MAX8784
Step-Up Regulator, Internal Charge Pumps, Switch
Control, and Operational Amplifier for TFT LCDs
10 ______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1 C1N Negative Terminal of Flying Capacitor C1
2 C1P Positive Terminal of Flying Capacitor C1
3 BGND Operational Amplifier and Charge-Pump Supply Ground
4 SUP
Operational Amplifier and Charge-Pump Supply Input. Connect SUP to AVDD. Bypass SUP to BGND with
0.1µF capacitor.
5 POS1 Operational Amplifier Noninverting Input
6 NEG1 Operational Amplifier Inverting Input
7 OUT1 Operational Amplifier Output
8 OUT2 Operational Amplifier Output
9 NEG2 Operational Amplifier Inverting Input
10 POS2 Operational Amplifier Noninverting Input
11 POS3 Operational Amplifier Noninverting Input
12 OUT3 Operational Amplifier Output
13, 19,
20, 26
N.C. No Connection. Not internally connected.
14 ADEL
Step-Up Regulator Delay Input. Connect a capacitor from ADEL to AGND to set the delay time. A 5µA current
source charges C
ADEL
. ADEL is internally pulled to AGND by a 20Ω resistor in shutdown. For details, see the
Power-Up Sequence section.
15 GDEL
Positive Charge-Pump Startup Delay and High-Voltage Switch Delay Input. Connect a capacitor from GDEL to
AGND to set the delay time. A 5µA current source charges C
GDEL
. GDEL is internally pulled to AGND by a
20Ω resistor in shutdown. For details, see the Power-Up Sequence section.
16 CTL
High-Voltage Switch Control Input. When CTL is high, the switch between GON and POUT is turned on and
the switch between GON and DRN is turned off. When CTL is low, the switch between GON and DRN is
turned on and the switch between GON and POUT is turned off. For details, see the High-Voltage Switch
Control section.
17 HVS HVS Mode Input. Connect HVS to V
CC
to enable HVS mode. For details, see the HVS Mode section.
18 DRVN Negative Charge-Pump Regulator Output. Connect DRVN to the negative charge-pump flying capacitor(s).
21 FBN
Negative Charge-Pump Regulator Feedback Input. Connect FBN to the center of a resistive voltage-divider
between the negative output and REF. Place the resistive voltage-divider within 5mm of FBN. For details, see
the Output-Voltage Selection section.
22 REF Reference Output. Connect a 0.22µF capacitor from REF to AGND.
23 AGND Analog Ground
24 V
CC
V
CC
Supplies the Internal Reference and Other Internal Circuitry. Connect V
CC
to the input supply voltage
and bypass V
CC
to AGND with a minimum 1µF ceramic capacitor.
25 SHDN Active-Low Shutdown. When SHDN is low, the device enters its low-power shutdown mode.
27, 28 PGND Power Ground
29, 30 LX
Step-Up Regulator Switching Node. Connect inductor and Schottky diode to LX and minimize trace area for
lowest EMI.
