DC1898A - Demo Manual

DEMO MANUAL DC1898A
LTC3899EFE
Triple Output Synchronous Step-Up/
Dual Step-Down Supply
Description
Demonstration circuit 1898A is a triple output synchronous step-up/dual step-down supply featuring the
LTC3899EFE. The circuit is using a drop-in layout: the
main buck circuit components fit in an area of ¾˝ × 1½˝,
while the main boost circuit area is ¾˝ × 1¾˝. The package style for the LTC3899EFE is a 38-pin exposed pad
TSSOP package.
The main features of the board include rail tracking (buck
channels only), an internal 5V linear regulator for bias,
separate RUN pins for each output, a DRVSET jumper to
set the gate drive voltage and a Mode selector that allows
the converter to run in CCM, pulse skip or Burst Mode®
operation. Synchronization to an external clock is also
possible.
The LTC3899EFE buck outputs are supplied from the boost
output. With this boost-then-buck topology, the buck
outputs maintain regulation over the entire input range.
The resultant wide input voltage range of 2.5V to 60V is
suitable for automotive or other battery fed applications
where low quiescent current is important. The LT3899EFE
data sheet gives a complete description of the part, operation and application information. The data sheet must be
read in conjunction with this quick start guide for demo
circuit 1898A.
Design files for this circuit board are available at
http://www.linear.com/demo/DC1898A
L, LT, LTC, LTM, Burst Mode, 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
Specifications are at TA = 25°C
SYMBOL
PARAMETER
CONDITIONS
MIN
VIN
Input Supply Range
VOUT1
Output1 Voltage Range
VIN = 2.5V*–60V, IOUT1 = 0A to 5A
VOUT2
Output2 Voltage Range
VOUT3
Output3 Voltage Range
fSW
Typical Free Running Switching Frequency
Efficiency
See Figures 3,4 and 5 for Efficiency Curves
TYP
MAX
60
V
4.90
5.0
5.10
V
VIN = 2.5V*–60V, IOUT2 = 0A to 3A
8.33
8.5
8.67
V
VIN = 2.5V*–10V#, IOUT3 = 0A to 5.5A**,
IOUT1,2 = 0A
9.70
10.0
10.30
V
2.5
VIN = 12V, VOUT1 = 5.0V, IOUT1 = 5A
VIN = 48V, VOUT1 = 5.0V, IOUT1 = 5A
VIN = 12V, VOUT2 = 8.5V, IOUT2 = 3A
VIN = 48V, VOUT2 = 8.5V, IOUT2 = 3A
VIN = 5V, VOUT3 = 10.0V, IOUT3 = 5.5A**
UNITS
350
kHz
92.1
82.6
96.1
89.5
93.4
%
%
%
%
%
# When VIN > VOUT3 Then VOUT3 Follows VIN
* VIN Needs to Be > 4.5V (DRVSET=“6V”) or > 8V (DRVSET=“10V”) to Start Up.
** Maximum Output Current Roughly Covers the Full Load from VOUT1 and VOUT2. No Extra Current Is Allowed.
dc1898af
1
DEMO MANUAL DC1898A
Quick Start Procedure
Demonstration circuit DC1898A is easy to set up to
evaluate the performance of the LTC3899EFE. Refer to
Figure 1 for proper measurement equipment setup and
follow the procedure below:
NOTE. When measuring the input or output voltage ripple,
care must be taken to avoid a long ground lead on the
oscilloscope probe. Measure the input or output voltage
ripple by touching the probe tip directly across the VIN
or VOUT and GND terminals or directly across relevant
capacitor. See Figure 2 for proper scope probe technique.
1.Place jumpers in the following positions:
JP1:
JP2:
JP4:
JP5:
JP8:
ON
ON
ON
Burst Mode
6V
2.With power off, connect the input power supply to VIN
and GND.
3.Turn on the power at the input.
NOTE. Make sure that the input voltage does not exceed 60V.
4.Check for the proper output voltages.
VOUT1 = 4.900V to 5.100V,
VOUT2 = 8.330V to 8.670V
VOUT2 = 9.700V to 10.300V
NOTE. If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
5.Once the proper output voltages are established, adjust
the loads within the operating range and observe the
output voltage regulation, ripple voltage, efficiency and
other parameters.
IOUT1
+
+
VOUT1
LOAD
–
–
–
–
VOUT2
+
IOUT2
LOAD
+
IOUT3
IIN
VOUT3
+
LOAD
–
+
+
–
VIN
–
+
VIN SUPPLY
–
dc1898 F01
Figure 1. Proper Measurement Equipment Setup
2
dc1898af
DEMO MANUAL DC1898A
Quick Start Procedure
+
VIN
VOUT
GND
–
COUT
GND
Figure 2. Measuring Input or Output Ripple Across Terminals or Directly Across Bulk Capacitor
FREQUENCY SYNCHRONIZATION AND MODE SELECTION
Demonstration circuit 1898A’s Mode selector allows the
converter to run in forced continuous operation, pulse skip
operation, Burst Mode or be synchronizing to an external
clock by changing the position of JP5.
Table 1. Mode Selection and Synchronized Operation Options
CONFIGURATION
JP5
Forced Continuous Operation
‘FCM’
Pulse Skip Operation
‘PS/Sync’
Synchronized to Ext. Clock Applied to CLKIN Pin
‘PS/Sync’
Burst Mode Operation
‘Burst’
RAIL TRACKING
Demonstration circuit 1898A is configured for an on board
soft start circuit. The soft start ramp rate can be adjusted
by changing the value of C2 and C47. Demonstration circuit
1898A can also be modified to track an external reference.
Refer to Table 2 and Table 3 for tracking options and to
the data sheet for more details.
Table 2. VOUT1 Tracking Options
CONFIGURATION
Soft Start Without Tracking (Default)
VOUT1 Tracking Scaled VOUT2
R2
R3
C2
TRK/SS1 CAP
OPEN
OPEN
0.1µF
Open
Resistor
Divider
Open
Open
Table 3. VOUT2 Tracking Options
CONFIGURATION
R34
R37
C47
TRK/SS2 CAP
Soft Start Without Tracking (Default)
0Ω
OPEN
0.1µF
OPEN
VOUT2 Equals External Ramp
0Ω
OPEN
OPEN
External Ramp
Resistor
Divider
OPEN
External Ramp
VOUT2 Tracking Scaled External Ramp
dc1898af
3
DEMO MANUAL DC1898A
optional inductor dcr current sensing
Demonstration circuit 1898A provides an optional circuit
for Inductor DCR Current Sensing. Inductor DCR Current
Sensing uses the DCR of the inductor to sense the inductor
current instead of discrete sense resistors. The advantages
of DCR sensing are lower cost, reduced board space and
higher efficiency, but the disadvantage is a less accurate
current limit. If DCR sensing is used, be sure to select an
inductor current with a sufficiently high saturation current
or use an iron powder type material.
Refer to Table 4 for Optional Inductor DCR Current Sensing
setup and to the data sheet for more details.
Table 4. Tracking Options
CONFIGURATION
CHANNEL1
RS1
R29
R30
C14
R45
R47
R61
CHANNEL2
RS2
R39
R40
C15
R51
R53
R62
CHANNEL3
RSNS1,2
R80
R81
C56
R89
R90
R91
Ref. Sch.
Ref. Sch.
Ref. Sch.
Ref. Sch.
OPEN
OPEN
OPEN
0Ω Copper
OPEN
OPEN
Current Sense Resistor (Default)
Inductor DCR Current Sensing
Calculated Value from Data Sheet
0Ω
Low Quiescent Current Applications and Measurement
The typical quiescent current (Iq) of the LTC3899 controller
is 29µA in sleep mode as specified in the LTC3899 data
sheet. However, the input current of the DC1898A board
can be higher than this value because of additional circuit
outside of the IC. To reduce the total input current, large
value FB divider resistors should be used.
EFFICIENCY (%)
typical efficiency vs load current
95
94 VOUT1 = 5V/5A
93 fSW = 350kHz
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
0.01
VIN = 12V, BURST MODE
VIN = 24V, BURST MODE
VIN = 48V, BURST MODE
0.1
LOAD CURRENT (A)
1
dc1898 F03
Figure 3. Channel 1 Typical Efficiency vs Load Current
4
dc1898af
DEMO MANUAL DC1898A
EFFICIENCY (%)
typical efficiency vs load current
98
97 VOUT2 = 8.5V/3A
96 fSW = 350kHz
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
0.01
VIN = 12V, FCM
VIN = 24V, FCM
VIN = 48V, FCM
0.1
LOAD CURRENT (A)
1
10
dc1898 F04
Figure 4. Channel 2 Typical Efficiency vs Load Current
100
EFFICIENCY (%)
90
VIN = 5V, FCM
80
70
60
50
0.1
VO = 10V/5.5A
fSW = 350kHz
(EQUIVALENT TO FULL LOAD FROM VOUT1 & VOUT2)
1
LOAD CURRENT (A)
10
dc1898 F05
Figure 5. Channel 3 Typical Efficiency vs Load Current
dc1898af
5
DEMO MANUAL DC1898A
typical efficiency vs load current
100
EFFICIENCY (%)
90
80
70
60
50
VOUT2 = 8.5V/3A
fSW = 350kHz
40
BURST
PULSE SKIP
FCM
30
0.01
0.1
LOAD CURRENT (A)
1
10
dc1898 F06
Figure 6. Channel 2 VIN = 12V Efficiency vs Load Current
Parts List
ITEM
QTY REFERENCE
Required Circuit Components
1
3
CIN1, CIN2, COUT10
2
8
3
COUT6-COUT9,
PART DESCRIPTION
MANUFACTURER/PART NUMBER
CAP., ALUM., 33µF, 63V, 20%, HVP
SUN ELECT., 63HVP33M
CAP., 2.2µF, X7R, 100V, 10%, 1210
AVX, 12101C225KAT2A
CIN6, CIN7, C50, C51
4
1
COUT1
CAP., 22µF, X7R, 10V, 20%, 1206
TAIYO YUDEN,
LMK316ABJ226ML-T
5
1
COUT2
CAP., POSCAP, 220µF, 6.3V, 20%, 7343
PANASONIC, 6TPB220ML
6
1
COUT4
CAP., 4.7µF, X7R, 16V, 20%, 1206
TDK, C3216X7R1C475M
7
1
COUT5
CAP., POSCAP, 68µF, 10V, 20%, 7343
PANASONIC, 10TPC68M
8
7
C2, C4, C17, C20, C21, C47, C52
CAP., 0.1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E104K080AA
9
1
C11
CAP., 4.7µF, X5R, 6.3V, 10%, 0805
AVX, 08056D475KAT2A
10
11
12
13
14
15
16
17
18
19
20
21
22
23
4
1
1
1
1
2
1
1
4
2
1
1
1
4
C14, C15, C56, C62
C41
C42
C43
C44
C61, C64
C53
C54
C65-C68
C69, C70
L1
L2
L3
Q1, Q2, Q3, Q4
CAP., 1000pF, X7R, 50V, 10%, 0603
CAP., 1500pF, X7R, 50V, 10%, 0603
CAP., 100pF, NP0, 5%, 50V, 0603
CAP., 68pF, NP0, 50V, 10%, 0603
CAP., 2200pF, X7R, 50V, 10%, 0603
CAP., 1µF, X5R, 16V, 10%, 0603
CAP., 820pF, NP0, 50V, 10%, 0603
CAP., 0.01µF, X7R, 50V, 10%, 0603
CAP., 1µF, X7R, 50V, 10%, 0805
CAP., 0.22µF, X7R, 50V, 10%, 0805
IND, 4.9µH, 20%, HCI SMD
IND, 6.5µH, 20%, HCI SMD
IND, 1.2µH, 20%, HCI SMD
XSTR., MOSFET, N-CH, 80V, 12.3mΩ, 40A, PG-TSDSON-8
AVX, 06035C102KAT2A
AVX, 06035C152KAT2A
AVX, 06035A101JAT2A
AVX, 06035A680KAT2A
AVX, 06035C222KAT2A
AVX, 0603YD105KAT2A
AVX, 06035A821JAT2A
TDK, C1608X7R1H103K080AA
MURATA, GRM21BR71H105KA12L
KEMET, C0805F224K5RACTU
Würth Elektronik, 744314490
Würth Elektronik, 744314650
Würth Elektronik, 744325120
INFINEON, BSZ123N08NS3 G
6
dc1898af
DEMO MANUAL DC1898A
Parts List
ITEM
24
25
26
27
28
29
30
31
32
33
34
QTY
2
2
1
1
2
1
1
16
2
REFERENCE
Q8, Q10
RSNS1, RSNS2
RS1
RS2
R4, R5
R86
R27
R29, R30, R34, R36, R39, R40,
R70, R73, R78, R80, R87,
R94, R95, R96, R97, R98
R35, R31
35
PART DESCRIPTION
XSTR., MOSFET, N-CH, 75V, 100A, 4.2mΩ, PG-TDSON-8
RES., 0.006Ω, 1/2W, 1%, 2010
RES., 0.009Ω, 1/4W, 1%, 1206
RES., 0.015Ω, 1/4W, 1%, 1206
RES., 0Ω, 1/2W, 2010
RES., 2.2Ω, 1/10W, 5%, 0603
RES., 357k, 1/10W, 1%, 0603
RES., 0Ω, 1/10W, 0603
MANUFACTURER/PART NUMBER
INFINEON, BSC042NE7NS3 G
VISHAY, WSL20106L000FEA
VISHAY, WSL12069L000FEA
VISHAY, WSL1206R0150FEA
VISHAY, CRCW20100000Z0EF
VISHAY, CRCW06032R20JNEA
VISHAY, CRCW0603357KFKEA
VISHAY, CRCW06030000Z0EA
RES., 15k, 1/10W, 5%, 0603
VISHAY, CRCW060315K0JNEA
3
R32, R33
RES., 68.1k, 1/10W, 1%, 0603
VISHAY, CRCW060368K1FKEA
36
1
R43
RES., 649k, 1/10W, 1%, 0603
VISHAY, CRCW0603649KFKEA
37
1
R48
RES.,100k, 1/10W, 5%, 0603
VISHAY, CRCW0603100KJNEA
38
1
R75
RES., 3.6k, 1/10W, 1%, 0603
VISHAY, CRCW06033K60FKEA
39
1
R81
RES., 22Ω, 1/10W, 5%, 0603
VISHAY, CRCW060322R0JNEA
40
1
U1
I.C., LTC3899EFE#PBF
LINEAR TECH., LTC3899EFE#PBF
CAP., OPTION, 1210
CAP., OPTION, 2.2µF, X7R, 100V, 10%, 1210
CAP., OPTION, 1206
CAP., OPTION, 0603
OPTION
Additional Demo Board Circuit Components
1
0
CIN8, CIN9, C58, C59
2
0
C50, C51
3
0
C32, C36
4
0
C37, C38, C48, C49,
5
C57, C55, C60, C63
6
0
D5 OPT (? PACKAGE TYPE)
7
0
D6-D8 OPT
8
0
Q5, Q7 (OPTION)
9
0
Q9, Q11 OPT
10
0
Q12-Q15 OPT
11
0
Q16-Q19 OPT
12
0
R2, R3, R26, R28, R37,
13
R38, R41, R45, R47, R51
14
R53, R55, R61, R62, R72,
15
R74, R79, R82, R85,
16
R89, R90-R93, R98, R99
Hardware: For Demo Board Only
1
17 E1, E9-E14, E23-E27, E30-E34
2
4
JP1, JP2, JP4, JP8
3
1
JP7
4
2
J8, J7
5
1
JP5
6
7
8
1
4
4
JP1, JP2, JP4, JP8
OPTION
OPTION
OPTION
OPTION
VISHAY, Si4910DY-T1-GE3
DIODE, SCHOTTKY OPTION
DIODE, OPTION, SOD-323
XSTR., MOSFET, N-CH, 40V, SO-8
XSTR., MOSFET, N-CH (? PACKAGE TYPE)
XSTR., OPTION (WHAT PACKAGE TYPE?)
XSTR., OPTION (WHAT PACKAGE TYPE?)
RES., OPTION, 0603
OPTION
TEST POINT, TURRET, .094" MTG. HOLE
MILL-MAX, 2501-2-00-80-00-00-07-0
CONN., HEADER, 1 × 3, 2mm, Brass, Gold Flash Overall
SULLINS, NRPN031PAEN-RC
CONN., HEADER, 1 × 4, 2mm, Brass, Gold Flash Overall
CONN., JACK, BANANA, Non-Insulated, 0.218" Brass Nickel
Plate
SULLINS, NRPN041PAEN-RC
CONN., HEADER, 2 × 3, 2mm, Brass, Gold Flash Overall
PCB, DC1898A
SHUNT, 2mm, GOLD PLATING
STANDOFF, NYLON, SNAP-ON, 0.500"
KEYSTONE, 575-4
SULLINS, NRPN032PAEN-RC
DEMO CIRCUIT 1898A
SAMTEC, 2SN-BK-G
KEYSTONE, 8833
dc1898af
7
D
C
B
A
1
R73
E26
R37
0
VSW2
VSW1
3
2
R45
OPT
S2-
OPT
R53
S1-
OPT
2. INSTALL SHUNTS AS SHOWN.
2
1. ALL RESISTORS ARE IN OHMS, 0603.
ALL CAPACITORS ARE IN MICROFARADS, 0603.
1%
0
OPT
OPT
R61
3
R62
JP4
R47
OFF
2
VBIAS
1
OPT
RUN3
ON
R41
3
OPT
JP1
2
VBIAS
1
C48
OFF
OPT
R38
OPT
R51
VBIAS
1
0.1uF
VOUT2
68.1K
R33
R36
68.1K
0
VL2-
S2+
VL1-
S1+
OPT
R26
C60
OPT
OPT
R28
VSW3
C42
1500pF
OPT
R89
R92
OPT
100pF
C41
VOUT3
R43
649K
1%
R27
357K
1%
VOUT3
R31
15K
OPT
C49
OPT
C37
1%
INTVCC
OPT
C38
1%
1%
R87
R32
VOUT1
INTVCC
RUN1
ON
C52
0.1uF
C47
0.1uF
C2
OPT
VOUT3
OPT
R74
0
JP2
ON
OFF
R2
OPT
OPT
R34
RUN2
E33
E32
E23
E10
E9
4
3
2
1
NOTE: UNLESS OTHERWISE SPECIFIED
NOTE:
WHEN DCR SENSING IS IMPLEMENTED,
SHORT RSENSE1 & RSENSE2.
REMOVE R30, R29, R40, R39, R80 & R81
STUFF R61, R62 AND R91 WITH 0 OHMS.
CALCULATE R45, R47 & C14, R51, R53 & C15
AND R89, R90 & C56 PER THE DATA SHEET.
ALSO REFER TO QSG FOR EXAMPLE.
OPTIONAL DCR SENSING
RUN3
RUN2
RUN1
SS3
TRACK / SS2
TRACK / SS1
R3
VOUT2
JP7 FSW
350kHz
PROGRAM
535kHz
0
1
2
3
S3+
OPT
R90
R97
0
ITH3
ITH2
C44
2.2nF
18
2
PLLIN/MODE
DRVSET
VPRG3
RUN3
RUN2
RUN1
TRK/SS3
TRK/SS2
TRK/SS1
ITH3
ITH2
ITH1
VFB3
VFB2
VFB1
VL3-
U1
FCM
PS/SYNC
BURST
SGND
EXTVCC
R80
0
C64
1uF
C56
E34
E31
1000pF
LTC3899EFE
6
4
2
S1+
TG1
36
S2-
16
OPT
R55
R39
0
R95
0
R93
1uF
R30
0
R40
0
2
VOUT1
R86
R85
VBIAS
2.2
OPT
4
VIN
4
5
VOUT3
4
4
Q11
OPT
4
4
Q4
BSZ123N08NS3G
4
4
Q1
BSZ123N08NS3G
Q2
BSZ123N08NS3G
Q8
BSC042NE7NS3G
DRVCC
0.1uF
C21
OPT
D7
DRVCC
Q10
BSC042NE7NS3G
0.1uF
C4
D8 OPT
1000pF
C15
4.7uF
C11
2
D6 OPT
1000pF
C14
VOUT2
1
1
OPT
0
R96
0
C61
TG3
31
BG3
SW3
32
29
BOOST3
30
27
S2+
17
EXTVCC
BG2
R94
0
R98
BOOST2
24
25
23
R29
0
C20
0.1uF
0.1uF
C17
TG2
VBIAS
BG1
22
28
26
33
34 BOOST1
35
S1-
3
C62
1000pF
4
EXTVCC
R81
100
OPT
C63
BG3
TG3
SW3
BOOST3
EXTVCC
SENSE2-
SENSE2+
BG2
SW2
BOOST2
TG2
VBIAS
DRVCC
BG1
BOOST1
SW1
TG1
SENSE1+
SENSE1-
100K
R48
INTVCC
5
* OUTPUT 10V ONLY WHEN VIN < 10V, OTHERWISE VOUT3 FOLLOWS VIN.
DON'T CONNECT ANY LOAD.
** VIN NEEDS TO BE >4.5V TO START UP.
OPT
S3-
JP5
MODE
FREQ
R99
OPT
20
38
15
RUN2 14
RUN1 13
7
21
SS2
SS3
37
11
19
1
SS1
INTVCC
R91
6
5
10
R79
OPT
1%
ITH1
R75
3.6K
3
6V
DRVSET
JP8
10V
RUN3
10nF
C54
820pF
15K
C53
1%
68pF
0
VFB2
VFB1
OPT
VFB3
R78
R35
C43
1%
R70
C55
R72
OPT
5
3
1
INTVCC
INTVCC 12
E1
SENSE3+
S3+ 8
CLKIN
PGND
39
4
SENSE3S3- 9
3
4
6
2
4
BG1
OPT
C57
OPT
R82
R4
0
OPT
Q7-1
Q7-2
C51
2.2uF
100V
L2 6.5uH
C59
OPT.
6
HZ
DING L.
SCALE = NONE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
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
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
VL2-
7
0.015
RS2
0.009
RS1
7
CIN7
2.2uF
100V
1210
COUT7
2.2uF
100V
1210
2
DATE:
N/A
SIZE
CIN9
OPT
1210
8
VIN
VIN+
GND
VIN-
GND
**
LTC3899EFE
DEMO CIRCUIT 1898A
Tuesday, November 04, 2014
8
SHEET 1
2
OF 2
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
E30
J8
2.5V - 60V
J7
E27
TRIPLE OUTPUT SYNCHRONOUS
STEP-UP/DUAL STEP-DOWN SUPPLY
IC NO.
VOUT3
GND
8.5V / 3A
VOUT2
GND
5V / 5A
VOUT1
DATE
1-31-14
10V / 5.5A *
E24
E14
E13
E12
E11
DING L.
APPROVED
+ COUT10
33uF
E25
63V
C36
OPT
1206
OPT
CIN1
+ CIN2
33uF
63V
COUT9
2.2uF
100V
1210
VOUT3
TECHNOLOGY
CIN8
OPT.
100V
1210
VIN
COUT8
2.2uF
100V
1210
+ COUT5
68uF
10V
7343
VOUT2
+ COUT2
220uF
6.3V
VOUT1
C32
DESCRIPTION
REVISION HISTORY
PRODUCTION
COUT4
4.7uF
16V
1206
COUT1
22uF
6.3V
REV
TITLE: SCHEMATIC
_
ECO
CIN6
2.2uF
100V
1210
COUT6
2.2uF
100V
1210
VIN2
APPROVALS
RSNS2
0.006
RSNS1
0.006
VSW2
VIN1
VL1-
C58
OPT.
L1 4.9uH
C50
2.2uF
100V
VSW1
VL3-
R5
0
VOUT3
OPT
Q5-1
Q5-2
CUSTOMER NOTICE
BG3
VSW3
TG3
BG2
VSW2
TG2
VIN2
L3 1.2uH
OPT
D5
VSW1
TG1
VSW3
Q9 OPT
2
4
Q3
BSZ123N08NS3G
1
2
3
2
5
6
7
8
1
2
3
1
2
3
5
6
7
8
5
6
7
8
5
6
7
8
1
2
3
5
6
7
8
1
2
3
5
6
7
8
1
2
3
1
2
3
1
1
2
3
5
6
7
8
5
6
7
8
1
2
5
6
3
7
8
5
6
3
7
8
1
1
8
2
SHT 2
1
D
C
B
A
DEMO MANUAL DC1898A
Schematic Diagram
dc1898af
BG3
VSW3
TG3
4
Q14
OPT
4
Q12
OPT
5
6
7
8
1
2
3
5
6
7
8
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
SHT 1
C70
0.22uF
CUSTOMER NOTICE
4
Q15
OPT
4
Q13
OPT
C69
0.22uF
SHT 1
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
SCALE = NONE
DING L.
HZ
APPROVALS
BG2
VSW2
TG2
BG1
VSW1
TG1
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES.
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APP ENG.
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
1
2
3
5
6
7
8
1
2
3
5
6
7
8
1
2
3
IC NO.
VIN1
VIN2
C68
1uF
C66
1uF
VIN2
VIN1
LTC3899EFE
DEMO CIRCUIT 1898A
SHEET 2
2
OF 2
RE V .
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
C67
1uF
C65
1uF
TRIPLE OUTPUT SYNCHRONOUS
STEP-UP/DUAL STEP-DOWN SUPPLY
DATE: Tuesday, February 25, 2014
N/A
SIZE
4
Q19
OPT
4
Q16
OPT
TECHNOLOGY
TITLE: SCHEMATIC
4
Q18
OPT
4
Q17
OPT
5
6
7
8
1
2
3
5
6
7
8
1
2
3
5
6
7
8
1
2
3
5
6
7
8
1
2
3
VOUT3
DEMO MANUAL DC1898A
Schematic Diagram
dc1898af
9
DEMO MANUAL DC1898A
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 application engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
10 Linear Technology Corporation
dc1898af
LT 0115 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2015