MAX1536ETI+ Maxim Integrated Products, MAX1536ETI+ Datasheet

IC PWM STEP-DN DC-DC CONV 28TQFN

MAX1536ETI+

Manufacturer Part Number
MAX1536ETI+
Description
IC PWM STEP-DN DC-DC CONV 28TQFN
Manufacturer
Maxim Integrated Products
Type
Step-Down (Buck), PWM - Current Moder
Datasheet

Specifications of MAX1536ETI+

Internal Switch(s)
Yes
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
0.7 ~ 5.5 V
Current - Output
3.6A
Frequency - Switching
1.4MHz
Voltage - Input
3 ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
*
Package / Case
28-TQFN Exposed Pad
Voltage - Supply
3 V ~ 5.5 V
Frequency-max
1.4MHz
Duty Cycle
100%
Pwm Type
Current Mode
Buck
Yes
Boost
No
Flyback
No
Inverting
No
Doubler
No
Divider
No
Cuk
No
Isolated
No
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX1536 constant-off-time, pulse-width-modulated
(PWM) step-down DC-to-DC converter is ideal for use in
+5.0V and +3.3V to low voltages for notebook and sub-
notebook computers. The MAX1536 features an internal
PMOS power switch and internal synchronous rectifica-
tion for high efficiency and reduced component count. No
external Schottky diode is required across the internal
synchronous rectifier switch. The internal 54mΩ PMOS
power switch and 47mΩ NMOS synchronous-rectifier
switch easily deliver continuous load currents up to 3.6A.
The MAX1536 produces dynamically adjustable output
voltages for chipsets and graphics processor cores using
a logic-level control signal. The MAX1536 achieves effi-
ciencies as high as 96%.
The MAX1536 uses a unique current-mode, constant-off-
time, PWM control scheme. It has selectable Idle
Mode
operation, or fixed-PWM mode for low output ripple. The
programmable constant-off-time architecture allows a
wide range of switching frequencies up to 1.4MHz, opti-
mizing performance trade-offs between efficiency, output
switching noise, component size, and cost. The
MAX1536 features a digital soft-start to limit surge cur-
rents during startup, a 100% duty-cycle mode for low-
dropout operation, and a low-power shutdown mode that
disconnects the input from the output and reduces supply
current below 1µA. The MAX1536 is available in a 28-pin
thin QFN package with an exposed backside pad.
19-2729; Rev 1; 8/05
Chipset/Graphics Cores
with Dual-Supply Voltages
Active Termination Buses
Idle Mode is a trademark of Maxim Integrated Products, Inc.
________________________Applications
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.
Down Regulator with Dynamic Output Voltage Control
TM
TOP VIEW
A "+" SIGN WILL REPLACE THE FIRST PIN INDICATOR ON LEAD-FREE PACKAGES.
to maintain high efficiency during light-load
3.6A, 1.4MHz, Low-Voltage, Internal-Switch Step-
22
23
24
25
26
27
28
________________________________________________________________ Maxim Integrated Products
21
1
20
2
General Description
EXPOSED PADDLE
19
3
THIN QFN
MAX1536
Pin Configuration
18
4
Notebook Computers
DDR Memory Termination
17
5
16
6
15
7
14
13
12
11
10
9
8
♦ Dynamically Selectable Output Voltage from
♦ Internal PMOS/NMOS Switches
♦ +3.0V to +5.5V Input Voltage Range
♦ 1.4MHz Maximum Switching Frequency
♦ 2V ±0.75% Reference Output
♦ Constant-Off-Time PWM Operation
♦ Selectable Idle Mode/PWM Operation at Light
♦ 100% Duty Factor in Dropout
♦ Digital Soft-Start Inrush Current Limiting
♦ <1µA Typical Shutdown Supply Current
♦ <750µA Quiescent Supply Current
♦ Thermal Shutdown
♦ 1% V
♦ External Reference Input
♦ Power-Good Window Comparator
♦ Selectable Power-Good Blanking Time During
+Denotes lead-free package.
MAX1536ETI
MAX1536ETI+
+0.7V to V
Loads
Output-Voltage Transition
54mΩ/47mΩ On-Resistance at V
63mΩ/53mΩ On-Resistance at V
+3.0V TO +5.5V
PART
V
OUT
IN
Accuracy Over Line and Load
IN
Minimal Operating Circuit
-40
-40
TEMP RANGE
o
o
IN
V
SHDN
COMP
PGOOD
TOFF
SKIP
C to +85
C to +85
CC
Ordering Information
MAX1536
o
o
C
C
PGND
AGND
REFIN
PIN-PACKAGE
28 Thin QFN 5mm x 5mm
28 Thin QFN 5mm x 5mm
REF
LX
FB
IN
IN
Features
= +4.5V
= +3.0V
+0.7V TO V
V
OUT
IN
1

Related parts for MAX1536ETI+

MAX1536ETI+ Summary of contents

Page 1

... Typical Shutdown Supply Current ♦ <750µA Quiescent Supply Current ♦ Thermal Shutdown ♦ OUT ♦ External Reference Input ♦ Power-Good Window Comparator ♦ Selectable Power-Good Blanking Time During Output-Voltage Transition PART MAX1536ETI MAX1536ETI+ +Denotes lead-free package +3.0V TO +5. ...

Page 2

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control ABSOLUTE MAXIMUM RATINGS , IN, SHDN, SKIP to AGND ................................-0. OD, OD, GATE, PGOOD to AGND...........................-0.3V to +6V COMP, FB, REF to AGND.........................................-0.3V to ...

Page 3

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure SHDN IN CC values are +25°C.) A PARAMETER SYMBOL ...

Page 4

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control ELECTRICAL CHARACTERISTICS (Circuit of Figure +3.3V, V SHDN IN CC PARAMETER SYMBOL PWM CONTROLLER Input Voltage ...

Page 5

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control ELECTRICAL CHARACTERISTICS (continued) (Circuit of Figure SHDN IN CC PARAMETER SYMBOL INPUTS AND OUTPUTS V S HDN V Logic Input Threshold S ...

Page 6

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control (MAX1536 Circuit of Figure +25°C, unless otherwise noted.) A OUTPUT VOLTAGE vs. OUTPUT CURRENT (V = 3.3V 1.2µH) IN 1.806 R = 75kΩ ...

Page 7

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control (MAX1536 Circuit of Figure +25°C, unless otherwise noted.) A STARTUP AND SHUTDOWN (HEAVY LOAD) 400µs/div V = 3.3V 1.8V OUT LOAD ...

Page 8

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control PIN NAME 1, 21, Inductor Connection. Connection for the drains of the PMOS power switch and NMOS synchronous-rectifier LX 24, 26 switch. Connect all LX pins together. 2, ...

Page 9

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control Standard Application Circuit The MAX1536 standard application circuit (Figure 1) generates a dynamically adjustable output voltage typical of graphic processor core requirements. See Table 1 for component selections. ...

Page 10

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control V IN +3.0V TO +5.5V 10Ω 2.2µF 100kΩ POWER GOOD PWM MODE IDLE MODE ON OFF R TOFF 75kΩ Figure 1. MAX1536 Standard Application Circuit Table 1. Recommended ...

Page 11

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control Table 2. Component Manufacturers SUPPLIER Coilcraft Coiltronics Kemet Sanyo Sumida Taiyo Yuden TDK TOKO PGOOD REF PGOOD COMPARATOR REFIN OD OD GATE FBLANK Figure 2. MAX1536 Functional Diagram ...

Page 12

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control Shutdown ( Drive SHDN low to disable the MAX1536 and reduce the supply current to less than 1µA. In shutdown, all cir- cuitry and internal MOSFETs turn off, ...

Page 13

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control Thermal Shutdown The MAX1536 features a thermal fault-protection circuit. When the junction temperature rises above +165°C, a thermal sensor shuts down the MAX1536 regardless The ...

Page 14

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control   V OUT =     where REFIN Setting Dynamic Output Voltages ...

Page 15

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control = − µ TOFF OFF V is typically 1.1V and the recommended values TOFF for R range from 30.1kΩ to 499kΩ for ...

Page 16

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control Applications Information Multioutput Voltage Settings The MAX1536 is optimized to work in applications that require two dynamic output voltages; however, discrete logic or a DAC connected to REFIN ...

Page 17

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control The following points are in order of decreasing importance: 1) Minimize switched-current and high-current ground loops. Connect the input capacitor’s ground, the out- put capacitor’s ground, and PGND ...

Page 18

Low-Voltage, Internal-Switch Step- Down Regulator with Dynamic Output Voltage Control (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information www.maxim-ic.com/packages.) MARKING XXXXX PIN # 1 ...

Page 19

... 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 ____________________ 19 © 2005 Maxim Integrated Products ...

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