LTC3218

5

3218fa

TYPICAL PERFORMANCE CHARACTERISTICS

2x Mode CPO Output Ripple

PIN FUNCTIONS

CP, CM (Pin 1, Pin 9): Charge Pump Flying Capacitor. A

2.2µF X5R or X7R ceramic capacitor should be connected

from CP to CM.

CPO (Pin 2): Output of the Charge Pump. This pin may

be enabled or disabled using the ENT and ENF inputs.

A 4.7µF X5R or X7R ceramic capacitor is required from

CPO to GND.

ENT (Pin 4): Input. The ENT pin is used to enable the

part into torch mode and bring it into shutdown mode.

An internal 250kΩ resistor pulls this pin to GND when

left floating.

A resistor connected between this pin and GND is used

to set the LED torch current level.

A resistor connected between this pin and GND is used

to set the LED flash current level.

ENF (Pin 7): Input. The ENF pin is used to enable the

part into flash mode and bring it into shutdown mode.

An internal 250kΩ resistor pulls this pin to GND when

left floating. A safety timer will disable the part if this pin

is held high for more than 2 seconds.

GND (Pin 8): Ground. This pin should be connected directly

to a low impedance ground plane.

should be bypassed with a low impedance ceramic capaci-

tor to GND of at least 1.6µF of capacitance.

Exposed Pad (Pin 11): Ground. This pad must be soldered

to a low impedance ground plane for optimum thermal

performance.

2.9

4.5

3.3

3.7

4.1

3.1

3.5

3.9

4.3

3218 G13

40

50

70

80

90

100

60

50mA

100mA

150mA

200mA

300mA

500ns/DIV

50mV/DIV

AC COUPLED

3218 G14