Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - voltage regulator - special purpose TQFN 40 EP (5x5)

General Description

The MAX17021/MAX17082/MAX17482 are 2/1-phase-

interleaved Quick-PWM™ step-down VID power-supply

controllers for notebook CPUs. True out-of-phase oper-

ation reduces input ripple current requirements and

output- voltage ripple, while easing component selec-

tion and layout difficulties. The Quick-PWM control pro-

vides instantaneous response to fast load-current

steps. Active voltage positioning reduces power dissi-

pation and bulk output capacitance requirements and

allows ideal positioning compensation for tantalum,

polymer, or ceramic bulk output capacitors.

A slew-rate controller allows controlled transitions between

VID codes, controlled soft-start and shutdown, and con-

trolled exit from suspend. A thermistor-based temperature

sensor provides a programmable thermal-fault output

(VRHOT). A current monitor output (IMON) provides an

analog current output proportional to the power consumed

by the CPU (MAX17082/MAX17482 only). Output under-

voltage, overvoltage (MAX17021/MAX17082 only), and

thermal protection shut the controller down when any of

these faults are detected. A voltage-regulator power-OK

(PWRGD) output indicates the output is in regulation.

Additionally, the MAX17021/MAX17082/MAX17482 fea-

ture true differential current sense and a phase-good

(PHASEGD) output that indicates a phase imbalance

fault condition.

The MAX17021 supports the IMVP-6+ specification

while the MAX17082/MAX17482 support the IMVP-6.5

requirements. The MAX17021/MAX17082/MAX17482

are available in a 5mm x 5mm, 40-pin TQFN package.

Applications

IMVP-6+/IMVP-6.5 Core Supply

Multiphase CPU Core Supply

Voltage-Positioned, Step-Down Converters

Notebook/Desktop Computers

Blade Servers

Features

o Single-/Dual-Phase, Quick-PWM Controllers

o MAX17021 IMVP-6+ (Montevina)

o MAX17082/MAX17482 IMVP-6.5 (Calpella)

o ±0.5% V

OUT

Accuracy Over Line, Load, and

Temperature

o 7-Bit 0 to 1.50V VID Control

o Dynamic Phase Selection Optimizes Active/Sleep

Efficiency

o Transient Phase Overlap Reduces Output

Capacitance

o Integrated Boost Switches

o Active Voltage Positioning with Adjustable Gain

o Programmable 200kHz to 800kHz Switching

Frequency

o Accurate Current Balance and Current Limit

o Adjustable Slew-Rate Control

o Power-Good, Clock Enable, and Thermal-Fault

Outputs

o Phase Current Imbalance Fault Output

o Drives Large Synchronous Rectifier MOSFETs

o 4V to 26V Battery Input-Voltage Range

o Undervoltage and Thermal-Fault Protection

o Overvoltage Protection (MAX17021/MAX17082)

o Soft-Startup and Soft-Shutdown

MAX17021/MAX17082/MAX17482

Dual-Phase, Quick-PWM Controllers for

IMVP-6+/IMVP-6.5 CPU Core Power Supplies

________________________________________________________________

Maxim Integrated Products

BST1

LX1

DL1

DH2

LX2

BST2

VRHOT

DL2

DH1

N.C. (IMON)

ILIM

TIME

CCI

FBAC

GNDS

THRM

PGDIN

SHDN

TON

V3P3

PWRGD

PHASEGD

DPRSLPVR

PSI

CSP2

CSN2

CSP1

DPRSTP (SLOW)

CSN1

CLKEN

MAX17021

(MAX17082)

MAX17482

THIN QFN

TOP VIEW

() DESIGNATES MAX17082/MAX17482 PIN NAME.

*EXPOSED PAD. CONNECTED TO GND.

12 4 567

27282930 26 24 23 22

8910

*EP

Pin Configuration

Ordering Information

19-4372; Rev 2; 7/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,

or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

Denotes a lead-free(Pb)/RoHS-compliant package.

EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX17021GTL+ -40°C to +105°C 40 TQFN-EP*

MAX17082GTL+ -40°C to +105°C 40 TQFN-EP*

MAX17482GTL+ -40°C to +105°C 40 TQFN-EP*

Quick-PWM is a trademark of Maxim Integrated Products, Inc.

Summary of content (48 pages)

PAGE 1
9-4372; Rev 2; 7/09 KIT ATION EVALU LE B A IL A AV Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies IMVP-6+/IMVP-6.5 Core Supply BST2 LX2 DL2 TOP VIEW DH2 Pin Configuration VRHOT o o o o o o VDD o o o DL1 o o o DH1 Applications o LX1 The MAX17021 supports the IMVP-6+ specification while the MAX17082/MAX17482 support the IMVP-6.5 requirements. The MAX17021/MAX17082/MAX17482 are available in a 5mm x 5mm, 40-pin TQFN package.
PAGE 2
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ABSOLUTE MAXIMUM RATINGS VCC, VDD, V3P3 to GND ...........................................-0.3V to +6V D0–D6 to GND..........................................................-0.3V to +6V PGDIN, DPRSLPVR, PSI to GND..............................-0.3V to +6V DPRSTP (MAX17021) to GND ..................................-0.3V to +6V SLOW (MAX17082/MAX17482) to GND...................-0.
PAGE 3
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN1 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL t ON MIN TYP MAX -10 +10 RTIME = 35.
PAGE 4
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN1 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 5
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN1 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 6
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN1 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 7
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN1 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = 0°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 8
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN2 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = -40°C to +105°C, unless otherwise noted.
PAGE 9
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN2 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = -40°C to +105°C, unless otherwise noted.) (Note 4) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 250 350 mV IMVP-6.5 (MAX17082) 1.45 1.
PAGE 10
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, VIN = 10V, VCC = VDD = VSHDN = VPGDIN = VPSI = VILIM = 5V, V3P3 = 3.3V, DPRSLPVR = GNDS = GND, VCSP1 = VCSN1 = VCSP2 = VCSN2 = 1.0000V, FB = FBAC, RFBAC = 3.57kΩ from FBAC to CSN1, D6–D0 = [0101000]; MAX17082/MAX17482: VSLOW = 5V; MAX17021: DPRSTP = GND; TA = -40°C to +105°C, unless otherwise noted.
PAGE 11
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies 7V 1.05 1.00 12V 80 0.89 OUTPUT VOLTAGE (V) 90 1.10 0.90 MAX17021 toc02 MAX17021 toc01 100 EFFICIENCY (%) OUTPUT VOLTAGE (V) 1.15 OUTPUT VOLTAGE vs. LOAD CURRENT (VOUT(LFM) = 0.875V) EFFICIENCY vs. LOAD CURRENT (VOUT(HFM) = 1.075V) 20V 70 MAX17021 toc03 OUTPUT VOLTAGE vs. LOAD CURRENT (VOUT(HFM) = 1.075V) SKIP MODE 0.88 0.87 0.86 PWM MODE 0.85 60 0.84 10 0 20 30 40 0.1 50 1.0 0 100.0 10.
PAGE 12
Typical Operating Characteristics (continued) (Circuit of Figure 1. VIN = 12V, VCC = VDD = 5V, SHDN = VCC, D0–D6 set for 1.075V, TA = +25°C, unless otherwise specified.) 30 20 MAX17021 toc11 40 30 20 0.5 40 0.4 30 0.3 20 0.2 0.1 610 608 606 604 602 600 598 596 594 592 590 0.8175 0.8165 0.8155 0.8145 0.8135 0 0.8125 0 0.8115 0 0.8105 10 0.8095 10 0.8085 0.6 50 10 0.8075 MAX17021 toc12 VOUT = 1.
PAGE 13
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies MAX17021 toc18 MAX17021 toc17 MAX17021 toc16 50A 10A VID CODE CHANGE (SLOW = GND) LOAD-TRANSIENT RESPONSE (LFM MODE) LOAD TRANSIENT RESPONSE (HFM MODE) 5V 20A A A 1.075V A 0 5A 1.075V B B 1V 0.875V B 25A 0.975V C 20A 5A 0 C 0 D C D 5A 5A 20µs/div 20µs/div 20μs/div A. IOUT = 10A TO 50A B. VOUT, 50mV/div A. IOUT = 5A TO 20A B. VOUT, 50mV/div C. ILX1, 10A/div D. ILX2, 10A/div C. ILX1, 10A/div D.
PAGE 14
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Typical Operating Characteristics (continued) (Circuit of Figure 1. VIN = 12V, VCC = VDD = 5V, SHDN = VCC, D0–D6 set for 1.075V, TA = +25°C, unless otherwise specified.) BIAS SUPPLY REMOVAL (UVLO RESPONSE) OUTPUT OVERVOLTAGE WAVEFORM MAX17021 toc23 MAX17021 toc24 5V A A 0.875V 0.875V 0 B 5V B 0 5V C 0 0 5V C 0 5V 0 D 10A E 0 100μs/div A. VOUT, 500mV/div B. DL_, 5V/div 40μs/div C.
PAGE 15
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies PIN NAME 4 ILIM FUNCTION Valley Current-Limit Adjustment Input. The valley current-limit threshold voltage at CSP_ to CSN_ equals precisely 1/10 of the differential TIME to ILIM voltage over a 0.1V to 0.5V range (10mV to 50mV current-sense range). The negative current-limit threshold is nominally -125% of the corresponding valley current-limit threshold.
PAGE 16
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies MAX17021/MAX17082/MAX17482 Pin Description (continued) 16 PIN NAME 13 SHDN 14 DPRSLPVR 15 PSI 16 TON 17 V3P3 18 CLKEN 19 PWRGD FUNCTION Shutdown Control Input. This input cannot withstand the battery voltage. Connect to VCC for normal operation. Connect to ground to put the IC into its 1μA max shutdown state.
PAGE 17
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies PIN 20 21 22 23 24 25 26 27 28 29 30 31 NAME FUNCTION Phase-Good Current-Balance Open-Drain Output. Used to signal the system that one of the two phases either has a fault condition or is not matched with the other. Detection is done by identifying the need for a large on-time difference between phases in order to achieve or move towards current PHASEGD balance. PHASEGD is low in shutdown.
PAGE 18
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Pin Description (continued) PIN NAME 32–38 D0–D6 39 CSP1 40 CSN1 — EP 18 FUNCTION Low-Voltage VID DAC Code Input. The D0–D6 inputs do not have internal pullups. These 1.0V logic inputs are designed to interface directly with the CPU. The output voltage is set by the VID code indicated by the logic-level voltages on D0–D6 (see Table 4). Positive Current-Sense Input for Phase 1.
PAGE 19
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ON OFF (VRON) 31 14 15 1 32 33 34 35 VID INPUTS 36 37 38 SHDN DPRSLPVR VDD PSI D0 TON D1 D2 D3 BST1 D4 DH1 D5 LX1 D6 CSP1 ILIM TIME CCI CSN2 V3P3 CSP2 R4 1.9kΩ 16 30 R9 0Ω 28 C4 29 0.22μF 27 NLO 19 25 18 R6 13kΩ VCC 2 PHASEGD BST2 PWRGD DH2 VRHOT LX2 CLKEN NHI DL2 PWR L1 R10 1.21kΩ R11 1.50kΩ D1 R12 20kΩ 7 12 C10 1000pF C11 0.22μF 21 R13 0Ω 23 C8 22 0.
PAGE 20
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Detailed Description Table 1 lists the component selection for standard applications. Table 2 lists component suppliers for the MAX17021/MAX17082/MAX17482/MAX17482. Free-Running, Constant-On-Time PWM Controller with Input Feed-Forward The Quick-PWM control architecture is a pseudo-fixedfrequency, constant-on-time, current-mode regulator with voltage feed-forward (Figure 3).
PAGE 21
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies IMVP-6+ SV IMVP-6+ LV IMVP-6.5 AUBURNDALE SV CORE IMVP-6.5 AUBURNDALE LV CORE TIME-ILIM Resistance (R1) 10k 10k 10k 10k ILIM-GND Resistance (R2) 59k 59k 59k 59k FB Resistance (RFB) 4.32k 8.45k 4.02k 6.34k IMON Resistance LX_-CSP_ Resistance N/A N/A 9.09k 18.2k 1.21k 1.21k 1.21k 1.21k 1.50k 1.50k 1.50k 1.
PAGE 22
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies 13 ON OFF (VRON) 14 31 AGND 15 1 32 33 34 35 VID INPUTS 36 37 38 SHDN SLOW VDD PSI 5 D0 TON D1 D2 D3 BST1 D4 DH1 D5 LX1 D6 MAX17082 MAX17482 ILIM CSN1 TIME CSN2 V3P3 1.1V R3 56Ω R4 1.9kΩ CSP2 R5 10kΩ 20 19 25 18 R6 13kΩ VCC 2 30 PWRGD BST2 VRHOT DH2 LX2 THRM 27 NLO NHI DL2 PWR L1 R10 1.21kΩ R11 1.50kΩ D1 R12 20kΩ 7 12 21 C10 1000pF C11 0.
PAGE 23
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies MAX17021/MAX17082/MAX17482 BST2 THRM DH2 MAX17021 (MAX17082/MAX17482) VRHOT EN2 LX2 SECONDARY PHASE DRIVERS DL2 GND 0.3 x VCC BLANK CSP2 PHASEGD 10x CSN2 Q CSP1 TRIG ONE-SHOT ILIM Q TIME CCI PHASE 2 ON-TIME 10x CSN1 5ms STARTUP DELAY CURRENTBALANCE FAULT MINIMUM OFF-TIME TRIG 200kΩ CSN2 ONE-SHOT Gm(CCI) PHASE 1 ON-TIME VCC CSP1 FB ONE-SHOT REF (2.
PAGE 24
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Dual 180° Out-of-Phase Operation The two phases in the MAX17021/MAX17082/ MAX17482 operate 180° out-of-phase to minimize input and output filtering requirements, reduce electromagnetic interference (EMI), and improve efficiency.
PAGE 25
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies tor current reverses at light- or negative-load currents. With reversed inductor current, the inductor’s EMF causes LX_ to go high earlier than normal, extending the on-time by a period equal to the DH_-rising dead time.
PAGE 26
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Use the worst-case inductance and RDCR values provided by the inductor manufacturer, adding some margin for the inductance drop over temperature and load. To minimize the current-sense error due to the currentsense inputs’ bias current (ICSP_ and ICSN_), choose R1||R2 to be less than 2kΩ and use the previous equation to determine the sense capacitance (CEQ).
PAGE 27
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies VOS(IBAL) IOS(IBAL) = ILMAIN - ILSEC = RSENSE where RSENSE is the effective sense resistance seen at the current-sense pins and VOS(IBAL) is the current-balance offset specification in the Electrical Characteristics table. The worst-case current mismatch occurs immediately after a load transient due to inductor value mismatches resulting in different di/dt for the two phases.
PAGE 28
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Differential Remote Sense The MAX17021/MAX17082/MAX17482 include differential, remote-sense inputs to eliminate the effects of voltage drops along the PCB traces and through the processor’s power pins. The feedback-sense node connects to the voltage-positioning resistor (R FB ).
PAGE 29
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies INPUTS SHDN GND DPRSTP DPRSLPVR (SLOW) X Rising X High X (High) High X (High) High High Falling High Low (High) High (Low) X X X X Low Low High High X X PSI PHASE OPERATION* X Disabled X Multiphase pulse-skipping 1/8 RTIME slew rate Startup/Boot. When SHDN is pulled high, the MAX17021/ MAX17082/MAX17482 begin the startup sequence.
PAGE 30
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Table 4. IMVP-6+/IMVP-6.5 Output-Voltage VID DAC Codes D6 D5 D4 D3 D2 D1 D0 OUTPUT VOLTAGE (V) D6 D5 D4 D3 D2 D1 D0 OUTPUT VOLTAGE (V) 0 0 0 0 0 0 0 1.5000 1 0 0 0 0 0 0 0.7000 0 0 0 0 0 0 1 1.4875 1 0 0 0 0 0 1 0.6875 0 0 0 0 0 1 0 1.4750 1 0 0 0 0 1 0 0.6750 0 0 0 0 0 1 1 1.4625 1 0 0 0 0 1 1 0.
PAGE 31
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies D6 D5 D4 D3 D2 D1 D0 OUTPUT VOLTAGE (V) D6 D5 D4 D3 D2 D1 D0 OUTPUT VOLTAGE (V) 0 1 0 0 0 0 0 1.1000 1 1 0 0 0 0 0 0.3000 0 1 0 0 0 0 1 1.0875 1 1 0 0 0 0 1 0.2875 0 1 0 0 0 1 0 1.0750 1 1 0 0 0 1 0 0.2750 0 1 0 0 0 1 1 1.0625 1 1 0 0 0 1 1 0.2625 0 1 0 0 1 0 0 1.0500 1 1 0 0 1 0 0 0.2500 0 1 0 0 1 0 1 1.
PAGE 32
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Suspend Mode When the processor enters low-power deeper sleep mode, the IMVP-6 CPU sets the VID DAC code to a lower output voltage and drives DPRSLPVR high. The MAX17021/MAX17082/MAX17482 respond by slewing the internal target voltage to the new DAC code, switching to single-phase operation, and letting the output voltage gradually drift down to the deeper sleep voltage.
PAGE 33
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies • Standard C4 Deeper Sleep Exit: When exiting deeper sleep (DPRSLPVR pulled low) while the output voltage is regulating to the deeper sleep voltage, the MAX17021/MAX17082/MAX17482 immediately activate all enabled phases and ramp the output voltage to the LFM DAC code provided by the processor at the slew rate set by RTIME. The controller blanks PWRGD, PHASEGD, and CLKEN until 20μs after the transition is completed. See Figure 6.
PAGE 34
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.
PAGE 35
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.
PAGE 36
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies CPU FREQ CPU LOAD VID (D0–D6) CPU CORE VOLTAGE PSI INTERNAL PWM CONTROL 2-PHASE PWM 1-PHASE PWM 2-PHASE PWM PWRGD BLANK HIGH IMPEDANCE BLANK HIGH IMPEDANCE CLKEN BLANK LOW BLANK LOW BLANK HIGH IMPEDANCE PHASEGD tBLANK 20μs typ tBLANK 20μs typ 32 SWITCHING CYCLES ON DH2 Figure 8.
PAGE 37
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Automatic Pulse-Skipping Switchover In skip mode (DPRSLPVR = high), an inherent automatic switchover to PFM takes place at light loads (Figure 9). This switchover is affected by a comparator that truncates the low-side switch on-time at the inductor current’s zero crossing. The zero-crossing comparator senses the inductor current across the low-side MOSFETs.
PAGE 38
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Power-Up Sequence (POR, UVLO) The MAX17021/MAX17082/MAX17482 are enabled when SHDN is driven high (Figure 10). The internal reference powers up first. Once the reference exceeds its UVLO threshold, the internal analog blocks are turned on and masked by a 50μs one-shot delay. The PWM controller is then enabled.
PAGE 39
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies where dVTARGET/dt = 12.5mV/μs x 71.5kΩ/RTIME is the slew rate. Slowly discharging the output capacitors by slewing the output over a long period of time keeps the average negative inductor current low (damped response), thereby eliminating the negative output-voltage excursion that occurs when the controller discharges the output quickly by permanently turning on the low-side MOSFET (underdamped response).
PAGE 40
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies pulse-skipping operation (DPRSLPVR = high), the OVP threshold is set to default. When the OVP circuit detects an overvoltage fault, the MAX17021/MAX17082 immediately force DL1 high and pull DH1 and DH2 low. This action turns on the synchronous-rectifier MOSFETs with 100% duty and, in turn, rapidly discharges the output filter capacitor and forces the output low.
PAGE 41
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies BST_ (RBST_)* INPUT (VIN) CBST_ DH_ NH • L LX_ CBYP VDD DL_ NL (CNL)* PGND • I ILOAD(PHASE) = LOAD ηTOTAL (RBST_)* OPTIONAL—THE RESISTOR LOWERS EMI BY DECREASING THE SWITCHING NODE RISE TIME. (CNL)* OPTIONAL—THE CAPACITOR REDUCES LX_ TO DL_ CAPACITIVE COUPLING THAT CAN CAUSE SHOOT-THROUGH CURRENTS. • Figure 11.
PAGE 42
MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Inductor Selection Setting the Current Limit The switching frequency and operating point (% ripple current or LIR) determine the inductor value as follows: The minimum current-limit threshold must be high enough to support the maximum load current when the current limit is at the minimum tolerance value.
PAGE 43
Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Output Capacitor Stability Considerations For Quick-PWM controllers, stability is determined by the value of the ESR zero relative to the switching frequency.
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MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies For most applications, nontantalum chemistries (ceramic, aluminum, or OS-CON) are preferred due to their resistance to inrush surge currents typical of systems with a mechanical switch or connector in series with the input. If the Quick-PWM controller is operated as the second stage of a two-stage power-conversion system, tantalum input capacitors are acceptable.
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Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies ΔI ⎛ ⎞ ILOAD = ηTOTAL ⎜ IVALLEY(MAX) + INDUCTOR ⎟ ⎝ ⎠ 2 ⎛ ILOAD(MAX)LIR ⎞ = ηTOTALIVALLEY(MAX) + ⎜ ⎟ 2 ⎝ ⎠ where I VALLEY(MAX) is the maximum valley current allowed by the current-limit circuit, including threshold tolerance and on-resistance variation. The MOSFETs must have a good-size heatsink to handle the overload power dissipation.
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MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Minimum Input-Voltage Requirements and Dropout Performance The output-voltage-adjustable range for continuousconduction operation is restricted by the nonadjustable minimum off-time one-shot and the number of phases. For best dropout performance, use the slower (200kHz) on-time settings.
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Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies • • • Keep the high-current, gate-driver traces (DL_, DH_, LX_, and BST_) short and wide to minimize trace resistance and inductance. This is essential for high-power MOSFETs that require low-impedance gate drivers to avoid shoot-through currents. CSP_ and CSN_ connections for current limiting and voltage positioning must be made using Kelvinsense connections to guarantee the current-sense accuracy.
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MAX17021/MAX17082/MAX17482 Dual-Phase, Quick-PWM Controllers for IMVP-6+/IMVP-6.5 CPU Core Power Supplies Revision History REVISION NUMBER REVISION DATE 0 11/08 1 7/09 DESCRIPTION Initial release PAGES CHANGED — Correction to non-OVP version, update IMON equations, fix errors in Figures 1, 2, and 4 1, 2, 4, 13, 14, 16, 19, 22, 25, 33–36, 39, 40, 46, 47 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product.