Low-Noise, Dual-Output, Regulated Charge Pump

for GaAsFET, LCD, and VCO Supplies

6

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9

SYNC

Clock Synchronizing Input. Connect an external 20kHz

MAX768 to that frequency. Connect SYNC to GND to select the internal 25kHz clock, or to IN for the inter-

nal 100kHz clock.

13

V+

Doubler Charge-Pump Output. See Table 2 for capacitor selection.

15

IN

Supply (3V to 5.5V). Bypass IN with 4.7µF to GND.

NAME

FUNCTION

1

C1-

Negative Terminal of the Doubler Charge-Pump Capacitor. See Table 2 for capacitor selection.

16

C2+

Positive Terminal of the Inverter Charge-Pump Capacitor. See Table 2 for capacitor selection.

PIN

14

C1+

Positive Terminal of the Doubler Charge-Pump Capacitor. See Table 2 for capacitor selection.

11

SETP

Set Positive Output Voltage Input. Connect SETP to GND for factory-preset +5V output. Connect a resistor

divider between POUT, SETP, and GND for custom output voltage setting.

12

POUT

Positive Regulator Output. See Table 2 for capacitor selection.

10

RDY

Output-Ready Indicator. This open-drain output pulls to GND when the negative output voltage (NOUT) is

within 10% of the regulation voltage.

5

NOUT

Negative Regulator Output. See Table 2 for capacitor selection.

7

NSHDN

Negative-Supply Shutdown Input. Pull

NSHDN low to turn off the inverting charge pump, the negative reg-

ulator, and the bias-ready indicator. If

PSHDN is also low, the part completely shuts down.

8

PSHDN

Positive-Supply Shutdown Input. Pull

PSHDN low to turn off the positive regulator. If NSHDN is also low,

the part completely shuts down.

6

SETN

Set Negative Output Voltage Input. Connect SETN to GND for factory-preset -5V. Connect a resistor

divider between NOUT, SETN, and GND for custom output voltage setting.

3

C2-

Negative Terminal of the Inverter Charge-Pump Capacitor

4

V-

Inverter Charge-Pump Output. See Table 2 for capacitor selection.

2

GND

Ground

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