5

LTC1262

Operation

The LTC1262 uses a charge pump tripler to generate 12V

by a 300kHz oscillator. When the oscillator output is low,

C2 are stacked in series with the bottom plate of C1 pulled

oscillator pulse gating scheme. A resistor divider senses

To reduce supply current the LTC1262 may be put into

shutdown mode by floating the SHDN pin or taking it to

resistor divider are switched off to reduce supply current

to typically 0.5

µA. At the same time an internal switch

exits shutdown and the charge pump operates to raise

Choice of Capacitors

The LTC1262 is tested with the capacitors shown in

Figure 2. C1 and C2 are 0.22

µF ceramic capacitors and

Table 1 if other choices are desired.

Table 1. Recommended Capacitor Types and Values

CAPACITOR

CERAMIC

TANTALUM

ALUMINUM

C1, C2

0.22

µF to 1µF

Not

Not

Recommended

Recommended

2

µF (Min)

4.7

µF (Min)

10

µF (Min)

1

µF (Min)

4.7

µF (Min)

10

µF (Min)

C1 and C2 should be ceramic capacitors with values in the

range of 0.22

µF to 1µF. Higher values provide better load

regulation. Tantalum capacitors are not recommended as

the higher ESR of these capacitors degrades performance

desired. The LTC1262 does not require a 0.1

µF capacitor

Maximum Load Current

The LTC1262 will source up to 50mA continuously without

to the device will result.