IC CTRLR PWM STP-DN TRIPL 32WQFN

MAX15048ETJ+

Manufacturer Part NumberMAX15048ETJ+
DescriptionIC CTRLR PWM STP-DN TRIPL 32WQFN
ManufacturerMaxim Integrated Products
MAX15048ETJ+ datasheet
 


Specifications of MAX15048ETJ+

ApplicationsPower Supply Controller, SequencerVoltage - Supply4.7 V ~ 23 V
Current - Supply6mAOperating Temperature-40°C ~ 85°C
Mounting TypeSurface MountPackage / Case32-WQFN Exposed Pad
Number Of Outputs3Output Voltage5 V
Input Voltage4.7 V to 23 VSupply Current6 mA
Switching Frequency200 KHzMounting StyleSMD/SMT
Maximum Operating Temperature+ 85 CMinimum Operating Temperature- 40 C
Lead Free Status / RoHS StatusLead free / RoHS CompliantVoltage - Input-
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19-5110; Rev 0; 1/10
General Description
The MAX15048/MAX15049 are triple-output pulse-width
modulated (PWM), step-down, DC-DC controllers with
tracking (MAX15048) and sequencing (MAX15049)
options. The devices operate over the 4.7V to 23V input-
voltage range. Each PWM controller provides an adjustable
output down to 0.6V and delivers up to 15A of load current
with excellent load and line regulation. The MAX15049 can
start into prebiased outputs. The MAX15048/MAX15049
are optimized for high-performance, small-size power-
management solutions.
The options of coincident or ratiometric tracking (MAX15048)
or output sequencing (MAX15049) allow the tailoring of
the power-up/power-down sequence depending on the
system requirements. Each of the MAX15048/MAX15049
PWM sections utilizes a voltage-mode control scheme with
external compensation, allowing for good noise immunity
and maximum flexibility with a wide selection of inductor
values and capacitor types. Each PWM section operates at
the same fixed switching frequency that is programmable
from 200kHz to 1.2MHz. Each converter, operating at up to
1.2MHz with 120N out-of-phase, increases the input capaci-
tor ripple frequency up to 3.6MHz, reducing the RMS input
ripple current and thus the size of the input bypass capaci-
tor significantly. The MAX15048/MAX15049 integrate boost
diodes for additional system cost savings.
The MAX15048/MAX15049 include internal undervolt-
age lockout (UVLO) with hysteresis and digital soft-start
(MAX15048/MAX15049)/soft-stop (MAX15048) for glitch-
free power-up and power-down of the converter. The
power-good circuitry (PGOOD) monitors all three outputs
and provides a power-good signal to the system control/
processor when all outputs are within regulation. Protection
features include lossless valley-mode current limit, hiccup
mode output short-circuit protection, and thermal shutdown.
The MAX15048/MAX15049 are available in space-saving,
5mm x 5mm, lead-free, 32-pin TQFN-EP packages and
are specified for operation over the -40NC to +85NC
extended temperature range.
Point-of-Load DC-DC Converters
ASIC/CPU/DSP Core and I/O Voltages
DDR Power Supply
Base-Station Power Supplies
Telecom and Networking Power Supplies
RAID Control Power Supplies
Set-Top Boxes
_______________________________________________________________ Maxim Integrated Products 1
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.
Triple-Output Buck Controllers
with Tracking/Sequencing
S 4.7V to 23V or 5V ±10% Input Voltage Range
S Triple-Output Synchronous Buck Controllers with
120° Out-of-Phase Operation
S Prebias Power-Up (MAX15049)
S Output Voltage Adjustable Down to 0.6V
S Coincident/Ratiometric Tracking (MAX15048)
S Accurate Sequencing Through Enable Threshold
(MAX15049)
S External Compensation for Maximum Flexibility
S Digital Soft-Start (MAX15048/MAX15049) and Soft-
Stop (MAX15048)
S Lossless Valley-Mode Current Sensing Using
R
DS(ON)
S PGOOD Output
S Integrated Bootstrap Diodes
S Programmable Switching Frequency from 200kHz
to 1.2MHz
S Thermal Shutdown and Hiccup Mode Short-Circuit
Protection
S Space-Saving (5mm x 5mm), 32-Pin TQFN
Package
PART
MAX15048ETJ+
MAX15049ETJ+
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Simplified Typical Operating
Circuit (Coincident Tracking)
IN
V
OUT3
Applications
V
OUT1
Features
of the Low-Side MOSFET
Ordering Information
TEMP RANGE
PIN-PACKAGE
-40
C to +85
C
32 TQFN-EP*
N
N
-40
C to +85
C
32 TQFN-EP*
N
N
EN1
IN
DH3
LX3
DH1
BST3
LX1
DL3
MAX15048
PGND3
BST1
DL1
FB3
COMP3
PGND1
FB1
COMP1
EN3
V
REG
V
OUT1
V
OUT2
V
OUT3
SOFT-START
SOFT-STOP
COINCIDENT TRACKING OUTPUTS
IN
V
OUT1

MAX15048ETJ+ Summary of contents

  • Page 1

    ... S PGOOD Output S Integrated Bootstrap Diodes S Programmable Switching Frequency from 200kHz to 1.2MHz S Thermal Shutdown and Hiccup Mode Short-Circuit Protection S Space-Saving (5mm x 5mm), 32-Pin TQFN Package PART MAX15048ETJ+ MAX15049ETJ+ +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. Simplified Typical Operating Circuit (Coincident Tracking OUT3 Applications ...

  • Page 2

    Triple-Output Buck Controllers with Tracking/Sequencing ABSOLUTE MAXIMUM RATINGS IN, LX_ to SGND ...................................................-0.3V to +30V BST_ to SGND .......................................................-0.3V to +30V BST_ to LX_ .............................................................-0.3V to +6V REG, DREG_, EN_ SGND .............................-0.3V to +6V PGOOD, FB_, COMP_ to ...

  • Page 3

    ELECTRICAL CHARACTERISTICS (continued 12V 5V REG DREG_ noted. Typical values are +25NC.) (Note PARAMETER SYMBOL OSCILLATOR Switching Frequency Range (Each Converter) Switching ...

  • Page 4

    Triple-Output Buck Controllers with Tracking/Sequencing ELECTRICAL CHARACTERISTICS (continued 12V 5V REG DREG_ noted. Typical values are +25NC.) (Note PARAMETER SYMBOL ENABLE/PGOOD EN_ ...

  • Page 5

    0V DREG_ REG PGND_ CONVERTER 1 OUTPUT VOLTAGE vs. LOAD CURRENT 3.330 3.328 3.325 3.323 3.320 3.318 3.315 3.313 V = 12V IN 3.310 3.308 ...

  • Page 6

    Triple-Output Buck Controllers with Tracking/Sequencing (V = 12V 0V DREG_ REG PGND_ OPERATING SUPPLY CURRENT vs. SWITCHING FREQUENCY 15 DRIVERS SWITCHING 14 NO-OUTPUT LOAD V = 12V ...

  • Page 7

    0V DREG_ REG PGND_ COINCIDENT SHUTDOWN (MAX15048) V EN1 V OUT1 V OUT2 V OUT3 WITH FIGURE 10 CONFIGURED FOR COINCIDENT TRACKING 1ms/div CHANNEL 2 SHORT CIRCUIT (COINCIDENT TRACKING) ...

  • Page 8

    Triple-Output Buck Controllers with Tracking/Sequencing (V = 12V 0V DREG_ REG PGND_ 120° OUT-OF-PHASE OPERATION V LX1 V LX2 V LX3 1 µ s/div CONVERTER 1 SHORT-CIRCUIT CONDITION (HICCUP MODE) V OUT1 ...

  • Page 9

    0V DREG_ REG PGND_ STARTUP INTO PREBIASED OUTPUT (1.2V PREBIASED) V EN1 V OUT1 1ms/div LOAD-TRANSIENT RESPONSE (I = 1.5A TO 3A) 0UT1 I OUT1 V OUT1 (AC-COUPLED) V ...

  • Page 10

    Triple-Output Buck Controllers with Tracking/Sequencing TOP VIEW *EXPOSED PAD. PIN NAME Oscillator Timing Resistor Connection. Connect a 15.6kI to 93.75kI resistor from RT to SGND program the switching frequency from 200kHz to 1.2MHz. Analog Ground. Connect SGND ...

  • Page 11

    PIN NAME Controller Power-Good Output. Pull up PGOOD with a resistor to a positive voltage below 5.5V. For the MAX15048, PGOOD output releases when all three V 12 PGOOD MAX15049, PGOOD output releases when all three controllers are out of ...

  • Page 12

    Triple-Output Buck Controllers with Tracking/Sequencing IN LDO REG EN 0.60V 0.55V 0.6V THERMAL REF SHDN DOWN1 V REF DIGITAL CLK1 SOFT-START AND -STOP GM FB1 COMP1 CLK1 RT OSC RAMP LEVEL SHIFT CLK2 CLK3 12 _____________________________________________________________________________________ 0.60V EN1 0.55V V ...

  • Page 13

    V REF DOWN2/3 DIGITAL V REF CLK2/3 SOFT-START AND -STOP V R2/3 GM EN2/3 FB2/3 COMP2/3 CLK2/3 RAMP LEVEL SHIFT MAX15048 PWM CONTROLLERS 2 AND 3 ______________________________________________________________________________________ Triple-Output Buck Controllers with Tracking/Sequencing Functional Diagrams (continued) SHDN OFF OVL CONFIG OVL2/3 ...

  • Page 14

    Triple-Output Buck Controllers with Tracking/Sequencing IN LDO REG EN 0.60V 0.55V 0.6V THERMAL REF SHDN DOWN1 V REF DIGITAL CLK1 SOFT-START GM FB1 COMP1 CLK1 RT OSC RAMP CLK2 CLK3 14 _____________________________________________________________________________________ Functional Diagrams (continued) 0.60V EN1 0.55V V REGOK ...

  • Page 15

    V REF DIGITAL CLK2/3 SOFT-START GM PREBIAS FB2/3 COMP2/3 CLK2/3 RAMP LEVEL CLK SHIFT ______________________________________________________________________________________ Triple-Output Buck Controllers with Tracking/Sequencing Functional Diagrams (continued) 0.60V EN2/3 0.55V OFF2/3 SHDN OVL2/3 OVERLOAD 2/3 MAX MANAGEMENT SET DOMINANT LATCH S ...

  • Page 16

    Triple-Output Buck Controllers with Tracking/Sequencing Detailed Description The MAX15048/MAX15049 are triple-output, PWM, step- down, DC-DC controllers with tracking and sequencing options. The devices operate over the 4.7V to 23V or 5V Q10% input voltage range. Each PWM controller pro- vides ...

  • Page 17

    MOSFET Gate Drivers and Internal Boost Switch DREG_ is the supply input for the low-side MOSFET driver. Connect DREG_ to REG externally. Every time the low-side MOSFET switches on, high peak current is drawn from DREG_ for a short time. ...

  • Page 18

    Triple-Output Buck Controllers with Tracking/Sequencing MAX15049 Output-Voltage Sequencing (EN_) In Figure 1c, when sequencing, the enable input must be above 0.6V for each PWM controller to start. The V outputs and EN_ inputs can be daisy-chained to gener- ate power ...

  • Page 19

    COUNT CURRENT LIMIT N CL CLR COUNT CLR CLR Figure 3. Hiccup-Mode Block Diagram just before the beginning of a new PWM cycle, the con- troller skips that cycle. During severe overload or ...

  • Page 20

    Triple-Output Buck Controllers with Tracking/Sequencing ( programmable between 200kHz and 1.2MHz SW (see the Setting the Switching Frequency section). The peak-to-peak inductor current (DI the peak-to-peak output ripple, is worst at the maximum input voltage. See the Output-Capacitor ...

  • Page 21

    Use the following equations to calculate the required ESR, ESL, and capacitance value during a load step: ∆ V ESR = ESR I STEP I × t RESPONSE STEP C = OUT ∆ ∆ V × t ESL ...

  • Page 22

    Triple-Output Buck Controllers with Tracking/Sequencing Below are equations that define the power modulator MOD(DC) V RAMP π × × ZERO, ESR π × 2 ESR C ESR ...

  • Page 23

    The desired (compensated) rolloff follows a -20dB/ decade slope (and commensurate 90° of phase shift), and, in this example, occurs at approximately six times the uncompensated crossover frequency, f example, a Type II compensator provides stable closed- loop operation, leveraging ...

  • Page 24

    Triple-Output Buck Controllers with Tracking/Sequencing As with the previous example, the actual gain and phase response is overlaid on the power modulator’s asymp- totic gain response readily observed that the more dramatic gain and phase transition at or ...

  • Page 25

    Design procedures for both Type II and Type III compen- sators are shown below. Type II: Compensation when f CO When the f is lower than f ZERO, ESR a Type II compensation network provides the neces- sary closed-loop response. ...

  • Page 26

    Triple-Output Buck Controllers with Tracking/Sequencing Type III: Compensation when previously indicated, the position of the output capac- itor’s inherent ESR zero is critical in designing an appro- priate compensation network. When low-ESR ceramic output capacitors are used, ...

  • Page 27

    P2 8) Place a second pole ( 2 below one-half the switching frequency π × × Calculate R using the following equation FB_ = × ...

  • Page 28

    Triple-Output Buck Controllers with Tracking/Sequencing IN V OUT3 Figure 8. MAX15048 Ratiometric Tracker Typical Operating Circuit 28 _____________________________________________________________________________________ DH3 LX3 BST3 DL3 MAX15048 PGND3 FB3 COMP3 EN3 V REG IN EN1 IN DH1 LX1 BST1 DL1 PGND1 FB1 COMP1 V ...

  • Page 29

    IN V OUT3 V OUT2 Figure 9. MAX15049 Sequencer Typical Operating Circuit ______________________________________________________________________________________ Triple-Output Buck Controllers with Tracking/Sequencing DH3 LX3 BST3 DL3 MAX15049 PGND3 FB3 COMP3 EN3 V REG IN EN1 IN DH1 LX1 BST1 DL1 PGND1 FB1 COMP1 V ...

  • Page 30

    Triple-Output Buck Controllers with Tracking/Sequencing 470µF 22µF 22µF V OUT3 1µH (1.2V/6A) 0.1µF 100µF 100µF 1500pF 15kI V OUT2 22pF Figure 10. Evaluation Kit Schematic Configured for the MAX15049 (Sequencer) 30 _____________________________________________________________________________________ V IN 10µF 1µF 0.1µF DH3 LX3 BST3 ...

  • Page 31

    ... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 2010 Maxim Integrated Products © ...