MAX1880 ,Quad-Output TFT LCD DC-DC Converters with BufferFeaturesThe MAX1778/MAX1880–MAX1885 multiple-output ● 500kHz/1MHz Current-Mode PWM Step-Up Regulato ..
MAX1880EUG ,Quad-Output TFT LCD DC-DC Converters with BufferFeaturesThe MAX1778/MAX1880–MAX1885 multiple-output 500kHz/1MHz Current-Mode PWM Step-UpDC-DC con ..
MAX1880EUG ,Quad-Output TFT LCD DC-DC Converters with BufferApplicationsTFT LCD Notebook DisplaysTypical Operating Circuit appears at end of data sheet.TFT LCD ..
MAX1880EUG+ ,Quad-Output TFT LCD DC-DC Converters with BufferApplicationsTypical operating Circuit appears at end of data sheet.● TFT LCD Notebook DisplaysPin C ..
MAX1880EUG+ ,Quad-Output TFT LCD DC-DC Converters with BufferMAX1778/MAX1880–MAX1885 Quad-Output TFT LCD DC/DC Converters with Buffer
MAX1880EUG+T ,Quad-Output TFT LCD DC-DC Converters with BufferFeaturesThe MAX1778/MAX1880–MAX1885 multiple-output ● 500kHz/1MHz Current-Mode PWM Step-Up Regulato ..
MAX4834ETT30C ,250mA LDO Linear Regulators with Current-Limiting SwitchApplicationsMAX4835ETTxy_dd+T -40°C to +85°C 6 TDFN-EP*● SDIO Ports and Devices ● Notebook Computer ..
MAX4835ETT18BD2V+T ,250mA LDO Linear Regulators with Current-Limiting SwitchElectrical Characteristics(V = V + 1V, SHDN = IN, C = 3.3µF, T = -40°C to +85°C, unless otherwise n ..
MAX4837ETT25BD3+ ,500mA LDO Linear Regulators with Current-Limiting SwitchApplicationsMAX4836ETTxy_-T -40°C to +85°C 6 TDFN-6SDIO Ports and Devices Notebook ComputersMAX4837 ..
MAX4838EXT+T ,Overvoltage Protection Controllers with Status FLAGELECTRICAL CHARACTERISTICS(V = +5V (MAX4838–MAX4841), V = +4V (MAX4842), T = -40°C to +85°C, unless ..
MAX4838EXT-T ,Overvoltage Protection Controllers with Status FLAGApplicationsTypical Operating CircuitCell PhonesDigital Still CamerasPDAs and Palmtop DevicesINPUTO ..
MAX483CPA ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversFeaturesThe MAX481, MAX483, MAX485, MAX487–MAX491, and' In µMAX Package: Smallest 8-Pin SOMAX1487 a ..
MAX1880
Quad-Output TFT LCD DC-DC Converters with Buffer
General DescriptionThe MAX1778/MAX1880–MAX1885 multiple-output
DC-DC converters provide the regulated voltages required
by active matrix thin-film transistor (TFT) liquid crystal
displays (LCD) in a low-profile TSSOP package. One
high-power step-up converter and two low-power charge
pumps convert the 2.7V to 5.5V input voltage into three
independent output voltages. A built-in linear regulator and
VCOM buffer complete the power-supply requirements.
The main step-up converter accurately generates an
externally set output voltage up to 13V that can supply the
display’s row/column drivers. The converter’s high switch-
ing frequency and current-mode PWM architecture provide
fast transient response and allow the use of small low-
profile inductors and ceramic capacitors. The low-power BiCMOS control circuitry and internal 14V switch (0.35Ω
N-channel MOSFET) enable efficiencies up to 91%.
The dual low-power charge pumps (MAX1778/MAX1880/
MAX1881/MAX1882 only) independently regulate one
positive output (VPOS) and one negative output (VNEG).
These low-power outputs use external diode and capaci-
tor stages (as many stages as required) to regulate output
voltages up to +40V and -40V. A unique control scheme
minimizes output ripple as well as capacitor sizes for both
charge pumps.
A resistor-programmable, 40mA, low-dropout linear
regulator (MAX1778/MAX1881/MAX1883/MAX1884 only)
provides preregulation or postregulation for any of the
supplies. For higher current applications, an external
transistor can be added. Additionally, the VCOM buffer
provides a high current output that is ideal for driving the
capacitive backplane of TFT LCD panels. The VCOM
buffer’s output voltage is preset with an internal 50%
resistive-divider or can be externally adjusted for other
voltages.
The MAX1778/MAX1880–MAX1885 are protected against
output undervoltage and thermal overload conditions by a
latched fault detection circuit that shuts down the device.
All devices are available in the ultrathin TSSOP package
(1.1mm max height).
Applications●TFT LCD Notebook Displays●TFT LCD Desktop Monitor Panels
Features●500kHz/1MHz Current-Mode PWM Step-Up
Regulator Up to +13V Main High-Power Output ±1% Accurate High Efficiency (91%)●Dual Regulated Charge-Pump Outputs (MAX1778/
MAX1880–MAX1882 only) Up to +40V Positive Charge-Pump Output Up to -40V Negative Charge-Pump Output●Low-Dropout 40mA Linear Regulator (MAX1778/
MAX1881/MAX1883/MAX1884 only) Up to +15V LDO Input●Optional Higher Current with External Transistor●2.7V to 5.5V Input Supply●Internal Supply Sequencing and Soft-Start●Power-Ready Output●Adjustable Fault-Detection Latch●Thermal Protection (+160°C)●0.1μA Shutdown Current●0.7mA IN Quiescent Current●Ultra-Small External Components●Thin TSSOP Package (1.1mm max height)
Typical operating Circuit appears at end of data sheet.
Pin Configurations and Selector Guide appear at end of
data sheet.+Denotes lead(Pb)-free/RoHS-compliant package.
PARTTEMP RANGEPIN-PACKAGE
MAX1778EUG-40°C to +85°C24 TSSOP
MAX1778EUG+-40°C to +85°C24 TSSOP
MAX1880EUG-40°C to +85°C24 TSSOP
MAX1881EUG-40°C to +85°C24 TSSOP
MAX1882EUG-40°C to +85°C24 TSSOP
MAX1883EUP-40°C to +85°C20 TSSOP
MAX1884EUP-40°C to +85°C20 TSSOP
MAX1885EUP-40°C to +85°C20 TSSOP
MAX1778/MAX1880–MAX1885Quad-Output TFT LCD DC/DC
Converters with Buffer
Ordering Information
IN, SHDN, TGND, FLTSET to GND...........................-0.3V to +6V
DRVN to GND........................................-0.3V to (VSUPN + 0.3V)
DRVP to GND........................................-0.3V to (VSUPP + 0.3V)
PGND to GND.....................................................................±0.3V
RDY, SUPB to GND................................................-0.3V to +14V
LX, SUPP, SUPN to PGND .....................................-0.3V to +14V
SUPL to GND..........................................................-0.3V to +18V
LDOOUT to GND....................................-0.3V to (VSUPL + 0.3V)
INTG, REF, FB, FBN, FBP to GND...............-0.3V to (VIN + 0.3V)
FBL to GND.............-0.3V to the lower of (VSUPL + 0.3V) or +6V
BUFOUT, BUF+, BUF- to GND..............-0.3V to (VSUPB + 0.3V)
Continuous Power Dissipation (TA = +70°C)
20-Pin TSSOP (derate 10.9mW/°C above +70°C)......879mW
24-Pin TSSOP (derate 12.2mW/°C above +70°C)......975mW
Operating Temperature Range
MAX1778EUG, MAX1883EUP.........................-40°C to +85°C
Junction Temperature.......................................................+150°C
Storage Temperature Range..............................-65°C to +150°C
Lead Temperature (soldering, 10s)...................................+300°C
(VIN = +3.0V, SHDN = IN, VSUPP = VSUPN = VSUPB = VSUPL = 10V, LDOOUT = FBL, BUF- = BUFOUT, BUF+ = FLTSET = TGND =
PGND = GND, CREF = 0.22μF, CBUF = 1μF, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInput Supply RangeVIN2.75.5V
Input Undervoltage ThresholdVUVLOVIN rising, 40mV hysteresis (typ)2.22.42.6V
IN Quiescent Supply CurrentIIN
VFB = VFBP =
1.5V, VFBN =
-0.2V
MAX1778/MAX1880/
MAX1883 (fOSC = 1MHz)0.71MAX1881/MAX1882/
MAX1884/MAX1885
(fOSC = 500kHz)
SUPP Quiescent CurrentISUPPVFBP = 1.5V
MAX1778/MAX1880
(fOSC = 1MHz)0.40.7
MAX1881/MAX1882
(fOSC = 500kHz)0.30.5
SUPN Quiescent CurrentISUPNVFBN = -0.2V
MAX1778/MAX1880
(fOSC = 1MHz)0.40.7
MAX1881/MAX1882
(fOSC = 500kHz)0.30.5
IN Shutdown CurrentVSHDN = 0, VIN = 5V0.110µA
SUPP Shutdown CurrentVSHDN = 0, VSUPP = 13V,
MAX1778/MAX1880/MAX1881/MAX18820.110µA
SUPN Shutdown CurrentVSHDN = 0, VSUPN = 13V,
MAX1778/MAX1880/MAX1881/MAX18820.110µA
SUPL Shutdown CurrentVSHDN = 0, VSUPL = 13V
MAX1778/MAX1881/MAX1883/MAX18840.110µA
SUPB Shutdown CurrentVSHDN = 0, VSUPB = 13V613µA
MAX1778/MAX1880–MAX1885Quad-Output TFT LCD DC/DC
Converters with Buffer
Absolute Maximum RatingsStresses 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
(VIN = +3.0V, SHDN = IN, VSUPP = VSUPN = VSUPB = VSUPL = 10V, LDOOUT = FBL, BUF- = BUFOUT, BUF+ = FLTSET = TGND =
PGND = GND, CREF = 0.22μF, CBUF = 1μF, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
MAIN STEP-UP CONVERTERMain Output Voltage RangeVMAINVIN13V
FB Regulation VoltageVFBIntegrator enabled, CINTG = 1000pF1.2341.2471.260VIntegrator disabled (INTG = REF)1.2201.280
FB Input Bias CurrentIFBVFB = 1.25V, INTG = GND-50+50nA
Operating FrequencyfOSCMAX1778/MAX1880/MAX18830.8511.15MHz
MAX1881/MAX1882/MAX1884/MAX1885425500575kHz
Oscillator Maximum Duty Cycle808591%
Load RegulationILX = 0 to 200mA,
VMAIN = 10V
Integrator enabled,
CINTG = 1000pF0.01
Integrator disabled
(INTG = REF)0.2
Line Regulation0.1%/V
Integrator Transconductance317µS
LX Switch On-ResistanceRLX(ON)ILX = 100mA0.350.7Ω
LX Leakage CurrentILXVLX = 13V0.0120µA
LX Current LimitILIM
Phase I = soft-start (1024/fOSC)0.2750.380.5Phase II = soft-start (1024/fOSC)0.75
Phase III = soft-start (1024/fOSC)1.12
Phase IV = fully on (after 3072/fOSC)1.151.51.85
Maximum RMS LX Current1A
Soft-Start PeriodtSSPower-up to the end of Phase III3072 / fOSCs
FB Fault Trip LevelFalling edge, FLTSET = GND1.071.11.14V
Falling edge, FLTSET = 1V0.9550.991.025
POSITIVE CHARGE PUMP (MAX1778/MAX1880/MAX1881/MAX1882 only)SUPP Input Supply RangeVSUPP2.713V
Operating FrequencyfCHP0.5 x fOSCHz
FBP Regulation VoltageVFBP1.21.251.3V
FBP Input Bias CurrentIFBPVFBP = 1.5V-50+50nA
DRVP PCH On-ResistanceRPCH(ON)510Ω
DRVP NCH On-ResistanceRNCH(ON)
VFBP = 1.2V24Ω
VFBP = 1.3V20kΩ
Maximum RMS DRVP Current0.1A
FBP Power-Ready Trip LevelRising edge1.091.1251.16V
FBP Fault Trip LevelFalling edge, FLTSET = GND1.081.111.16VFalling edge, FLTSET = 1V0.9550.991.025
MAX1778/MAX1880–MAX1885Quad-Output TFT LCD DC/DC
Converters with Buffer
Electrical Characteristics (continued)
(VIN = +3.0V, SHDN = IN, VSUPP = VSUPN = VSUPB = VSUPL = 10V, LDOOUT = FBL, BUF- = BUFOUT, BUF+ = FLTSET = TGND =
PGND = GND, CREF = 0.22μF, CBUF = 1μF, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
NEGATIVE CHARGE PUMP (MAX1778/MAX1880/MAX1881/MAX1882 only)SUPN Input Supply RangeVSUPN2.713V
Operating FrequencyfCHP0.5 x fOSCHz
FBN Regulation VoltageVFBN-500+50mV
FBN Input Bias CurrentIFBNVFBN = 0-50+50nA
DRVN PCH On-ResistanceRPCH(ON)510Ω
DRVN NCH On-ResistanceRNCH(ON)VFBN = +50mV24Ω
VFBN = -50mV20kΩ
Maximum RMS DRVN Current0.1A
FBN Power-Ready Trip LevelFalling edge80125165mV
FBN Fault Trip LevelRising edge80140190mV
LOW-DROPOUT LINEAR REGULATOR (MAX1778/MAX1881/MAX1883/MAX1884 only)SUPL Input Supply RangeVSUPL4.515V
SUPL Undervoltage LockoutRising edge, 50mV hysteresis (typ)3.844.3V
SUPL Quiescent CurrentISUPLILDO = 100µA120220µA
Dropout Voltage (Note 1)VDROPLDO is set to
regulate at 9V
ILDO = 40mA130300mV
ILDO = 5mA70
FBL Regulation VoltageVFBLVSUPL = 10V, LDO regulating at 9V,
ILDO = 15mA1.2351.251.265V
LDO Load RegulationVSUPL = 10V, LDO regulating at 9V,
ILDO = 100µA to 40mA1.2%
LDO Line RegulationVSUPL = 4.5V to 15V, FBL = LDOOUT,
ILDO = 15mA0.02%/V
FBL Input Bias CurrentIFBLVFBL = 1.25V-0.8+0.8µA
LDO Current LimitILDOLIMVSUPL = 10V, VLDOOUT = 9V, VFBL = 1.2V40130220mA
VCOM BUFFERSUPB Input Supply RangeVSUPB4.513V
SUPB Quiescent CurrentISUPBVSUPB = 13V420850µA
BUFOUT Leakage Current-10+10µA
Power-Supply Rejection RatioPSRRVSUPB = 4.5V to 13V, VCM = 2.25V8598dB
Input Common-Mode Voltage
RangeVCM|VOS| < 10mV1.28.8V
Common-Mode Rejection RatioCMRRVCM = 1.2V to 8.8V75dB
Input Bias CurrentIBIASVCM = 5V-100-10+100nA
Input Offset CurrentIOSVCM = 5V-100+100nA
Gain Bandwidth ProductGBWCBUF = 1µF13kHz
MAX1778/MAX1880–MAX1885Quad-Output TFT LCD DC/DC
Converters with Buffer
Electrical Characteristics (continued)
(VIN = +3.0V, SHDN = IN, VSUPP = VSUPN = VSUPB = VSUPL = 10V, LDOOUT = FBL, BUF- = BUFOUT, BUF+ = FLTSET = TGND =
PGND = GND, CREF = 0.22μF, CBUF = 1μF, TA = 0°C to +85°C. Typical values are at TA = +25°C, unless otherwise noted.)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSOutput VoltageVBUFOUTBUF+ = GND
IBUFOUT = 04.995.01
IBUFOUT = ±5mA4.975.03V
IBUFOUT = ±45mA4.935.07
Input Offset VoltageVOS
VSUPB = 4.5V to
13V, VCM = 1.2V to
(VSUPB - 1.2V)
IBUFOUT = ±5mA-30+30
IBUFOUT = ±45mA-70+70
Output Voltage Swing HighVOHIBUFOUT = -45mA, ∆VOS = 1V99.6V
Output Voltage Swing LowVOLIBUFOUT = +45mA, ∆VOS = 1V0.41V
Peak Buffer Output Current±150mA
BUF+ Dual Mode™ Threshold
VoltageFalling edge, 20mV hysteresis (typ)80125170mV
REFERENCEReference VoltageVREF-2µA < IREF < 50µA1.2311.251.269V
Reference Undervoltage
Threshold0.91.051.2V
LOGIC SIGNALSSHDN Input Low Voltage0.9V
SHDN Input High Voltage2.1V
SHDN Input CurrentISHDN0.011µA
FLTSET Input Voltage Range0.67 x
VREF
0.85 x
VREFV
FLTSET Threshold VoltageRising edge, 25mV hysteresis (typ)80125170mV
FLTSET Input CurrentVFLTSET = 1V0.150nA
RDY Output Low VoltageISINK = 2mA0.250.5V
RDY Output High LeakageVRDY = 13V0.011µA
Thermal ShutdownRising temperature160°C
MAX1778/MAX1880–MAX1885Quad-Output TFT LCD DC/DC
Converters with Buffer
Electrical Characteristics (continued)
