MAX17126BETM+T ,Multi-Output Power Supplies with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVsFeaturesThe MAX17126B generates all the supply rails for thin- S 8.0V to 16.5V IN Supply Voltage Ra ..
MAX17126ETM+ ,Multi-Output Power Supplies with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVsFeaturesThe MAX17126/MAX17126A generate all the supply rails S 8.0V to 16.5V IN Supply-Voltage Rang ..
MAX17126ETM+T ,Multi-Output Power Supplies with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVsELECTRICAL CHARACTERISTICS(Circuit of Figure 1, V = V = 12V, V = V = 15V, T = 0°C to +85°C. Typical ..
MAX17126ETM+TC49 ,Multi-Output Power Supplies with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVsfeatures high output cur-S 48-Pin, 7mm x 7mm, Thin QFN Packagerent (Q200mA), fast slew rate (45V/Fs ..
MAX17129ETE+ ,Low-Cost, 6-String WLED Drivers with Quick-PWM Step-Up Convertersapplications that can trade off component size for operating frequency. Low feedback voltage at eac ..
MAX1712EEG ,High-Speed, Digitally Adjusted Step-Down Controllers for Notebook CPUsFeaturesThe MAX1710/MAX1711 step-down controllers are♦ Ultra-High Efficiency intended for core CPU ..
MAX4541CUA+ ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesMAX4541–MAX454419-1202; Rev 4; 6/07Low-Voltage, Single-Supply Dual SPST/SPDT Analog Switches
MAX4541EKA+T ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesApplicationsMAX4541CSA 0°C to +70°C 8 SO —Battery-Operated Systems Test EquipmentMAX4541CPA 0°C ..
MAX4541EKA-T ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesMAX4541–MAX454419-1202; Rev 3; 8/02Low-Voltage, Single-Supply Dual SPST/SPDT Analog Switches
MAX4541ESA ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesMAX4541–MAX454419-1202; Rev 3; 8/02Low-Voltage, Single-Supply Dual SPST/SPDT Analog Switches
MAX4541ESA+ ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesFeatures♦ 60Ω max (33Ω typ) Low RONThe MAX4541–MAX4544 are precision, dual analogswitches designed ..
MAX4541EUA ,Low-Voltage, Single-Supply Dual SPST/SPDT Analog SwitchesELECTRICAL CHARACTERISTICS—Single +5V Supply(V+ = +5V ±10%, GND = 0, V = 2.4V, V = 0.8V, T = T to T ..
MAX17126BETM+T
Multi-Output Power Supplies with VCOM Amplifier and High-Voltage Gamma Reference for LCD TVs
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
EVALUATION KIT AVAILABLE General Description
The MAX17126B generates all the supply rails for thin-
film transistor liquid-crystal display (TFT LCD) TV panels
operating from a regulated 12V input. They include a
step-down and a step-up regulator, a positive and a
negative charge pump, an operational amplifier, a high-
accuracy high-voltage gamma reference, and a high-
voltage switch control block. The device can operate
from input voltages from 8V to 16.5V and is optimized
for an LCD TV panel running directly from 12V supplies.
The step-up and step-down switching regulators feature
internal power MOSFETs and high-frequency opera-
tion allowing the use of small inductors and capacitors,
resulting in a compact solution. The step-up regulator
provides TFT source driver supply voltage, while the
step-down regulator provides the system with logic sup-
ply voltage. Both regulators use fixed-frequency current-
mode control architectures, providing fast load-transient
response and easy compensation. A current-limit func-
tion for internal switches and output-fault shutdown
protects the step-up and step-down power supplies
against fault conditions. The device provides soft-start
functions to limit inrush current during startup. In addi-
tion, the device integrates a control block that can drive
an external p-channel MOSFET to sequence power to
source drivers.
The positive and negative charge-pump regulators pro-
vide TFT gate-driver supply voltages. Both output volt-
ages can be adjusted with external resistive voltage-
dividers. A logic-controlled, high-voltage switch block
allows the manipulation of the positive gate-driver supply.
The device includes one high-current operational ampli-
fier designed to drive the LCD backplane (VCOM). The
amplifier features high output current (Q200mA), fast
slew rate (45V/Fs), wide bandwidth (20MHz), and rail-to-
rail outputs.
Also featured in the device is a high-accuracy, high-
voltage adjustable reference for gamma correction.
The device is available in a small (7mm x 7mm), ultra-thin
(0.8mm), 48-pin TQFN package and operates over the
-40NC to +85NC temperature range.
Applications
LCD TV Panels
Features
S 8.0V to 16.5V IN Supply Voltage Range
S Selectable Frequency (500kHz/750kHz)
S Current-Mode Step-Up Regulator
Fast Load-Transient Response
High-Accuracy Output Voltage (1.0%)
Built-In 20V, 3.5A, 100mI MOSFET
High Efficiency
Adjustable Soft-Start
Adjustable Current Limit
Low Duty-Cycle Operation (13.2VIN - 13.5V AVDD)
S Current-Mode Step-Down Regulator
Fast Load-Transient Response
Built-In 20V, 3.2A, 100mI MOSFET
High Efficiency
3ms Internal Soft-Start
S Adjustable Positive Charge-Pump Regulator
S Adjustable Negative Charge-Pump Regulator
S Integrated High-Voltage Switch with Adjustable
Turn-On Delay
S High-Speed Operational Amplifier
±200mA Short-Circuit Current
45V/µs Slew Rate
S High-Accuracy Reference for Gamma Buffer
±1% Feedback Voltage
Up to 30mA Load Current
Low-Dropout Voltage 0.5V at 60mA
S External p-Channel Gate Control for AVDD
Sequencing
S XAO Comparator
S Input Undervoltage Lockout and Thermal-
Overload Protection
S 48-Pin, 7mm x 7mm, TQFN Package
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Ordering Information
Visit www.maximintegrated.com/products/patents for
PARTTEMP RANGEPIN-PACKAGE
MAX17126BETM+-40NC to +85NC48 TQFN-EP*
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
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.
INVL, IN2, VOP, EN, FSEL to GND .......................-0.3V to +24V
PGND, OGND, CPGND to GND ..........................-0.3V to +0.3V
DLY1, GVOFF, THR, VL to GND ..........................-0.3V to +7.5V
REF, FBP, FBN, FB1, FB2, COMP, SS, CLIM,
XAO, VDET, VREF_FB, OUT to GND .............-0.3V, (VL+ 0.3)
GD, GD_I to GND ..................................................-0.3V to +24V
LX1 to PGND .........................................................-0.3V to +24V
OPP, OPN, OPO to OGND .......................-0.3V to (VOP + 0.3V)
DRVP to CPGND ....................................-0.3V to (SUPP + 0.3V)
DRVN to CPGND ....................................-0.3V to (SUPN + 0.3V)
LX2 to PGND ................................................-0.7 to (IN2 + 0.3V)
SUPN to GND .............................................-0.3V to (IN2 + 0.3V)
SUPP to GND ..........................................-0.3V to (GD_I + 0.3V)
BST to VL ...............................................................-0.3V to +30V
VGH to GND ..........................................................-0.3V to +40V
VGHM, DRN to GND .....................................-0.3V, VGH + 0.3V
VGHM to DRN .......................................................-0.3V to +40V
VREF_I to GND ......................................................-0.3V to +24V
VREF_O to GND .......................................-0.3V, (VREF_I + 0.3)V
REF Short Circuit to GND ..........................................Continuous
RMS LX1 Current (total for both pins) ..................................3.2A
RMS PGND CURRENT (total for both pins) .........................3.2A
RMS IN2 Current (total for both pins) ..................................3.2A
RMS LX2 Current (total for both pins) ..................................3.2A
RMS DRVN, DRVP Current ..................................................0.8A
RMS VL Current ..................................................................50mA
Continuous Power Dissipation (TA = +70NC)
TQFN (derated 38.5mW/NC above +70NC) ............3076.9mW
Junction Temperature .....................................................+160NC
Storage Temperature Range ............................-65NC to +165NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, VINVL= VIN2 = 12V, VVOP = VVREF_I = 15V, TA = 0°C to +85°C. Typical values are at TA = +25NC, unless oth-
erwise noted.)
ABSOLUTE MAXIMUM RATINGS
PARAMETERCONDITIONSMINTYPMAXUNITS
GENERAL
INVL, IN2 Input Voltage Range816.5V
INVL + IN2 Quiescent CurrentOnly LX2 switching (VFB1 = VFBP = 1.5V, VFBN = 0V)
EN = VL, FSEL = high1020mA
INVL + IN2 Standby CurrentLX2 not switching (VFB1 = VFB2 = VFBP = 1.5V,
VFBN = 0V), EN = VL, FSEL = high245mA
SMPS Operating FrequencyFSEL = INVL or high impedance630750870kHzFSEL = GND420500580
INVL Undervoltage-Lockout
ThresholdINVL rising, 150mV typical hysteresis6.07.08.0V
VL REGULATOR
VL Output VoltageIVL = 25mA, VFB1 = VFB2 = VFBP = 1.1V, VFBN = 0.4V
(all regulators switching)4.8555.15V
VL Undervoltage-Lockout
ThresholdVL rising, 50mV typical hysteresis3.53.94.3V
REFERENCE
REF Output VoltageNo external load1.23751.2501.2625V
REF Load Regulation0V < ILOAD < 50FA5mV
REF Sink CurrentIn regulation10FA
REF Undervoltage-Lockout
ThresholdRising edge, 250mV typical hysteresis1.01.2V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VINVL= VIN2 = 12V, VVOP = VVREF_I = 15V, TA = 0°C to +85°C. Typical values are at TA = +25NC, unless oth-
erwise noted.)
PARAMETERCONDITIONSMINTYPMAXUNITS
STEP-DOWN REGULATOR
OUT Voltage in Fixed ModeFB2 = GND, no load
(Note 1)
0°C < TA = +85°C3.253.33.35VTA = +25°C3.2673.333
FB2 Voltage in Adjustable
Mode
VOUT = 2.5V, no load
(Note 1)
0°C < TA = +85°C1.231.251.27VTA = +25°C1.23751.2625
FB2 Adjustable Mode Threshold
VoltageDual Mode™ comparator0.100.150.20V
Output Voltage Adjust Range1.55V
FB2 Fault-Trip LevelFalling edge0.961.01.04V
FB2 Input Leakage CurrentVFB2 = 1.25V 50125200nA
DC Load Regulation0V < ILOAD < 2A0.5%
DC Line RegulationNo load, 10.8V < VIN2 < 13.2V0.1%/V
LX2-to-IN2 nMOS Switch
On-Resistance100200mI
LX2-to-GND2 nMOS Switch
On-Resistance61023I
BST-to-VL pMOS Switch
On-Resistance4030110I
Low-Frequency Operation
OUT ThresholdLX2 only0.8V
Low-Frequency Operation
Switching Frequency
FSEL = INVL125kHzFSEL = GND83
LX2 Positive Current LimitMAX171262.503.203.90A
Soft-Start Ramp TimeZero to full limit3ms
Maximum Duty Factor707885%
Minimum Duty Factor
Char/Design Limit Only10%
STEP-UP REGULATOR
Output Voltage RangeVIN20V
Oscillator Maximum Duty Cycle707885%
FB1 Regulation VoltageFB1 = COMP, CCOMP = 1nF1.23751.251.2625V
FB1 Fault Trip LevelFalling edge 0.961.01.04V
FB1 Load Regulation0V < ILOAD < full0.5%
FB1 Line Regulation10.8V < VIN < 13.2V0.08%/V
FB1 Input Bias CurrentVFB1 = 1.25V30125200nA
FB1 TransconductanceDI = Q2.5FA at COMP, FB1 = COMP150320560FS
FB1 Voltage GainFB1 to COMP1400V/V
LX1 Leakage CurrentVFB1 = 1.5V, VLX1 = 20V1040FA
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VINVL= VIN2 = 12V, VVOP = VVREF_I = 15V, TA = 0°C to +85°C. Typical values are at TA = +25NC, unless oth-
erwise noted.)
PARAMETERCONDITIONSMINTYPMAXUNITS
LX1 Current Limit
VFB1 = 1.1V, RCLIM = unconnected3.03.54.2VFB1 = 1.1V, with RCLIM at CLIM pin-20%
3.5 -
(68k/
RCLIM)
+20%
CLIM VoltageRCLIM = 60.5kI0.560.6250.69V
Current-Sense Transresistance0.190.210.25V/A
LX1 On-Resistance100185mI
Soft-Start PeriodCSS < 200pF16ms
SS Charge CurrentVSS = 1.2V456FA
POSITIVE CHARGE-PUMP REGULATORS
GD_I Input Supply Range8.020V
GD_I Input Supply CurrentVFBP = 1.5V (not switching)0.150.3mA
GD_I Overvoltage ThresholdGD_I rising, 250mV typical hysteresis (Note 2)20.12122V
FBP Regulation Voltage1.23751.251.2625V
FBP Line Regulation ErrorVSUP = 11V to 16V, not in dropout0.2%/V
FBP Input Bias CurrentVFBP = 1.5V, TA = +25°C-50+50nA
DRVP p-Channel MOSFET
On-Resistance1.53I
DRVP n-Channel MOSFET
On-Resistance12I
FBP Fault Trip LevelFalling edge 0.961.01.04V
Positive Charge-Pump
Soft-Start Period
7-bit voltage ramp with filtering to prevent high peak
currents 500kHz frequency4ms
750kHz frequency3ms
NEGATIVE CHARGE-PUMP REGULATORS
FBN Regulation VoltageVREF - VFBN0.991.001.01V
FBN Input Bias CurrentVFBN = 0mV, TA = +25°C-50+50nA
FBN Line Regulation ErrorVIN2 = 11V to 16V, not in dropout0.2%/V
DRVN PCH On-Resistance1.53I
DRVN NCH On-Resistance12I
FBN Fault Trip LevelRising edge720800880mV
Negative Charge-Pump Soft-
Start Period
7-bit voltage ramp with filtering to prevent high peak
currents 500kHz frequency3ms
750kHz frequency2
AVDD SWITCH GATE CONTROL
GD to GD_I Pullup ResistanceEN = GND2550I
GD Output Sink CurrentEN = VL51015FA
GD Done ThresholdEN = VL, VGD_I - VGD567V
OPERATIONAL AMPLIFIERS
VOP Supply Range820V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VINVL= VIN2 = 12V, VVOP = VVREF_I = 15V, TA = 0°C to +85°C. Typical values are at TA = +25NC, unless oth-
erwise noted.)
PARAMETERCONDITIONSMINTYPMAXUNITS
VOP Overvoltage Fault
ThresholdVVOP = rising, hysteresis = 200mV (Note 2)20.12122V
VOP Supply CurrentBuffer configuration, VOPP = VOPN = VOP/2, no load-10-2+6mA
Input Offset Voltage2V < (VOPP, VOPN ) < (VVOP - 2V)314mV
Input Bias Current2V < (VOPP, VOPN ) < (VVOP - 2V)-1+1FA
Input Common-Mode
Voltage Range0VOPV
Input Common-Mode
Rejection Ratio2V < (VOPP, VOPN ) < (VVOP - 2V)80dB
Output Voltage Swing HighIOPO = 25mAVOP -
VOP -
150mV
Output Voltage Swing LowIOPO = -25mA150300mV
Large-Signal Voltage Gain2V < (VOPP, VOPN ) < (VOP - 2V)80dB
Slew Rate2V < (VOPP, VOPN ) < (VOP - 2V)45V/Fs
-3dB Bandwidth2V < (VOPP, VOPN ) < (VOP - 2V)20MHz
Short-Circuit CurrentShort to VVOP/2, sourcing200mAShort to VVOP/2, sinking200
HIGH-VOLTAGE SWITCH ARRAY
VGH Supply Range35V
VGH Supply Current150300FA
VGHM-to-VGH Switch
On-ResistanceVDLY1 = 2V, GVOFF = VL510I
VGHM-to-VGH Switch
Saturation CurrentVVGH - VVGHM > 5V150390mA
VGHM-to-DRN Switch
On-ResistanceVDLY1 = 2V, GVOFF = GND2050I
VGHM-to-DRN Switch
Saturation CurrentVVGHM - VDRN > 5V75200mA
VGHM-to-GND Switch
On-ResistanceDLY1 = GND1.02.54.0kI
GVOFF Input Low Voltage0.6V
GVOFF Input High Voltage1.6V
GVOFF Input CurrentVGVOFF = 0V or VL, TA = +25°C-1+1FA
GVOFF-to-VGHM Rising
Propagation Delay
1kI from DRN to CPGND, VGVOFF = 0V to VL step, no
load on VGHM, measured from GVOFF = 2V to VGHM
= 20%
100ns
GVOFF-to-VGHM Falling
Propagation Delay
1kI from DRN to CPGND, VGVOFF = VL to 0V step, no
load on VGHM, DRN falling, no load on DRN and VGHM,
measured from VGVOFF = 0.6V to VGHM = 80%
200ns
THR-to-VGHM Voltage Gain9.41010.6V/V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VINVL= VIN2 = 12V, VVOP = VVREF_I = 15V, TA = 0°C to +85°C. Typical values are at TA = +25NC, unless oth-
erwise noted.)
PARAMETERCONDITIONSMINTYPMAXUNITS
SEQUENCE CONTROL
EN Pulldown Resistance1MI
DLY1 Charge CurrentVDLY1 = 1V; when DLY1 cap is not used, there is no
delay6810FA
EN, DLY1 Turn-On Threshold1.191.251.31V
DLY1 Discharge Switch
On-ResistanceEN = GND or fault tripped10I
FBN Discharge Switch
On-Resistance(EN = GND and INVL < UVLO) or fault tripped3kI
GAMMA REFERENCE
VREF_I Input Voltage Range1018.0V
VREF_I Input Bias CurrentNo load125250FA
VREF_O Dropout VoltageIVREF_O = 60mA0.250.5V
VREF_FB Regulation VoltageVVREF_I = 13.5V, 1mA P IVREF_O P 30mA, VVREF_O = 9.5V1.2431.2501.256V
VVREF_I from 10V to 18V, IVREF_O = 20mA, VVREF_O = 9.5VP 0.9mV/V
VREF_O Maximum Output
Current60mA
XAO FUNCTION
VDET ThresholdVDET rising1.2251.251.275V
VDET Hysteresis50mV
VDET Input Bias Current50175300nA
XAO Output VoltageVDET = AGND, IPGOOD = 1mA0.4V
FAULT DETECTION
Duration-to-Trigger FaultFor UVP only50ms
Step-Up Short-Circuit ProtectionFB1 falling edge0.36 x
VREF
0.4 x
VREF
0.44 x
VREFV
Step-Down Short-Circuit
Protection
Adjustable mode FB2 falling0.18 x
VREF
0.2 x
VREF
0.22 x
VREFVFixed mode OUT falling, internal feedback divider
voltage
0.18 x
VREF
0.2 x
VREF
0.22 x
VREF
Positive Charge-Pump
Short-Circuit ProtectionFBP falling edge0.36 x
VREF
0.4 x
VREF
0.44 x
VREFV
Negative Charge-Pump
Short-Circuit ProtectionVREF - VFBN0.40.450.5V
Thermal-Shutdown ThresholdLatch protection+160NC
SWITCHING FREQUENCY SELECTION
FSEL Input Low Voltage500kHz 0.6V
FSEL Input High Voltage750kHz1.6V
FSEL Pullup Resistance1MI
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS
(VINVL = VIN2 = 12V, VVOP = VVREF_I = 15V, TA = -40NC to +85NC.) (Note 3)
PARAMETERCONDITIONSMINTYPMAXUNITS
GENERAL
INVL, IN2 Input-Voltage Range816.5V
SMPS Operating FrequencyFSEL = INVL or high impedance630870kHzFSEL = GND420580
INVL Undervoltage-Lockout
ThresholdINVL rising, 150mV typical hysteresis6.08.0V
VL REGULATOR
VL Output VoltageIVL = 25mA, VFB1 = VFB2 = VFB = 1.1V, VFBN = 0.4V
(all regulators switching)4.855.15V
VL Undervoltage-Lockout
ThresholdVL rising, 50mV typical hysteresis3.54.3V
REFERENCE
REF Output VoltageNo external load1.2351.265V
REF Undervoltage-Lockout
ThresholdRising edge, 25mV typical hysteresis1.2V
STEP-DOWN REGULATOR
OUT Voltage in Fixed ModeFB2 = GND, no load (Note 1)3.2673.333V
FB2 Voltage in Adjustable ModeVOUT = 2.5V, no load (Note 1)1.23751.2625V
FB2 Adjustable Mode
Threshold VoltageDual-mode comparator0.100.20V
Output Voltage Adjust Range1.55V
FB2 Fault Trip LevelFalling edge0.961.04V
LX2-to-IN2 nMOS Switch
On-Resistance200mI
LX2-to-GND2 nMOS Switch
On-Resistance623I
BST-to-VL pMOS Switch
On-Resistance40110I
LX2 Positive Current LimitMAX171262.503.90A
Maximum Duty Factor7085%
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(VINVL = VIN2 = 12V, VVOP = VVREF_I = 15V, TA = -40NC to +85NC.) (Note 3)
PARAMETERCONDITIONSMINTYPMAXUNITS
STEP-UP REGULATOR
Output-Voltage RangeVIN20V
Oscillator Maximum Duty Cycle7085%
FB1 Regulation VoltageFB1 = COMP, CCOMP = 1nF1.23751.2625V
FB1 Fault Trip LevelFalling edge0.961.04V
FB1 TransconductanceDI = Q2.5FA at COMP, FB1 = COMP150560FS
LX1 Input Bias CurrentVFB1 = 1.5V, VLX1 = 20V40FA
LX1 Current Limit
VFB1 = 1.1V, RCLIM = unconnected3.04.2VFB1 = 1.1V , with RCLIM at CLIM pin,
limit = 3.5A - (68kW/RCLIM)-20%+20%
CLIM VoltageRCLIM = 60.5kI0.560.69V
Current-Sense Transresistance0.190.25V/A
LX1 On-Resistance185mI
SS Charge CurrentVSS = 1.2V46FA
POSITIVE CHARGE-PUMP REGULATORS
GD_I Input Supply Range8.020V
GD_I Input Supply CurrentVFBP = 1.5V (not switching)0.2mA
GD_I Overvoltage ThresholdGD_I rising, 250mV typical hysteresis (Note 2)20.122V
FBP Regulation Voltage1.2431.256V
FBP Line Regulation ErrorVSUP = 11V to 16V, not in dropout0.2%/V
DRVP p-Channel MOSFET
On-Resistance3I
DRVP n-Channel MOSFET
On-Resistance1I
FBP Fault Trip LevelFalling edge0.961.04V
NEGATIVE CHARGE-PUMP REGULATORS
FBN Regulation VoltageVREF - VFBN0.991.01V
FBN Line Regulation ErrorVIN2 = 11V to 16V, not in dropout0.2%/V
DRVN PCH On-Resistance3I
DRVN NCH On-Resistance1I
FBN Fault Trip LevelRising edge720880mV
AVDD SWITCH GATE CONTROL
GD Output Sink CurrentEN = VL515FA
GD Done ThresholdEN = VL, VGD_I - VGD57V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(VINVL = VIN2 = 12V, VVOP = VVREF_I = 15V, TA = -40NC to +85NC.) (Note 3)
PARAMETERCONDITIONSMINTYPMAXUNITS
OPERATIONAL AMPLIFIERS
VOP Supply Range820V
VOP Overvoltage Fault ThresholdVOP = rising, hysteresis = 200mV (Note 2)20.122V
VOP Supply CurrentBuffer configuration, VOPP = VOPN = VOP/2, no load4mA
Input Offset Voltage2V < (VOPP, VOPN ) < (VOP - 2V)-12+8mV
Input Common-Mode
Voltage Range0OVINV
Output Voltage Swing HighIOPO = 25mAVOP -
320mV
Output Voltage Swing LowIOPO = -25mA300mV
Short-Circuit CurrentShort to VOPO/2, sourcing200mAShort to VOPO/2, sinking200
HIGH-VOLTAGE SWITCH ARRAY
VGH Supply Range35V
VGH Supply Current300FA
VGHM-to-VGH Switch
On-ResistanceVDLY1 = 2V, GVOFF = VL10I
VGHM-to-VGH Switch
Saturation CurrentVVGH - VVGHM > 5V150mA
VGHM-to-DRN Switch
On-ResistanceVDLY1 = 2V, GVOFF = GND50I
VGHM-to-DRN Switch
Saturation CurrentVVGHM - VDRN > 5V75mA
VGHM-to-GND Switch
On-ResistanceDLY1 = GND1.04.0kI
GVOFF Input Low Voltage0.6V
GVOFF Input High Voltage1.6V
THR-to-VGHM Voltage Gain9.410.6V/V
SEQUENCE CONTROL
EN Input Low Voltage0.6V
EN Input High Voltage1.6V
DLY1 Charge CurrentVDLY1 = 1V; when DLY1 cap is not used,
there is no delay610FA
DLY1 Turn-On Threshold1.191.31V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
ELECTRICAL CHARACTERISTICS (continued)
(VINVL = VIN2 = 12V, VVOP = VVREF_I = 15V, TA = -40NC to +85NC.) (Note 3)
Note 1: When the step-down inductor is in continuous conduction (EN = VL or heavy load), the output voltage has a DC regulation
level lower than the error comparator threshold by 50% of the output voltage ripple. In discontinuous conduction (EN = GND
with light load), the output voltage has a DC regulation level higher than the error comparator threshold by 50% of the output
voltage ripple.
Note 2: Disables boost switching if either GD_I or VOP exceeds the threshold. Switching resumes when no threshold is exceeded.
Note 3: Specifications to TA = -40NC are guaranteed by design, not production tested.
PARAMETERCONDITIONSMINTYPMAXUNITS
GAMMA REFERENCE
VREF_I Input Voltage Range1018.0V
VREF_I Undervoltage LockoutVREF_I rising5.2V
VREF_I Input Bias CurrentNo load250FA
VREF_O Dropout VoltageIVREF_O = 60mA0.5V
VREF_FB Regulation VoltageVREF_I = 13.5V, 1mA ≤ IVREF_O ≤ 30mA1.23751.2625V
VREF_I from 10V to 18V, IVREF_O = 20mAP 0.9mV/V
VREF_O Maximum
Output Current60mA
XAO FUNCTION
VDET ThresholdVDET rising1.2251.275V
XAO Output VoltageVDET = AGND, IPGOOD = 1mA0.4V
FAULT DETECTION
Step-Up Short-Circuit
ProtectionFB1 falling edge0.36 x
VREF
0.44 x
VREFV
Step-Down Short-Circuit
Protection
Adjustable mode FB2 falling0.18 x
VREF
0.22 x
VREFV
Fixed mode OUT falling, internal feedback divider
voltage
0.18 x
VREF
0.22 x
VREFV
Positive Charge-Pump
Short-Circuit ProtectionFBP falling edge0.36 x
VREF
0.44 x
VREFV
Negative Charge-Pump
Short-Circuit ProtectionVREF - VFBN0.40.5V
SWITCHING FREQUENCY SELECTION
FSEL Input Low Voltage500kHz0.6V
FSEL Input High Voltage750kHz1.6V
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
STEP-DOWN REGULATOR EFFICIENCY
vs. LOAD CURRENT
MAX17126B toc01
LOAD CURRENT (A)
EFFICIENCY (%)
750kHz
500kHz
STEP-DOWN REGULATOR OUTPUT
VOLTAGE vs. LOAD CURRENT
MAX17126B toc02
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
750kHz
500kHz
STEP-UP REGULATOR EFFICIENCY
vs. LOAD CURRENT
MAX17126B toc05
EFFICIENCY (%)
750kHz
500kHz
STEP-UP REGULATOR OUTPUT
VOLTAGE vs. LOAD CURRENT
MAX17126B toc06
OUTPUT VOLTAGE (V)
750kHz
500kHz
STEP-DOWN REGULATOR LOAD
TRANSIENT RESPONSE (0.3A TO 1.8A) MAX17126B toc03
VOUT
(AC-COUPLED)
200mV/div
IL2
1A/div
ILOAD
1A/div
20Fs/div
L = 4.7FH
STEP-DOWN REGULATOR HEAVY-LOAD
SOFT-START (1A) MAX17126B toc04VIN
5V/div
VOUT
1V/div0V
IL2
1A/div
LX2
10V/div
4ms/div
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
SWITCHING FREQUENCY
vs. INPUT VOLTAGE
MAX17126B toc10
VIN (V)
SWITCHING FREQUENCY (kHz) 1210
GAMMA REFERENCE LINE REGULATION
(LOAD = 20mA)
MAX17126B toc12
GAMMA REFERENCE VOLTAGE (V)
GAMMA REFERENCE LOAD
REGULATION (VREF = 16V)
MAX17126B toc13
LOAD CURRENT (mA)
GAMMA REFERENCE VOLTAGE (V)
REFERENCE VOLTAGE LOAD
REGULATION
MAX17126B toc11
REFERENCE VOLTAGE (V)
SWITCHING
NO SWITCHING
STEP-UP REGULATOR PULSED LOAD
TRANSIENT RESPONSE (0.1A TO 1.9mA)MAX17126B toc08IL1
1A/div
10Fs/div
L = 10FH
VAVDD
(AC-COUPLED)
200mV/div
ILOAD
1A/div
STEP-UP REGULATOR HEAVY LOAD
SOFT-START (0.5A)MAX17126B toc09
IL1
1A/div
1ms/div
VAVDD
5V/div
VGD
5V/div
5V/div
STEP-UP REGULATOR LOAD TRANSIENT
RESPONSE (0.1A TO 1.1A) MAX17126B toc07IL1
1A/div
20Fs/div
L = 10FH
VAVDD
(AC-COUPLED)
200mV/div
ILOAD
1A/div
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
POSITIVE CHARGE-PUMP REGULATOR
NORMALIZED LINE REGULATION
MAX17126B toc14
SUPP VOLTAGE (V)
GON
ERROR (%)161514131211
IGON = 0A
IGON = 25mA
POSITIVE CHARGE-PUMP REGULATOR
NORMALIZED LOAD REGULATION
MAX17126B toc15
LOAD CURRENT (mA)
OUTPUT CURRENT ERROR (%)
POSITIVE CHARGE-PUMP REGULATOR
LOAD-TRANSIENT RESPONSE
MAX17126B toc16
ILOAD
20mA/div
40Fs/div
VGON
(AC-COUPLED)
200mV/div
60mA
10mA
NEGATIVE CHARGE-PUMP REGULATOR
NORMALIZED LINE REGULATION
MAX17126B toc17
SUPN VOLTAGE (V)
GOFF
ERROR (%)14131211109
IGON = 25mA
IGON = 0mA
NEGATIVE CHARGE-PUMP REGULATOR
NORMALIZED LOAD REGULATION
MAX17126B toc18
OUTPUT VOLTAGE ERROR (%)
NEGATIVE CHARGE-PUMP REGULATOR
LOAD TRANSIENT RESPONSE
MAX17126B toc19
ILOAD
20mA/div
20Fs/div
VGOFF
(AC-COUPLED)
200mV/div
60mA
10mA
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
OPERATIONAL AMPLIFIER RAIL-TO-RAIL
INPUT/OUTPUT WAVEFORMSMAX17126B toc22
4Fs/div
VOPP
5V/div
VCOM
5V/div
OPERATIONAL AMPLIFIER LOAD
TRANSIENT RESPONSEMAX17126B toc23
1Fs/div
VCOM
(AC-COUPLED)
500mV/div
IVCOM
100mA/div
OPERATIONAL AMPLIFIER
LARGE-SIGNAL STEP RESPONSEMAX17126B toc24
VOPP
5V/div
VCOM
OPERATIONAL AMPLIFIER
SMALL-SIGNAL STEP RESPONSEMAX17126B toc25
VOPP
(AC-COUPLED)
200mV/div
VCOM
(AC-COUPLED)
200mV/div
OP AMP SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX17126B toc21
VOP VOLTAGE (V)
VOP SUPPLY CURRENT (1817161514131211109
POWER-UP SEQUENCE OF ALL
SUPPLY OUTPUTS
MAX17126B toc20
10ms/div
VIN
VOUT
VGOFF
VAVDD
VGON
VCOM
VDLY1
VGHM
VIN = 10V/div
VOUT = 5V/div
VGOFF = 10V/div
VAVDD =10V/div
VGON = 20V/div
VCOM = 10V/div
VDLY1 = 5V/div
VGHM = 50V/div
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
Pin Configuration
VIN SUPPLY CURRENT vs. VIN VOLTAGE
MAX17126B toc26
INPUT VOLTAGE (V)
INVL CURRENT (121016
ALL OUTPUT SWITCHING
NO OUTPUT SWITCHING
BUCK OUTPUT SWITCHING
HIGH-VOLTAGE SWITCH CONTROL
FUNCTION (VGHM WITH 470pF LOAD)MAX17126B toc27
4Fs/div
VGVOFF
5V/div
VGHM
10V/div
TOP VIEW
MAX17126B
TQFNLX2
LX2
BST
IN2
IN2
GND
VDET
INVL
FSEL
CLIM23456789101112
VREF_O
VREF_FB
REF
FBN
GND
DRVN
SUPN
DRN
VGHM
VGH
FBP
DLY1
N.C.OUT
FB2
GVOFF
XAO
OPOOPN
OPP
OGND
VOP
VREF_I3534333231302928272625
LX1LX1PGNDPGNDGD_IGDFB1COMPTHRSUPPCPGNDDRVP
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Pin Description
PINNAMEFUNCTIONVREF_IGamma Reference InputVOPOperational Amplifier Power SupplyOGNDOperational Amplifier Power GroundOPPOperational Amplifier Noninverting InputOPNOperational Amplifier Inverting InputOPOOperational Amplifier OutputXAOVoltage Detector OutputGVOFFHigh-Voltage Switch-Control Block Timing Control Input. See the High-Voltage Switch Control
section for details.ENEnable Input. Enable is high, turns on step-up converter and positive charge pump.FB2
Step-Down Regulator Feedback Input. Connect FB2 to GND to select the step-down converter’s 3.3V
fixed mode. For adjustable mode, connect FB2 to the center of a resistive voltage-divider between the
step-down regulator output (OUT) and GND to set the step-down regulator output voltage. Place the
resistive voltage-divider within 5mm of FB2.OUTStep-Down Regulator Output Voltage Sense. Connect OUT to step-down regulator output.N.C.Not Connected
13, 14LX2
Step-Down Regulator Switching Node. LX2 is the source of the internal n-channel MOSFET connected
between IN2 and LX2. Connect the inductor and Schottky catch diode to both LX2 pins and minimize
the trace area for lowest EMI.BSTStep-Down Regulator Bootstrap Capacitor Connection. Power supply for high-side gate driver. Connect
a 0.1FF ceramic capacitor from BST to LX2.
16, 17IN2Step-Down Regulator Power Input. Drain of the internal n-channel MOSFET connected between IN2
and LX2.
18, 44GNDAnalog GroundVDETVoltage-Detector Input. Connects VDET to the center of a resistor voltage-divider between input voltage
and GND to set the trigger point of XAO.INVLInternal 5V Linear Regulator and the Startup Circuitry Power Supply. Bypass VINVL to GND with 0.22FF
close to the IC.VL
5V Internal Linear Regulator Output. Bypass VL to GND with 1FF minimum. Provides power for the
internal MOSFET driving circuit, the PWM controllers, charge-pump regulators, logic, and reference
and other analog circuitry. Provides 25mA load current when all switching regulators are enabled. VL is
active whenever input voltage is high enough.FSELFrequency Select Pin. Connect FSEL to VL or INVL or disconnect FSEL pin for 750kHz operation.
Connect to GND for 500kHz operation.CLIMBoost Current-Limit Setting Input. Connects a resistor from CLIM to GND to set current limit for boost
converter.SS
Soft-Start Input. Connects a capacitor from SS to GND to set the soft-start time for the step-up converter.
A 5FA current source starts to charge CSS when GD is done. See the Step-Up Regulator External pMOS
Pass Switch section for description. SS is internally pulled to GND through 1kI resistance when EN is
low OR when VL is below its UVLO threshold.
25, 26LX1Step-Up Regulator Power-MOSFET n-Channel Drain and Switching Node. Connects the inductor and
Schottky catch diode to both LX1 pins and minimizes the trace area for lowest EMI.
27, 28PGNDStep-Up Regulator Power GroundStep-Up Regulator External pMOS Pass Switch Source Input. Connects to the cathode of the step-up
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126B
Pin Description (continued)
PINNAMEFUNCTIONGDStep-Up Regulator External pMOS Pass Switch Gate Input. A 10FA P 20% current source pulls down on
the gate of the external pFET when EN is high.FB1
Boost Regulator Feedback Input. Connects FB1 to the center of a resistive voltage-divider between the
boost regulator output and GND to set the boost regulator output voltage. Place the resistive voltage-
divider within 5mm of FB1.COMPCompensation Pin for the Step-Up Regulator Error Amplifier. Connects a series resistor and capacitor
from COMP to ground.THR
VGHM Low-Level Regulation Set-Point Input. Connects THR to the center of a resistive voltage-divider
between AVDD and GND to set the VGHM falling regulation level. The actual level is 10 x VTHR. See the
Switch Control section for details.SUPPPositive Charge-Pump Drivers Power Supply. Connects to the output of the boost regulator (AVDD) and
bypasses to CPGND with a 0.1FF capacitor. SUPP is internally connected to GD_I.CPGNDCharge Pump and Buck Power GroundDRVPPositive Charge-Pump Driver Output. Connects DRVP to the positive charge-pump flying capacitor(s).DLY1
High-Voltage Switch Array Delay Input. Connects a capacitor from DLY1 to GND to set the delay time
between when the positive charge pump finishes its soft-start and the startup of this high-voltage switch
array. A 10FA current source charges CDLY1. DLY1 is internally pulled to GND through 50I resistance
when EN is low or when VL is below its UVLO threshold.FBP
Positive Charge-Pump Regulator Feedback Input. Connects FBP to the center of a resistive voltage-
divider between the positive charge-pump regulator output and GND to set the positive charge-pump
regulator output voltage. Place the resistive voltage-divider within 5mm of FBP.VGHSwitch Input. Source of the internal high-voltage p-channel MOSFET between VGH and VGHM.VGHMInternal High-Voltage MOSFET Switch Common Terminal. VGHM is the output of the high-voltage switch-
control block.DRNSwitch Output. Drain of the internal high-voltage p-channel MOSFET connected to VGHM.SUPNNegative Charge-Pump Drivers Power Supply. Bypass to CPGND with a 0.1FF capacitor. SUPN is
internally connected to IN2.DRVNNegative Charge-Pump Driver Output. Connects DRVN to the negative charge-pump flying capacitor(s).FBN
Negative Charge-Pump Regulator Feedback Input. Connect FBN to the center of a resistive voltage-
divider between the negative output and REF to set the negative charge-pump regulator output voltage.
Place the resistive voltage-divider within 5mm of FBN.REFReference Output. Connects a 0.22FF capacitor from REF to GND. All power outputs are disabled until
REF exceeds its UVLO threshold.VREF_FB
Gamma Reference Feedback Input. Connect VREF_FB to the center of a resistive voltage-divider
between VREF_O and GND to set the gamma reference output voltage. Place the resistive voltage-
divider within 5mm of VREF_FB.VREF_OGamma Reference OutputEPExposed Pad. Connects EP to GND, and ties EP to a copper plane or island. Maximizes the area of this
copper plane or island to improve thermal performance.
