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Part: MAX1884EUP
Category:
Power Management
-> Battery Management
Description: MAX1778, MAX1880, MAX1881, MAX1882, MAX1883, MAX1884, MAX1885 Quad-output TFT LCD DC-DC Converters With Buffer
Company: Maxim Integrated Products
Datasheet: Download MAX1884EUP datasheet File size : 505 kB
Request For quote: Find where to buy MAX1884EUP
Datasheet text preview:
19-1979; Rev 0a; 3/01
Quad-Output TFT LCD DC-DC Converters with Buffer
General Description
T h e MAX1778/MAX1880MAX1885 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 switching 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 (0.35 N-channel MOSFET) enable efficiencies up to 91%. T h e dual low-power charge pumps (MAX1778/ MAX1880/MAX1881/MAX1882 only) independently regulate one positive output (VPOS) and one negative outp u t (V N E G ) . These low-power outputs use external d i o d e and capacitor 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 r e g u l a t o r (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 i n t e r n a l 50% resistive-divider or can be externally adjusted for other voltages. T h e MAX1778/MAX1880MAX1885 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).
Features
o 500kHz/1MHz Current-Mode PWM Step-Up Regulator Up to +13V Main High-Power Output ±1% Accurate High Efficiency (91%) o Dual Regulated Charge-Pump Outputs (MAX1778/MAX1880/MAX1881/MAX1882 only) Up to +40V Positive Charge-Pump Output Up to -40V Negative Charge-Pump Output o Low-Dropout 40mA Linear Regulator (MAX1778/MAX1881/MAX1883/MAX1884 only) Up to +15V LDO Input o Optional Higher Current with External Transistor o 2.7V to 5.5V Input Supply o Internal Supply Sequencing and Soft-Start o Power-Ready Output o Adjustable Fault-Detection Latch o Thermal Protection (+160°C) o 0.1µA Shutdown Current o 0.7mA IN Quiescent Current o Ultra-Small External Components o Thin TSSOP Package (1.1mm max height)
MAX1778/MAX1880MAX1885
Ordering Information
PART MAX1778EUG MAX1880EUG MAX1881EUG MAX1882EUG MAX1883EUP MAX1884EUP MAX1885EUP TEMP. RANGE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C PIN-PACKAGE 24 TSSOP 24 TSSOP 24 TSSOP 24 TSSOP 20 TSSOP 20 TSSOP 20 TSSOP
Applications
TFT LCD Notebook Displays TFT LCD Desktop Monitor Panels
Typical Operating Circuit appears at end of data sheet. Pin Configurations and Selector Guide appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products
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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.
Quad-Output TFT LCD DC-DC Converters with Buffer MAX1778/MAX1880MAX1885
ABSOLUTE MAXIMUM RATINGS
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
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
(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.)
PARAMETER Input Supply Range Input Undervoltage Threshold SYMBOL VIN V UVLO VIN rising, 40mV hysteresis (typ) MAX1778/MAX1880/ MAX1883 (fOSC = 1MHz) MAX1881/MAX1882/ MAX1884/MAX1885 (fOSC = 500kHz) MAX1778/MAX1880 (fOSC = 1MHz) MAX1881/MAX1882 (fOSC = 500kHz) MAX1778/MAX1880 (fOSC = 1MHz) MAX1881/MAX1882 (fOSC = 500kHz) CONDITIONS MIN 2.7 2.2 2.4 0.7 TYP MAX 5.5 2.6 1 mA 0.6 1 UNITS V V
IN Quiescent Supply Current
IIN
VFB = VFBP = 1.5V, VFBN = -0.2V
0.4 0.3 0.4 0.3 0.1 0.1 0.1 0.1 6
0.7 mA 0.5 0.7 mA 0.5 10 10 10 10 13 µA µA µA µA µA
SUPP Quiescent Current
IS U P P
VFBP = 1.5V
SUPN Quiescent Current
ISUPN
VFBN = -0.2V
IN Shutdown Current SUPP Shutdown Current SUPN Shutdown Current SUPL Shutdown Current SUPB Shutdown Current
VSHDN = 0, VIN = 5V VSHDN = 0, VSUPP = 13V, MAX1778/MAX1880/MAX1881/MAX1882 VSHDN = 0, VSUPN = 13V, MAX1778/MAX1880/MAX1881/MAX1882 VSHDN = 0, VSUPL = 13V MAX1778/MAX1881/MAX1883/MAX1884 VSHDN = 0, VSUPB = 13V
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Quad-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.)
PARAMETER MAIN STEP-UP CONVERTER Main Output Voltage Range FB Regulation Voltage FB Input Bias Current Operating Frequency Oscillator Maximum Duty Cycle Integrator enabled, CINTG = 1000pF Integrator disabled (INTG = REF) V MAIN VFB IFB fOSC Integrator enabled, CINTG = 1000pF Integrator disabled (INTG = REF) VFB = 1.25V, INTG = GND MAX1778/MAX1880/MAX1883 MAX1881/MAX1882/MAX1884/MAX1885 VIN 1.234 1.220 -50 0.85 425 80 1 500 85 0.01 % 0.2 0.1 317 RL X( ON ) ILX ILX = 100mA VLX = 13V Phase I = soft-start (1024/fOSC) LX Current Limit ILIM Phase II = soft-start (1024/fOSC) Phase III = soft-start (1024/fOSC) Phase IV = fully-on (after 3072/fOSC) Maximum RMS LX Current Soft-Start Period FB Fault Trip Level tSS Power-up to the end of Phase III Falling edge, FLTSET = GND Falling edge, FLTSET = 1V 1.07 0.955 2.7 0.5 x fOSC 1.2 VFBP = 1.5V VFBP = 1.2V VFBP = 1.3V Rising edge Falling edge, FLTSET = GND Falling edge, FLTSET = 1V 20 0.1 1.09 1.08 0.955 1.125 1.11 0.99 1.16 1.16 1.025 -50 5 2 1.25 1.3 +50 10 4 1.15 0.275 0.35 0.01 0.38 0.75 1.12 1.5 1 3072 / fOSC 1.1 0.99 1.14 1.025 13 1.85 A s V 0.7 20 0.5 A %/V µs µA 1.247 13 1.260 1.280 +50 1.15 575 91 V V nA MHz kHz % SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX1778/MAX1880MAX1885
Load Regulation
ILX = 0 to 200mA, VMAIN = 10V
Line Regulation Integrator Transconductance LX Switch On-Resistance LX Leakage Current
POSITIVE CHARGE PUMP (MAX1778/MAX1880/MAX1881/MAX1882 ONLY) V SUPP SUPP Input Supply Range Operating Frequency FBP Regulation Voltage FBP Input Bias Current DRVP PCH On-Resistance DRVP NCH On-Resistance Maximum RMS DRVP Current FBP Power-Ready Trip Level FBP Fault Trip Level fCHP V FBP IFBP R PCH(ON) R NCH(ON)
V Hz V nA k A V V
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