LTC3216 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC3216
Linear Technology
'LTC3216' PDF : 12 Pages View PDF
LTC3216
TYPICAL PERFORMANCE CHARACTERISTICS (TA = 25°C unless otherwise specified)
2x Mode CPO Output Ripple
Charge Pump Mode Switching
and Input Current
VCPO
20mV/DIV
A/C COUPLED
VIN = 3.6V
500ns/DIV
ICPO = 400mA
3216 G12
VCPO
1V/DIV
IVIN
500mA/DIV
EN2
5V/DIV
VIN = 3V
1ms/DIV
3216 G13
PIN FUNCTIONS
C2+, C1+, C2–, C1– (Pins 1, 2, 10, 12): Charge Pump
Flying Capacitor Pins. A 2.2μF X5R or X7R ceramic ca-
pacitor should be connected from C1+ to C1– and from
C2+ to C2–.
CPO (Pin 3): Output. CPO is the output of the charge
pump. This pin may be enabled or disabled using the EN1
and EN2 inputs. A 4.7μF X5R or X7R ceramic capacitor is
required from CPO to GND.
ISET1/ISET2 (Pins 4, 6): LED Current Programming Resistor
Pins. The ISET1 and ISET2 pins will servo to 1.22V. Resistors
connected between each of these pins and GND are used
to set the high and low LED current levels. Connecting
a resistor of 2k or less will cause the LTC3216 to enter
overcurrent shutdown mode.
ILED (Pin 5): Output. ILED is the LED current source output.
The LED is connected between CPO (anode) and ILED
(cathode). The current into the ILED pin is set via the EN1
and EN2 inputs, and the programming resistors connected
from ISET2 and ISET1 to GND.
EN1/EN2 (Pins 7, 8): Inputs. The EN1 and EN2 pins are
used to select which current level is being supplied to the
LED, as well as to put the part into shutdown mode. The
truth table for these pins is as follows:
Truth Table
EN1
0
1
0
1
EN2
MODE
0
Shutdown
0
Low Current
1
High Current
1
Low + High Current
VIN (Pin 9): Power. Supply voltage for the LTC3216. VIN
should be bypassed with a 2.2μF or greater low impedance
ceramic capacitor to GND.
GND (Pin 11): Charge Pump Ground. This pin should be
connected directly to a low impedance ground plane.
Exposed Pad (Pin 13): Control Signal Ground. This pad
must be soldered to a low impedance ground plane for
optimum thermal and electrical performance.
3216fc
5
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