LTC3450 Datasheet, PDF (7/12 Pages) Linear Technology – Triple Output Power Supply for Small TFT-LCD Displays

LTC3450
PI FU CTIO S
V3X (Pin 15): Charge Pump Tripler Output. This output is
15.3V (nom) at no load and is capable of delivering up to
500µA to a load. V3X should be bypassed to GND with a
0.1µF X5R type ceramic capacitor.
V_INV (Pin 16): Positive Voltage Input for the Charge Pump
Inverter. The charge pump inverter will generate a nega-
tive voltage corresponding to the voltage applied to V_INV.
Connecting V_INV to 5V or 10V will generate –5V or –10V
respectively on V_NEG. See Applications section for –15V
generation.
Exposed Pad (Pin 17): The exposed pad must be con-
nected to V_NEG (Pin 3) on the PCB. Do not connect the
exposed pad to GND.
BLOCK DIAGRA
V_IN
1.5V TO
4.6V
C1
2.2µF
L1
47µH
V_{IN 6}
SW
8
SYNCHRONOUS
PWM BOOST
SHUTDOWN
CONVERTER
MODE
BLANK SCAN
4
OSCILLATOR
550kHz
69kHz
OFF ON
SHDN
5
GLOBAL SHUTDOWN
7 ^VOUT
CHARGE PUMP
DOUBLER
IN
OUT
SHUTDOWN
CHARGE PUMP
TRIPLER
IN
OUT
SHUTDOWN
9
GND
CHARGE PUMP
INVERTER
IN
OUT
SHUTDOWN
C1⁺
11
C1^–
10
V2X
12
CF1
0.1µF
C2⁺
14
C2^–
13
V3X
15
CF2
0.1µF
16 ^VINV
C3⁺
1
C3^–
2
3 ^VNEG
CF3
0.1µF
3450 TA01
AV_DD
5.1V/10mA
C2
2.2µF
10V
C7
1µF
VGH (3 × AV_DD)
15V/500µA
C8
0.47µF
VGL
–10V/500µA
C11
0.47µF
3450f
7