MAX1889ETE+ Maxim Integrated Products, MAX1889ETE+ Datasheet

IC PWR SUP TRPL LCD 16-TQFN

MAX1889ETE+

Manufacturer Part Number
MAX1889ETE+
Description
IC PWR SUP TRPL LCD 16-TQFN
Manufacturer
Maxim Integrated Products
Datasheet

Specifications of MAX1889ETE+

Applications
Controller, TFT, LCD
Voltage - Input
2.7 ~ 5.5 V
Number Of Outputs
3
Voltage - Output
2.7 ~ 13 V
Operating Temperature
0°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
16-TQFN Exposed Pad
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX1889 provides the three regulated output volt-
ages required for active matrix, thin-film transistor liquid
crystal displays (TFT LCDs). It combines a high-perfor-
mance step-up regulator with two linear-regulator con-
trollers and multiple levels of protection circuitry for a
complete power-supply system.
The main DC-DC converter is a high-frequency
(500kHz/1MHz), current-mode step-up regulator with
an integrated N-channel power MOSFET that allows the
use of ultra-small inductors and ceramic capacitors.
With its high closed-loop bandwidth performance, the
MAX1889 provides fast transient response to pulsed
loads while operating with efficiencies over 85%. The
positive and negative linear-regulator controllers post-
regulate charge-pump outputs for TFT gate-on and
gate-off supplies.
The MAX1889 has a unique input switch control that
can replace the typical input fuse by disconnecting the
load from the input supply when a fault is detected.
The fault detector monitors all three regulated output
voltages and can monitor current from the input supply
as well. Additionally, the MAX1889 enters thermal shut-
down when its overtemperature threshold is reached.
The MAX1889 undervoltage lockout is set at 2.5V (max)
to allow the input supply to droop under pulsed load
conditions while avoiding any unexpected behavior
when its input voltage dips momentarily. Also, the built-
in soft-start and cycle-by-cycle current limiting prevent
input surge currents during power-up.
The MAX1889 is available in a 16-pin thin QFN pack-
age with a maximum thickness of 0.8mm for ultra-thin
LCD panel design.
19-2485; Rev 1; 10/02
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.
Notebook Computer Displays
LCD Monitors
Car Navigation Displays
________________________________________________________________ Maxim Integrated Products
General Description
Triple-Output TFT LCD Power Supply
Applications
o High-Performance Step-Up Regulator
o Positive Linear-Regulator Controller
o Negative Linear-Regulator Controller
o Triple-Level Protection Against Smoke or Fire
o 2.7V to 5.5V Input Operating Range
o Ultra-Small External Components
o 1µA Shutdown Current (max)
o 1mA Quiescent Current (max)
o Ultra-Thin 16-Pin QFN Package
* Future product—Contact factory for availability.
MAX1889ETE
MAX1889EGE*
(0.8mm Maximum Thickness)
TOP VIEW
with Fault Protection
Fast Transient Response
Current-Mode Control Architecture
Built-In High-Efficiency N-Channel Power
MOSFET
Current-Limit Comparator
>85% Efficiency
Selectable Switching Frequency
(500kHz/1MHz)
Internal Soft-Start
Input Switch Replaces Input Fuse
Output Overload Detection with Timer Latch
Thermal Shutdown
PART
SHDN
PGND
GND
REF
1
2
3
4
- 40°C to + 85° C
- 40°C to + 85° C
TEMP RANGE PIN-PACKAGE
16
5
Ordering Information
(5mm x 5mm)
THIN QFN
15
MAX1889
6
Pin Configuration
14
7
16 Thi n Q FN ( 5m m
16 QFN ( 5m m
13
8
12
11
10
9
Features
TGND
LX
FREQ
FBP
5m m )
5m m )
1

Related parts for MAX1889ETE+

MAX1889ETE+ Summary of contents

Page 1

... LCD panel design. Notebook Computer Displays LCD Monitors Car Navigation Displays ________________________________________________________________ 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. with Fault Protection o High-Performance Step-Up Regulator ...

Page 2

Triple-Output TFT LCD Power Supply with Fault Protection ABSOLUTE MAXIMUM RATINGS IN, SHDN, OCN, OCP, FB, FBP, FBN, FREQ to GND ...............................-0.3V to +6V PGND to GND.....................................................................±0. PGND ............................................................-0.3V to +14V DRVP to GND .........................................................-0.3V to +30V REF, ...

Page 3

Triple-Output TFT LCD Power Supply ELECTRICAL CHARACTERISTICS (continued) = 3V, SHDN = IN 0.22µF, PGND = GND REF PARAMETER SYMBOL FBP Line Regulation Bandwidth DRVP Sink Current DRVP Off-Leakage Current NEGATIVE LINEAR-REGULATOR CONTROLLER FBN Regulation ...

Page 4

Triple-Output TFT LCD Power Supply with Fault Protection ELECTRICAL CHARACTERISTICS = 3V, SHDN = IN 0.22µF, PGND = GND REF PARAMETER SYMBOL IN Supply Range V IN ULVO Threshold V UVLO IN Quiescent Current I ...

Page 5

Triple-Output TFT LCD Power Supply ELECTRICAL CHARACTERISTICS (continued) = 3V, SHDN = IN 0.22µF, PGND = GND REF PARAMETER SYMBOL LOGIC SIGNAL (FREQ) Input Low Voltage Input High Voltage Input Current OVERCURRENT COMPARATOR Input Offset ...

Page 6

Triple-Output TFT LCD Power Supply with Fault Protection (Circuit of Figure +3.3V MAIN otherwise noted.) STEP-UP REGULATOR OUTPUT VOLTAGE vs. LOAD CURRENT (V = 13V) MAIN 13.1 13.0 12 2.7V IN 12.8 V ...

Page 7

Triple-Output TFT LCD Power Supply (Circuit of Figure +3.3V MAIN otherwise noted.) POWER-UP SEQUENCE FROM SLOW-RISING INPUT SUPPLY MAX1889 toc10 20V C 10V -10V 2ms/div A: ...

Page 8

Triple-Output TFT LCD Power Supply with Fault Protection (Circuit of Figure +3.3V MAIN otherwise noted.) POSITIVE CHARGE-PUMP INCREMENTAL EFFICIENCY vs. LOAD CURRENT 100 EFF = (V OUT ...

Page 9

Triple-Output TFT LCD Power Supply (Circuit of Figure +3.3V MAIN otherwise noted.) NEGATIVE LINEAR-REGULATOR LOAD-TRANSIENT RESPONSE MAX1889 toc22 -6.95V A - -10mA 400µs/div -7V, 50mV/div, AC-COUPLED ...

Page 10

Triple-Output TFT LCD Power Supply with Fault Protection PIN NAME Active-Low Shutdown Control Input. Pull SHDN below the 0.4V logic-low level to turn off all sections SHDN of the device and pull the GATE pin high. Pull SHDN above the ...

Page 11

Triple-Output TFT LCD Power Supply V IN 2. 51.1kΩ C22 10Ω 1000pF C1 0.47µF R3 150kΩ 1MΩ 1MΩ 0.1µ 3kΩ C9 2200pF 0.15µF 15kΩ 150kΩ ...

Page 12

Triple-Output TFT LCD Power Supply with Fault Protection REF REFERENCE 1.25V REF EN REFOK + - + UVLO 2.70V COMPARATOR 2.35V - ONP ONMN SEQUENCE AND FAULT DETECTOR THERMAL SHUTDOWN MAX1889 Figure 2. MAX1889 System Functional Diagram 12 ______________________________________________________________________________________ FREQ ...

Page 13

Triple-Output TFT LCD Power Supply Table 1. Component List DESIGNATION DESCRIPTION 3.3µF, 6.3V X5R ceramic capacitors (0805) C2, C3 Taiyo Yuden JMK212BJ335MG 4.7µF, 10V X7R ceramic capacitors (1210) C4, C5, C6 Taiyo Yuden LMK352BJ475MF 1.0A, 30V Schottky diode (S-flat) D1 ...

Page 14

Triple-Output TFT LCD Power Supply with Fault Protection Depending on the input-to-output voltage ratio, the reg- ulator controls the output voltage and the power deliv- ered to the output by modulating the duty cycle (D) of the power MOSFET in ...

Page 15

Triple-Output TFT LCD Power Supply Positive Linear-Regulator Controller The positive linear regulator provides the positive high voltage for the TFT LCD gate drivers. The high voltage can be produced using a charge-pump circuit as shown in Figure 1. Use as ...

Page 16

Triple-Output TFT LCD Power Supply with Fault Protection Power-Up Sequencing and Inrush Current Control Once SHDN is high, the MAX1889 enables the UVLO circuitry and compares the input voltage with the UVLO rising threshold (2.7V, typ). If the input voltage ...

Page 17

Triple-Output TFT LCD Power Supply The minimum inductance value, peak current rating, series resistance, and size are factors to consider when selecting the inductor. These factors influence the con- verter’s efficiency, maximum output load capability, transient response time, and output ...

Page 18

Triple-Output TFT LCD Power Supply with Fault Protection Therefore, the dominant pole and the RHP zero deter- mine the loop response of the step-up regulator. The fre- quency of the dominant pole is DOMINANT _ 2π where ...

Page 19

Triple-Output TFT LCD Power Supply The input capacitor (C ) reduces the current peaks IN drawn from the input supply and reduces noise injection into the device. Two 3.3µF ceramic capacitors are used in the standard application circuit (Figure 1) ...

Page 20

Triple-Output TFT LCD Power Supply with Fault Protection If the junction temperature is +100°C, the maximum on- state resistance overtemperature is Ω × + × 005 . 100 25 DS MAX ( ...

Page 21

Triple-Output TFT LCD Power Supply The number of negative charge-pump stages is given by DOPOUT = N NEG MAIN where N is the number of negative charge-pump NEG stages the ...

Page 22

Triple-Output TFT LCD Power Supply with Fault Protection The transistor’s current gain limits the guaranteed maxi- mum output current to:   LOAD MAX ( ) DRV  where I is the ...

Page 23

Triple-Output TFT LCD Power Supply To avoid excessive voltage coupling, a small capacitor can be added in parallel with the base resistor. The resulting RC time constant should be between 5µs to 50µs. Stability Requirements The MAX1889 linear-regulator controllers use ...

Page 24

Triple-Output TFT LCD Power Supply with Fault Protection Applications Information PC Board Layout Careful PC board layout is extremely important for proper operation. Use the following guidelines for good PC board layout: 1) Minimize the area of high-current loops by ...

Page 25

Triple-Output TFT LCD Power Supply Additional Application Circuits Operation with Output Voltage >13V The maximum output voltage of the step-up regulator is 13V, which is limited by the absolute maximum rating of the internal power MOSFET. To achieve higher output ...

Page 26

Triple-Output TFT LCD Power Supply with Fault Protection - Figure 10. Controlling Power-Up Sequence with External Delay If the voltage difference is less than 400mV, then the emitter of the ...

Page 27

Triple-Output TFT LCD Power Supply Figure 11. Disabling Input Protection MOSFET Switch ______________________________________________________________________________________ with Fault Protection GATE SWITCH IN STEP-UP CONTROL OCP REGULATOR OCN MAX1889 REF REF GND MAIN ...

Page 28

Triple-Output TFT LCD Power Supply with Fault Protection -7V Figure 12. Generating Gamma Reference Voltage 28 ______________________________________________________________________________________ STEP-UP REGULATOR DRVN MAX1889 NEGATIVE REGULATOR FBN POSITIVE REF REGULATOR REF GND V P ...

Page 29

Triple-Output TFT LCD Power Supply (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.) ______________________________________________________________________________________ with Fault Protection Package Information 29 ...

Page 30

Triple-Output TFT LCD Power Supply with Fault Protection (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.) 30 ______________________________________________________________________________________ Package Information (continued) ...

Page 31

Triple-Output TFT LCD Power Supply (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.) ______________________________________________________________________________________ with Fault Protection Package Information (continued) 31 ...

Page 32

... 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. 32 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Package Information (continued) Printed USA is a registered trademark of Maxim Integrated Products ...

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