MAX8546EUB+ Maxim Integrated Products, MAX8546EUB+ Datasheet

IC CNTRLR STEP DOWN 10-UMAX

MAX8546EUB+

Manufacturer Part Number
MAX8546EUB+
Description
IC CNTRLR STEP DOWN 10-UMAX
Manufacturer
Maxim Integrated Products
Type
Step-Down (Buck)r
Datasheet

Specifications of MAX8546EUB+

Internal Switch(s)
No
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
0.8 ~ 23 V
Current - Output
15A
Frequency - Switching
300kHz
Voltage - Input
2.7 ~ 28 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
10-MSOP, Micro10™, 10-uMAX, 10-uSOP
Power - Output
444mW
Input Voltage
2.7 V to 28 V
Switching Frequency
300 KHz
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX8545/MAX8546/MAX8548 are voltage-mode
pulse-width-modulated (PWM), step-down DC-DC con-
trollers ideal for a variety of cost-sensitive applications.
They drive low-cost n-channel MOSFETs for both the
high-side switch and synchronous rectifier, and require
no external current-sense resistor. These devices can
supply output voltages as low as 0.8V.
The MAX8545/MAX8546/MAX8548 have a wide 2.7V to
28V input range, and do not need any additional bias
voltage. The output voltage can be precisely regulated
from 0.8V to 0.83 x V
ciency up to 95%. Lossless short-circuit and current-limit
protection is provided by monitoring the R
low-side MOSFET. The MAX8545 and MAX8548 have a
current-limit threshold of 320mV, while the MAX8546 has
a current-limit threshold of 165mV. All devices feature
foldback-current capability to minimize power dissipation
under short-circuit condition. Pulling the COMP/EN pin
low with an open-collector or low-capacitance, open-
drain device can shut down all devices.
The MAX8545/MAX8546 operate at 300kHz and the
MAX8548 operates at 100kHz. The MAX8545/MAX8546/
MAX8548 are compatible with low-cost aluminum elec-
trolytic capacitors. Input undervoltage lockout prevents
proper operation under power-sag operations to prevent
external MOSFETs from overheating. Internal soft-start is
included to reduce inrush current. These devices are
offered in space-saving 10-pin µMAX
19-2795; Rev 2; 6/07
+Denotes a lead-free package.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
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.
MAX8545EUB
MAX8545EUB+
MAX8546EUB
MAX8546EUB+
MAX8548EUB
MAX8548EUB+
Set-Top Boxes
Graphic Card and Video
Supplies
Desktops and Desknotes
PCI Express Power
Supplies
Telecom Power Supplies
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
________________________________________________________________ Maxim Integrated Products
Low-Cost, Wide Input Range, Step-Down
Controllers with Foldback Current Limit
IN
Ordering Information
. These devices can provide effi-
General Description
Notebook Docking
Station Supplies
Cable Modems and
Routers
Networking Power
Supplies
PIN-
PACKAGE
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
10 µMAX
®
Applications
packages.
DS(ON)
CODE
U10-2
U10-2
U10-2
U10-2
U10-2
U10-2
PKG
of the
♦ 2.7V to 28V Input Range
♦ Foldback Short-Circuit Protection
♦ No Additional Bias Supply Needed
♦ 0.8V to 0.83 x V
♦ Up to 95% Efficiency
♦ Low-Cost External Components
♦ No Current-Sense Resistor
♦ All n-Channel MOSFET Design
♦ Adaptive Gate Drivers Eliminate Shoot-Through
♦ Lossless Overcurrent and Short-Circuit
♦ 300kHz Switching Frequency
♦ 100kHz Switching Frequency (MAX8548)
♦ Pin-Compatible with the MAX1967
♦ Thermal Shutdown
Pin Configuration appears at end of data sheet.
MAX8545
MAX8546
MAX8548
ON
Protection
(MAX8545/MAX8546)
OFF
OPTIONAL
PART
2.7V TO 28V
INPUT
Typical Operating Circuit
V
COMP/
EN
IN
IN
MAX8545
MAX8546
MAX8548
Output
V
CC
FREQUENCY
SWITCHING
VL
(kHz)
GND
300
300
100
BST
DH
LX
DL
FB
Selector Guide
CURRENT-LIMIT
Features
THRESHOLD
(mV)
-320
-165
-320
UP TO 6A
OUTPUT
0.9 x V
0.8V TO
IN
1

Related parts for MAX8546EUB+

MAX8546EUB+ Summary of contents

Page 1

... MAX8545EUB -40°C to +85°C 10 µMAX MAX8545EUB+ -40°C to +85°C 10 µMAX MAX8546EUB -40°C to +85°C 10 µMAX MAX8546EUB+ -40°C to +85°C 10 µMAX -40°C to +85°C MAX8548EUB 10 µMAX MAX8548EUB+ -40°C to +85°C +Denotes a lead-free package. µMAX is a registered trademark of Maxim Integrated Products, Inc. ...

Page 2

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND unless otherwise noted GND ............................................................-0.3V to +30V GND .............................-0.3V, lower (VL + 0.3V) CC ...

Page 3

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit ELECTRICAL CHARACTERISTICS (continued 5V -40°C to +85°C, unless otherwise noted. Typical values are PARAMETER SYMBOL ERROR AMPLIFIER ...

Page 4

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit ( 5V, typical values are EFFICIENCY vs. LOAD CURRENT (CIRCUIT OF FIGURE 1; TABLE 1a) 100 ...

Page 5

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit ( 5V, typical values are CHANGE IN OUTPUT VOLTAGE vs. INPUT VOLTAGE 1.84 1.83 1.82 1.81 1.80 1.79 1.78 2.5 3.0 ...

Page 6

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit ( 5V, typical values are STARTUP WAVEFORM 1ms/div SHORT-CIRCUIT WAVEFORM 1ms/div 6 _______________________________________________________________________________________ Typical Operating Characteristics (continued) ...

Page 7

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit PIN NAME Compensation Input. Pull COMP/EN low with an open-collector or open-drain device to turn 1 COMP/EN off the output Feedback Input. Connect a resistive-divider network to set ...

Page 8

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit Detailed Description The MAX8545/MAX8546/MAX8548 are BiCMOS switch- mode power-supply controllers designed to implement simple, buck-topology regulators in cost-sensitive applications. The main power-switching circuit consists of two n-channel MOSFETs, an inductor, ...

Page 9

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit from high-voltage inputs. With high input voltages, the required duty factor is approximately: + × OUT where ...

Page 10

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit +2.7V TO +5.5V INPUT C10 C11 *FOLLOW THE DATA SHEET DESIGN PROCEDURE TO SELECT THE EXTERNAL COMPONENTS FOR THE MAX8545/MAX8548. Figure 1. Typical Application Circuit (2.7V ...

Page 11

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit A limitation of sensing current across a MOSFET’s on- resistance is that the current-limit threshold is not accu- rate since MOSFET R specifications are not DS(ON) precise. This type of ...

Page 12

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit with DH and DL to slow down the switching transitions. However, adding series resistors increases the power dissipation of the MOSFET, so ensure temperature rat- ings of the MOSFET are ...

Page 13

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit has a gain drop of 40dB per decade, and a phase shift of 180°. The error amplifier must compensate for this gain drop and phase shift to achieve a stable ...

Page 14

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit GENERATOR COMP/EN R2 C10 Figure 3. Compensation Scheme ground terminals flush against one another. Follow these guidelines for good PCB layout: 1) Keep the high-current paths short, especially at the ...

Page 15

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit Table 1a. Component Selection for Standard Applications for V 5.5V 1. (Figure 1) OUT (MAX8546 Only) COMPONENT QTY DESCRIPTION 1µF, 10V X7R ceramic capacitors C1, C4 ...

Page 16

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit Table 2a. Component Selection for Standard Applications for V 24V 2. (Figure 2) OUT (MAX8546 Only) COMPONENT QTY DESCRIPTION 1µF, 10V X7R ceramic capacitor C1 1 ...

Page 17

Low-Cost, Wide Input Range, Step-Down Controllers with Foldback Current Limit Pin Configuration TOP VIEW COMP/ BST MAX8545 MAX8546 MAX8548 GND μMAX ...

Page 18

... 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. 18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2007 Maxim Integrated Products 4X S ...

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