite DC gain of EA
amplifier with current mode control. By utilizing the G-
NAVPTM topology, the operating frequency of the RT8845A
varies with VID, load and input voltage to further enhance
the efficiency even in CCM. Moreover, the G-NAVPTM with
CCRCOT (Constant Current Ripple COT) technology
provides superior output voltage ripple over the entire input/
output range. The RT8845A provides complete fault
protection functions including Over-Voltage (OV), Negative
Voltage (NV), Over-Current (OC) and Under-Voltage
Lockout (UVLO). The RT8845A is available in the WQFN-
40L 5x5 package.
The RT8845A features external reference input and PWM-
VID dynamic output voltage control, in which the feedback
voltage is regulated and tracks external input reference
voltage. Other features include adjustable switching
frequency, dynamic phase number control, internal/external
soft- start, power good indicator, and enable functions.
Multi-Phase PWM Controller
Power State Indicator
Support 1.8V PWM-VID Interface
External Reference Input Control
PWM-VID Dynamic Voltage Control
Dynamic Phase Number Control
Adjustable Current Limit Threshold
Adjustable Switching Frequency
Support an Ultra-Low Output Voltage as Standby
Power Good Indicator
GPU Core Supply for nVidia OVR4 + Spec.
QW : WQFN-40L 5x5 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
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Copyright ©2020 Richtek Technology Corporation. All rights reserved.
DS8845A-01 January 2020
is a registered trademark of Richtek Technology Corporation.