MAX1997ETJ Maxim Integrated Products, MAX1997ETJ Datasheet - Page 15

• Manufacturer Part Number: MAX1997ETJ
• Description: LCD Drivers
• Manufacturer: Maxim Integrated Products

Specifications of MAX1997ETJ

• Dc: 0618
• Lead Free Status / Rohs Status: No

The standard application circuit (Figure 1) of the
MAX1997 is a complete power-supply system for TFT
liquid-crystal displays. The circuit generates 9V for source
drivers, +20V and -7V for gate drivers, a 2.5V logic supply
for the timing controller, a 8.6V gamma reference voltage,
and a VCOM buffer. The input voltage range is from 2.7V
to 5.5V. Table 1 lists the selected component options and
Table 2 lists the component suppliers.
The MAX1997 and MAX1998 contain a high-perfor-
mance step-up switching regulator, two low-cost linear-
regulator controllers, and multiple levels of protection
circuitry. The MAX1997 also includes two additional lin-
ear-regulator controllers and a high-current VCOM
buffer. Figure 2 shows the MAX1997/MAX1998 system
functional diagram. The output voltage of the main
step-up regulator (V
with an external resistive voltage-divider. High switch-
ing frequency (375kHz/750kHz/1.5MHz) and current-
mode control provide fast transient response and allow
the use of low-profile inductors and ceramic capacitors.
Table 1. Selected Component List
SuperSOT is a trademark of Fairchild Semiconductor.
Table 2. Component Suppliers
Quintuple/Triple-Output TFT LCD Power Supplies
Fairchild
Sumida
Taiyo Yuden
TDK
Toshiba
DESIGNATION
SUPPLIER
C4, C5, C6
D2, D3, D4
Standard Application Circuit
C2, C13
Q2, Q3
D5, D6
D1
N1
Q1
Q4
L1
P1
______________________________________________________________________________________
MAIN
Detailed Description
with Fault Protection and VCOM Buffer
) can be set from V
10µF, 6.3V X5R ceramic capacitors (1206), TDK C3216X5R0J106M
4.7µF, 10V X7R ceramic capacitors (1210), Taiyo Yuden LMK352BJ475MF
1.0A, 30V Schottky diode (S-flat), Toshiba CRS02
200mA, 25V dual-series Schottky diodes (SOT23), Fairchild BAT54S
200mA, 75V diode (SOT23), Fairchild MMBD4148
3.0µH, 1.3A inductor, Sumida CLS5D11HP-3R0NC
1.9A, 30V N-channel MOSFET (SuperSOT™-3), Fairchild FDN357P
2.4A, 20V P-channel MOSFET (SuperSOT-3), Fairchild FDN304P
3A, 25V PNP bipolar transistor (SuperSOT-3), Fairchild FSB749
200mA, 40V PNP bipolar transistors (SOT23), Fairchild MMBT3906
200mA, 40V NPN bipolar transistor (SOT23), Fairchild MMBT3904
408-822-2000
847-545-6700
800-348-2496
847-803-6100
949-455-2000
PHONE
IN
to 13V
The low R
external component count and achieves high efficiency
using a lossless current-sense architecture.
Two charge pumps take energy from the main step-up
regulator’s switching node (LX) to generate positive and
negative supplies. Additional capacitor and diode stages
can be used to generate supply voltages greater than
+35V and less than -15V. The positive and negative
linear-regulator controllers postregulate the charge-pump
supply voltages and allow users to program the power-up
sequence as well.
The high-current VCOM buffer of the MAX1997 is ideal for
driving the backplane of a TFT LCD panel. It requires only
a 0.47µF ceramic output capacitor for stability. The
MAX1997’s two additional linear-regulator controllers can
be used to build the gamma reference and logic supply.
The unique input switch control of the MAX1997/
MAX1998 senses the current drawn from the input
power supply by monitoring the voltage drop across
the input P-channel MOSFET. The protection MOSFET
and all regulator outputs latch off if an overcurrent
condition lasts for more than the fault timer period.
408-822-2102
847-545-6720
847-925-0899
847-390-4405
949-859-3963
DESCRIPTION
FAX
DS(ON)
internal power MOSFET minimizes the
www.fairchildsemi.com
www.sumida.com
www.t-yuden.com
www.component.tdk.com
www.toshiba.com
WEBSITE
15