MAX686EEE+ Maxim Integrated Products, MAX686EEE+ Datasheet

IC SUPPLY LCD BIAS INV 16-QSOP

MAX686EEE+

Manufacturer Part Number
MAX686EEE+
Description
IC SUPPLY LCD BIAS INV 16-QSOP
Manufacturer
Maxim Integrated Products
Type
Step-Up (Boost), Invertingr
Datasheet

Specifications of MAX686EEE+

Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
±27.5V
Current - Output
100mA
Frequency - Switching
300kHz
Voltage - Input
2.7 ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
16-QSOP
Power - Output
667mW
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX686 DAC-controlled boost/inverter IC converts
a positive input voltage to a positive or negative LCD
bias voltage up to +27.5V or -27.5V. The device features
an internal N-channel MOSFET switch, programmable
current limiting, and an internal 6-bit digital-to-
analog converter (DAC) for digital adjustment of the
output voltage. It comes in a small 16-pin QSOP pack-
age (same size as an 8-pin SO).
The MAX686 uses a current-limited, pulse-frequency-
modulation (PFM) control scheme to provide high effi-
ciency over a wide range of load conditions. Its high
switching frequency (up to 300kHz) allows the use of
small external components.
An LCDON output allows the LCD bias voltage to be
automatically disabled when the display logic voltage is
removed, protecting the display. The MAX686 has a
+2.7V to +5.5V input voltage range for the IC, and a
+0.8V to +27.5V input voltage range for the inductor.
Typical quiescent supply current is 65µA. Shutdown
current is 1.5µA.
The MAX686 offers high-level integration to save space,
reduce power consumption, and increase battery life,
making it an excellent choice for battery-powered
portable equipment. The MAX629 is similar to the
MAX686, except that it does not contain a built-in DAC.
Both devices have evaluation kits to facilitate designs.
19-1327; Rev 1; 2/98
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
TOP VIEW
Positive or Negative LCD Bias
Personal Digital Assistants
Notebook Computers
Portable Data-Collection Terminals
Palmtop Computers
Varactor Tuning Diode Bias
DACOUT
PGND
SHDN
ISET
POL
V
DN
UP
DD
________________________________________________________________ Maxim Integrated Products
1
2
3
4
5
6
7
8
General Description
LCD Bias Supply with Internal Switch
MAX686
QSOP
Pin Configuration
Applications
16
15
14
13
12
11
10
9
LX
N.C.
LCDON
GND
V
POK
FB
REF
CC
DAC-Controlled Boost/Inverter
*
Functional Diagram appears at end of data sheet.
____________________________Features
Dice are specified at T
DAC CONTROL
V
V
MAX686C/D
MAX686EEE
0.1 F
CC
IN
Internal 500mA, 28V N-Channel Switch
(no external FET required)
Adjustable Output Voltage to +27.5V or -27.5V
6-Bit DAC-Controlled Output Voltage
Up to 90% Efficiency
Small 16-Pin QSOP Package
Power-OK Indicator
65µA Quiescent Current
1.5µA Shutdown Current
Up to 300kHz Switching Frequency
= 0.8V TO 27.5V
= 2.7V TO 5.5V
(Same size as 8-pin SO)
PART
ON/OFF
V
V
UP
DN
SHDN
POL
Typical Operating Circuit
CC
DD
GND
TEMP. RANGE
-40°C to +85°C
MAX686
A
22 H
0°C to +70°C
= +25°C, DC parameters only.
Ordering Information
DACOUT
LCDON
PGND
ISET
POK
REF
LX
FB
MBR0530L
R3
Dice*
16 QSOP
PIN-PACKAGE
0.1 F
R1
R2
V
OUT
1

Related parts for MAX686EEE+

MAX686EEE+ Summary of contents

Page 1

... ISET 6 SHDN 7 DACOUT 8 QSOP ________________________________________________________________ Maxim Integrated Products For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. DAC-Controlled Boost/Inverter ____________________________Features Internal 500mA, 28V N-Channel Switch (no external FET required) Adjustable Output Voltage to +27.5V or -27.5V ...

Page 2

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch ABSOLUTE MAXIMUM RATINGS Voltage , ISET, POK, POL, SHDN UP, DN GND ...........................................-0.3V to +6V DD FB, REF, DACOUT to GND.......................-0. PGND to GND .....................................................-0.3V to ...

Page 3

LCD Bias Supply with Internal Switch ELECTRICAL CHARACTERISTICS (continued +5V 0.1µ REF PARAMETER SYMBOL REFERENCE AND FB INPUT REF Output Voltage REF Load Regulation FB Set Point FB ...

Page 4

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch ELECTRICAL CHARACTERISTICS ( +5V 0.1µ REF PARAMETER SYMBOL Supply Voltage (Note Input Voltage V Supply Current I + ...

Page 5

LCD Bias Supply with Internal Switch __________________________________________Typical Operating Characteristics (Circuits of Figures 1 and EFFICIENCY vs. LOAD CURRENT (V = +24V) OUT ...

Page 6

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch _____________________________Typical Operating Characteristics (continued) (Circuits of Figures 1 and LINE-TRANSIENT RESPONSE (ISET = ...

Page 7

LCD Bias Supply with Internal Switch _____________________________Typical Operating Characteristics (continued) (Circuits of Figures 1 and POWER-UP RESPONSE (NEGATIVE CONFIGURATION) SHDN 5V/div V OUT 5V/div SET 4.7k L 500 ...

Page 8

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch V = 0.8V TO 27. 2.7V TO 5.5V CC 0.1 F DAC CONTROL ON/OFF Figure 1. Boost Configuration: Positive Output Voltage V = 0.8V TO 27.5V IN ...

Page 9

LCD Bias Supply with Internal Switch V = 0.8V TO 27. 2.7V TO 5.5V CC 0.1 F DAC CONTROL Figure 3. Alternative Negative Output Voltage Application Circuit Detailed Description The MAX686 is a step-up converter ...

Page 10

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch Power-OK Comparator POK is the input to the power-OK comparator. The comparator drives an internal N-channel MOSFET. The MOSFET’s open-drain output, LCDON, can drive an external PNP transistor or P-channel MOSFET, switch- ...

Page 11

LCD Bias Supply with Internal Switch Note that for a positive output voltage decreases. V DACOUT OUT(MAX 0V, and V DACOUT OUT(MIN 1.25V. DACOUT Setting the Minimum Negative Output Voltage For a negative ...

Page 12

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch 0. 27. 2. 5.5V 0.1 F MAX686 DACOUT FB Figure 4. Feed-Forward Capacitor Table 1. Component Suppliers ...

Page 13

LCD Bias Supply with Internal Switch MBR0530L 0. 27. DACOUT LCDON FB R4 MAX686 POK R5 GND Figure 6. Using the POK for Input Voltage Monitoring Feed-Forward Capacitors Parallel a ...

Page 14

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch 2. 5. MAX686 100 DACOUT Figure 8. Using a Common Supply-Voltage Source R6 turns it ...

Page 15

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch BIAS DD GND UP DIGITAL 6-BIT DN INTERFACE DAC SHDN POL REF REFERENCE 1.25V ERROR FB AMP 1.125V POK POK COMPARATOR ______________________________________________________________________________________ Functional Diagram MAX686 BANDGAP 1.125V ON-TIME/ OFF-TIME ...

Page 16

DAC-Controlled Boost/Inverter LCD Bias Supply with Internal Switch 16 ______________________________________________________________________________________ Chip Information TRANSISTOR COUNT: 1325 SUBSTRATE CONNECTED TO GND ...

Related keywords