Datasheet
Multi-Output Power Supplies with VCOM Amplifier
and High-Voltage Gamma Reference for LCD TVs
MAX17126/MAX17126A
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Pin Description (continued)
PIN NAME FUNCTION
30 GD
Step-Up Regulator External pMOS Pass Switch Gate Input. A 10FA P 20% current source pulls down
on the gate of the external pFET when EN is high.
31 FB1
Boost Regulator Feedback Input. Connects FB1 to the center of a resistive voltage-divider between the
boost regulator output and GND to set the boost regulator output voltage. Place the resistive voltage-
divider within 5mm of FB1.
32 COMP
Compensation Pin for the Step-Up Regulator Error Amplifier. Connects a series resistor and capacitor
from COMP to ground.
33 THR
VGHM Low-Level Regulation Set-Point Input. Connects THR to the center of a resistive voltage-divider
between AVDD and GND to set the V
GHM
falling regulation level. The actual level is 10 x V
THR
. See the
Switch Control section for details.
34 SUPP
Positive Charge-Pump Drivers Power Supply. Connects to the output of the boost regulator (AVDD) and
bypasses to CPGND with a 0.1FF capacitor. SUPP is internally connected to GD_I.
35 CPGND Charge Pump and Buck Power Ground
36 DRVP Positive Charge-Pump Driver Output. Connects DRVP to the positive charge-pump flying capacitor(s).
37 DLY1
High-Voltage Switch Array Delay Input. Connects a capacitor from DLY1 to GND to set the delay time
between when the positive charge pump finishes its soft-start and the startup of this high-voltage switch
array. A 10FA current source charges C
DLY1
. DLY1 is internally pulled to GND through 50I resistance
when EN is low or when VL is below its UVLO threshold.
38 FBP
Positive Charge-Pump Regulator Feedback Input. Connects FBP to the center of a resistive voltage-
divider between the positive charge-pump regulator output and GND to set the positive charge-pump
regulator output voltage. Place the resistive voltage-divider within 5mm of FBP.
39 VGH Switch Input. Source of the internal high-voltage p-channel MOSFET between VGH and VGHM.
40 VGHM
Internal High-Voltage MOSFET Switch Common Terminal. VGHM is the output of the high-voltage
switch-control block.
41 DRN Switch Output. Drain of the internal high-voltage p-channel MOSFET connected to VGHM.
42 SUPN
Negative Charge-Pump Drivers Power Supply. Bypass to CPGND with a 0.1FF capacitor. SUPN is inter-
nally connected to IN2.
43 DRVN
Negative Charge-Pump Driver Output. Connects DRVN to the negative charge-pump flying
capacitor(s).
45 FBN
Negative Charge-Pump Regulator Feedback Input. Connect FBN to the center of a resistive voltage-
divider between the negative output and REF to set the negative charge-pump regulator output voltage.
Place the resistive voltage-divider within 5mm of FBN.
46 REF
Reference Output. Connects a 0.22FF capacitor from REF to GND. All power outputs are disabled until
REF exceeds its UVLO threshold.
47 VREF_FB
Gamma Reference Feedback Input. Connect VREF_FB to the center of a resistive voltage-divider
between VREF_O and GND to set the gamma reference output voltage. Place the resistive voltage-
divider within 5mm of VREF_FB.
48 VREF_O Gamma Reference Output
— EP
Exposed Pad. Connects EP to GND, and ties EP to a copper plane or island. Maximizes the area of this
copper plane or island to improve thermal performance.