MAX1513ETP ,2.7 to 5.5 V, TFT-LCD power-supply controllerFeatures♦ 2.7V to 5.5V Input Supply RangeThe MAX1513/MAX1514 provide complete power-sup-ply solutio ..
MAX1513ETP+ ,TFT-LCD Power-Supply ControllersFeatures♦ 2.7V to 5.5V Input Supply RangeThe MAX1513/MAX1514 provide complete power-sup-ply solutio ..
MAX1513ETP+T ,TFT-LCD Power-Supply ControllersELECTRICAL CHARACTERISTICS(Circuit of Figure 1, V = 3V, V = 10V, SDFR = IN, C = 0.22µF, T = 0°C to ..
MAX1515ETG ,+1.3 V to +3.6 V, Low-voltage, internal switch, step-down/DDR regulatorfeatures dual internal♦ 1MHz Maximum Switching Frequencyn-channel MOSFET power switches for high ef ..
MAX1515ETG+ ,Low-Voltage, Internal Switch, Step-Down/DDR Regulatorfeatures dual internal♦ 1MHz Maximum Switching Frequencyn-channel MOSFET power switches for high ef ..
MAX1515ETG+T ,Low-Voltage, Internal Switch, Step-Down/DDR RegulatorApplications VCCMAX1515 V = VOUT TTNotebook DDR Memory Termination COMPLXPGOODFBActive-Termination ..
MAX4163ESA+ ,SOT23, Micropower, Single-Supply, Rail-to-Rail I/O Op AmpsMAX4162/MAX4163/MAX416419-1195; Rev 3; 1/10UCSP, Micropower, Single-Supply, 10V,Rail-to-Rail I/O Op ..
MAX4163ESA+T ,SOT23, Micropower, Single-Supply, Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS: 3V Operation(V = 3V, V = 0V, V = V /2, V = V /2, R connected to V /2, T ..
MAX4163ESA+T ,SOT23, Micropower, Single-Supply, Rail-to-Rail I/O Op AmpsMAX4162/MAX4163/MAX416419-1195; Rev 3; 1/10UCSP, Micropower, Single-Supply, 10V,Rail-to-Rail I/O Op ..
MAX4163ESA-T ,SOT23, Micropower, Single-Supply, Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS: 3V Operation(V = 3V, V = 0V, V = V /2, V = V /2, R connected to V /2, T ..
MAX4163EUA ,SOT23 / Micropower / Single-Supply / Rail-to-Rail I/O Op AmpsELECTRICAL CHARACTERISTICS: +3V Operation(V =+3V, V = 0V, V = V / 2, V = V / 2, R tied to V / 2, T ..
MAX4163EUA ,SOT23 / Micropower / Single-Supply / Rail-to-Rail I/O Op AmpsGeneral Description ________
MAX1513ETP
2.7 to 5.5 V, TFT-LCD power-supply controller
General DescriptionThe MAX1513/MAX1514 provide complete power-sup-
ply solutions for active-matrix thin-film transistor (TFT)
liquid-crystal displays (LCDs). Both devices include a
high-performance step-up regulator controller, three lin-
ear-regulator controllers, and an adjustable delay block
for startup sequencing. The MAX1513 includes an
additional linear-regulator controller and a high-perfor-
mance buffer amplifier. The MAX1513/MAX1514 can
operate from 2.7V to 5.5V input supplies and provide
overload protection with timer delay latch on all the reg-
ulated outputs.
The step-up regulator controller drives an external N-
channel MOSFET to generate the regulated supply volt-
age for the panel source-driver ICs. Its current-mode
control architecture provides fast transient response to
pulsed loads. The high switching frequency (up to
1.5MHz) allows the use of ultra-small inductors and
ceramic capacitors while achieving efficiencies over 85%
using lossless current sensing. The internal soft-start lim-
its the input surge current during startup.
The gate-on and gate-off linear-regulator controllers of
the MAX1513/MAX1514 provide regulated TFT gate-on
and gate-off supplies. The gate-on supply is activated
after an adjustable delay following the step-up regulator.
The logic linear-regulator controller can be used to cre-
ate a low-voltage logic supply. The gamma linear-regula-
tor controller of the MAX1513 can be used to generate a
gamma-correction reference supply or another general-
purpose supply rail.The MAX1513’s high-performance
buffer amplifier can drive the LCD backplane (VCOM)
or the gamma-correction divider string.
The MAX1513/MAX1514 are available in 4mm ✕4mm
20-pin thin QFN packages with a maximum thickness of
0.8mm, suitable for ultra-thin LCD panel design.
ApplicationsNotebook Computer Displays
LCD Monitors and TVs
Automotive Displays
Features2.7V to 5.5V Input Supply RangeInput-Supply Undervoltage LockoutCurrent-Mode Step-Up Controller
Fast Transient Response to Pulsed Load
High Efficiency
Lossless Current Sensing
430kHz/750kHz/1.5MHz Switching FrequencyLinear-Regulator Controllers for VGON, VGOFFLinear-Regulator Controller for Logic SupplyHigh-Performance Buffer Amplifier (MAX1513 Only)Additional Linear-Regulator Controller
(MAX1513 Only)Power-Up Sequence and VGONDelay ControlVMAIN, VGON, VGOFF, VGAMMAShutdown ControlTimer-Delay Fault Latch for All OutputsThermal-Overload Protection
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Ordering Information
Pin Configuration appears at end of data sheet.
Minimal Operating Circuit
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
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.
FB, FBP, FBN, FBG, FBL, IN, CS+,
CS-, SDFRto GND...............................................-0.3V to +6V
DEL, GATE, REF to GND.............................-0.3V to (VIN+ 0.3V)
SUPB to GND.........................................................-0.3V to +14V
OUTB, FBPB to GND..............................-0.3V to (VSUPB+ 0.3V)
DRVP, DRVG, DRVL to GND..................................-0.3V to +30V
DRVN to GND.....................................(VIN- 28V) to (VIN+ 0.3V)
OUTB Continuous Output Current....................................±75mA
Continuous Power Dissipation (TA= +70°C)
20-Pin TQFN (derate 16.9mW/°C above +70°C).......1349mW
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
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, VIN= 3V, VSUPB= 10V, SDFR= IN, CREF= 0.22µF, TA
= 0°C to +85°C. Typical values are at TA= +25°C, unless
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, VIN= 3V, VSUPB= 10V, SDFR= IN, CREF= 0.22µF, TA
= 0°C to +85°C. Typical values are at TA= +25°C, unless
otherwise noted.)
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
ELECTRICAL CHARACTERISTICS (continued)(Circuit of Figure 1, VIN= 3V, VSUPB= 10V, SDFR= IN, CREF= 0.22µF, TA
= 0°C to +85°C. Typical values are at TA= +25°C, unless
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
ELECTRICAL CHARACTERISTICS(Circuit of Figure 1, VIN= 3V, VSUPB= 10V, SDFR= IN, CREF= 0.22µF, TA
= -40°C to +85°C, unless otherwise noted.) (Note 1)
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, VIN= 3V, VSUPB= 10V, SDFR= IN, CREF= 0.22µF, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
Note 1:Specifications to -40°C are guaranteed by design, not production tested.
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Typical Operating Characteristics
(Circuit of Figure 1, VIN= 5V, VMAIN= 15V, VGON= 25V, VGOFF= -10V, VLOGIC= 3.3V, VGAMMA= 14.7V, TA= +25°C, unless other-
wise noted.)
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
BUFFER-AMPLIFIER LARGE-SIGNAL
STEP RESPONSE
MAX1513/14 toc10
1µs/div
VFBPB
5V/div
AC-COUPLED
VOUTB
5V/div
AC-COUPLED
BUFFER-AMPLIFIER
LOAD-TRANSIENT RESPONSE
MAX1513/14 toc11
1µs/div
VOUTB
1V/div
AC-COUPLED
IOUTB
50mA/div
0mA
Typical Operating Characteristics (continued)
(Circuit of Figure 1, VIN= 5V, VMAIN= 15V, VGON= 25V, VGOFF= -10V, VLOGIC= 3.3V, VGAMMA= 14.7V, TA= +25°C, unless other-
wise noted.)
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Figure 1. Typical Operating Circuit of the MAX1513
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Figure 2. Typical Operating Circuit of the MAX1514
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Figure 3. MAX1513/MAX1514 Functional Diagram
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
Typical Operating Circuit
The typical operating circuit of the MAX1513 (Figure 1) is
a complete power-supply system for TFT LCDs. The cir-
cuit generates a +15V source-driver supply, +25V and
-10V gate-driver supplies, a +3.3V logic supply for the
timing controller, a 14.7V gamma-correction string supply
and a VCOM buffer. The typical operating circuit of the
MAX1514 (Figure 2) is similar to that of the MAX1513
except the gamma-correction string supply and the
VCOM buffer have been eliminated. The input voltage
range for the IC is from +2.7V to +5.5V. The typical oper-
ating circuits’ listed load currents are available from a
+4.5V to +5.5V supply. Table 1 lists recommended com-
ponent options, and Table 2 lists the component suppli-
ers’ contact information.
Detailed Description
The MAX1513 and MAX1514 contain a high-perfor-
mance, step-up switching-regulator controller and three
linear-regulator controllers (two positive and one nega-
tive). The MAX1513 also includes an additional linear-reg-
ulator controller and a high-current buffer amplifier. Figure
3 shows the MAX1513/MAX1514 functional diagram.
Main Step-Up Regulator Controller
The main step-up regulator controller drives an external
N-channel power MOSFET to generate the TFT-LCD
source-driver supply. The controller employs a current-
mode, fixed-frequency PWM architecture to maximize
loop bandwidth and provide fast transient response to
pulsed loads found in source-driver applications. The
multilevel control input SDFRsets the switching fre-
quency to 430kHz, 750kHz, or 1.5MHz. The high
switching frequency allows the use of low-profile induc-
tors and ceramic capacitors to minimize the thickness
of LCD panel designs, while maintaining high efficiency
using a lossless current-sense method. The IC’s built-in
soft-start function reduces the inrush current during
startup.
The controller regulates the output voltage and the
power delivered to the output by modulating the duty
cycle (D) of the power MOSFET in each switching cycle.
The duty cycle of the MOSFET is approximated by:
Figure 4 shows the functional diagram of the step-up
regulator controller. The core of the controller is a multi-
input summing comparator that sums three signals: the
output-voltage error signal with respect to the reference
voltage, the current-sense signal, and the slope-com-
pensation ramp. On the rising edge of the internal
clock, the controller sets a flip-flop, which turns on the
external N-channel MOSFET, applying the input voltage
across the inductor. The current through the inductor
ramps up linearly, storing energy in its magnetic field.
Once the sum of the feedback voltage error, slope
compensation, and current-sense signals trip the multi-
MAX1513/MAX1514
TFT-LCD Power-Supply Controllers
input PWM comparator, the flip-flop is reset and the
MOSFET turns off. Since the inductor current is continu-
ous, a transverse potential develops across the inductor
that turns on the diode (D1). The voltage across the
inductor then becomes the difference between the out-
put voltage and the input voltage. This discharge condi-
tion forces the current through the inductor to ramp
down, transferring the energy stored in the magnetic
field to the output capacitor and the load. The N-channel
MOSFET is kept off for the rest of the clock cycle.
Current Limiting and
Current-Sense Amplifier (CS+, CS-)
The internal current-limit circuit resets the PWM flip-flop
and turns off the external power MOSFET whenever the
voltage difference between CS+ and CS- exceeds
125mV (typ). The tolerance on this current limit is
±20%. Use the minimum value of the current limit to
select components of the current-sense network.
Lossless Current Sense
The lossless current-sense method uses the DC resis-
tance (DCR) of the inductor as the sense element.
Figure 5 shows a simplified step-up regulator using the
basic lossless current-sensing method. An RC network
is connected in parallel with the step-up inductor (L).
The voltage across the sense capacitor (CS) is the
input to the current-sense amplifier. To prevent the
sense amplifier from seeing large common-mode
switching voltages, the sense capacitor should always
be connected to the nonswitching end of the inductor
(i.e., the input of the step-up regulator).
Lossless current sense can be easily understood using
complex frequency domain analysis. The voltage
across the inductor is given by:
where L is the inductance, RLis the DCR of the induc-
tor, and ILis the inductor current. The voltage across
the sense capacitor is given by:
where RSis the series resistor in the sense network andis the sense capacitor. The above equation can be
rewritten as:
Therefore, the sense capacitor voltage is directly pro-
portional to the inductor current if the time constant of
the RC sense network matches the time constant of the
inductor/DCR. The sense method is equivalent to using
a current-sense resistor that has the same value as the
inductor DCR.
