Overview
The NCP81247MNTXG is a dual output, four plus two phase buck controller designed by onsemi, optimized for Intel’s IMVP8 CPUs. This controller is tailored for desktop and notebook CPU applications, offering advanced features such as true differential voltage sensing, differential inductor DCR current sensing, and adaptive voltage positioning. It utilizes Dual-Edge pulse-width modulation (PWM) combined with DCR current sensing to provide an ultra-fast initial response to dynamic load events and reduce system cost. The device also features phase shedding during light load operation and auto frequency scaling to maintain excellent transient performance.
Key Specifications
| Parameter | Min | Typ | Max | Units | Test Conditions |
|---|---|---|---|---|---|
| Input Voltage Range (VCC) | 4.75 | 5.0 | 5.25 | V | -40°C < TA < 100°C; CVCC = 0.1 μF |
| Switching Frequency Range | 180 kHz | - | 1.17 MHz | - | - |
| UVLO Threshold (VCC rising) | - | - | 4.5 | V | - |
| UVLO Threshold (VCC falling) | 3.8 | - | - | V | - |
| Over Voltage Threshold During Soft-Start | - | - | 2.5 | V | CSREF Rising |
| Over Current Protection (OCP) Threshold | 7.5 | 10 | 11.5 | A | Main Rail, Rlim = 20 kΩ |
| Power Good Output Voltage (VRDY) | - | - | 0.3 | V | Output Low Voltage, IVDD(A)_VRDY = 4 mA |
Key Features
- Meets Intel’s IMVP8 Specification
- Current Mode Dual Edge Modulation for fast initial response to transient loading
- Dual high performance operational error amplifiers
- Dynamic Reference Injection for simplified loop compensation
- Accurate Total Summing Current Amplifier for droop and digital current monitoring
- DAC with droop feed-forward injection
- Dual high impedance differential voltage and total current sense amplifiers
- Phase-to-phase dynamic current balancing
- “Lossless” DCR current sensing for current balancing
- Adaptive Voltage Positioning (AVP)
- Power saving phase shedding
- Over Voltage Protection (OVP) & Under Voltage Protection (UVP)
- Over Current Protection (OCP)
- Dual Power Good Output with internal delays
Applications
- IMVP8 Desktop CPUs
- Gaming Systems
- Notebook CPUs
Q & A
- What is the NCP81247MNTXG optimized for?
The NCP81247MNTXG is optimized for Intel’s IMVP8 CPUs.
- What modulation technique does the NCP81247MNTXG use?
The NCP81247MNTXG uses Current Mode Dual Edge pulse-width modulation (PWM).
- What is the switching frequency range of the NCP81247MNTXG?
The switching frequency range is from 180 kHz to 1.17 MHz.
- How does the NCP81247MNTXG handle phase shedding?
The device can shed phases during light load operation and auto frequency scale to maintain excellent transient performance.
- What protection features does the NCP81247MNTXG include?
The device includes Over Voltage Protection (OVP), Under Voltage Protection (UVP), and Over Current Protection (OCP).
- How is the phase configuration determined in the NCP81247MNTXG?
The phase configuration is determined by sampling the PWM1/SV_ADDR pin during startup and using external resistors to set the SVID address and phase configuration.
- What is the purpose of the PSYS pin in the NCP81247MNTXG?
The PSYS pin is an analog input that monitors the total platform system power and facilitates reporting back current through the SVID interface.
- How can phases be disabled in the NCP81247MNTXG?
Phases can be disabled by pulling the relevant CSP pin directly to 5 V.
- What is the role of the Dynamic Reference Injection feature?
The Dynamic Reference Injection feature simplifies loop compensation by eliminating the need to compromise between closed-loop transient response and Dynamic VID performance.
- What is the function of the Total Current Summing Amplifier?
The Total Current Summing Amplifier sums the phase currents into a single temperature-compensated total current signal used for output voltage droop, total current limit, and output current monitoring.
- Is the NCP81247MNTXG available in Pb-free and Halide-free packages?
