MAX8529EEG+T Datasheet MAX8529EEG+, MAX8529EEG+T | P1-P3

General Description

The MAX8529 dual, synchronized, step-down controller

generates two outputs from input supplies ranging from

4.75V to 23V. Each output is adjustable from sub-1V

to 18V. Input voltage ripple and total RMS input ripple

current are reduced by synchronized 180-degree out-of-

phase operation.

The switching frequency is adjustable from 600kHz to

1.5MHz with an external resistor. Alternatively, the con-

troller can be synchronized to an external clock gener-

ated to another MAX8529 or a system clock. One

MAX8529 can be set to generate an in-phase, or 90-

degree out-of-phase, clock signal for synchronization

with additional controllers. This allows two controllers to

operate either as an interleaved two- or four-phase sys-

tem with each output shifted by 90 degrees. These

devices also feature soft-start and soft-stop.

The MAX8529 eliminates the need for current-sense

resistors by utilizing the low-side MOSFET’s on-resis-

tance as a current-sense element. This protects the

DC-to-DC components from damage during output

overload conditions or when output short circuit faults

without requiring a current-sense resistor. Adjustable

foldback current limit reduces power dissipation during

short-circuit conditions. The MAX8529 includes a

power-on reset output to signal the system when both

outputs reach regulation.

The MAX8529 is available in a 24-pin QSOP package. An

evaluation kit is available to speed designs.

Applications

xDSL Modems and Routers

DSP, ASIC, and FPGA Power Supplies

Set-Top Boxes

Broadband Routers

Features

♦ Low Output Noise in DSL Band

♦ Ceramic Input/Output Capacitors

♦ Step-Down or Step-Up/Step-Down Operation

♦ Four Output, 90-Degree Out-of-Phase Operation

(Using Two MAX8529s)

♦ Foldback Current Limit

♦ 4.75V to 23V Input Supply Range

♦ 0 to 18V Output Voltage Range (Up to 6A)

♦ > 90% Efficiency

♦ Fixed-Frequency PWM Operation

♦ Adjustable 600kHz to 1.5MHz Switching

Frequency

♦ External SYNC Input

♦ Clock Output for Master/Slave Synchronization

♦ Soft-Start and Soft-Stop

♦ RST Output with 140ms Minimum Delay

♦ Lossless Current Limit (No Sense Resistor)

MAX8529

1.5MHz Dual 180° Out-of-Phase

PWM Step-Down Controller with POR

________________________________________________________________ Maxim Integrated Products 1

LX2

DH2

BST2OSC

ILIM2

FB2

COMP2

TOP VIEW

DL2

PGND

DL1CKO

GND

REF

V+

BST1

DH1

LX1

COMP1

FB1

ILIM1

SYNC

QSOP

MAX8529

RST

Pin Configuration

Ordering Information

19-2696; Rev 1; 4/07

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

PART TEMP RANGE PIN-PACKAGE

MAX8529EEG -40°C to +85°C 24 QSOP

MAX8529

1.5MHz Dual 180° Out-of-Phase

PWM Step-Down Controller with POR

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

V+ to GND ..............................................................-0.3V to +25V

PGND to GND .......................................................-0.3V to +0.3V

to GND ..................-0.3V to the lower of +6V and (V+ + 0.3V)

BST1, BST2 to GND ...............................................-0.3V to +30V

LX1 to BST1..............................................................-6V to +0.3V

LX2 to BST2..............................................................-6V to +0.3V

DH1 to LX1 ..............................................-0.3V to (V

BST1

+ 0.3V)

DH2 to LX2 ..............................................-0.3V to (V

BST2

+ 0.3V)

DL1, DL2 to PGND........................................-0.3V to (V

+ 0.3V)

CKO, REF, OSC, ILIM1, ILIM2,

COMP1, COMP2 to GND ..........................-0.3V to (V

+ 0.3V)

FB1, FB2, RST, SYNC, EN to GND...........................-0.3V to +6V

to GND Short Circuit..............................................Continuous

REF to GND Short Circuit ...........................................Continuous

Continuous Power Dissipation (T

= +70°C)

24-Pin QSOP (derate 9.4mW/°C above +70°C)...........762mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

ELECTRICAL CHARACTERISTICS

(V+ = 12V, EN = ILIM_ = V

, SYNC = GND, I

= 0mA, PGND = GND, C

REF

= 0.22µF, C

= 4.7µF (ceramic), R

OSC

= 10kΩ,

compensation components for COMP_ are from Figure 1, T

= -40°C to +85°C (Note 1), unless otherwise noted.)

PARAMETER CONDITIONS MIN TYP MAX UNITS

GENERAL

(Note 2) 4.75 23.00

V+ Operating Range

= V+ (Note 2) 4.75 5.50

V+ Operating Supply Current V

unloaded, no MOSFETs connected 4.0 4.8 7.0 mA

V+ Standby Supply Current EN = LX_ = FB_ = 0V R

OSC

= 10kΩ 0.50 0.65 1.00 mA

Thermal Shutdown Rising temperature, typical hysteresis = 10°C 160 °C

ILIM_ = V

75 100 125

ILIM_

= 100kΩ 32 50 62

Current-Limit Threshold PGND - LX_

ILIM_

= 600kΩ 225 300 375

REGULATOR

Output Voltage 5.5V < V+ < 23V, 1mA < I

LOAD

< 50mA 4.75 5 5.25 V

Undervoltage Lockout

Trip Level

4.4 4.55 4.7 V

REFERENCE

Output Voltage I

REF

= 0µA 1.98 2.00 2.02 V

Reference Load Regulation 0µA < I

REF

< 50µA 0 4 10 mV

SOFT-START

Digital Ramp Period

Internal 6-bit DAC for one converter to ramp from 0V to

full scale (Note 3)

1024

DC-to-

Clocks

Soft-Start Steps 64 Steps

FREQUENCY

Low End of Range R

OSC

= 10kΩ 540 600 600 kHz

High End of Range R

OSC

= 5kΩ 1020 1200 1380 kHz

DH_ Minimum Off-Time R

OSC

= 5kΩ 110 160 ns

MAX8529

1.5MHz Dual 180° Out-of-Phase

PWM Step-Down Controller with POR

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V+ = 12V, EN = ILIM_ = V

, SYNC = GND, I

= 0mA, PGND = GND, C

REF

= 0.22µF, C

= 4.7µF (ceramic), R

OSC

= 10kΩ,

compensation components for COMP_ are from Figure 1, T

= -40°C to +85°C (Note 1), unless otherwise noted.)

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

SYNC Range

Internal oscillator nominal frequency must be set to half

of the SYNC frequency

1000 2800 kHz

High 100

SYNC Input Pulse Width (Note 3)

Low 100

SYNC Rise/Fall Time (Note 3) 100 ns

ERROR AMPLIFIER

FB_ Input Bias Current 250 nA

FB_ Input Voltage Set Point 0.99 1.00 1.01 V

0°C to +85°C 1.25 1.8 2.70

FB_ to COMP_ Transconductance

-40°C to +85°C 1.2 1.8 2.9

DRIVERS

DL_, DH_ Break-Before-Make Time C

LOAD

= 5nF 30 ns

Low 1.5 2.5

DH_ On-Resistance

High 3 5

Low 0.6 1.5

DL_ On-Resistance

High 3 5

LOGIC INPUTS (EN, SYNC)

Input Low Level Typical 15% hysteresis, V

= 4.75V 0.8 V

Input High Level V

= 5.5V 2.4 V

Input High/Low Bias Current V

= 0 or 5.5V -1 +0.1 +1 µA

LOGIC OUTPUTS (CKO)

Output Low Level V

= 5V, sinking 5mA 0.4 V

Output High Level V

= 5V, sourcing 5mA 4.0 V

COMP_

Pulldown Resistance During

Shutdown and Current Limit

17 Ω

RST OUTPUT

Output-Voltage Trip Level

Both FBs must be over this to allow the reset timer to

start; there is no hysteresis

0.87 0.9 0.93 V

= 5V, sinking 3.2mA 0.4

Output Low Level

= 1V, sinking 0.4mA 0.3

Output Leakage V+ = V

= 5V, V

RST

= 5.5V, V

= 1V 1 µA

Reset Timeout Period V

FB_

= 1V 140 315 560 ms

FB_ to Reset Delay FB_ overdrive from 1V to 0.85V 4 µs

Note 1: Specifications to -40°C are guaranteed by design and not production tested.

Note 2: Operating supply range is guaranteed by V

line regulation test. Connect V+ to V

for 5V operation.

Note 3: Guaranteed by design and not production tested.

P1-P3 P4-P6 P7-P9 P10-P12 P13-P15 P16-P18 P19-P20

MAX8529EEG+T

Mfr. #:

Buy MAX8529EEG+T

Manufacturer:

Maxim Integrated

Description:

Switching Controllers 1.5MHz Dual 180 Out-of-Phase

Lifecycle:

New from this manufacturer.

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MAX8529EEG+T

MAX8529EEG+T

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