5
dc1728af
DEMONSTRATION CIRCUIT
1728A QUICK START GUIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SCHEMATIC DIAGRAM
5
5
4
4
3
3
2
2
1
1
D
D
C
C
B
B
A
A
ALL CAPACITORS ARE IN MICROFARADS.
NOTES: UNLESS OTHERWISE SPECIFIED
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE IN OHMS, 0402.
GND
SHDN
VOUT
-1.5A MAX
GND
*
CAPACITOR C1 IS AN OPTIONAL PART. IT WAS INSERTED ON THE DC1728A TO
DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE USE OF LONG INPUT
LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, THE CAPACITOR
IS NOT NEEDED. SEE APPLICATION NOTE AN88 FOR MORE DETAILS.
*
VIN
-1.9V TO -30V
-1.22V
-2.5V
-5.0V
-12.0V
-15.0V
USER
SELECT
SUNCON
50CE10BSS
ON OFF
USER SELECT
VIN
VOUT
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
LT3015EDD
1
1
11
02
,0
2 li
rp
A ,
ya
ds
en
de
W
1.5A, LOW NOISE, NEGATIVE REGULATOR
KT
EDWIN L.
N/A
DEMO CIRCUIT 1728A
WITH PRECISION CURRENT LIMIT
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
LT3015EDD
1
1
11
02
,0
2 li
rp
A ,
ya
ds
en
de
W
1.5A, LOW NOISE, NEGATIVE REGULATOR
KT
EDWIN L.
N/A
DEMO CIRCUIT 1728A
WITH PRECISION CURRENT LIMIT
SIZE
DATE:
.
V
E
R
.
O
N
CI
SHEET
OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035 Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SCHEMATIC
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
www.linear.com
1
LT3015EDD
1
1
11
02
,0
2 li
rp
A ,
ya
ds
en
de
W
1.5A, LOW NOISE, NEGATIVE REGULATOR
KT
EDWIN L.
N/A
DEMO CIRCUIT 1728A
WITH PRECISION CURRENT LIMIT
REVISION HISTORY
DESCRIPTION
DATE
APPROVED
ECO
REV
EDWIN L.
PRODUCTION
1
04-20-11
_
REVISION HISTORY
DESCRIPTION
DATE
APPROVED
ECO
REV
EDWIN L.
PRODUCTION
1
04-20-11
_
REVISION HISTORY
DESCRIPTION
DATE
APPROVED
ECO
REV
EDWIN L.
PRODUCTION
1
04-20-11
_
R3 3.65k
R3 3.65k
R2 0
R2 0
R1 3.48k
R1 3.48k
E3E3
COUT 10uF 25V 1206
COUT 10uF 25V 1206
R4 11.0k
R4 11.0k
CIN 10uF 50V 1210
CIN 10uF 50V 1210
RSD 0
RSD 0
R7 OPT
R7 OPT
E5E5
JP1JP1
1
3
2
4
U1 LT3015EDD
U1 LT3015EDD
GND
5
IN
1
ADJ
6
OUT
8
IN
2
SHDN
3
GND
4
OUT
7
IN
9
E1E1
+
C1 10uF 50V
+
C1 10uF 50V
R6 39.2k
R6 39.2k
+
C2
7343
OPT
+
C2
7343
OPT
JP2 HD2X6-079
JP2 HD2X6-079
1
3
5
6
4
2
7
9
8
10
11
12
E4E4
E2E2
R9 100k
R9 100k
R5 30.9k
R5 30.9k
R8 OPT
R8 OPT
