Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - voltage regulators - DC DC switch controllers SSOP 28

General Description

The MAX5038/MAX5041 dual-phase, PWM controllers

provide high-output-current capability in a compact

package with a minimum number of external compo-

nents. The MAX5038/MAX5041 utilize a dual-phase,

average current-mode control that enables optimal use

of low R

DS(ON)

MOSFETs, eliminating the need for exter-

nal heatsinks even when delivering high output currents.

Differential sensing enables accurate control of the out-

put voltage, while adaptive voltage positioning provides

optimum transient response. An internal regulator

enables operation with input voltage ranges of +4.75V to

+5.5V or +8V to +28V. The high switching frequency, up

to 500kHz per phase, and dual-phase operation allow

the use of low-output inductor values and input capacitor

values. This accommodates the use of PC board-

embedded planar magnetics achieving superior reliabili-

ty, current sharing, thermal management, compact size,

and low system cost.

The MAX5038/MAX5041 also feature a clock input

(CLKIN) for synchronization to an external clock, and a

clock output (CLKOUT) with programmable phase delay

(relative to CLKIN) for paralleling multiple phases. The

MAX5038 offers a variety of factory-trimmed preset output

voltages (see Selector Guide) and the MAX5041 offers an

adjustable output voltage from +1.0V to +3.3V.

The MAX5038/MAX5041 operate over the extended

industrial temperature range (-40°C to +85°C) and are

available in a 28-pin SSOP package. Refer to the

MAX5037 data sheet for a VRM 9.0-compatible, VID-

controlled output voltage controller in a 44-pin MQFP or

QFN package.

Applications

Servers and Workstations

Point-Of-Load High-Current/High-Density

Telecom DC-DC Regulators

Networking Systems

Large-Memory Arrays

RAID Systems

High-End Desktop Computers

Features

♦ +4.75V to +5.5V or +8V to +28V Input Voltage

Range

♦ Up to 60A Output Current

♦ Internal Voltage Regulator for a +12V or +24V

Power Bus

♦ True Differential Remote Output Sensing

♦ Two Out-Of-Phase Controllers Reduce Input

Capacitance Requirement and Distribute Power

Dissipation

♦ Average Current-Mode Control

Superior Current Sharing Between Individual

Phases and Paralleled Modules

Accurate Current Limit Eliminates MOSFET and

Inductor Derating

♦ Integrated 4A Gate Drivers

♦ Selectable Fixed Frequency 250kHz or 500kHz Per

Phase (Up to 1MHz for 2 Phases)

♦ Fixed (MAX5038) or Adjustable (MAX5041) Output

Voltages

♦ 0.5% Accurate Reference (MAX5041B)

♦ External Frequency Synchronization from 125kHz

to 600kHz

♦ Internal PLL with Clock Output for Paralleling

Multiple DC-DC Converters

♦ Thermal Protection

♦ 28-Pin SSOP Package

MAX5038/MAX5041

Dual-Phase, Parallelable, Average Current-Mode

Controllers

________________________________________________________________Maxim Integrated Products 1

19-2514; Rev 3; 8/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

PART

TEMP RANGE

PIN-

PACKAGE

OUTPUT

VOLTAGE

MAX5038EAI12

-40°C to +85°C 28 SSOP

Fixed +1.2V

MAX5038EAI15

-40°C to +85°C 28 SSOP

Fixed +1.5V

MAX5038EAI18

-40°C to +85°C 28 SSOP

Fixed +1.8V

MAX5038EAI25

-40°C to +85°C 28 SSOP

Fixed +2.5V

MAX5038EAI33

-40°C to +85°C 28 SSOP

Fixed +3.3V

MAX5041EAI

-40°C to +85°C 28 SSOP

Adj +1.0V to

+3.3V

MAX5041BEAI

-40°C to +85°C 28 SSOP

Adj +1.0V to

+3.3V

Pin Configuration appears at end of data sheet.

Summary of content (26 pages)

PAGE 1
9-2514; Rev 3; 8/04 Dual-Phase, Parallelable, Average Current-Mode Controllers The MAX5038/MAX5041 dual-phase, PWM controllers provide high-output-current capability in a compact package with a minimum number of external components. The MAX5038/MAX5041 utilize a dual-phase, average current-mode control that enables optimal use of low RDS(ON) MOSFETs, eliminating the need for external heatsinks even when delivering high output currents.
PAGE 2
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers ABSOLUTE MAXIMUM RATINGS IN to SGND.............................................................-0.3V to +30V BST_ to SGND…………………………………….…-0.3V to +35V DH_ to LX_ ................................-0.3V to [(VBST_ - VLX_) + 0.3V] DL_ to PGND ..............................................-0.3V to (VCC + 0.3V) BST_ to LX_ ..............................................................-0.3V to +6V VCC to SGND..............................
PAGE 3
Dual-Phase, Parallelable, Average Current-Mode Controllers (VCC = +5V, circuit of Figure 1, TA = -40°C to +85°C, unless otherwise noted. Typical specifications are at TA = +25°C.
PAGE 4
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers ELECTRICAL CHARACTERISTICS (continued) (VCC = +5V, circuit of Figure 1, TA = -40°C to +85°C, unless otherwise noted. Typical specifications are at TA = +25°C.) (Note 1) PARAMETER 3dB Bandwidth Minimum Output Current Drive SENSE+ to SENSE- Input Resistance SYMBOL f3dB CONDITIONS MIN CDIFF = 20pF TYP MAX 3 IOUT(DIFF) 1.
PAGE 5
Dual-Phase, Parallelable, Average Current-Mode Controllers EFFICIENCY vs. OUTPUT CURRENT AND INPUT VOLTAGE f = 500kHz 60 VIN = +5V VOUT = +1.8V 40 30 30 20 VOUT = +1.8V fSW = 250kHz 0 IOUT (A) EFFICIENCY vs. OUTPUT CURRENT AND OUTPUT VOLTAGE EFFICIENCY vs. OUTPUT CURRENT AND OUTPUT VOLTAGE SUPPLY CURRENT vs. FREQUENCY AND INPUT VOLTAGE 80 VOUT = +1.5V 70 η (%) VOUT = +1.1V 60 50 40 40 30 30 20 VOUT = +1.8V 12.0 11.5 11.0 10.5 ICC (mA) VOUT = +1.8V 90 MAX5038/41 toc05 VOUT = +1.
PAGE 6
Typical Operating Characteristics (continued) (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) OUTPUT VOLTAGE vs. OUTPUT CURRENT AND ERROR AMP GAIN (RF / RIN) 53 VIN = +12V VOUT = +1.8V RF / RIN = 15 1.80 DIFFERENTIAL AMPLIFIER BANDWIDTH MAX5038/41 toc12 3.5 90 45 3.0 PHASE 0 2.5 52 VOUT (V) 51 50 49 PHASE 2 48 PHASE 1 GAIN (V/V) RF / RIN = 12.5 1.75 1.70 RF / RIN = 7.5 47 -90 1.5 -135 GAIN 1.0 RF / RIN = 10 1.65 -45 2.0 -180 0.5 46 1.3 1.4 1.5 1.6 1.
PAGE 7
Dual-Phase, Parallelable, Average Current-Mode Controllers PLL LOCKING TIME 250kHz TO 350kHz AND 350kHz TO 250kHz MAX5038/41 toc21 LOW-SIDE DRIVER (DL_) SINK AND SOURCE CURRENT HIGH-SIDE DRIVER (DH_) SINK AND SOURCE CURRENT MAX5038/41 toc20 MAX5038/41 toc19 CLKOUT 5V/div 350kHz DH_ 1.6A/div PLLCMP 200mV/div DL_ 1.
PAGE 8
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers Typical Operating Characteristics (continued) (Circuit of Figure 1, TA = +25°C, unless otherwise noted.) OUTPUT RIPPLE INPUT STARTUP RESPONSE MAX5038/41 toc28 MAX5038/41 toc29 VPGOOD 1V/div VOUT 1V/div VOUT (AC-COUPLED) 10mV/div VIN 5V/div VIN = +12V VOUT = +1.75V IOUT = 52A VIN = +12V VOUT = +1.
PAGE 9
Dual-Phase, Parallelable, Average Current-Mode Controllers PIN NAME 1, 13 CSP2, CSP1 Current-Sense Differential Amplifier Positive Input. Senses the inductor current. The differential voltage between CSP_ and CSN_ is amplified internally by the current-sense amplifier gain of 18. 2, 14 CSN2, CSN1 Current-Sense Differential Amplifier Negative Input. Senses the inductor current. 3 PHASE Phase-Shift Setting Input.
PAGE 10
Dual-Phase, Parallelable, Average Current-Mode Controllers MAX5038/MAX5041 Functional Diagram EN IN +5V LDO REGULATOR UVLO POR TEMP SENSOR VCC TO INTERNAL CIRCUITS CSP1 CSN1 CSP1 DRV_VCC SHDN CSN1 CLP1 DH1 CLP1 CLK SGND MAX5038 MAX5041 LX1 PHASE 1 DL1 GMIN PGND PHASELOCKED LOOP CLKIN BST1 RAMP1 CLKOUT PLLCMP RAMP GENERATOR DIFF SENSE- 0.6V DIFF AMP PGND SENSE+ EAOUT EAN ERROR AMP DRV_VCC VREF = VOUT for VOUT ≤ 1.8V (MAX5038) VREF = VOUT/2 for VOUT > 1.8V (MAX5038) VREF = +1.
PAGE 11
Dual-Phase, Parallelable, Average Current-Mode Controllers output current capacity. For maximum ripple rejection at the input, set the phase shift between phases to 90° for two paralleled converters, or 60° for three paralleled converters. Paralleling the MAX5038/MAX5041s improves design flexibility in applications requiring upgrades (higher load). The MAX5038/MAX5041 (Figures 1 and 2) average current-mode PWM controllers drive two out-of-phase buck converter channels.
PAGE 12
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers Dual-phase converters with an out-of-phase locking arrangement reduce the input and output capacitor ripple current, effectively multiplying the switching frequency by the number of phases. Each phase of the MAX5038/MAX5041 consists of an inner average current loop controlled by a common outer-loop voltage- SENSE SENSE + 3 CSN1 PHASE CSP1 error amplifier (VEA) that corrects the output voltage errors.
PAGE 13
Dual-Phase, Parallelable, Average Current-Mode Controllers Internal Oscillator The internal oscillator generates the 180° out-of-phase clock signals required by the pulse-width modulation (PWM) circuits. The oscillator also generates the 2VP-P voltage ramp signals necessary for the PWM comparators. Connect CLKIN to SGND to set the internal oscillator frequency to 250kHz or connect CLKIN to VCC to set the internal oscillator to 500kHz.
PAGE 14
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers CCF CLP1 CSP1 CSN1 RCF MAX5038 CCFF CA1 VIN R F* IPHASE1 CEA1 SENSE+ DRIVE 1 CPWM1 RS RIN* DIFF AMP VEA SENSE- VOUT VIN COUT CEA2 VREF CPWM2 IPHASE2 DRIVE 2 RS LOAD CSN2 CSP2 CLP2 CA2 CCF RCF *RF AND RIN ARE EXTERNAL TO MAX5038 (RF = R8, RIN = R7, FIGURE 1) CCCF Figure 3a.
PAGE 15
Dual-Phase, Parallelable, Average Current-Mode Controllers than the average current limit (48mV). Proper inductor selection ensures that only extreme conditions trip the peak-current comparator, such as a cracked output inductor. The 112mV voltage threshold for triggering the peak-current limit is twice the full-scale average current-limit voltage threshold. The peak-current comparator has a delay of only 260ns.
PAGE 16
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers Differential Amplifier The differential amplifier (DIFF AMP) facilitates output voltage remote sensing at the load (Figures 3a and 3b). It provides true differential output voltage sensing while rejecting the common-mode voltage errors due to highcurrent ground paths. Sensing the output voltage directly at the load provides accurate load voltage sensing in high-current environments.
PAGE 17
Dual-Phase, Parallelable, Average Current-Mode Controllers VOLTAGE-POSITIONING WINDOW VCNTR + ∆VOUT/2 VCNTR VCNTR - ∆VOUT/2 1/2 LOAD NO LOAD FULL LOAD LOAD (A) Figure 5. Defining the Voltage-Positioning Window Set the voltage-positioning window (∆VOUT) using the resistive feedback of the VEA. Use the following equations to calculate the voltage-positioning window for the MAX5038: I × RIN ∆VOUT = OUT 2 × GC × RF GC = 0.
PAGE 18
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers Overload Conditions Average current-mode control has the ability to limit the average current sourced by the converter during a fault condition. When a fault condition occurs, the VEA output clamps to +0.9V with respect to the common-mode voltage (VCM = +0.6V) and is compared with the output of the current-sense amplifiers (CA1 and CA2) (see Figures 3a and 3b).
PAGE 19
Dual-Phase, Parallelable, Average Current-Mode Controllers MAX5038/MAX5041 CSN1 CSP1 SENSE+ VIN SENSEDH1 VCC LX1 PHASE DL1 VCC CLKIN VIN VIN MAX5038/ MAX5041 DH2 LX2 IN DL2 DIFF EAN CSP2 CSN2 EAOUT PGND SGND CLKOUT CSN1 CSP1 CLKIN VIN DH1 VCC LX1 PHASE DL1 MAX5038/ MAX5041 IN VIN DH2 DIFF * LX2 LOAD * DL2 EAN CSP2 EAOUT CSN2 PGND SGND CLKOUT CSN1 CSP1 CLKIN VIN DH1 VCC LX1 PHASE DL1 MAX5038/ MAX5041 IN VIN DH2 DIFF LX2 DL2 EAN EAOUT *FOR MAX5041 ONLY.
PAGE 20
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers VIN = +12V C1, C2 2 x 47µF VCC C31 R3 2.2Ω C32 C39 0.1µF R4 PLLCMP CLKIN IN VIN C3–C7 5 x 22µF SENSE- SENSE+ CSN1 CSP1 DH1 Q1 L1 0.6µH R1 1.35mΩ LX1 DL1 C12 0.47µF Q2 D1 BST1 VCC VCC EN D3 C38 4.7µF C40 0.1µF D4 OVPIN VCC R7 VIN MAX5038 (MASTER) DIFF 4 x 22µF C8–C11 EAN RX DH2 R8 Q3 L2 0.6µH EAOUT R2 1.35mΩ LX2 DL2 Q4 D2 CLP1 CLP2 PGND SGND CLKOUT PHASE PGOOD CSN2 CSP2 R6 C13 0.
PAGE 21
Dual-Phase, Parallelable, Average Current-Mode Controllers MAX5038/MAX5041 Table 1. Component List DESIGNATION QTY C1, C2 2 47µF,16V X5R input-filter capacitors TDK C5750X5R1C476M DESCRIPTION C3–C11 9 22µF, 16V input-filter capacitors TDK C4532X5R1C226M C12, C13 2 0.47µF, 16V capacitors TDK C1608X5R1A474K C14, C15 2 100µF, 6.3V, output-filter capacitors Murata GRM44-1X5R107K6.
PAGE 22
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers Selecting higher switching frequencies reduces the inductance requirement, but at the cost of lower efficiency. The charge/discharge cycle of the gate and drain capacitances in the switching MOSFETs create switching losses. The situation worsens at higher input voltages, since switching losses are proportional to the square of input voltage. Use 500kHz per phase for VIN = +5V and 250kHz or less per phase for VIN > +12V.
PAGE 23
Dual-Phase, Parallelable, Average Current-Mode Controllers 2 (18) ⎞ ⎛2×C 2 OSS × VIN × fSW + 1.4R ⎟⎟ ⎜⎜ DS(ON) × I RMS − LO 3 ⎠ ⎝ IRMS−LO = (I ) ( ) 1− D 2 2 DC + I PK + IDC × IPK × 3 (19) For example, from the typical specifications in the Applications Information section with VOUT = +1.8V, the high-side and low-side MOSFET RMS currents are 9.9A and 24.1A, respectively.
PAGE 24
MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers The allowable deviation of the output voltage during the fast transient load dictates the output capacitance and ESR. The output capacitors supply the load step until the controller responds with a greater duty cycle. The response time (tRESPONSE) depends on the closed-loop bandwidth of the converter. The resistive drop across the capacitor ESR and capacitor discharge causes a voltage drop during a step load.
PAGE 25
Dual-Phase, Parallelable, Average Current-Mode Controllers CCF = 1 2 × π × fZ × RCF 1 CCFF = 2 × π × fP × RCF (30) (31) Pin Configuration TOP VIEW CSP2 1 28 CLKIN CSN2 2 27 CLKOUT 26 BST2 PHASE 3 PC Board Layout PLLCMP 4 Use the following guidelines to layout the switching voltage regulator. CLP2 5 25 DH2 24 LX2 MAX5038A MAX5041A 23 DL2 1) Place the VIN and VCC bypass capacitors close to the MAX5038/MAX5041.
PAGE 26
Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information, go to www.maxim-ic.com/packages. 2 SSOP.EPS MAX5038/MAX5041 Dual-Phase, Parallelable, Average Current-Mode Controllers 1 INCHES E H MILLIMETERS DIM MIN MAX MIN MAX A 0.068 0.078 1.73 1.99 A1 0.002 0.008 0.05 0.21 B 0.010 0.015 0.25 0.38 C D 0.09 0.20 0.004 0.008 SEE VARIATIONS E 0.205 e 0.212 0.0256 BSC 5.