Rainbow Electronics MAX8712 User Manual
General Description
The MAX8710/MAX8711/MAX8712 offer complete linear-regulator power-supply solutions for thin-film transistor (TFT) liquid-crystal-display (LCD) panels used in
LCD monitors and LCD TVs. All three devices include a
high-performance AVDD linear regulator, a positive
charge-pump regulator, a negative charge-pump regulator, and built-in power-up sequence control. The
MAX8710 and MAX8711 also include a high-current
operational amplifier. Additionally, the MAX8710 provides logic-controlled high-voltage switches to control
the positive charge-pump output.
The linear regulator directly steps down the input voltage to generate the supply voltage for the source-driver
ICs (AVDD). The two built-in charge-pump regulators
are used to generate the TFT gate-on and gate-off supplies. The high-current operational amplifier is typically
used to drive the LCD backplane (VCOM) and features
high output current (150mA), fast slew rate (12V/µs),
and wide bandwidth (12MHz). Its Rail-to-Rail®inputs
and output maximize flexibility.
The MAX8710 is available in a 24-pin thin QFN package,
the MAX8711 is available in a 16-pin thin QFN package,
and the MAX8712 is available in a 12-pin thin QFN package. All three packages are 4mm x 4mm with a maximum
thickness of 0.8mm for ultra-thin LCD panel design. They
operate over the -40°C to +100°C temperature range.
Applications
LCD Monitor Panel Modules
LCD TV Panel Modules
Features
♦ High-Performance Linear Regulator
1.6% Output Accuracy
Works with Small Ceramic Output Capacitors
Fast Transient Response
Foldback Current Limit
♦ 50mA Negative Regulated Charge Pump
♦ 20mA Positive Regulated Charge Pump with
Adjustable Delay
♦ Built-In Power-Up Sequence
♦ High-Current Operational Amplifier
(MAX8710/MAX8711)
±150mA Output Short-Circuit Current
12V/µs Slew Rate
12MHz, -3dB Bandwidth
Rail-to-Rail Inputs/Output
♦ Dual-Mode™ High-Voltage Switches (MAX8710)
♦ Thermal Protection
♦ Latched Fault Protection with Timer
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
________________________________________________________________ Maxim Integrated Products 1
FBN
SUPCP
DRVN
DLP
POSB
SUPB
OUTB
NEGB
MODE
CTL
GND
INL
OUTL
FBL
SHDN
DRVP
FBP
SRC
VGON
VP
AVDD
GON
DRN
THR
REF
IN
IN
VGOFF
CTL
AVDD
VCOM
REF
REF
AVDD
VIN
MAX8710
Minimum Operating Circuit
24
23
22
21
20
19
SRC
FBN
DLP
MODE
FBL
CTL
7
8
9
10
11
12
IN
OUTL
SUPCP
DRVN
DRVP
N.C.
13
14
15
16
17
18
GND
OUTB
SUPB
THR
FBP
SHDN
6
5
4
3
2
1
NEGB
INL
POSB
REF
DRN
GON
MAX8710
THIN QFN 4mm x 4mm
TOP VIEW
Pin Configurations
Ordering Information
PART
PIN-PACKAGE
MAX8710ETG
24 Thin QFN 4mm x 4mm
MAX8711ETE
16 Thin QFN 4mm x 4mm
MAX8712ETC
12 Thin QFN 4mm x 4mm
19-3174; Rev 0; 1/04
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.
Pin Configurations continued at end of data sheet.
EVALUATION KIT
AVAILABLE
Rail-to-Rail is a registered trademark of Motorola, Ltd. Dual Mode is a trademark of Maxim Integrated Products, Inc.
TEMP RANGE
-40°C to +100°C
-40°C to +100°C
-40°C to +100°C
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 27V, TA= 0°C to +85°C. Typical values are at TA=
+25°C, unless otherwise noted.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
CTL, FBL, FBP, FBN, SHDN, REF, THR to GND ......-0.3V to +6V
MODE, DLP to GND ....................................-0.3V to V
REF
+ 0.3V
IN, INL, OUTL (MAX8710) to GND.........................-0.3V to +28V
SUPCP, SUPB , OUTL (MAX8711, MAX8712)
to GND................................................................-0.3V to +14V
POSB, OUTB, NEGB to GND ....................-0.3V to V
SUPB
+ 0.3V
DRVN, DRVP to GND ..............................-0.3V to V
SUPCP
+ 0.3V
SRC to GND ...........................................................-0.3V to +30V
GON, DRN to GND......................................-0.3V to V
SRC
+ 0.3V
DRN to GON............................................................-30V to +30V
OUTB Maximum Continuous Output Current....................±75mA
DRVP RMS Output Current .................................................90mA
DRVN RMS Output Current..............................................-150mA
Continuous Power Dissipation (T
A
= +70°C)
24-, 16-, and 12-Pin Thin QFN 4mm x 4mm
(derate 16.9mW/°C above +70°C).............................1349mW
Operating Temperature Range .........................-40°C to +100°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER CONDITIONS
UNITS
IN Operating Supply Range 8 28 V
SHDN = GND 0.2 0.4
IN Quiescent Current
SHDN = 3.3V 2.5
mA
Duration to Trigger Fault Condition 2
16
oscillator clock cycles 44 ms
REF Output Voltage -10µA < I
REF
< 1mA (excluding internal load) 4.9 5.0 5.1 V
SUPCP Input Supply Range 2.7
V
Charge-Pump Regulators Operating
Frequency
kHz
Thermal Shutdown Rising temperature, 15°C hysteresis
°C
LINEAR REGULATOR
INL Operation Supply Range V
OUTL
< V
INL
728V
Dropout Voltage I
OUTL
= 50mA
300 mV
FBL Regulation Voltage I
OUTL
= 50mA
V
FBL Input Bias Current V
FBL
= 2.5V 50 nA
FBL Fault Trip Level Falling edge
V
V
INL
= V
IN
= 10.8V~13.2V, V
OUTL
= 10V,
I
OUTL
= 50mA
15
FBL Line-Regulation Error
V
INL
= V
IN
= 10V~28V, V
OUTL
= 9V, I
OUTL
= 50mA 10
mV
Bandwidth Guaranteed by design
kHz
Maximum OUTL Current V
FBL
= 2.4V
mA
OUTL Soft-Start Period 2
12
oscillator clock cycles in a 7-bit DAC 3 ms
OUTL Load Regulation V
IN
= 12V, 5mA < I
OUTL
< 300mA 2 %
OPERATIONAL AMPLIFIER
SUPB Supply Operating Range 4.5
V
SUPB Supply Current Buffer configuration, V
POSB
= 4V, no load 0.7 1.0 mA
Input Offset Voltage (V
NEGB
, V
POSB
) = V
SUPB
/ 2, TA = +25°C012mV
Input Bias Current (V
NEGB
, V
POSB
) = V
SUPB
/ 2 -50 +1
nA
MIN TYP MAX
1275 1500 1725
2.46 2.50 2.54
1.92 2.00 2.08
+160
150
1000
300
13.2
13.2
+50
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 27V, TA= 0°C to +85°C. Typical values are at TA=
+25°C, unless otherwise noted.)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
Common-Mode Input Range V
NEGB
, V
POSB
0
V
Common-Mode Rejection Ratio 0 ≤ (V
NEGB
, V
POSB
) < V
SUPB
50 90 dB
Open-Loop Gain
dB
I
OUTB
= 100µA
V
SUPB
-15V
SUPB
- 2
Output Voltage Swing High
I
OUTB
= 5mA
V
SUPB
-
V
SUPB
mV
I
OUTB
= -100µA 2 15
Output Voltage Swing Low
I
OUTB
= -5mA 80 150
mV
Short to V
SUPB
/ 2, sourcing 50
Short-Circuit Current
Short to V
SUPB
/ 2, sinking 50
mA
Output Current
Buffer configuration, V
POSB
= 4V,
V
OUTB
error < ±10mV
mA
Power-Supply Rejection Ratio
60
dB
Slew Rate 12 V/µs
-3dB Bandwidth Buffer configuration, RL = 10kΩ, CL = 10pF 12
MHz
Gain-Bandwidth Product Buffer configuration, RL = 10kΩ, CL = 10pF 8
MHz
POSITIVE CHARGE-PUMP REGULATOR
FBP Regulation Voltage I
GON
= 10mA
V
FBP Line-Regulation Error
V
OUTL
(V
SUPCP
, MAX8710) = 10.8V~13.2V,
V
GON
= 27V, I
GON
= 20mA
25 mV
FBP Input Bias Current V
FBP
= 2.5V -50
nA
DRVP P-Channel On-Resistance 15 30 Ω
V
FBP
= 2.4V 6 12 Ω
DRVP N-Channel On-Resistance
V
FBP
= 2.6V 20 kΩ
FBP Fault Trip Level Falling edge
V
Positive Charge-Pump Soft-Start
Period
2
12
oscillator clock cycles in a 7-bit DAC
ms
NEGATIVE CHARGE-PUMP REGULATOR
FBN Regulation Voltage I
GOFF
= 10mA
300 mV
FBN Input Bias Current V
FBN
= 250mV -50
nA
FBN Line Regulation
V
OUTL
(V
SUPCP
, MAX8710) = 10.8V~13.2V,
V
VGOFF
= -6V, I
GOFF
= -50mA
25 mV
DRVN P-Channel On-Resistance 7.5 15 Ω
V
FBN
= 350mV 3 6 Ω
DRVN N-Channel On-Resistance
V
FBN
= 150mV 20 kΩ
FBN Fault Trip Level Rising edge
mV
Negative Charge-Pump Soft-Start
Period
2
12
oscillator clock cycles in a 7-bit DAC
ms
6V ≤ V
SUPB
≤ 13.2V, DC (V
125
NEGB
, V
POSB
150
) = V
SUPB
/ 2
2.425 2.500 2.575
1.92 2.00 2.08
200 250
- 80
150
140
±40
100
2.73
700
2.73
V
SUPB
+50
+50
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 27V, TA= 0°C to +85°C. Typical values are at TA=
+25°C, unless otherwise noted.)
PARAMETER CONDITIONS
UNITS
SEQUENCE CONTROL
SHDN Input Low Voltage 0.6 V
SHDN Input High Voltage 2.0 V
SHDN Input Current 1µA
DLP Capacitor Charge Current During startup, V
DLP
= 1.0V 4 5 6 µA
DLP Turn-On Threshold
2.5
V
SHDN = low or fault tripped; DLP, FBP, FBN to GND 10 Ω
Pin Discharge Switch On-Resistance
SHDN = low or fault tripped;
MODE, OUTL, GON, OUTB to GND
1kΩ
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
CTL Input Low Voltage 0.6 V
CTL Input High Voltage 2.0 V
CTL Input Leakage Current -1 +1 µA
CTL to GON Rising Propagation
Delay
V
MODE
= V
REF
, 1.5nF from GON to GND, V
CTL
= 0V to
3V step, no load on GON, measured from V
CTL
= 1.5V
to GON = 20%
100 ns
CTL to GON Falling Propagation
Delay
V
MODE
= V
REF
, 1.5nF from GON to GND, V
CTL
= 3V to
0V step, DRN falling, no load on DRN and GON,
measured from V
CTL
= 1.5V to GON = 80%
100 ns
SRC Input Voltage Range 28 V
SRC Input Current V
MODE
= V
REF
, VDLP = 3V, CTL = high 150
µA
DRN Input Current
V
MODE
= V
REF
, VDRN = 8V, VDLP = 3V, VCTL = 0V 26 40 µA
SRC Switch On-Resistance V
MODE
= V
REF
, VDLP = 3V, CTL = high 15 30 Ω
DRN Switch On-Resistance V
MODE
= V
REF
, VDLP = 3V, VCTL = 0V 30 Ω
MODE Switch On-Resistance 1kΩ
Mode 2 MODE Capacitor Charge
Current
42 50 64 µA
MODE Voltage Threshold for
Enabling DRN Switch Control in
Mode 2
2.3 2.5 2.7 V
MODE Current-Source Stop Voltage
Threshold
V
MODE
rising edge 3.3 3.5 3.7 V
THR to GON Voltage Gain 9.4 10
V/V
GON Falling Slew Rate
V/µs
MIN TYP MAX
2.375
V
< MODE current-source stop voltage threshold
MODE
2.625
250
13.5
10.6
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 27V, TA= -40°C to +100°C, unless otherwise noted.)
(Note 1)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
REF Output Voltage -10µA < I
REF
< 1mA (excluding internal load) 4.9 5.1 V
SUPCP Input Supply Range 2.7
V
Charge-Pump Regulators Operating
Frequency
kHz
LINEAR REGULATOR
Dropout Voltage I
OUTL
= 50mA 300 mV
FBL Regulation Voltage I
OUTL
= 50mA
V
FBL Fault Trip Level Falling edge
V
FBL Line-Regulation Error
V
INL
= V
IN
= 10.8V~13.2V, V
OUTL
= 10V,
I
OUTL
= 50mA
15 mV
Maximum OUTL Current V
FBL
= 2.4V
mA
OUTL Load Regulation V
IN
= 12V, 5mA < I
OUTL
< 300mA 2 %
OPERATIONAL AMPLIFIER
SUPB Supply Current Buffer configuration, V
POSB
= 4V, no load 1.0 mA
Input Offset Voltage (V
NEGB
, V
POSB
) = V
SUPB
/ 2 14 mV
I
OUTB
= 100µA
V
SUPB
-
15
Output Voltage Swing High
I
OUTB
= 5mA
V
SUPB
-
mV
I
OUTB
= -100µA 15
Output Voltage Swing Low
I
OUTB
= -5mA 150
mV
Short to V
SUPB
/ 2, sourcing 50
Short-Circuit Current
Short to V
SUPB
/ 2, sinking 50
mA
POSITIVE CHARGE-PUMP REGULATOR
FBP Regulation Voltage I
GON
= 10mA
V
FBP Line-Regulation Error
V
OUTL
(V
SUPCP
, MAX8710) = 10.8V~13.2V,
V
GON
= 27V, I
GON
= 20mA
25 mV
FBP Input Bias Current V
FBP
= 3V -50 +50 nA
DRVP P-Channel On-Resistance 30 Ω
V
FBP
= 2.4V 12 Ω
DRVP N-Channel On-Resistance
V
FBP
= 2.6V 20 kΩ
NEGATIVE CHARGE-PUMP REGULATOR
FBN Regulation Voltage I
GOFF
= 10mA
300 mV
FBN Line Regulation
V
OUTL
(V
SUPCP
, MAX8710) = 10.8V~13.2V,
V
GOFF
= -6V, I
GOFF
= -50mA
25 mV
DRVN P-Channel On-Resistance 15 Ω
V
FBN
= 350mV 6 Ω
DRVN N-Channel On-Resistance
V
FBN
= 150mV 20 kΩ
13.2
1200 1850
2.455 2.545
1.96 2.04
300
150
2.425 2.575
200
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
6 _______________________________________________________________________________________
Note 1: Specifications to -40°C and +100°C are guaranteed by design, not production tested.
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 27V, TA= -40°C to +100°C, unless otherwise noted.)
(Note 1)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
SEQUENCE CONTROL
SHDN Input Low Voltage 0.6 V
SHDN Input High Voltage 2.0 V
DLP Capacitor Charge Current During startup, V
DLP
= 1.0V 4 6 µA
DLP Turn-On Threshold
V
POSITIVE GATE-DRIVER TIMING AND CONTROL SWITCHES
SRC Input Current V
MODE
= V
REF
, V
DLP
= 3V, CTL = high 250 µA
DRN Input Current V
MODE
= V
REF
, V
DRN
= 8V, V
DLP
= 3V, V
CTL
= 0V 40 µA
SRC Switch On-Resistance V
MODE=VREF
, V
DLP
= 3V, CTL = high 30 Ω
Mode 2 MODE Capacitor Charge
Current
42 64 µA
MODE Voltage Threshold for
Enabling DRN Switch Control in
Mode 2
2.3 2.7 V
Typical Operating Characteristics
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 10V, TA= 0°C to +85°C. Typical values are at TA=
+25°C, unless otherwise noted.)
LINEAR-REGULATOR LINE REGULATION
MAX8710/11/12 toc01
INPUT VOLTAGE (V)
OUTPUT VOLTAGE ERROR (%)
2624222018161412
-4
-3
-2
-1
0
1
-5
10 28
V
OUTL
= 10V
I
OUTL
= 50mA
I
OUTL
= 300mA
LINEAR-REGULATOR LOAD REGULATION
MAX8710/11/12 toc02
LOAD CURRENT (mA)
OUTPUT VOLTAGE ERROR (%)
10010
-1.0
-0.5
0
0.5
-1.5
11000
V
OUTL
= 10V
V
INL
= 12V
LINEAR-REGULATOR LOAD-TRANSIENT
RESPONSE
MAX8710/11/12 toc03
20µs/div
A
10V
B
0mA
A: V
OUTL
, 50mV/div, AC-COUPLED
B: I
OUTL
, 200mA/div
V
MODE
< MODE current-source stop voltage threshold
2.375 2.625
MAX8710/MAX8711/MAX8712
Low-Cost Linear-Regulator
LCD Panel Power Supplies
_______________________________________________________________________________________ 7
LINEAR-REGULATOR PULSED
LOAD-TRANSIENT RESPONSE
MAX8710/11/12 toc04
4µs/div
A
10V
B
0mA
A: V
OUTL
, 100mV/div, AC-COUPLED
B: I
OUTL
, 500mA/div
LINEAR-REGULATOR OVERCURRENT
PROTECTION
MAX8710/11/12 toc05
10ms/div
A
0V
B
0mA
A: V
OUTL
, 5V/div
B: I
OUTL
, 500mA/div
CHARGE-PUMP NO-LOAD SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX8710/11/12 toc06
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
131211109
1.6
1.7
1.8
1.9
2.0
1.5
814
POSITIVE CHARGE-PUMP LOAD
REGULATION
MAX8710/11/12 toc07
LOAD CURRENT (mA)
OUTPUT VOLTAGE ERROR (%)
4020 3010
-1.5
-1.0
-0.5
0
0.5
-2.0
050
INPUT = 12V
POSITIVE CHARGE-PUMP
LINE REGULATION
MAX8710/11/12 toc08
INPUT VOLTAGE (V)
OUTPUT VOLTAGE ERROR (%)
131211
-0.8
-0.6
-0.4
-0.2
0
0.2
-1.0
10 14
20mA LOAD CURRENT
NEGATIVE CHARGE-PUMP LOAD
REGULATION
MAX8710/11/12 toc09
LOAD CURRENT (mA)
OUTPUT VOLTAGE ERROR (%)
60 8020 40
-1.00
-0.75
-0.50
-0.25
0.25
0
-1.25
0100
V
GOFF
= -5V
INPUT = 12V
NEGATIVE CHARGE-PUMP LINE
REGULATION
MAX8710/11/12 toc10
INPUT VOLTAGE (V)
OUTPUT VOLTAGE ERROR (%)
1312111098
-0.8
-0.6
-0.4
-0.2
0
0.2
-1.0
714
V
GOFF
= -5V
I
GOFF
= 50mA
POWER-UP SEQUENCE
MAX8710/11/12 toc11
10ms/div
A
0V
0V
C
B
0V
A: V
OUTL
, 10V/div
B: V
GOFF
, 5V/div
C: V
GON
, 10V/div
SWITCH CONTROL FUNCTION (MODE 1)
MAX8710/11/12 toc12
20µs/div
A
0V
0V
C
B
0V
A: V
GON
, 10V/div
B: V
MODE
, 5V/div
C: V
CTL
, 5V/div
C
GON
= 1.5nF
Typical Operating Characteristics (continued)
(Circuit of Figure 1. VIN= V
INL
= V
SUPCP
= 12V, V
OUTL
= V
SUPB
= 10V, V
SRC
= 10V, TA= 0°C to +85°C. Typical values are at TA=
+25°C, unless otherwise noted.)
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