Linear Technology DC1523A Quick setup guide

1
dc1523af
DEMO MANUAL DC1523A
DESCRIPTION
LTC3789EGN:
High Efficiency Synchronous
4-Switch Step-Up/Step-Down
DC/DC Converter
Demonstration circuit 1523A features the LTC
®
3789EGN,
a high efficiency switching step-up/down controller. The
DC1523A input range is from 5V to 36V. The output volt-
age is 12V. The board is capable of delivering up to 5A of
output current over the input voltage range.
The LTC3789EGN is a high performance switching regula-
tor controller designed to regulate the output using input
voltages above, below or equal to the output voltage.
Synchronous operation provides very high efficiency, up
to 97%. Constant frequency current mode architecture
allows phase-lockable frequency from 200kHz to 600kHz.
An accurate output current limit provides support for
battery charging. A wide input and output range with L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. All other trademarks are the property of their respective owners.
PERFORMANCE SUMMARY
smooth transfer function through all operating modes
makes the product ideal for automotive, telecom and
battery systems.
The MODE/PLLIN pin can select between pulse skipping
mode and forced continuous mode operation and allows
the IC to be synchronized to an external clock. A Power
Good output pin indicates when the output is within 7.5%
of its set point.
Design files for this circuit board are available at
http://www.linear.com/demo
PARAMETER CONDITIONS/NOTES VALUE
Minimum Input Voltage 5V
Maximum Input Voltage 36V
Output Voltage VOUT Regulation VIN = 5V to 36V, IOUT = 0A to 5A 12V ±2%
Maximum Continuous Output Current Some Airflow May be Needed at Low Input
Voltage and Continuous Full Load
5A DC
Default Operating Frequency R3 = 121k 400kHz
External Clock Synchronous Frequency Range 200kHz to 600kHz
Efficiency VIN = 5V to 36V, IOUT = 5A 88% to 97%. See Figures 3 and 6
Load Transient See Figure 5

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dc1523af
DEMO MANUAL DC1523A
QUICK START PROCEDURE
Figure 1. Proper Measurement Equipment Setup
Demonstration circuit 1523A is easy to set up to evalu-
ate the performance of the LTC3789EGN. Please refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below.
1. With power off, connect the input supply, load and
meters as shown in Figure 1. Preset the load to 0A and
VIN supply to 0V.
2. Set the current limit of the input supply high enough
so that the bench supply does not go into current limit
mode. Figure 2 shows input current as a function of
input voltage, at full load. Input current can reach 13A
at 5V input voltage.
3. Place jumpers in the following positions:
JP1 JP2
RUN MODE
ON CCM
4. Turn on the power at the input. Increase VIN to between
5V and 36V. The circuit will start and the output voltage
will regulate at 12V ±2%. The current draw at no load
is 20mA to 60mA depending on the input voltage.
5. Apply load and observe output voltage regulation, ripple
voltage, efficiency and other parameters. Efficiency and
power loss at full load is shown in Figure 3. Continuous
operation with full power and low input voltage may
require some airflow.
V
POWER
SUPPLY LOAD
DC1523A F01
+
–
A
V
+
–
A

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dc1523af
DEMO MANUAL DC1523A
QUICK START PROCEDURE
VIN (V)
5
8
10
14
20 30
DC1523A F02
6
4
10 15 25 35 40
2
0
12
CURRENT (A)
IOUT
IIN
VIN (V)
0
EFFICIENCY (%)
POWER LOSS (W)
92
96
40
DC1523A F03
88
84 10 20 30
515 25 35
100
90
94
86
98
4
6
2
0
8
3
5
1
7
EFFICIENCY
POWER LOSS
Figure 2. Input Current at Full Load (12V at 5A Out)
Figure 4. Output Ripple Voltage at 24VIN (Top), 12VIN (Middle),
6VIN (Bottom). Measured Across COUT1, BW = 20MHz, 100mV/Div
Figure 3. Efficiency and Power Loss at Full Load. The Power
Loss is Highest in Boost Mode Due to the High Inductor Current,
and Drops as Input Voltage Increases. Switching Losses Again
Increase when VIN > VOUT. All Four MOSFETs are Switching in
Buck-Boost Mode and This Shows Up as a Small Increase in
Losses When VIN = 11V to 15.5V
LOAD (A)
0
EFFICIENCY (%)
94
96
98
4
DC1523 F06
92
90
88 1235
6V
9V
12V
18V
24V
30V
36V
LOAD (A)
0
14
12
10
8
6
4
2
035
DC1523A F07
12 46
VOUT (V)
Figure 5. Load Transient Response
Figure 6. Efficiency at Various Input Voltages
Figure 7. Output Current Limit. (VIN = 12V. The Easiest Way to Do
This Test is with an Active Load in Voltage Mode)

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dc1523af
DEMO MANUAL DC1523A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Required Circuit Components
1 1 CC1 CAP., C0G, 1000pF, 50V, 10% 0603 AVX, 06035A102KAT2A
2 2 CC2, CSS CAP., X7R, 0.01μF, 50V, 10% 0603 AVX, 06035C103KAT2A
3 1 CIN1 CAP., Alum, 270μF, 50V, 20% SANYO, 50ME270WX+T
4 1 COUT1 CAP., OS-CON, 330μF, 16V, 20% SANYO, 16SEP330M+T
5 4 C1, C2, C16, C17 CAP., X7R, 22μF, 16V, 20% 1210 AVX, 1210YC226MAT2A
6 2 C4, C22 CAP., X7R, 0.22μF, 16V, 20% 0603 TAIYO YUDEN, EMK107BJ224MA
7 4 C5, C6, C9, C25 CAP., X7R, 3.3μF, 50V, 20% 1210 AVX, 12105C335MAT2A
8 1 C10 CAP., X7R, 2.2μF, 10V, 10% 0603 MURATA, GRM188R71A225K
9 1 C12 CAP., NPO, 390pF, 100V, 10% 1206 AVX, 12061A391KAT2A
10 1 C13 CAP., NPO, 1800pF, 100V, 10% 1206 AVX, 12061A182KAT2A
11 1 C14 CAP., X7R, 0.1μF, 50V, 10% 0603 AVX, 06035C104KAT2A
12 1 C15 CAP., X7R, 1μF, 50V, 20% 1206-1210 AVX, 12065C105MAT2A
13 1 C18 CAP., X7R, 10μF, 10V, 20% 1206 AVX, 1206ZC106MAT2A
14 1 C24 CAP., X7R, 1μF, 16V, 20% 0603 AVX, 0603YC105MAT2A
15 1 D2 DIODE, BAS16, SOT23 DIODES, BAS16
16 2 D7, D4 SCHOTTKY REC., DFLS160, PowerDI-123 DIODES INC., DFLS160
17 2 D5, D6 SCHOTTKY RECT., B240A SMA DIODES INC. B240A-13-F
18 1 D8 ZENER DIODE, 5.1V, BZX84C5V1, SOT23 DIODES INC. BZX84C5V1-7-F
19 1 L1 INDUCTOR, 4.7μH TOKO, FDA1254-4R7M
20 1 Q2 MOSFET N-CHAN., 40V VISHAY, Si7884BDP-T1-E3
21 1 Q4 MOSFET N-CHAN., 40V VISHAY, Si4840BDY-T1-E3
22 2 Q3, Q5 MOSFET N-CHAN., SiR496DP, 20V VISHAY, SiR496DP-T1-GE3
23 1 RC RES., CHIP., 14.7k, 0.1W, 1% 0603 VISHAY, CRCW060314K7FKEA
24 1 RFB1 RES., CHIP., 113k, 0.1W, 1% 0603 VISHAY, CRCW0603113KFKEA
25 1 RFB2 RES., CHIP., 8.06k, 0.1W, 1% 0603 VISHAY, CRCW06038K06FKEA
26 1 R1 RES., CHIP., 5.6Ω, 0.1W, 1% 0603 VISHAY, CRCW06035R60FKEA
27 2 R2, R18 Sensor Res., 0.01Ω, 1W, 2%, RL3720W Thin Film Tech., RL3720WT-R010-G-C
28 4 R3, R4, R13, R14 RES., CHIP., 100Ω, 0.1W, 5%, 0603 VISHAY, CRCW0603100RJNEA
29 1 R5 RES., CHIP., 15Ω, 0.125W, 1% 0603 VISHAY, CRCW060315R0FKEA
30 1 R7 RES., CHIP., 100k, 0.1W, 1% 0603 VISHAY, CRCW0603100KFKEA
31 3 R8, R11, R26 RES., CHIP., 10Ω, 0.1W, 5% 0603 VISHAY, CRCW060310R0JNEA
32 2 R10, R9 RES., CHIP., 1.24k, 0.1W, 1% 0603 VISHAY, CRCW06031K24FKEA
33 1 R20 Sensor Res., 0.004Ω, 1W, 2%, RL3720W Thin Film Tech., RL3720WT-R004-G-C
34 1 R21 RES., CHIP., 121k, 0.1W, 1% 0603 VISHAY, CRCW0603121K0FKEA
35 1 R24 RES., CHIP., 10k, 0.1W, 1% 0603 VISHAY, CRCW060310K0FKEA
36 1 R25 RES., CHIP., 0Ω, 0.125W, 0805 VISHAY, CRCW08050000Z0EA
37 1 R28 RES., CHIP., 5.6Ω, 1% 1206 VISHAY, CRCW12065R60FNEA
38 1 R29 RES., CHIP., 3.6Ω, 1% 1206 VISHAY, CRCW12063R60FNEA
39 1 R30 RES., CHIP., 33.2k, 0.1W, 1% 0603 VISHAY, CRCW060333K2FKEA
40 1 R31 RES., CHIP., 12.1k, 0.1W, 1% 0603 VISHAY, CRCW060312K1FKEA
41 1 U1 I.C.,VOLT. REG. Linear Tech. Corp.LTC3789EGN

5
dc1523af
DEMO MANUAL DC1523A
PARTS LIST
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
42 0 C3, C23, C26, C27 OPT CAP., 1210
43 1 CIN2 CAP., Alum, OPT
44 0 CF1, C11, CF, C7, C8 OPT CAP., 0603
45 0 COUT2 OPT
46 0 Q6 OPT Dual N-CHAN., Si7948DP, 60V
47 0 Q7 OPT Dual N-CHAN., Si7958DP, 40V
48 0 R6, R12, R22, R27 OPT RES., OPT
Hardware for Demo Board Only
49 4 TP1, TP2, TP3, TP7 TESTPOINT, TURRET, 0.061" PBF MILL-MAX, 2308-2-00-80-00-00-07-0
50 7 TP4-TP6, TP8, TP10-TP12 TESTPOINT, TURRET, 0.094" PBF MILL-MAX, 2501-2-00-80-00-00-07-0
51 1 JP1 3-PIN 0.079 SINGLE ROW HEADER SAMTEC, TMM103-02-L-S
52 2 JP2C, JP2B 2-PIN 0.079 SINGLE ROW HEADER SAMTEC, TMM102-02-L-S
53 2 XJP1, XJP2B SHUNT, 0.079" CENTER SAMTEC, 2SN-BK-G
54 4 J1, J2, J3, J4 CONNECTOR, BANANA JACK KEYSTONE, 575-4
55 4 (STAND-OFF) STAND-OFF, NYLON 0.25" KEYSTONE, 8831(SNAP ON)

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dc1523af
DEMO MANUAL DC1523A
SCHEMATIC DIAGRAMS
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
CIRCUITRY ON THIS SIDE MUST CONNECT TO POWER GND GROUNDPLANE
CIRCUITRY ON THIS SIDE MUST CONNECT TO SIGNAL GND GROUNDPLANE
<------ ------>
2. INSTALL SHUNTS AS SHOWN. 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. NOTE: UNLESS OTHERWISE SPECIFIED
MODE
VOS+
VOS+
VOUT
VIN
VOUT
INTVCC
INTVCC
VOUT
INTVCC
INTVCC
VIN+
VIN+
VOUT1
INTVCC
VIN
BG2 TG2 SW2
CS
TG1 SW1 BG1
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Friday, November 19, 2010
12
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Friday, November 19, 2010
12
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Friday, November 19, 2010
12
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
TAGE B.PRODUCTION3 07-02-10
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
TAGE B.PRODUCTION3 07-02-10
__
REVISION HISTORY DESCRIPTION DATEAPPROVEDECO REV
TAGE B.PRODUCTION3 07-02-10
__
R11 10R11 10
TP7
GND
TP7
GND
C4
0.22uF 16V
C4
0.22uF 16V
C10
2.2uF
C10
2.2uF
C6
3.3uF
50V 1210
C6
3.3uF
50V 1210
R29
3.6
1206
R29
3.6
1206
R26 10 R26 10
C22
0.22uF
16V
C22
0.22uF
16V
Q3
SiR496DP
Q3
SiR496DP
TP12
EXTVCC TP12 EXTVCC
CF1 OPT CF1 OPT
C26 OPT
1210
C26 OPT
1210
CC2
0.01uF
CC2
0.01uF
R5 15 Ohm 0805 R5 15 Ohm 0805
R7
100K
R7
100K
R9 1.24K R9 1.24K
R25
0
R25
0
R14
100
R14
100
R10 1.24K R10 1.24K
R8
10
R8
10
C13
1800pF 1206
C13
1800pF 1206
JP1
ON
OFF
RUN
JP1
ON
OFF
RUN
1 3 2
RC
14.7K
RC
14.7K
R6 OPT R6 OPT
C1
22uF 16V 1210
C1
22uF 16V 1210
R28 5.6 Ohm 1206 R28 5.6 Ohm 1206
R1 5.6 R1 5.6
C23 OPT 1210 C23 OPT 1210
C18
10uF 1206
C18
10uF 1206
J3 VIN
5V - 36V
J3 VIN
5V - 36V
CSS
0.01uF
CSS
0.01uF
R27
OPT
R27
OPT
C16
22uF 1210 16V C16 22uF 1210 16V
JP2B
PULSE
SKIP
JP2B
PULSE
SKIP
C3 OPT 1210 C3 OPT 1210
D7
DFLS160
D7
DFLS160
D6
B240A
D6
B240A
C7 OPTC7 OPT
+
COUT1
330uF
16V
+
COUT1
330uF
16V
C11
OPT
C11
OPT
+
CIN1
270uF
50V
+
CIN1
270uF
50V
D5
B240A
D5
B240A
C5
3.3uF
50V
1210
C5
3.3uF
50V
1210
D8
BZX84C5V1
D8
BZX84C5V1
RFB2
8.06K
RFB2
8.06K
TP8
INTVCC TP8 INTVCC
R2
0.010
2%
R2
0.010
2%
TP3 VIN+ TP3 VIN+
R18
0.010
2%
R18
0.010
2%
+
CIN2
OPT
+
CIN2
OPT
R12 OPT R12 OPT
TP6
VLOGIC TP6 VLOGIC
J4 GND J4 GND
Q5
SiR496DP
Q5
SiR496DP
Q4
Si4840BDY
Q4
Si4840BDY
TP5
SS TP5 SS
L1 4.7uH L1 4.7uH
R21
121K 1%
R21
121K 1%
R30
33.2K
R30
33.2K
J1
VOUT
12V @ 5A MAX
J1
VOUT
12V @ 5A MAX
C12 390pF
1206
C12 390pF
1206
TP11
SGND TP11 SGND
R3 100R3 100
TP2
VOS+
TP2
VOS+
JP2C
CCM
JP2C
CCM
C8 OPTC8 OPT
CC1 1000pF CC1 1000pF
C25
3.3uF
50V
1210
C25
3.3uF
50V
1210
R22
OPT
R22
OPT
C15
1uF
50V
1210
C15
1uF
50V
1210
TP4
PGOOD TP4 PGOOD
C9
3.3uF
50V
1210 C9
3.3uF
50V
1210
C17
22uF 1210 16V C17 22uF 1210 16V
C27
OPT
1210
C27
OPT
1210
CF OPT CF OPT
R20 0.004 R20 0.004
R13 100 R13 100
U1
LTC3789EGN
U1
LTC3789EGN
VFB
1
SS
2
SENSE1+
3
SENSE1-
4
ITH
5
SGND
6
MODE/PLLIN
7
FREQ
8
RUN
9
VINSNS
10
VOUTSNS
11
ILIM
12
IOSENSE+
13
IOSENSE-
14
NC
15
SW2
16
TG2
17
BOOST2
18
BG2
19
EXTVCC
20
INTVCC
21
VIN
22
PGND1
24
BOOST1
25
SW1
27
PGOOD
28
TG1
26
BG1
23
C2
22uF 16V 1210
C2
22uF 16V 1210
R24
10K
R24
10K
D2
BAS16
D2
BAS16
3 1
+
COUT2
330uF
16V
OPT
+
COUT2
330uF
16V
OPT
RFB1
113K
RFB1
113K
C24 1uF C24 1uF
J2 GND J2 GND
R4 100 R4 100
TP1
VOS-
TP1
VOS-
R31
12.1K
R31
12.1K
TP10
PLLIN TP10 PLLIN
D4
DFLS160
D4
DFLS160
Q2
Si7884BDP
Q2
Si7884BDP
C14
0.1uF
C14
0.1uF

7
dc1523af
DEMO MANUAL DC1523A
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 DIAGRAMS
5 5
4 4
3 3
2 2
1 1
D D C C B B A A
OPTIONAL CIRCUIT #1 (1.5A OUTPUT)
BG2 TG2TG1 SW2SW1
BG1 CS
VIN VOUT1
TG1 SW1 BG1
TG2 SW2 BG2
CS
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Thursday, June 17, 2010
22
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Thursday, June 17, 2010
22
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
SIZE DATE:
IC NO. REV.
SHEET OF
TITLE:
APPROVALS
PCB DES.
APP ENG.
TECHNOLOGY
Fax: [phone] Milpitas, CA 95035 Phone: [phone] 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
3
Thursday, June 17, 2010
22
HIGH EFFICIENCY STEP-UP/DOWN DC/DC CONVERTER
AK
TAGE B.
N/A
LTC3789EGN
DEMO CIRCUIT 1523A
Q6A
Si7948DP
Q6A
Si7948DP
2
8 1
7
Q6B
Si7948DP
Q6B
Si7948DP
4
6 3
5
Q7B
Si7958DP
Q7B
Si7958DP
4
6 3
5
Q7A
Si7958DP
Q7A
Si7958DP
2
8 1
7

8
dc1523af
DEMO MANUAL DC1523A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ●FAX: [phone] ●www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2010
LT 1210 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LTC) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LTC for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LTC from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LTC assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LTC currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LTC applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation

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