LTC3215 Linear Technology, LTC3215 Datasheet - Page 5

• Manufacturer Part Number: LTC3215
• Description: 700mA Low Noise High Current LED Charge Pump
• Manufacturer: Linear Technology

BLOCK DIAGRA
PI FU CTIO S
C2
Flying Capacitor Pins. A 2.2µF X5R or X7R ceramic
capacitor should be connected from C1
C2
CPO (Pin 3): Output. CPO is the output of the Charge
Pump. This pin may be enabled or disabled using the EN
input. A 4.7µF X5R or X7R ceramic capacitor is required
from CPO to GND.
I
The LED is connected between CPO (anode) and I
(cathode). The current into the I
programming resistor connected from I
LED
+
+
U
, C1
(Pin 4): Output. I
to C2
+
, C2
–
U
.
–
, C1
7
6
–
U
LED
EN
(Pins 1, 2, 8, 10): Charge Pump
V
IN
is the LED current source output.
W
CONTROL
LOGIC
OSCILLATOR
9
GND
LED
pin is set by the
+
SET
to C1
to GND.
–
and from
2
C1
CONTROL
LED
+
MODE
–
+
I
I
this pin and GND is used to set the LED current level.
Connecting a resistor of 2k or less will cause the LTC3215
to enter overcurrent shutdown mode.
EN (Pin 6): Input. The EN is used to enable the part or put
it into shutdown mode.
V
should be bypassed with a 2.2µF or greater low impedance
ceramic capacitor to GND.
GND (Pin 9): Charge Pump Ground. This pin should be
connected directly to a low impedance ground plane.
EXPOSED PAD (Pin 11): Control Signal Ground. This pad
must be soldered to a low impedance ground plane for
optimum thermal and electrical performance.
SET
SET
10
IN
C1
(Pin 7): Power. Supply voltage for the LTC3215. V
–
(Pin 5): LED Current Programming Resistor Pin. The
pin will servo to 1.22V. A resistor connected between
V
1.5X MODE: CPO = 4.6V
REF
2X MODE: CPO = 5.1V
1X MODE: CPO = V
1
C2
+
DETECTOR
DROPOUT
CURRENT
CONTROL
IN
SOURCE
5
I
SET
8
C2
–
11
GND
CPO
I
LED
3
4
3215 BD
LTC3215
5
3215f
IN