Datasheet

LT1946A
12
sn1946a 1946afs
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone]
●
FAX: [phone]
●
www.linear.com  LINEAR TECHNOLOGY CORPORATION 2001
LT/TP 1102 2K • PRINTED IN USA
PART NUMBER DESCRIPTION COMMENTS
LT1613 550mA (I
SW
), 1.4MHz, Step-Up DC/DC Converter V
IN
= 0.9V to 10V, V
OUT
to 34V, I
Q
= 3mA, I
SD
< 1µA, ThinSOT
TM
LT1615/LT1615-1 300mA/0.75mA (I
SW
), Constant Off-Time Step-Up V
IN
= 1V to 15V, V
OUT
to 34V, I
Q
= 20µA, I
SD
< 1µA, ThinSOT
DC/DC Converter
LT1930/LT1930A 1A (I
SW
), 1.2MHz/2.2MHz, Step-Up DC/DC Converter V
IN
= 2.6V to 16V, V
OUT
to 34V, I
Q
= 4.2mA/5.5mA, I
SD
< 1µA, ThinSOT
LT1946 1.5A (I
SW
), 1.2MHz, Step-Up DC/DC Converter V
IN
= 2.45V to 16V, V
OUT
to 34V, I
Q
= 3.2mA, I
SD
< 1µA, MS8
LT1961 1.5A (I
SW
), 1.25MHz, Step-Up DC/DC Converter V
IN
= 3V to 25V, V
OUT
to 35V, I
Q
= 0.9mA, I
SD
< 6µA, MS8E
ThinSOT is a trademark of Linear Technology Corporation.
Low Profile (<1.1mm Tall) Triple Output TFT Supply (8V, –8V, 24V)
V
IN
V
IN
3.3V
SW
FB
LT1946A
L1
1.2µH
D1
R3
5.23k
R2
28.7k
1946A TA05
C2
20µF
C5
0.1µF
C6
0.1µF
C7
0.1µF
C4
1µF
C3
2.2µF
C1
4.7µF
C
SS
100nF
D7
D2 D3
V
OFF
–8V
10mA
AV
DD
8V
375mA
V
ON
23V
5mA
D6
C8
0.1µF
V
C
SHDN
3
8
7
1
2
56
SS
COMP
+
D4 D5
C1–C8: X5R or X7R
C1: 4.7µF, 6.3V
C2: 2× 10µF, 10V
C3: 2.2µF, 10V
C4: 1µF, 25V
C5, C6, C8: 0.1µF, 10V
C7: 0.1µF, 16V
D1: MICROSEMI UPS120 OR EQUIVALENT
D2–D7: ZETEX BAT54S OR EQUIVALENT
L1: COILCRAFT LP01704-122MC
* EXPOSED PAD MUST ALSO BE GROUNDED
OFF ON
4
GND*
A
VDD
LOAD CURRENT (mA)
EFFICIENCY (%)
1946A TA06
90
85
80
75
70
65
60
55
50
0 100 200 300 400
V
ON
LOAD = 5mA
V
OFF
LOAD = 10mA
Efficiency
Start-Up Waveforms
1ms/DIV
A
VDD
5V/DIV
V
OFF
5V/DIV
I
IN
0.5A/DIV
V
ON
10V/DIV
Transient Response
50µs/DIV
A
VDD
50mV/DIV
AC COUPLED
I
LI
0.5A/DIV
350mA
200mA
I
LOAD
TYPICAL APPLICATIO S
U
RELATED PARTS
1946A TA07 1946A TA08