Datasheet

MAX8795A
TFT-LCD DC-DC Converter with
Operational Amplifiers
14 ______________________________________________________________________________________
Pin Description (continued)
PIN NAME FUNCTION
17 OUT4 Operational-Amplifier 4 Output
18 POS5 Operational-Amplifier 5 Noninverting Input
19 NEG5 Operational-Amplifier 5 Inverting Input
20 OUT5 Operational-Amplifier 5 Output
21 LX
n-Channel Power MOSFET Drain and Switching Node. Connect the inductor and Schottky diode to LX
and minimize the trace area for lowest EMI.
22 IN Supply Voltage Input. IN can range from 2.5V to 6V.
23 FB
Step-Up Regulator Feedback Input. Regulates to 1.233V (nominal). Connect a resistive voltage-divider
from the output (V
MAIN
) to FB to analog ground (AGND). Place the divider within 5mm of FB.
24 COMP
Step-Up Regulator Error-Amplifier Compensation Point. Connect a series RC from COMP to AGND.
See the Loop Compensation section for component selection guidelines.
25 FBP
Gate-On Linear-Regulator Feedback Input. FBP regulates to 1.25V (nominal). Connect FBP to the
center of a resistive voltage-divider between the regulator output and AGND to set the gate-on linear-
regulator output voltage. Place the resistive voltage-divider within 5mm of FBP.
26 DRVP
Gate-On Linear-Regulator Base Drive. Open drain of an internal n-channel MOSFET. Connect DRVP to
the base of an external pnp pass transistor. See the Pass-Transistor Selection section.
27 FBN
Gate-Off Linear-Regulator Feedback Input. FBN regulates to 250mV (nominal). Connect FBN to the
center of a resistive voltage-divider between the regulator output and REF to set the gate-off linear-
regulator output voltage. Place the resistive voltage-divider within 5mm of FBN.
28 DRVN
Gate-Off Linear-Regulator Base Drive. Open drain of an internal p-channel MOSFET. Connect DRVN to
the base of an external npn pass transistor. See the Pass-Transistor Selection section.
29 DEL
High-Voltage Switch Delay Input. Connect a capacitor from DEL to AGND to set the high-voltage
switch startup delay.
30 CTL
High-Voltage Switch Control Input. When CTL is high, the high-voltage switch between COM and SRC
is on and the high-voltage switch between COM and DRN is off. When CTL is low, the high-voltage
switch between COM and SRC is off and the high-voltage switch between COM and DRN is on. CTL is
inhibited by the undervoltage lockout or when the voltage on DEL is less than 1.25V.
31 DRN Switch Input. Drain of the internal high-voltage back-to-back p-channel MOSFETs connected to COM.
32 COM
Internal High-Voltage MOSFET Switch Common Terminal. Do not allow the voltage on COM to exceed
V
SRC
.
— EP Exposed Paddle. Must be connected to AGND. Do not use as the only ground connection.