Datasheet
LT1946
12
1946fb
© LINEAR TECHNOLOGY CORPORATION 2001
LT 0207 REV B • PRINTED IN USA
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
Low Profile, Triple Output TFT Supply (8V, –8V, 23V)
Efficiency
V
IN
V
IN
3.3V
SW
FB
LT1946
L1
5.4µH
D1
R3
5.23k
R2
28.7k
R
C
49.9k
1946 TA03
C2
20µF
C5
0.1µF
C6
0.1µF
C7
0.1µF
C4
1µF
C3
2.2µF
C1
4.7µF
C
C
470pF
C
SS
100nF
D7
D2 D3
V
OFF
–8V
10mA
AV
DD
8V
375mA
V
ON
23V
5mA
D6
C8
0.1µF
V
C
GND
SHDN
3
8
7
14
2
56
SS
COMP
+
D4 D5
C1 TO 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 TO D5: ZETEX BAT54S OR EQUIVALENT
L1: SUMIDA CDRH5D18-5R4
OFF ON
AV
DD
LOAD CURRENT (mA)
0
70
75
85
300
1946 TA03a
65
60
100 200 400
55
50
80
EFFICIENCY (%)
V
ON
LOAD = 5mA
V
OFF
LOAD = 10mA
Start-Up Waveforms
AV
DD
2V/DIV
V
ON
10V/DIV
V
OFF
5V/DIV
I
IN
200mA/V
1ms/DIV
1946 TA04
TYPICAL APPLICATIO
U
PART NUMBER DESCRIPTION COMMENTS
LT1613 1.4MHz Switching Regulator in 5-Lead ThinSOT
TM
5V at 200mA from 3.3V Input, ThinSOT Package
LT1615 Micropower Constant Off-Time DC/DC Converter in 5-Lead ThinSOT 20V at 12mA from 2.5V, ThinSOT Package
LT1930/LT1930A 1.2MHz/2.2MHz, 1A Switching Regulator in 5-Lead ThinSOT 12V at 300mA from 5V Input, ThinSOT Package
LT1944/LT1944-1 Dual 350mA Boost Converter V
IN
= 1.2V to 15V, V
OUT
to 34V, MS10 Package
LT1945 Dual ±250mA Boost Converter V
IN
= 1.2V to 15V, V
OUT
to ±34V, MS10 Package
LT1946A 2.7MHz, 1.5A Boost DC/DC Converter V
IN
= 2.45V to 16V, V
OUT
to 34V, MS8E Package
LT1947 3MHz, Dual Switching Regulator 8V at 200mA from 3.3V Input, 10-Lead MSOP Package
ThinSOT is a trademark of Linear Technology Corporation.
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