19-4425; Rev 1; 5/09
KIT
ATION
EVALU
BLE
AVAILA
Internal-Switch Boost Regulator with
High-Voltage Level Shifter for TFT LCDs
General Description
The MAX17088 includes a high-performance, step-up
regulator; a high-speed operational amplifier; a digitally
adjustable VCOM calibration device with nonvolatile
memory; an I
2
C interface; and a high-voltage, level-shift-
ing scan driver. The device is optimized for thin-film
transistor (TFT) liquid-crystal display (LCD) applications.
The MAX17088 is the successor to the MAX8798.
The step-up DC-DC converter provides the regulated
supply voltage for panel source driver ICs. The convert-
er is a 1.2MHz current-mode regulator with an integrat-
ed 20V n-channel power MOSFET. The high switching
frequency allows the use of ultra-small inductors and
ceramic capacitors. The current-mode control architec-
ture provides fast transient response to pulsed loads
typical of source driver loads. The step-up regulator
features soft-start and current limit.
The high-current operational amplifier is designed to drive
the LCD backplane (VCOM). The amplifier features high
output current (±150mA), fast slew rate (45V/µs), wide
bandwidth (20MHz), and rail-to-rail inputs and outputs.
The programmable VCOM calibrator is externally
attached to the VCOM amplifier’s resistive voltage-divider
and sinks a programmable current to adjust the VCOM
output-voltage level. An internal 7-bit digital-to-analog
converter (DAC) controls the sink current. The DAC is
ratiometric relative to BOOST and is guaranteed to be
monotonic over all operating conditions. The calibrator IC
includes an MTP to store the desired VCOM voltage
level. The 2-wire, I
2
C interface between the LCD panel
and the programming circuit minimizes panel connector
lead count and simplifies production equipment.
The high-voltage, level-shifting scan driver is designed
to drive the TFT panel gate drivers. Its three outputs
swing 65V (maximum) between +45V (maximum) and
-25V (minimum) and can swiftly drive capacitive loads.
To save power, the two complementary outputs are
designed to allow charge sharing during state changes.
The MAX17088 is available in a 36-pin (6mm x 6mm),
thin QFN package with a maximum thickness of 0.8mm
for ultra-thin LCD panels.
Features
o
1.8V to 5.5V IN Supply Voltage Range
o
1.8V to 4.0V V
DD
Input Voltage Range
o
1.2MHz Current-Mode Step-Up Regulator
Fast Transient Response
High-Accuracy Output Voltage (1.5%)
Built-In 20V, 1.9A, 150mΩ MOSFET
High Efficiency (> 85%)
Digital Soft-Start
o
High-Speed (20MHz) Operational Amplifier
±150mA Output Current
40V/µs Slew Rate
o
High-Voltage Drivers with Scan Logic
+45V to -25V Outputs
Output Charge Sharing
o
Programmable VCOM Calibrator
7-Bit Adjustable Current-Sink Output
I
2
C Interface
MTP Adjustment Memory
o
Thermal-Overload Protection
MAX17088
Simplified Operating Circuit
VN
VP
V
IN
V
MAIN
50kΩ
SHDN
IN
LX
DISH
1kΩ
CPV
SYSTEM
OE
STV
OECON
SCAN DRIVER
LOGIC
AND
GATE DRIVERS
1.9A
STEP-UP
REG
PGND
FB
COMP
AGND
GON
BOOST
NEG
VN
GOFF
STVP
CKVCS
VP
PANEL
CKVB
CKVBCS
VCOM
TO VCOM
BACKPLANE
Applications
Notebook Computer Displays
LCD Monitor Panels
VIN
CKV
VL
V
DD
3.3V
LINEAR
REG
VCOM CALIBRATOR
7
POS
BGND
OUT
GND
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
I
2
C
BUS
SDA
SCL
SCLS
WPP
WPN
SET
MAX17088ETX+
-40°C to +85°C
36 Thin QFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
MAX17088
________________________________________________________________
Maxim Integrated Products
1
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.
Internal-Switch Boost Regulator with
High-Voltage Level Shifter for TFT LCDs
MAX17088
ABSOLUTE MAXIMUM RATINGS
IN, VL,
SHDN
to AGND .........................................-0.3V to +7.5V
V
DD
, SDA, SCL, SCLS, WPN, WPP, SET to GND...-0.3V to +4.0V
OECON, CPV, OE, STV to AGND..........................-0.3V to +4.0V
COMP, FB to AGND ......................................-0.3V to (V
L
+ 0.3V)
DISH to GND ....................................................-6V to (V
L
+ 0.3V)
LX to PGND ............................................................-0.3V to +20V
OUT, VCOM, NEG, POS to BGND........-0.3V to (BOOST + 0.3V)
PGND, BGND, AGND to GND...............................-0.3V to +0.3V
GON to AGND ........................................................-0.3V to +50V
GOFF to AGND .............................................-30V to (V
IN
+ 0.3V)
GON to GOFF ......................................................................+70V
BOOST to BGND ....................................................-0.3V to +20V
CKV, CKVB, STVP, CKVCS,
CKVBCS to AGND..................(GOFF - 0.3V) to (GON + 0.3V)
LX, PGND RMS Current Rating.............................................2.4A
Continuous Power Dissipation (T
A
= +70°C)
NiPd Lead Frame with Nonconductive Epoxy
36-Pin, 6mm x 6mm Thin QFN
(derate 27.2mW/°C above +70°C) .........................2179.8mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= V
DD
= V
SHDN
= +3V, circuit of Figure 2, V
BOOST
= 8V, V
GON
= 23V, V
GOFF
= -12V, V
POS
= 0, V
NEG
= 1.5V, V
OE
= V
CPV
=
V
STV
= V
OECON
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
V
DD
Input Voltage Range
V
DD
Quiescent Current
V
DD
Undervoltage Lockout
IN Input Voltage Range
IN Quiescent Current
IN Undervoltage Lockout
Thermal Shutdown
VL Output Voltage
VL Undervoltage Lockout
VL Maximum Output Current
MAIN DC-DC CONVERTER
BOOST Supply Current
Operating Frequency
Oscillator Maximum Duty Cycle
FB Regulation Voltage
FB Load Regulation
FB Line Regulation
FB Input Bias Current
FB Transconductance
FB Voltage Gain
FB Fault Timer Trip Threshold
LX On-Resistance
LX Leakage Current
LX Current Limit
Current-Sense Transresistance
Soft-Start Period
0 < I
LOAD
< 200mA, transient only
V
IN
= 1.8V to 5.5V, FB to COMP
V
FB
= 1.25V, T
A
= +25°C
I = 5µA at COMP
FB to COMP
Falling edge
I
LX
= 1.2A, GOFF = GND
V
LX
= 18V, T
A
= +25°C
Duty cycle = 65%
1.6
0.25
0.96
-0.15
50
70
125
160
2400
1
150
0.01
1.9
0.42
3
1.04
300
20
2.2
0.55
LX not switching, no load on VL
LX switching, no load on VL
990
88
1.216
1.5
3
1170
92
1.235
-1
+0.15
200
280
2
4
1350
96
1.254
mA
kHz
%
V
%
%/V
nA
µS
V/V
V
m
µA
A
V/A
ms
V
DD
= 3V
V
DD
rising; typical hysteresis 200mV
(Note 1)
V
IN
= 3V, V
FB
= 1.5V, not switching
IN rising; typical hysteresis 100mV, GOFF = GND
Rising edge, hysteresis = 15
o
C
I
VL
= 100µA
VL rising, typical hysteresis 200mV
V
FB
= 1.1V
4.2
2.4
10
1.8
0.04
1.4
160
4.4
2.7
4.6
3.0
CONDITIONS
MIN
1.8
4
1.3
TYP
MAX
4.0
10
1.75
6.0
0.1
1.75
UNITS
V
µA
V
V
mA
V
o
C
BOOTSTRAP LINEAR REGULATOR (VL)
V
V
mA
2
_______________________________________________________________________________________
Internal-Switch Boost Regulator with
High-Voltage Level Shifter for TFT LCDs
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
DD
= V
SHDN
= +3V, circuit of Figure 2, V
BOOST
= 8V, V
GON
= 23V, V
GOFF
= -12V, V
POS
= 0, V
NEG
= 1.5V, V
OE
= V
CPV
=
V
STV
= V
OECON
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
OPERATIONAL AMPLIFIER
BOOST Supply Range
BOOST Overvoltage
Fault Threshold
BOOST Undervoltage
Fault Threshold
Large-Signal Voltage Gain
Common-Mode Rejection Ratio
Input Offset Voltage
Input Bias Current
Input Common-Mode
Voltage Range
VCOM Output-Voltage
Swing High
VCOM Output-Voltage Swing Low
VCOM Output-Current High
VCOM Output-Current Low
Slew Rate
-3dB Bandwidth
VCOM Short-Circuit Current
(Note 2)
(Note 3)
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
V
BOOST
/2
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V), T
A
= +25°C
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
I
VCOM
= 5mA
I
VCOM
= -5mA
V
VCOM
= V
BOOST
- 1V
V
VCOM
= 1V
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
1V < (V
NEG
, V
POS
) < (V
BOOST
- 1V)
Short to V
BOOST
/2, sourcing
Short to V
BOOST
/2, sinking
50
50
16.1
Rising edge, 60mV hysteresis, GOFF = GND
7
Monotonic overtemperature
-1
-1
-4
To GND, V
BOOST
= 18V
To GND, V
BOOST
= 6V
DAC full scale
When OUT is off
To ±0.5 LSB error band
V
SET
+
0.5V
(Note 5)
100
60
8.5
2.5
0.05
1
20
18
+1
+1
+2.5
+4
120
170.0
50.0
16
-25
-15
-50
0
V
BOOST
V
BOOST
- 100
- 50
50
-75
+75
40
20
150
150
45.0
16.5
100
5
18.1
19
1.0
120
75
-5
-2.5
+25
+12
+50
V
BOOST
18
19.9
1.4
V
V
V
dB
dB
mV
nA
V
mV
mV
mA
mA
V/µs
MHz
mA
CONDITIONS
MIN
TYP
MAX
UNITS
MAX17088
PROGRAMMABLE VCOM CALIBRATOR
GON Input Range
GON Threshold to Enable Program
SET Voltage Resolution
SET Differential Nonlinearity
SET Zero-Scale Error
SET Full-Scale Error
SET Current
SET External Resistance
(Note 4)
V
SET
/V
BOOST
Voltage Ratio
OUT Leakage Current
OUT Settling Time
OUT Voltage Range
MTP Write Cycles
MTP Write Time
V
V
Bits
LSB
LSB
LSB
µA
k
V/V
nA
µs
V
Times
ms
_______________________________________________________________________________________
3
Internal-Switch Boost Regulator with
High-Voltage Level Shifter for TFT LCDs
MAX17088
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
DD
= V
SHDN
= +3V, circuit of Figure 2, V
BOOST
= 8V, V
GON
= 23V, V
GOFF
= -12V, V
POS
= 0, V
NEG
= 1.5V, V
OE
= V
CPV
=
V
STV
= V
OECON
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
2-WIRE INTERFACE
Logic-Input Low Voltage (V
IL
)
Logic-Input High Voltage (V
IH
)
WPP Logic-Output Low Voltage
WPP Logic-Output High Voltage
GOFF = GND for SDA, SCL,
GOFF = -12V for WPN
GOFF = GND for SDA, SCL,
GOFF = -12V for WPN
I
WPP
= 1mA
I
WPP
= 1mA
V
DD
-
0.1
6
-1
5
DC
600
1300
C
b
= total capacitance of bus line in pF (Note 5)
C
b
= total capacitance of bus line in pF (Note 5)
10% of SDA to 90% of SCL
20 + 0.1
x C
b
20 + 0.1
x C
b
600
600
T
A
= +25°C
0
100
(Note 5)
600
1300
SDA, SCL (Note 5)
WPN = GND
WPN = V
DD
12
-25
V
GON
- V
GOFF
STV, CPV, OE, OECON = AGND
STV, CPV, OE, OECON = AGND
CKV, CKVB, STVP, -1mA output current
CKV, CKVB, STVP, +1mA output current
V
GOFF
+ 0.04
360
275
V
GOFF
+ 0.02
V
GON
- 0.035
50
V
GON
- 0.06
100
1
20
100
45
-2
65
550
400
V
V
V
µA
µA
V
V
ns
250
300
300
500
+1
0.7 x
V
DD
+0.1
0.3 x
V
DD
V
V
V
V
mA
µA
pF
kHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
M
CONDITIONS
MIN
TYP
MAX
UNITS
SDA Logic-Output Low Sink Current SDA forced to 3.3V, GOFF = GND
Logic Input Current
Input Capacitance
SCL Frequency (f
CLK
)
SCL High Time (t
CLH
)
SCL Low Time (t
CLL
)
SDA, SCL, SCLS Rise Time (t
R
)
SDA, SCL, SCLS Fall Time (t
F
)
S
START Condition Setup Time
(t
SVSTT
)
Data Input Hold Time (t
HDDAT
)
Data Input Setup Time (t
SUDAT
)
STOP Condition Setup Time
(t
SVSTP
)
Bus Free Time (t
UF
)
Input Filter Spike Suppression (t
SP
)
SCL - SCLS Switch Resistance
HIGH-VOLTAGE SCAN DRIVER
GON Input Voltage Range
GOFF Input Voltage Range
GON to GOFF
GON Supply Current
GOFF Supply Current
Output-Voltage Low
Output-Voltage High
SDA, SCL, SCL_S, WPN to V
DD
or GND, T
A
= +25°C
SDA, SCL, SCL_S
Propagation Delay Between OE
V
CPV
= 0, V
STV
= 0, C
LOAD
= 4.7nF, 50 , OE = 100kHz;
Rising Edge and CKV/CKVB Edge charge-sharing resistors = 500
4
_______________________________________________________________________________________
Internal-Switch Boost Regulator with
High-Voltage Level Shifter for TFT LCDs
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= V
DD
= V
SHDN
= +3V, circuit of Figure 2, V
BOOST
= 8V, V
GON
= 23V, V
GOFF
= -12V, V
POS
= 0, V
NEG
= 1.5V, V
OE
= V
CPV
=
V
STV
= V
OECON
= 0,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Output Slew Rate CKV, CKVB
Propagation Delay Between
STV and STVP
STVP Output Slew Rate
Charge-Sharing Discharge
Path Resistance
DISH Turn-On Threshold
STV, CPV, OE Input Low Voltage
STV, CPV, OE Input High Voltage
OECON Input Low Voltage
OECON Input High Voltage
OECON Sink Current
STV, CPV, OE
Input Current
V
OECON
= 5V = V
DD
V
STV
= V
DD
or GND,
V
CPV
= V
DD
or GND,
V
OE
= V
DD
or GND,
V
OECON
= V
DD
or GND, T
A
= +25°C
V
CKV
= GON or GOFF, high impedance
V
CKVB
= GON or GOFF, high impedance
V
CKVCS
= GON or GOFF, high impedance
V
CKVBCS
= GON or GOFF, high impedance
V
STVP
= GON or GOFF, high impedance
SHDN,
GOFF = GND
SHDN,
1.8V < V
IN
< 3.0V, GOFF = GND
SHDN,
3.0V < V
IN
< 5.5V
V
SHDN
= 0 or 3V, T
A
= +25°C
1.8
2.0
-1
+1
2.0
0.4
0.8
1.6
1.5
CONDITIONS
Without charge sharing,
STV = V
DD
, C
LOAD
= 4.7nF, 50 , R1 = R2 = 200
C
LOAD
= 4.7nF, STV = 100Hz, R = 200
C
LOAD
= 4.7nF, 50 , charge-sharing resistors = 200
CKV to CKVCS and CKVB to CKVBCS
Dish falling
MIN
TYP
30
50
200
50
100
-1.8
0.8
V
V
V
V
V
mA
100
MAX
UNITS
V/µs
ns
V/µs
MAX17088
-1
+1
µA
CKV, CKVB, STVP Output
High-Impedance Current
-1
+1
µA
CONTROL INPUTS
Input Low Voltage
Input High Voltage
SHDN
Input Current
0.6
V
V
µA
ELECTRICAL CHARACTERISTICS
(V
IN
= V
DD
= V
SHDN
= +3V, circuit of Figure 2, V
BOOST
= 8V, V
GON
= 23V, V
GOFF
= -12V, V
POS
= 0, V
NEG
= 1.5V, V
OE
= V
CPV
=
V
STV
= V
OECON
= 0,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 6)
PARAMETER
V
DD
Input Voltage Range
V
DD
Quiescent Current
V
DD
Undervoltage Lockout
IN Input Voltage Range
IN Quiescent Current
IN Undervoltage Lockout
V
DD
= 3V
V
DD
rising; typical hysteresis 200mV
(Note 1)
V
IN
= 3V, V
FB
= 1.5V, not switching
V
IN
rising; typical hysteresis 100mV, GOFF = GND
1.8
CONDITIONS
MIN
1.8
TYP
MAX
4.0
10
1.75
6.0
0.1
1.75
UNITS
V
µA
V
V
mA
V
_______________________________________________________________________________________
5
测试/测量
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