LTC3214 Linear Technology, LTC3214 Datasheet - Page 5

• Manufacturer Part Number: LTC3214
• Description: 500mA Camera LED Charge Pump
• Manufacturer: Linear Technology

BLOCK DIAGRA
PI FU CTIO S
C2
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
LED is connected between CPO (anode) and I
ode). The current into the I
connected to the I
I
resistor connected between this pin and GND is used to set
the LED current level.
LED
SET
+
–
U
, C1
.
(Pin 4): Input. I
(Pin 5): LED Current Programming Resistor Pin. A
+
, C2
U
–
, C1
–
SET
(Pins 1, 2, 8, 10): Charge Pump Flying
U
LED
pin and regulated internally.
7
6
is the LED current sense pin. The
V
EN
IN
W
250k
LED
+
OSCILLATOR
CONTROL
to C1
pin is set by a resistor
LOGIC
9
GND
–
and from C2
LED
2
C1
CONTROL
(cath-
+
MODE
+
to
+
–
10
C1
EN (Pin 6): Input. The EN pin is used to enable the part and
bring it into shutdown mode. An internal 250kΩ resistor
pulls this pin to GND when left floating.
V
should be bypassed with a 2.2µF to 4.7µF 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.
–
IN
CURRENT
CONTROL
SOURCE
(Pin 7): Power. Supply voltage for the LTC3214. V
V
REF
VOLTAGE
CLAMP
5
I
SET
1
C2
+
V
IN
58Ω
8
C2
11
GND
–
0.11Ω
CPO
I
LED
3
4
3214 BD
LTC3214
5
3214f
IN