LTC3202 Datasheet, PDF (4/12 Pages) Linear Technology – Low Noise, High Efficiency Charge Pump for White LEDs

LTC3202
TYPICAL PERFOR A CE CHARACTERISTICS
Short-Circuit Current vs Supply
Voltage
300
C_FLY = 1µF
V_FB = 0V
280
V_OUT = 0V
T_A = 25°C
260
240
220
200
180
2.7 3.0
3.3 3.6 3.9
INPUT SUPPLY (V)
4.2 4.5
3202 G07
V_OUT Soft-Start Ramp
V_{D0, D1}
2V/DIV
V_OUT
1V/DIV
V_IN = 3.6V
C_OUT = 1µF
200µs/DIV
3202 G08
Input and Output Ripple
V_IN
(AC COUPLED)
20mV/DIV
V_OUT
(AC COUPLED)
20mV/DIV
V_IN = 3.6V
500ns/DIV
C_IN = C_OUT = 1µF
I_OUT = 60mA
3202 G09
PI FU CTIO S
D1, D0 (Pin 1, 10): Control Inputs. D0 and D1 determine
the set point voltage of the FB pin (see Table 1).
FB (Pin 2): FB is the Feedback Input for the Regulation
Control Loop.
V_OUT (Pin 3): V_OUT is the Output of the Charge Pump. A low
impedance 1µF X5R or X7R ceramic capacitor is required
from V_OUT to GND.
V_IN (Pin 4): Input Supply Voltage. V_IN should be bypassed
with a 1µF to 4.7µF low impedance ceramic capacitor.
GND (Pin 5): Ground for the Charge Pump and Control
Circuitry. This pin should be connected directly to a low
impedance ground plane.
C2^–, C1^–, C1⁺, C2⁺ (Pin 6, 7, 8, 9): Charge Pump Flying
Capacitor Pins. A 1µF X5R or X7R ceramic capacitor
should be connected from C1⁺ to C1^– and from C2⁺ to
C2 ^–.
PGND (Pin 11, Exposed Pad DFN Only): Power Ground
for the Charge Pump. This pin must be connected directly
to a low impedance ground plane.
3202fa
4