Part Number: RT8881A

Function: Multi-Phase PWM Controller

Package: 52-Lead WQFN Type

Manufacturer: Richtek Technology

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Description

The RT8881A is a multi-phases PWM controller. Moreover, it is compliant with AMD SVI2 Voltage Regulator Specification to support both CPU core (VDD) and Northbridge portion (VDDNB) of the CPU. The RT8881A adopts the G-NAVPTM (Green-Native AVP), which is a Richtek’s proprietary topology. The G-NAVP makes it an easy setting controller to meet all AMD AVP (Adaptive Voltage Positioning) requirements.

1. Phase Shifting: In a multi-phase power delivery system, the PWM controller divides the load current into several phases by controlling multiple power stages (also known as power channels or phases). Each phase operates with a slightly different phase shift compared to the others. Phase shifting reduces the output voltage ripple and helps distribute the load evenly across the phases.

2. PWM Control: The PWM controller generates control signals for each phase. These control signals determine when each phase’s power stage should turn on and off. By adjusting the duty cycle (the ratio of on-time to off-time) of these control signals, the controller regulates the output voltage to the desired level.

3. Load Balancing: Multi-phase power delivery systems improve efficiency and reduce voltage ripple by distributing the load current across several phases. This load balancing helps minimize the stress on individual power components, such as inductors and capacitors, and allows for more efficient power delivery.

Features

1. Dual Outputs :

(1) 4/3/2/1-Phase for VDD
(2) 2/1/0-Phase for VDDNB

2. G-NAVP Topology

3. Support Dynamic Load-Line and Zero Load-Line

4. Diode Emulation Mode at Light Load Condition

5. SVI2 Interface to Comply with AMD Power Management Protocol

6. I2C Interface for Platform Configuration

7. Build-in ADC for VOUT and IOUT Reporting

Applications:

1. AMD SVI2 CPU

2. Desktop Computer

RT8881A PDF Datasheet

Part Number: 1200P60

Function: PWM Current−Mode Controller

Package: DIP, SOP 8 Pin type

Manufacturer: ON Semiconductor

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Description

1200P60 is PWM Current-Mode Controller for Low-Power Universal Off-Line Supplies.

A PWM (Pulse Width Modulation) current-mode controller is a type of control IC (Integrated Circuit) used in power electronics to regulate the output current of a switching power supply.

Housed in SOIC−8 or PDIP−8 package, the NCP1200 represents a major leap toward ultra−compact Switchmode Power Supplies. Due to a novel concept, the circuit allows the implementation of a complete offline battery charger or a standby SMPS with few external components. Furthermore, an integrated output short−circuit protection lets the designer build an extremely low−cost AC−DC wall adapter associated with a simplified feedback scheme.

With an internal structure operating at a fixed 40 kHz, 60 kHz or 100 kHz, the controller drives low gate−charge switching devices like an IGBT or a MOSFET thus requiring a very small operating power. Due to current−mode control, the NCP1200 drastically simplifies the design of reliable and cheap offline converters with extremely low acoustic generation and inherent pulse−by−pulse control. When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the skip cycle mode and provides excellent efficiency at light loads. Because this occurs at low peak current, no acoustic noise takes place. Finally, the IC is self−supplied from the DC rail, eliminating the need of an auxiliary winding. This feature ensures operation in presence of low output voltage or shorts.

Features:

• No Auxiliary Winding Operation

• Internal Output Short−Circuit Protection

• Extremely Low No−Load Standby Power

• Current−Mode with Skip−Cycle Capability

• Internal Leading Edge Blanking

• 250 mA Peak Current Source/Sink Capability

• Internally Fixed Frequency at 40 kHz, 60 kHz and 100 kHz

• Direct Optocoupler Connection

• Built−in Frequency Jittering for Lower EMI

• SPICE Models Available for TRANsient and AC Analysis

• Internal Temperature Shutdown

PWM current-mode controllers are commonly used in switch-mode power supplies, buck converters, boost converters, and flyback converters, among others. These controllers provide efficient and precise control over the output current, making them suitable for a wide range of power electronics applications.

Typical Applications:

• AC−DC Adapters

• Offline Battery Chargers

• Auxiliary/Ancillary Power Supplies (USB, Appliances, TVs, etc.)

1200P60 PDF Datasheet