- Precision Two-phase Buck PWM controller
- 0.5% System Accuracy Over-Temperature
- Active Voltage Positioning Capability
- Internal Gate Driver with 2A Driving Capability
- Superior Load Transient Response
- Dynamic Phase Adding/Dropping
- Voltage Selection Input
- 7-bit VSEL Input
- 0.500V to 1.500V in 25mV Steps
- Supports VSEL Change On-the-Fly
- Multiple Current-Sensing Schemes Supported
- Lossless Inductor DCR Current Sensing
- Precision Resistive Current Sensing
- Thermal Monitor
- User Programmable Switching Frequency
- Differential Remote GPU Voltage Sensing
- Static and Dynamic Current Sharing
- Overvoltage, Undervoltage and Overcurrent Protection
- Pb-Free (RoHS Compliant)
Increase in GPU clock frequency is accompanied by associated increase in the demand for power and transientcurrent slew rate. At the same time, the voltage tolerance requirement during steady-state and transient operation is becoming more stringent concerning advanced GPU. The ISL9502A is a two-phase PWM controller with embedded gate drivers, which is tailored to meet the power and dynamic requirements. The two-phase buck converter uses two interleaved channels to effectively double the output voltage ripple frequency and thereby reduce output voltage ripple amplitude with fewer components, lower component cost, reduced power dissipation, and smaller real estate area.
The heart of the ISL9502A is the patented R3™ (Robust Ripple Regulator) modulator. Compared with the traditional multiphase buck regulator, R3 technology has the fastest transient response. This is due to the R3 modulator commanding variable switching frequency during a load transient.
At heavy load operation of the active mode, ISL9502A commands the two phase continuous conduction mode (CCM) operation. While the pin SET3 is asserted at the medium or light load, the ISL9502A smoothly disables one phase and operates in a one-phase operation. Once in one-phase operation, when the GPU further lowers the load current, the ISL9502A enables diode emulation to maximize efficiency at light load depending on the logic of SET1 and SET2.
A 7-bit digital-to-analog converter (DAC) allows dynamic adjustment of the output voltage from 0.500V to 1.500V with 25mV step. A 0.5% system accuracy of the core output voltage over-temperature is achieved by the ISL9502A.
A unity-gain differential amplifier is provided for remote GPU die sensing. This allows the voltage on the GPU die to be accurately measured and regulated. Current sensing can be realized using either lossless inductor DCR sensing or precision resistor sensing. A single NTC thermistor network can thermally compensate the gain and the time constant of the DCR variations. Droop control, also referred to as adaptive voltage positioning (AVP), is implemented in ISL9502A to reduce output decoupling capacitors and achieve more cost-effective transient-load regulation.
|VIN (min) (V)||5||4.75||4.75||4.75|
|VIN (max) (V)||25||24||24||5.25|
|VOUT (min) (V)||0.5||0.3||0.3||0.7|
|VOUT (max) (V)||1.5||1.5||1.5||1.708|
|IOUT (max) (A)||60||50||100||60|
|VBIAS (V)||5 to 25||4.75 to 5.25||4.75 to 5.25|
|Applications||Graphics Processor Units (GPU)||IMVP-6||IMVP-6+|
|Max # of Outputs||1||1||1|
|Max # of Phases||2||2||2|
|Integrated MOSFET Driver(s)||Yes||No||Yes|