MAX768
Low-Noise, Dual-Output, Regulated Charge Pump
for GaAsFET, LCD, and VCO Supplies
6 _______________________________________________________________________________________
9 SYNC
Clock Synchronizing Input. Connect an external 20kHz ≤ f
CLK
≤ 240kHz to SYNC to synchronize the
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
______________________________________________________________Pin Description
