MAX8538EEI+ Maxim Integrated Products, MAX8538EEI+ Datasheet

IC CNTRLR BUCK DUAL 28-QSOP

MAX8538EEI+

Manufacturer Part Number
MAX8538EEI+
Description
IC CNTRLR BUCK DUAL 28-QSOP
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX8538EEI+

Applications
Controller, DDR
Voltage - Input
4.5 ~ 23 V
Number Of Outputs
2
Voltage - Output
0.8 ~ 3.6 V
Operating Temperature
0°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
28-QSOP
Output Voltage
0.8 V to 3.6 V
Output Current
30 A
Input Voltage
4.5 V to 23 V
Mounting Style
SMD/SMT
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Case
SSOP
Dc
05+
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX8537/MAX8539 controllers provide a complete
power-management solution for both double-data-rate
(DDR) and combiner supplies. The MAX8537 and
MAX8539 are configured for out-of-phase and in-phase
DDR power-supply operations, respectively, and gener-
ate three outputs: the main memory voltage (V
tracking sinking/sourcing termination voltage (V
the termination reference voltage (V
is configured as a dual out-of-phase controller for point-
of-load supplies. Each buck controller can source or
sink up to 25A of current, while the termination refer-
ence can supply up to 15mA output.
The MAX8537/MAX8538/MAX8539 use constant-
frequency voltage-mode architecture with operating
frequencies of 200kHz to 1.4MHz. An internal high-
bandwidth (25MHz) operational amplifier is used as an
error amplifier to regulate the output voltage. This
allows fast transient response, reducing the number of
output capacitors. An all-N-FET design optimizes effi-
ciency and cost. The MAX8537/MAX8538/MAX8539
have a 1% accurate reference. The second synchro-
nous buck controller in the MAX8537/MAX8539 and the
VTTR amplifier generate 1/2 V
V
This family of controllers uses a high-side current-sense
architecture for current limiting. ILIM pins allow the set-
ting of an adjustable, lossless current limit for different
combinations of load current and R
more accurate overcurrent limit is achieved by using
a sense resistor in series with the high-side FET.
Overvoltage protection is achieved by latching off the
high-side MOSFET and latching on the low-side MOSFET
when the output voltage exceeds 17% of its set output.
Independent enable, power-good, and soft-start features
enhance flexibility.
19-3141; Rev 1; 6/05
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.
Load, Tracking, and DDR Memory Power Supplies
TTR
Dual-Synchronous Buck Controllers for Point-of-
, and track the V
DDR Memory Power Supplies
Notebooks and Desknotes
Servers and Storage Systems
Broadband Routers
XDSL Modems and Routers
Power DSP Core Supplies
Power Combiner in Advanced VGA Cards
Networking Systems
RAMBUS Memory Power Supplies
________________________________________________________________ Maxim Integrated Products
DDQ
General Description
within ±1%.
DDQ
Applications
voltage for V
TTR
DSON
). The MAX8538
. Alternately,
DDQ
TT
TT
), and
), the
and
♦ MAX8537/MAX8539: Complete DDR Supplies
♦ MAX8538: Dual Nontracking Controller
♦ Out-of-Phase (MAX8537/MAX8538) or In-Phase
♦ 4.5V to 23V Wide Input Range (Operate Down to
♦ Tracking Supply Maintains V
♦ Adjustable Output from 0.8V to 3.6V with 1%
♦ VTTR Reference Sources and Sinks Up to 15mA
♦ 200kHz to 1.4MHz Adjustable Switching
♦ All-Ceramic Design Achievable
♦ >90% Efficiency
♦ Independent POK_ and EN_
♦ Adjustable Soft-Start and Soft-Stop for Each
♦ Lossless Adjustable-Hiccup Current Limit
♦ Output Overvoltage Protection
♦ 28-Pin QSOP Package
+Denotes lead-free package.
Pin Configurations appear at end of data sheet.
MAX8537EEI
M AX 8537E E I+
MAX8538EEI
M AX 8538E E I+
MAX8539EEI
M AX 8539E E I+
(MAX8539) Operation
1.8V Input with External 5V Supply)
Accuracy
Frequency
Output
PART
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
TEMP RANGE
Ordering Information
PACKAGE
28 QSOP
28 QSOP
28 QSOP
28 QSOP
28 QSOP
28 QSOP
TT
PIN-
= V
TTR
Features
OPERATION
Out-of-phase
Out-of-phase
Out-of-phase
Out-of-phase
= 1/2 V
nontracking
nontracking
In-phase
In-phase
tracking
tracking
tracking
tracking
DDQ
1

Related parts for MAX8538EEI+

MAX8538EEI+ Summary of contents

Page 1

... Power DSP Core Supplies Power Combiner in Advanced VGA Cards Networking Systems RAMBUS Memory Power Supplies ________________________________________________________________ Maxim Integrated Products 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. ♦ MAX8537/MAX8539: Complete DDR Supplies ♦ MAX8538: Dual Nontracking Controller ♦ ...

Page 2

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies ABSOLUTE MAXIMUM RATINGS V+ to GND ..............................................................-0.3V to +25V AVL GND........................................................-0.3V to +6V PGND to GND .......................................................-0.3V to +0.3V FB_, EN_, POK_ to GND...........................................-0.3V to +6V ...

Page 3

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies ELECTRICAL CHARACTERISTICS (continued) (V+ = 12V, EN_ = VL, BST_ = 6V, LX_ = 1V, VL load = 0mA 10nF 1µF, R ...

Page 4

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies ELECTRICAL CHARACTERISTICS (continued) (V+ = 12V, EN_ = VL, BST_ = 6V, LX_ = 1V, VL load = 0mA 10nF 1µF, R ...

Page 5

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies (Circuit of Figure +25°C, 400kHz switching frequency EFFICIENCY vs. LOAD CURRENT DDQ 100 SENSE RESISTOR = 0Ω 12V IN ...

Page 6

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies (Circuit of Figure +25°C, 400kHz switching frequency POWER-OK MAX8537 toc10 V DDQ 2V/div POK1 5V/div V TT 1V/div POK2 5V/div ...

Page 7

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies NAME NAME PIN (MAX8537/ (MAX8538) MAX8539) 1 BST2 BST2 2 DH2 DH2 3 LX2 LX2 4 ILIM2 ILIM2 5 POK1 POK1 6 DL2 DL2 7 POK2 POK2 8 ...

Page 8

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies NAME NAME PIN (MAX8537/ (MAX8538) MAX8539 DL1 DL1 24 PGND PGND 25 ILIM1 ILIM1 26 LX1 LX1 27 DH1 DH1 28 BST1 BST1 Detailed ...

Page 9

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies The MAX8537/MAX8538/MAX8539 step-down DC-DC converters use a PWM voltage-mode control scheme. An internal high-bandwidth (25MHz) operational amplifi used as an error amplifier to regulate the output ...

Page 10

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies Figure 1. Typical Application Circuit: MAX8537 DDR Memory Application (400kHz Switching) 10 ______________________________________________________________________________________ ...

Page 11

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies Figure 2. MAX8539 DDR Memory Application (400kHz Switching) ______________________________________________________________________________________ 11 ...

Page 12

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies Figure 3. MAX8538 PowerPC™ Application (400kHz Switching) PowerPC is a trademark of Motorola, Inc. 12 ______________________________________________________________________________________ ...

Page 13

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies Figure 4. MAX8538 Dual-Output Application (1MHz Switching) ______________________________________________________________________________________ 13 ...

Page 14

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies Power-Good Signal (POK_) The power-good signal (POK_ open-drain output. The MOSFET turns on and POK_ is held low until FB_ is ±12% from its nominal threshold ...

Page 15

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies by 10°C, resulting in a pulsed output during continuous thermal-overload conditions. During a thermal event, the switching converters are turned off, POK1 and POK2 are pulled low, and ...

Page 16

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies venting the output capacitor voltage from further devia- tion from its regulating value. Do not exceed the capacitor’s voltage or ripple current ratings. MOSFET Selection The MAX8537/MAX8538/MAX8539 controllers ...

Page 17

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies of the inductor ripple current (see the Inductor Selection section the high-side MOSFET DS(ON) is used for current sensing, make sure to use the maxi- ...

Page 18

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies where V MOD RAMP V RAMP π ...

Page 19

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies OUT GAIN CLOSED-LOOP GAIN (dB) 0 Figure 6. Error-Amplifier Compensation Circuit; Closed-Loop and Error-Amplifier Gain Plot for Case 1 GAIN (dB) 0 Figure 7. Closed-Loop ...

Page 20

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies FREQ OSC 1V EN1 COMP1 REFIN SS2 AVL BIAS GND EN2 COMP2 20 ______________________________________________________________________________________ MAX8537/MAX8539 Functional Diagram IMAX SENSE CONTROL LOGIC PWM REF 0.80V SOFT-START EAMP 0.936V OVP1 ...

Page 21

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies TOP VIEW BST2 1 DH2 2 LX2 3 ILIM2 4 POK1 5 DL2 6 POK2 7 EN2 8 EN1 9 FREQ 10 COMP2 11 FB2 12 SS2 13 ...

Page 22

Dual-Synchronous Buck Controllers for Point-of- Load, Tracking, and DDR Memory Power Supplies 2) Keep separate the power ground plane (connected to the sources of the low-side MOSFETs, pin 24, input capacitor ground, output capacitor ground, and VL decoupling capacitor ground) ...

Page 23

... 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 ____________________ 23 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc ...

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