IR IR3522和IR3506 DDR3电源解决方案

IR 公司的IR3522是XPHASE3TM DDR & VTT控制IC,而IR3506是XPHASE3TM DDR & VTT 相位IC,两者的组合可以实现全特性的DDR3电源解决方案.本文介绍了IR3522和IR3506的主要特性,方框图, IR3522输出1和输出2系统设置点测试电路, PWM 方框图和IR3522与IR3506的典型应用电路.

XPHASE3TM DDR & VTT CONTROL IC IR3522

The IR3522 Control IC combined with IR3506 xPHASE3TM Phase ICs implements a full featured DDR3 power solution. The IR3522 provides control functions for both the VTT (single phase) and VDDR (multiphase) power rails which can interfaces with any number of IR3506 ICs each driving and monitoring a single phase to power any number of DDR3 DIMMs. The xPHASE3TM architecture delivers a power supply that is smaller, more flexible, and easier to design while providing higher efficiency than conventional approaches.

IR3522主要特性:

I2C interface programs 1.025V< VREF1<1.612V, the VDD output voltage reference

I2C also programs the VTT tracking ratio ± 25 %, and provides digital ON/OFF control

Four different I2C addresses are selectible using 2 ADDR pins

Four different VREF1 voltages are selectible using 2 VID pins if I2C communication is not available

VTT tracking defaults to ½ the VDD Remote Sense Amp output voltage

Power Good output driven by an external bias input

VDD to VTT overvoltage protection

Soft-Stop turn-off to ensure VDDR and Vtt tracking

Fault activated Crowbar pin to drive external NMOS devices for external output voltage protection

Pin programmable slew rate of I2C programmed VREF1 voltage transitions

0.5% overall VDD system set point accuracy

Remote sense amplifiers provide differential sensing and requires less than 50uA bias current

Pin programmable per phase switching frequency of 250kHz to 1.5MHz

Complete protection including over-current, over-voltage, open remote sense, and open control

图1.IR3522方框图


图2.IR3522输出1系统设置点测试电路

图3.IR3522输出2系统设置点测试电路

图4.PWM 方框图


图5.IR3522 应用电路

XPHASE3TM DDR & VTT PHASE IC IR3506

The IR3506 Phase IC combined with IR3522 xPHASE3TM Control ICs implements a full featured DDR3 power solution. The IR3522 provides control functions for both the VDDR and VTT power rails and interfaces with any number of IR3506 Phase ICs each driving and monitoring a single phase to power any number of DDR3 DIMMs. The xPHASE3TM architecture delivers a power supply that is smaller, more flexible, and easier to design while providing higher efficiency than conventional approaches.

IR3506主要特性:

Power State Indicator (PSI) interface provides the capability to maximize efficiency at light loads

Anti-bias circuitry

7V/2A gate drivers (4A GATEL sink current)

Support loss-less inductor current sensing

Phase delay DFF bypassed during PSI assertion mode to improve output ripple performance

Over-current protection during PSI assertion mode operation

Integrated boot-strap synchronous PFET

Only four IC related external components per phase

3 wire analog bus connects Control and Phase ICs (VDAC, Error Amp, IOUT)

3 wire digital bus for accurate daisy-chain phase timing control without external components

Debugging function isolates phase IC from the converter

Self-calibration of PWM ramp, current sense amplifier, and current share amplifier

Single-wire bidirectional average current sharing

Soft-stop turn-off to insure VDDR and Vtt tracking

Small thermally enhanced 16L 3 x 3mm MLPQ package

RoHS Compliant

图6.IR3506方框图

图7.IR3506应用电路