MAX1714BEEE+ Maxim Integrated Products, MAX1714BEEE+ Datasheet

IC CNTRLR STP DWN HS 16-QSOP

MAX1714BEEE+

Manufacturer Part Number
MAX1714BEEE+
Description
IC CNTRLR STP DWN HS 16-QSOP
Manufacturer
Maxim Integrated Products
Type
Step-Down (Buck)r
Datasheet

Specifications of MAX1714BEEE+

Internal Switch(s)
No
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
2.5V, 3.3V, Adj
Current - Output
8A
Frequency - Switching
200kHz, 300kHz, 600kHz
Voltage - Input
2 ~ 28 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
16-QSOP
Power - Output
667mW
Output Voltage
1 V to 5.5 V
Output Current
3000 mA
Mounting Style
SMD/SMT
Switching Frequency
600 KHz
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Synchronous Pin
No
Topology
Buck
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX1714 pulse-width modulation (PWM) controller
provides the high efficiency, excellent transient
response, and high DC output accuracy needed for
stepping down high-voltage batteries to generate low-
voltage CPU core or chip-set/RAM supplies in notebook
computers.
Maxim’s proprietary Quick-PWM™ quick-response,
constant-on-time PWM control scheme handles wide
input/output voltage ratios with ease and provides
100ns “instant-on” response to load transients while
maintaining a relatively constant switching frequency.
The MAX1714 achieves high efficiency at a reduced
cost by eliminating the current-sense resistor found in
traditional current-mode PWMs. Efficiency is further
enhanced by an ability to drive very large synchronous-
rectifier MOSFETs.
Single-stage buck conversion allows these devices to
directly step down high-voltage batteries for the highest
possible efficiency. Alternatively, two-stage conversion
(stepping down the +5V system supply instead of the
battery) at a higher switching frequency allows the mini-
mum possible physical size.
The MAX1714 is intended for CPU core, chipset,
DRAM, or other low-voltage supplies as low as 1V. The
MAX1714A is available in a 20-pin QSOP package and
includes overvoltage protection. The MAX1714B is
available in a 16-pin QSOP package with no overvolt-
age protection. For applications requiring VID compli-
ance or DAC control of output voltage, refer to the
MAX1710/MAX1711 data sheet. For a dual output ver-
sion, refer to the MAX1715
Pin Configurations appear at end of data sheet.
19-1536; Rev 2; 8/05
Quick-PWM is a trademark of 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.
Future product—contact factory for availability.
Notebook Computers
CPU Core Supply
Chipset/RAM Supply as Low as 1V
1.8V and 2.5V I/O Supply
________________________________________________________________ Maxim Integrated Products
General Description
data sheet.
High-Speed Step-Down Controller
Applications
for Notebook Computers
♦ Ultra-High Efficiency
♦ No Current-Sense Resistor (Lossless I
♦ Quick-PWM with 100ns Load-Step Response
♦ 1% V
♦ 2.5V/3.3V Fixed or 1V to 5.5V Adjustable Output
♦ 2V to 28V Battery Input Range
♦ 200/300/450/600kHz Switching Frequency
♦ Overvoltage Protection (MAX1714A)
♦ Undervoltage Protection
♦ 1.7ms Digital Soft-Start
♦ Drives Large Synchronous-Rectifier FETs
♦ 2V ±1% Reference Output
♦ Power-Good Indicator
+Denotes lead-free package.
MAX1714AEEP
MAX1714AEEP+
MAX1714BEEE
MAX1714BEEE+
Range
+5V INPUT
PART
OUT
V
SHDN
ILIM
REF
PGOOD
FB
Accuracy Over Line and Load
CC
MAX1714
Minimal Operating Circuit
AGND
(GND)
(GND)
PGND
SKIP
OUT
V
BST
DH
DD
V+
LX
DL
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Ordering Information
4.5V TO 28V
BATTERY
( ) ARE FOR THE MAX1714B ONLY.
20 QSOP
20 QSOP
16 QSOP
16 QSOP
PIN-PACKAGE
Features
LIMIT
1.25V TO 2V
OUTPUT
)
1

Related parts for MAX1714BEEE+

MAX1714BEEE+ Summary of contents

Page 1

... Undervoltage Protection ♦ 1.7ms Digital Soft-Start ♦ Drives Large Synchronous-Rectifier FETs ♦ 2V ±1% Reference Output ♦ Power-Good Indicator PART MAX1714AEEP MAX1714AEEP+ MAX1714BEEE MAX1714BEEE+ +Denotes lead-free package. +5V INPUT Applications Features LIMIT Accuracy Over Line and Load Ordering Information TEMP RANGE PIN-PACKAGE -40° ...

Page 2

High-Speed Step-Down Controller for Notebook Computers ABSOLUTE MAXIMUM RATINGS V+ to AGND (Note 1)..............................................-0.3V to +30V AGND (Note 1) .....................................-0. PGND to AGND (Note 1) ................................................... ±0.3V SHDN, PGOOD, OUT to AGND ...

Page 3

ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, 4A components from Table +15V, V noted.) (Note 1) PARAMETER Overvoltage Trip Threshold With respect to error comparator threshold (MAX1714A only) Overvoltage Fault Propagation FB forced 2% above trip threshold ...

Page 4

High-Speed Step-Down Controller for Notebook Computers ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, 4A components from Table +15V, V noted.) (Note 1) PARAMETER TON V Level CC TON Float Voltage TON Reference Level TON AGND Level TON ...

Page 5

ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure 1, 4A components from Table +15V, V wise noted.) (Notes 1, 5) PARAMETER Measured at FB with respect to error comparator PGOOD Trip Threshold threshold, falling edge PGOOD Output Low Voltage ...

Page 6

High-Speed Step-Down Controller for Notebook Computers _____________________________Typical Operating Characteristics (continued) (Circuit of Figure 1, components from Table 1, V FREQUENCY vs. LOAD CURRENT (4A COMPONENTS 2.5V) OUT 350 V = 7V, 15V, PWM MODE IN 300 250 V ...

Page 7

Operating Characteristics (continued) (Circuit of Figure 1, components from Table 1, V LOAD-TRANSIENT RESPONSE (4A COMPONENTS 2.5V, 300kHz) OUT 10µs/div AC-COUPLED, 100mV/div OUT B = INDUCTOR CURRENT, 2A/div C = ...

Page 8

High-Speed Step-Down Controller for Notebook Computers PIN PIN NAME MAX1714A MAX1714B – N.C. 11 SHDN OUT 6 5 ILIM 7 6 REF 8 – AGND 10 7 PGOOD ...

Page 9

Standard Application Circuit The standard application circuit (Figure 1) generates a low-voltage rail for general-purpose use in a notebook computer (I/O supply, fixed CPU core supply, DRAM supply). This DC-DC converter steps down a battery or AC adapter voltage to ...

Page 10

High-Speed Step-Down Controller for Notebook Computers Table 1. Component Selection for Standard Applications COMPONENT 2. Input Range 7V to 20V Frequency 300kHz Q1 High-Side Fairchild Semiconductor MOSFET 1/2 FDS6982A Q2 Low-Side Fairchild Semiconductor MOSFET 1/2 FDS6982A D2 Rectifier ...

Page 11

28V V+ TON FROM ON-TIME COMPUTE OUT TON TON Q TRIG 1-SHOT SKIP REF SHDN MAX1714A ONLY REF REF +12% -6% PGOOD OVP/UVLO LATCH NOTE: IN THE MAX1714B, AGND AND PGND ARE INTERNALLY CONNECTED ...

Page 12

High-Speed Step-Down Controller for Notebook Computers where K is set by the TON pin-strap connection and 0.075V is an approximation to accommodate for the expected drop across the low-side MOSFET switch. One-shot timing error increases for the shorter on-time settings ...

Page 13

V -V BATT OUT = ∆ ON-TIME TIME Figure 3. Pulse-Skipping/Discontinuous Crossover Point multiple-output applications that use a flyback trans- former or coupled inductor. Current-Limit Circuit (ILIM) The current-limit circuit employs a unique “valley” cur- rent-sensing algorithm ...

Page 14

High-Speed Step-Down Controller for Notebook Computers +5V 5Ω BST DH LX MAX1714 Figure 5. Reducing the Switching-Node Rise Time POR, UVLO, and Soft-Start Power-on reset (POR) occurs when V approximately 2V, resetting the fault latch and soft-start counter, and preparing ...

Page 15

Table 3. Operating Mode Truth Table SHDN SKIP DL MODE 0 X High Shutdown Below 1 Switching No Fault AGND Run (PWM Switching CC Low Noise Run 1 AGND Switching (PFM/PWM High Fault 2) Maximum load ...

Page 16

High-Speed Step-Down Controller for Notebook Computers Inductor Selection The switching frequency and inductor operating point determine the inductor value as follows OUT IN OUT L = ⋅ ⋅ ⋅ LIR I IN LOAD(MAX) ...

Page 17

A 1µA minimum divider current is recommended. Output Capacitor Selection The output filter capacitor must have low enough effective series resistance (ESR) to meet output ripple and load- transient requirements, yet have high enough ESR to sat- ...

Page 18

High-Speed Step-Down Controller for Notebook Computers For optimal circuit reliability, choose a capacitor that has less than 10°C temperature rise at the peak ripple current. Power MOSFET Selection Most of the following MOSFET guidelines focus on the challenge of obtaining ...

Page 19

24V* IN 1µF ON/OFF 0.22µF * FOR HIGHER MINIMUM INPUT VOLTAGE, * LESS OUTPUT CAPACITANCE IS ACCEPTABLE. Figure 7. All-Ceramic-Capacitor Application Table 5. Approximate K-Factor Errors TON K APPROXIMATE SETTING FACTOR K-FACTOR (kHz) (µs) ERROR (%) ...

Page 20

... PC boards (2 oz vs. 1 oz) can enhance full-load efficiency more. Correctly routing PC board traces is a difficult task that must be approached in terms of fractions of centimeters, 0.2V Dual Mode is a trademark of Maxim Integrated Products. Fixed Output Voltages for a +3.3V output, or connect FB CC with a Resistor-Divider OUT  ...

Page 21

V BATT DH MAX1714 DL PGND (GND) OUT FB AGND (GND ARE FOR THE MAX1714B ONLY. Figure 9. Setting V with a Resistor-Divider OUT where a single milliohm of excess trace resistance causes a measurable efficiency penalty. • ...

Page 22

High-Speed Step-Down Controller for Notebook Computers ON/OFF 100k Figure 10. 5V Powered, 7A CPU Buck Regulator TOP VIEW DH 1 N.C. 2 SHDN MAX1714A OUT 5 ILIM 6 REF 7 AGND 8 N.C. 9 PGOOD 10 22 ...

Page 23

ALL ANALOG GROUNDS CONNECT TO AGND ONLY MAX1714 V CC REF LIM AGND VIA TO SOURCE OF Q2 CONNECT AGND TO PGND BENEATH IC, 1 POINT ONLY. SPLIT ANALOG GND PLANE AS SHOWN. NOTES: "STAR" GROUND IS ...

Page 24

... 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. 24 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc ...

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