Application Circuits
Typical Application Circuits
Applications Diagram
TemplateByTechPubs
MAX25222/ MAX25222C
MAX25222/
MAX
25222C
LX
LX
Inverting Converter Input. Connect 10μF + 0.1μF ceramic capacitors from this pin to ground for proper operation.
INN
INN
Boost Output and Input to Positive and Negative Charge-Pump Drivers. Bypass HVINP with a 10μF output capacitor placed close to the pin.
HVINP
HVINP
Switched Output of Boost Converter. Connect a bypass capacitor of value 2.2μF from AVDD to PGND.
AVDD
AVDD
Negative Source-Driver Output Voltage. Connect ceramic capacitors of value 0.1μF and 10μF from this pin to GND with the smallest capacitor closest to the pin.
NAVDD
N
AVDD
DC-DC Inverting Converter Inductor/Diode Connection.
LXN
LXN
EP
EP
Enable Input Pin. When EN is low, the device is in shutdown. When EN is taken high, the device is active. In stand-alone mode, the outputs are turned on in the stored sequence when EN goes high.
EN
EN
Ground Connection
GND
GND
Negative Charge-Pump Push-Pull Drive Output.
DN
DN
Positive Connection for First Flying Capacitor. Connect a 22nF capacitor from FC1- to FC1+.
FC1+
FC1+
Supply Voltage for Positive Charge Pump. PGVDD is connected to HVINP by means of an internal switch when the positive charge pump is enabled. Bypass PGVDD with a ceramic capacitor of 1μF to GND.
PGVDD
PGVDD
Supply Connection for Display Bias Circuitry. Bypass IN with local 10μF and 0.1μF capacitors.
IN
IN
Output of Negative Charge-Pump Block. Connect a 1μF capacitor from this pin to GND.
VGOFF
VGOFF
Output of Positive Charge-Pump Block. Connect a 1μF capacitor from VGON to GND.
VGON
VGON
FAULT OUTPUT
FAULT OUTPUT
TFT POWER INPUT
TFT POWER
INPUT
TFT POWER INPUT
TFT POWER
INPUT
FLT
FLT
TFT POWER INPUT
TFT POWER
INPUT
Logic Ground.
DGND
D
GND
Device Address Select pin. Connect to GND or V18 to Select the Device I2C Address. See the I2C address table. To use stand-alone mode (without I2C) leave the ADD pin open. In this mode, the device turns on all outputs in the programmed sequence when EN is taken high.
ADD
ADD
Ground Connection for Boost Switching Device and VCOM Buffer. Connect to GND using a low-impedance trace.
PGND
P
GND
Bidirectional I2C Data Pin.
SDA
S
DA
I2C Clock Pin.
SCL
S
CL
I2C BUS
I
2
C BUS
Bootstrap Capacitor Connection for Synchronous Rectifier Driver. Connect a 0.1μF ceramic capacitor between BST and LXP.
BST
BST
Negative Supply for VCOM Buffer. Connect a ceramic capacitor of at least 1μF from VCOMN to GND.
VCOMN
VCOMN
Output of VCOM amplifier.
VCOM
VCOM
T
T
Temperature Sensor Pin. When using the temperature compensation function, connect an NTC from TEMP to GND. If unused, leave TEMP unconnected.
TEMP
TEMP
Negative Source-Driver Output Voltage. Connect ceramic capacitors of value 0.1μF and 10μF from this pin to GND with the smallest capacitor closest to the pin.
NAVDD
N
AVDD
Drive Output for External npn Pass Transistor for VCOMN regulator. Connect to the base of the external npn transistor.
VCB
VCB
Output of Internal 1.8V Regulator. Connect a 1μF capacitor from V18 to GND.
V18
V18
Programming Voltage. Apply a voltage of 8.5V to this pin during the programming of non-volatile registers. Connect to GND through a resistor during normal operation.
VPROG
VPROG
Negative Connection for First Flying Capacitor. Connect a 22nF capacitor from FC1- to FC1+.
FC1-
FC1-
Positive Connection for Second Flying Capacitor. Connect a 22nF capacitor from FC2- to FC2+.
FC2+
FC2+
Negative Connection for Second Flying Capacitor. Connect a 22nF capacitor from FC2- to FC2+.
FC2-
FC2-
Reference Resistor Pin. When using the temperature compensation function, connect a resistor from RREF to GND. If unused, leave RREF unconnected.
RREF
R
REF
Ground Connection for Charge Pumps.
CPGND
CP
GND
1mF
1
m
F
0.1mF
0.1
m
F
1mF
1
m
F
1mF
1
m
F
1mF
1
m
F
0.1mF
0.1
m
F
10mF
10
m
F
10mF
10
m
F
2.2mF
2.2
m
F
10mF
10
m
F
1kW
1k
W
