DC2422A - Demo Manual

DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
LTC7812EUH
Wide VIN, Step-Up + Step-Down
DC/DC Converter
DESCRIPTION
Demonstration circuit DC2422A is a step-up + step-down
DC/DC converter featuring the LTC®7812EUH, a high performance dual output (Boost + Buck) synchronous DC/
DC switching regulator controller. This board has three
different configurations:
n
n
n
DC2422A-A:Regulated VOUT to 12V
DC2422A-B:Quasi regulated VOUT between 10V and
16V
DC2422A-C:Dual outputs:12V (boost channel)
5V (buck channel)
This circuit enables a drop-in layout where the total circuit
area is only 1½" by 1". The LTC7812EUH is in a 32-lead
exposed pad QFN package.
The main features of the board include rail tracking (buck
channel only), an internal 5V linear regulator for bias,
separate RUN pins for each output 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.
PERFORMANCE SUMMARY
SYMBOL PARAMETER
VIN
VOUT1
The LTC7812 buck input is supplied from the boost output
for the DC2422A-A and DC2422A-B only. With this boostthen-buck topology, the buck output maintains regulation
over the entire input range. The wide input voltage range
of 4V to 36V is suitable for automotive or other battery
fed applications where low quiescent current is important.
The DC2422A-B is designed such that VOUT is partially
regulated between 10V and 16V for higher efficiency
(Figure 4a), reduced power loss, and switching noise.
When VIN is between 10V and 16V, it operates in passthru mode with the boost synchronous FET fully on and
the buck in drop-out with >99% duty cycle. When VIN is
below 10V, the boost is activated and when VIN is above
16V, the buck is activated as shown in Figure 4b.
The LT7812 data sheet gives a complete description of
the part, operation and application information and must
be read in conjunction with this quick start guide.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2422A
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
of Linear Technology Corporation. All other trademarks are the property of their respective
owners.
Specifications are at TA = 25°C
CONDITIONS
MIN
Input Supply Range
Output1 Voltage Range
= 0A to 8A†
11.7
DC2422A-B: VIN = 4V* – 36V, IOUT1 = 0A to 8A†
9.7
DC2422A-A: VIN = 4V* – 36V, IOUT1
DC2422A-C: VIN = 4V* – 36V, IOUT1 = 0A to 8A†
VBUS
VBUS Voltage Range (DC2422A-C only)
fSW
Typical Free Running Switching Frequency
Efficiency
See Figures 3, 4, 5 and 6 for Efficiency
Curves
TYP
4
MAX
36
12
UNITS
V
12.3
V
16.3
V
4.9
5**
5.1
V
11.7
12
12.3
V
350
kHz
DC2422A-A:VIN = 8V, VOUT1 = 12V, IOUT1 = 8A
VIN = 12V, VOUT1 = 12V, IOUT1 = 8A
VIN = 36V, VOUT1 = 12V, IOUT1 = 8A
93
95.4
95
%
%
%
DC2422A-B:VIN = 8V, VOUT1 = 10V, IOUT1 = 8A
VIN = 12V, VOUT1 = 12V, IOUT1 = 8A
VIN = 36V, VOUT1 = 16V, IOUT1 = 6A
94.8
97.2
95.8
%
%
%
DC2422A-C:VIN = 8V, VBUS = 12V, Ibus = 8A
VIN = 12V, VOUT1 = 5V, IOUT1 = 8A
VIN = 36V, VOUT1 = 5V, IOUT1 = 8A
95.8
94
91.9
%
%
%
†I
OUT1 starts to derate when VIN < 8V, *VIN needs to be >4.5V to start up, **VOUT1 follows VIN when VIN < 5V.
dc2422af
1
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
QUICK START PROCEDURE
Demonstration circuit DC2422A is easy to set up to evaluate
the performance of the LTC7812EUH. Refer to Figure 1
for proper measurement equipment setup and follow the
procedure below:
3. Turn on the power at the input.
NOTE: Make sure that the input voltage is higher than
8V and does not exceed 36V.
4. Check for the proper output voltages for different boards.
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.
DC2422A-B:9.7V < VOUT1 < 16.3V,
1. Place jumpers in the following positions:
NOTE: If there is no output, temporarily disconnect the
load to make sure that the load is not set too high.
JP1:
ON
JP2:
ON
JP3:
Burst Mode
BURST
2. With power off, connect the input power supply to VIN
and GND.
DC2422A-A: VOUT1 = 11.7V to 12.3V,
DC2422A-C: VOUT1 = 4.9V to 5.1V; VBUS = 11.7V to
12.3V.
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.
IOUT
–
–
+
IOUT
LOAD
+
–
–
LOAD
+
+
IIN
+
–
+
VIN SUPPLY
–
Figure 1. Proper Measurement Equipment Setup
dc2422af
2
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
QUICK START PROCEDURE
+
COUT
VOUT
–
GND
Figure 2. Measuring Input or Output Ripple Directly Across Ceramic Capacitor
FREQUENCY SYNCHRONIZATION AND MODE SELECTION
Demonstration circuit DC2422A’s Mode selector allows
the converter to run in forced continuous operation, pulse
skip operation, Burst Mode operation or be synchronizing
to an external clock by changing the position of JP3.
Table 1. Mode Selection and Synchronized Operation Options
CONFIGURATION
JP3
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 DC2422A is configured for an onboard soft-start circuit. The soft-start ramp rate can be
adjusted by changing the value of C47. Demonstration
circuit DC2422A can also be modified to track an external
reference. Refer to Table 2 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 External Reference
R34
R37
OPEN
OPEN
Resistor Divider
C47
TRK/SS1 CAP
0.1µF
OPEN
OPEN
External Reference
OPTIONAL INDUCTOR DCR CURRENT SENSING
Demonstration circuit 2422A 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 3 for Optional Inductor DCR Current Sensing
setup and to the data sheet for more details.
dc2422af
3
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
OPTIONAL INDUCTOR DCR CURRENT SENSING
Table 3. Optional Inductor DCR Current Sensing
CHANNEL1
CONFIGURATION
RS1
CHANNEL2
Current Sense Resistor (Default)
Inductor DCR Current Sensing
R39
R40
C15
R51
R53
R62
RS2
R80
R81
C56
R89
R90
R91
Ref. Sch.
Ref. Sch.
Ref. Sch.
Ref. Sch.
OPEN
OPEN
OPEN
0Ω Copper
OPEN
OPEN
Low Quiescent Current Applications and Measurement
The typical quiescent current (IQ) of the LTC7812 controller
is 28µA in sleep mode as specified in the LTC7812 data
sheet. However, the input current of the DC2422A 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. In addition, some
100
Calculated Value from Data Sheet
0Ω
of the optional pull-up resistors should be removed from
the board. Refer to Table 4 for the low input quiescent
current setup.
Table 4. Low Input Quiescent Current Configuration
Reference Designator
R46
Function
Stuffing Option
R92
PGOOD1
OV2
OPEN
OPEN
VOUT1 = 12V EFFICIENCY
90
EFFICIENCY (%)
80
70
60
50
VIN = 8V BURST
VIN = 36V BURST
VIN = 8V FCM
VIN = 36V FCM
40
30
0.1
1
IOUT (A)
10
dc2422a F03
Figure 3. DC2422A-A VOUT1 Typical Efficiency vs Load Current
VOUT1
100
90
VOUT = VIN
VBUCK
EFFICIENCY (%)
80
70
VBOOST
60
BUCK
ACTIVE
PASS-THRU
WIRE MODE
50
VIN = 12V
VIN = 8V
VIN = 36V
40
30
0.1
1
IOUT (A)
BOOST
ACTIVE
10
10V
16V
dc2422a F04b
VIN
dc2422a F04a
Figure 4a. DC2422A-B VOUT1 Typical FCM Efficiency vs Load Current
Figure 4b. DC2422A-B Partially Regulated VOUT
dc2422af
4
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
OPTIONAL INDUCTOR DCR CURRENT SENSING
100
95
100
VIN = 8V, VBUS = 12V EFFICIENCY
90
80
85
EFFICIENCY (%)
EFFICIENCY (%)
90
80
75
70
65
60
50
60
PULSE SKIP
BURST
FCM
55
50
0.1
70
1
IOUT (A)
10
30
0.1
dc2422a F05
20MHz BW
20mV/DIV
20mV/DIV
dc2422 F07
Figure 7. DC2422A-A VOUT1 Voltage Ripple at VIN = 8V
5µs/DIV
20MHz BW
20mV/DIV
50mV/DIV
Figure 9. DC2422A-A VOUT1 2A – 4A – 2A
Load Transient at VIN = 8V
10
dc2422a F06
dc2422 F08
Figure 8. DC2422A-A VOUT1 Voltage Ripple at VIN = 36V
20MHz BW
dc2422 F09
1
IOUT (A)
Figure 6. DC2422A-C VOUT1 Typical Efficiency vs Load Current
20MHz BW
200µs/DIV
VIN = 8V BURST
VIN = 36V BURST
VIN = 8V FCM
VIN = 36V FCM
40
Figure 5. DC2422A-C VBUS Typical Efficiency vs Load Current
5µs/DIV
VOUT1 = 5V EFFICIENCY
200µs/DIV
dc2422 F10
Figure 10. DC2422A-A VOUT1 2A – 4A – 2A
Load Transient at VIN = 36V
dc2422af
5
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
DC2422A-A Required Circuit Components
1
1
CIN1
CAP, 33µF, 63V, 20%, ELEC
SUN ELEC. 63HVH33M
2
1
COUT1
CAP, 100µF, 50V, 20%, ELEC
PANASONIC, EEHZA1H101P
3
6
CIN2, CIN3, CIN4, COUT6, COUT8, C59, C80
CAP, 10µF, X7R, 50V, 10%, 1210
AVX, 12105C106KAT2A
4
1
COUT4
CAP, 4.7µF, X7R, 16V, 20%, 1206
TDK, C3216X7R1C475M
5
2
COUT5, COUT11
CAP, 150µF, 16V, 20% 7343
PANASONIC, 16TQC150MYF
6
5
C4, C17, C21, C47, C52
CAP, 0.1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E104K
7
2
C5, C51
CAP, 4.7µF, X5R, 50V, 10%, 0805
TDK, C2012X5R1H475K125AB
8
4
C15, C53, C56, C62
CAP, 1nF, X7R, 50V, 10%, 0603
AVX, 06035C102KAT2A
9
1
C43
CAP, 68pF, NPO, 50V, 10%, 0603
AVX, 06035A680KAT2A
10
1
C44
CAP, 2.2nF, X7R, 50V, 10%, 0603
AVX, 06035C222KAT2A
11
1
C54
CAP, 10nF, X7R, 50V, 10%, 0603
TDK, C1608X7R1H103K
12
1
C61
CAP, 1µF, X5R, 25V, 20%, 0603
TDK, C1608X5R1E105M
13
1
C64
CAP, 4.7µF X5R, 10V, 20%, 0603
AVX, 0603ZD475MAT2A
14
2
D1, D2
DIODE, SCHOTTKY, 40V, 3A, SOD323
CENTRAL SEMI, CMDSH-4E
15
0
D3
DIODE, SCHOTTKY, 40V, 3A, SMB
DIODES INC, B340B-13-F OPTION
16
0
L1
IND, 4.7µH
COILCRAFT, XAL7070-472
17
0
L2
IND, 1.0µH
COILCRAFT, XAL7070-102
18
2
Q1, Q2
XSTR, N-CHANNEL MOSFET
INFINEON, BSC093N04LS
19
2
Q21, Q22
XSTR, N-CHANNEL MOSFET
INFINEON, BSC027N04LS
20
1
RS1
RES., SENSE, 0.003Ω, 1/2W, 1%, 2010
VISHAY, WSL20103L000FEA
21
2
RS2, RS3
RES., SENSE, 0.004Ω, 1/2W, 1%, 2010
VISHAY, WSL20104L000FEA
22
1
R33
RES., 35.7k, 1/10W, 1%, 0603
VISHAY, CRCW060335K7FKEA
23
1
R35
RES., 15k, 1/10W, 5%, 0603
VISHAY, CRCW060315K0JNEA
24
1
R43
RES., 499k, 1/10W, 1%, 0603
VISHAY, CRCW0603499KFKEA
25
3
R46, R48, R92
RES., 100k, 1/10W, 5%, 0603
VISHAY, CRCW0603100KJNEA
26
1
R75
RES., 3.6k, 1/10W, 1%, 0603
VISHAY, CRCW06033K60FKEA
27
1
R78
RES., 549k, 1/10W, 1%, 0603
VISHAY, CRCW0603549KFKEA
28
1
R79
RES., 49.9k, 1/10W, 1%, 0603
VISHAY, CRCW060349K9FKEA
29
1
R81
RES., 100Ω, 1/10W, 5%, 0603
VISHAY, CRCW0603100RJNEA
30
1
R86
RES., 2.2Ω, 1/10W, 5%, 0603
VISHAY, CRCW06032R20JNEA
31
1
U1
IC, LOW IQ, 38V BOOST + BUCK
SYNCHRONOUS CONTROLLER
LINEAR TECH. LTC7812EUH#PBF
dc2422af
6
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
1
0
C1, C2, C3, C6, CIN5, C68
CAP, OPTION, 1210
OPTION
2
0
COUT2
CAP, OPTION
OPTION
3
0
C36
CAP, OPTION, 1206
OPTION
4
0
C39, C40, C66, C67, C73, C74, C78, C79
CAP, OPTION, 0805
OPTION
5
0
C49, C55, C57, C60, C63, C65, C77
CAP, OPTION, 0603
OPTION
6
0
L3
IND, OPTION
COILCRAFT, OPTION
7
0
Q9, Q11, Q18, Q19
XSTR, N-CHANNEL MOSFET
OPTION
8
9
R34, R36, R39, R40, R70, R72, R80, R95, R96
RES., 0Ω, 1/10W, 0603
VISHAY, CRCW06030000Z0EA
9
0
R37, R51, R53, R55, R62, R85, R89, R90, R91,
R93, R94
RES., OPTION, 0603
OPTION
10
0
R82
RES., OPTION, 1206
OPTION
11
0
R100
RES., OPTION , 0805
OPTION
12
0
R101
RES., OPTION, 1210
OPTION
13
1
R102
RES., 0Ω, 2010
VISHAY, CRCW20100000Z0EF
Hardware: For Demo Board Only
1
15
E1-E15
TURRET
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1, JP2
CONN., HEADER, 1X3, 2mm
WURTH ELEKTRONIK, 620 003 111 21
3
1
JP3
CONN., HEADER, 2X3, 2mm
WURTH ELEKTRONIK, 620 006 211 21
4
3
XJP1, XJP2, XJP3
SHUNT, 2mm
WURTH ELEKTRONIK, 608 002 134 21
5
6
J1, J2, J3, J4, J5, J6
JACK, BANANA
KEYSTONE, 575-4
6
4
STANDOFF, SNAP ON
KEYSTONE, 8833
dc2422af
7
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
SUN ELEC. 63HVH33M
DC2422A-B Required Circuit Components
1
1
CIN1
CAP, 33µF, 63V, 20%, ELEC
2
1
COUT1
CAP, 100µF, 50V, 20%, ELEC
PANASONIC, EEHZA1H101P
3
6
CIN2, CIN3, CIN4, COUT6, COUT8, C59, C80
CAP, 10µF, X7R, 50V, 10%, 1210
AVX, 12105C106KAT2A
4
1
COUT4
CAP, 4.7µF, X7R, 16V, 20%, 1206
TDK, C3216X7R1C475M
5
2
COUT5, COUT11
CAP, 150µF, 16V, 20% 7343
PANASONIC, 16TQC150MYF
6
5
C4, C17, C21, C47, C52
CAP, 0.1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E104K
7
2
C5, C51
CAP, 4.7µF, X5R, 50V, 10%, 0805
TDK, C2012X5R1H475K125AB
8
4
C15, C53, C56, C62
CAP, 1nF, X7R, 50V, 10%, 0603
AVX, 06035C102KAT2A
9
1
C43
CAP, 68pF, NPO, 50V, 10%, 0603
AVX, 06035A680KAT2A
10
1
C44
CAP, 2.2nF, X7R, 50V, 10%, 0603
AVX, 06035C222KAT2A
11
1
C54
CAP, 10nF, X7R, 50V, 10%, 0603
TDK, C1608X7R1H103K
12
1
C61
CAP, 1µF, X5R, 25V, 20%, 0603
TDK, C1608X5R1E105M
13
1
C64
CAP, 4.7µF X5R, 10V, 20%, 0603
AVX, 0603ZD475MAT2A
14
2
D1, D2
DIODE, SCHOTTKY, 40V, 3A, SOD323
CENTRAL SEMI, CMDSH-4E
15
0
D3
DIODE, SCHOTTKY, 40V, 3A, SMB
DIODES INC, B340B-13-F OPTION
16
0
L1
IND, 4.7µH
COILCRAFT, XAL7070-472
17
0
L2
IND, 1.0µH
COILCRAFT, XAL7070-102
18
2
Q1, Q2
XSTR, N-CHANNEL MOSFET
INFINEON, BSC093N04LS
19
2
Q21, Q22
XSTR, N-CHANNEL MOSFET
INFINEON, BSC027N04LS
20
1
RS1
RES., SENSE, 0.003Ω, 1/2W, 1%, 2010
VISHAY, WSL20103L000FEA
21
2
RS2, RS3
RES., SENSE, 0.004Ω, 1/2W, 1%, 2010
VISHAY, WSL20104L000FEA
22
1
R33
RES., 26.7k, 1/10W, 1%, 0603
VISHAY, CRCW060326K7FKEA
23
1
R35
RES., 15k, 1/10W, 5%, 0603
VISHAY, CRCW060315K0JNEA
24
1
R43
RES., 499k, 1/10W, 1%, 0603
VISHAY, CRCW0603499KFKEA
25
3
R46, R48, R92
RES., 100k, 1/10W, 5%, 0603
VISHAY, CRCW0603100KJNEA
26
1
R75
RES., 3.6k, 1/10W, 1%, 0603
VISHAY, CRCW06033K60FKEA
27
1
R78
RES., 365k, 1/10W, 1%, 0603
VISHAY, CRCW0603365KFKEA
28
1
R79
RES., 49.9k, 1/10W, 1%, 0603
VISHAY, CRCW060349K9FKEA
29
1
R81
RES., 100Ω, 1/10W, 5%, 0603
VISHAY, CRCW0603100RJNEA
30
1
R86
RES., 2.2Ω, 1/10W, 5%, 0603
VISHAY, CRCW06032R20JNEA
31
1
U1
IC, LOW IQ, 38V BOOST + BUCK
SYNCHRONOUS CONTROLLER
LINEAR TECH. LTC7812EUH#PBF
dc2422af
8
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
1
0
C1, C2, C3, C6, CIN5, C68
CAP, OPTION, 1210
OPTION
2
0
COUT2
CAP, OPTION
OPTION
3
0
C36
CAP, OPTION, 1206
OPTION
4
0
C39, C40, C66, C67, C73, C74, C78, C79
CAP, OPTION, 0805
OPTION
5
0
C49, C55, C57, C60, C63, C65, C77
CAP, OPTION, 0603
OPTION
6
0
L3
IND, OPTION
COILCRAFT, OPTION
7
0
Q9, Q11, Q18, Q19
XSTR, N-CHANNEL MOSFET
OPTION
8
9
R34, R36, R39, R40, R70, R72, R80, R95, R96
RES., 0Ω, 1/10W, 0603
VISHAY, CRCW06030000Z0EA
9
0
R37, R51, R53, R55, R62, R85, R89, R90, R91, RES., OPTION, 0603
R93, R94
OPTION
10
0
R82
RES., OPTION, 1206
OPTION
11
0
R100
RES., OPTION, 0805
OPTION
12
0
R101
RES., OPTION, 1210
OPTION
13
1
R102
RES., 0Ω, 2010
VISHAY, CRCW20100000Z0EF
Hardware: For Demo Board Only
1
15
E1-E15
TURRET
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1, JP2
CONN., HEADER, 1X3, 2mm
WURTH ELEKTRONIK, 620 003 111 21
3
1
JP3
CONN., HEADER, 2X3, 2mm
WURTH ELEKTRONIK, 620 006 211 21
4
3
XJP1, XJP2, XJP3
SHUNT, 2mm
WURTH ELEKTRONIK, 608 002 134 21
5
6
J1, J2, J3, J4, J5, J6
JACK, BANANA
KEYSTONE, 575-4
6
4
STANDOFF, SNAP ON
KEYSTONE, 8833
dc2422af
9
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
DC2422A-C Required Circuit Components
1
1
CIN1
CAP, 33µF, 63V, 20%, ELEC
SUN ELEC. 63HVH33M
2
1
COUT1
CAP, 100µF, 50V, 20%, ELEC
PANASONIC, EEHZA1H101P
3
6
CIN2, CIN3, CIN4, COUT6, COUT8, C59, C80
CAP, 10µF, X7R, 50V, 10%, 1210
AVX, 12105C106KAT2A
4
1
COUT4
CAP, 4.7µF, X7R, 16V, 20%, 1206
TDK, C3216X7R1C475M
5
2
COUT5, COUT11
CAP, 150µF, 16V, 20% 7343
PANASONIC, 16TQC150MYF
6
5
C4, C17, C21, C47, C52
CAP, 0.1µF, X7R, 25V, 10%, 0603
TDK, C1608X7R1E104K
7
2
C5, C51
CAP, 4.7µF, X5R, 50V, 10%, 0805
TDK, C2012X5R1H475K125AB
8
4
C15, C53, C56, C62
CAP, 1nF, X7R, 50V, 10%, 0603
AVX, 06035C102KAT2A
9
1
C43
CAP, 68pF, NPO, 50V, 10%, 0603
AVX, 06035A680KAT2A
10
1
C44
CAP, 2.2nF, X7R, 50V, 10%, 0603
AVX, 06035C222KAT2A
11
1
C54
CAP, 10nF, X7R, 50V, 10%, 0603
TDK, C1608X7R1H103K
12
1
C61
CAP, 1µF, X5R, 25V, 20%, 0603
TDK, C1608X5R1E105M
13
1
C64
CAP, 4.7µF X5R, 10V, 20%, 0603
AVX, 0603ZD475MAT2A
14
2
D1, D2
DIODE, SCHOTTKY, 40V, 3A, SOD323
CENTRAL SEMI, CMDSH-4E
15
0
D3
DIODE, SCHOTTKY, 40V, 3A, SMB
DIODES INC, B340B-13-F OPTION
16
0
L1
IND, 4.7µH
COILCRAFT, XAL7070-472
17
0
L2
IND, 1.0µH
COILCRAFT, XAL7070-102
18
2
Q1, Q2
XSTR, N-CHANNEL MOSFET
INFINEON, BSC093N04LS
19
2
Q21, Q22
XSTR, N-CHANNEL MOSFET
INFINEON, BSC027N04LS
20
1
RS1
RES., SENSE, 0.003Ω, 1/2W, 1%, 2010
VISHAY, WSL20103L000FEA
21
2
RS2, RS3
RES., SENSE, 0.004Ω, 1/2W, 1%, 2010
VISHAY, WSL20104L000FEA
22
1
R33
RES., 68.1k, 1/10W, 1%, 0603
VISHAY, CRCW060368K1FKEA
23
1
R35
RES., 15k, 1/10W, 5%, 0603
VISHAY, CRCW060315K0JNEA
24
1
R43
RES., 357k, 1/10W, 1%, 0603
VISHAY, CRCW0603357KFKEA
25
3
R46, R48, R92
RES., 100k, 1/10W, 5%, 0603
VISHAY, CRCW0603100KJNEA
26
1
R75
RES., 3.6k, 1/10W, 1%, 0603
VISHAY, CRCW06033K60FKEA
27
1
R78
RES., 453k, 1/10W, 1%, 0603
VISHAY, CRCW0603453KFKEA
28
1
R79
RES., 49.9k, 1/10W, 1%, 0603
VISHAY, CRCW060349K9FKEA
29
1
R81
RES., 100Ω, 1/10W, 5%, 0603
VISHAY, CRCW0603100RJNEA
30
1
R86
RES., 2.2Ω, 1/10W, 5%, 0603
VISHAY, CRCW06032R20JNEA
31
1
U1
IC, LOW IQ, 38V BOOST + BUCK
SYNCHRONOUS CONTROLLER
LINEAR TECH. LTC7812EUH#PBF
dc2422af
10
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Additional Demo Board Circuit Components
1
0
C1, C2, C3, C6, CIN5, C68
CAP, OPTION, 1210
OPTION
2
0
COUT2
CAP, OPTION
OPTION
3
0
C36
CAP, OPTION, 1206
OPTION
4
0
C39, C40, C66, C67, C73, C74, C78, C79
CAP, OPTION, 0805
OPTION
5
0
C49, C55, C57, C60, C63, C65, C77
CAP, OPTION, 0603
OPTION
6
0
L3
IND, OPTION
COILCRAFT, OPTION
7
0
Q9, Q11, Q18, Q19
XSTR, N-CHANNEL MOSFET
OPTION
8
9
R34, R36, R39, R40, R70, R72, R80, R95, R96
RES., 0Ω, 1/10W, 0603
VISHAY, CRCW06030000Z0EA
9
0
R37, R51, R53, R55, R62, R85, R89, R90, R91,
R93, R94, R100
RES., OPTION, 0603
OPTION
10
0
R82
RES., OPTION, 1206
OPTION
11
1
R101
RES., 0Ω, 2010
VISHAY, CRCW20100000Z0EF
12
0
R102
RES., OPTION, 1210
OPTION
Hardware: For Demo Board Only
1
15
E1-E15
TURRET
MILL-MAX, 2501-2-00-80-00-00-07-0
2
2
JP1, JP2
CONN., HEADER, 1X3, 2mm
WURTH ELEKTRONIK, 620 003 111 21
3
1
JP3
CONN., HEADER, 2X3, 2mm
WURTH ELEKTRONIK, 620 006 211 21
4
3
XJP1, XJP2, XJP3
SHUNT, 2mm
WURTH ELEKTRONIK, 608 002 134 21
5
6
J1, J2, J3, J4, J5, J6
JACK, BANANA
KEYSTONE, 575-4
6
4
STANDOFF, SNAP ON
KEYSTONE, 8833
dc2422af
11
D
C
B
A
OFF
E12
E11
0
JP1
3
2
1
R37
OPT
R46
100K
INTVCC
R34
RUN1
ON
E10
E9
VOUT1
OFF
JP2
RUN2
ON
0
C77
OPT
*
R36
R33
3
2
1
OPT
C49
R43
1
2
1. ALL RESISTORS AND CAPACITORS ARE 0603.
NOTE: UNLESS OTHERWISE SPECIFIED
PGOOD1
RUN2
RUN1
TRACK / SS1
FREQ
E8
C60
OPT
VBUS
*
0
R70
68pF
1nF
C47
0.1uF
10nF
C54
C53
15K
R35
C43
R78
*
C55 OPT
R72
0
R94
OPT
INTVCC
11
4
15
5
3
JP3
R33
35.7K
26.7K
68.1K
SGND
PGOOD1
RUN2
RUN1
SS2
TRK/SS1
ITH2
ITH1
VFB2
VFB1
FREQ
BURST
PS/SYNC
FCM
R43
499K
499K
357K
*
C64
4.7uF
R80
0
4
4
R81
100
OPT
C63
BOOST1
32
S1-
8
TG2
29
R102
0
0
OPT
BG2
SW2
30
27
BOOST2
28
25
S1+
7
EXTVCC
BG1
31
1
TG1
R39
0
0
R95
0
R96
C17
0.1uF
VBIAS
C62
1nF
INTVCC
2
26
23
18
20
21
22
R101
OPT
OPT
0
BG2
TG2
SW2
BOOST2
EXTVCC
SENSE1-
SENSE1+
BG1
SW1
BOOST1
TG1
VBIAS
N/C
SGND
SGND
SGND
OV2
R48
100K
INTVCC
R78
549K
365K
453K
1nF
C56
U1
LTC7812EUH
6
4
2
PLLIN/MODE
ASSY VOUT1
‐A
12V
‐B
12V
‐C
5V
16
3
RUN2 19
RUN1 17
0.1uF
C52
SS2
SS1
R75
3.6K
ITH2
ITH1
C44
2.2nF
6
14
R79
49.9K
VFB2
VFB1
9
10
5
3
1
INTVCC
INTVCC 24
CLKIN
MODE
PGND
33
3
SENSE2+
S2+ 12
E7
2
SENSE213
S2-
C4
0.1uF
1nF
C15
5
INTVCC
4
*
R102
2010
OPT
C57
VIN
6
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
DL
SCALE = NONE
LT
PCB DES.
7
DATE:
N/A
TECHNOLOGY
**
CIN4
10uF
50V
1210
COUT11
150uF
16V
7343
CIN5
OPT
1210
100uF
50V
+
+ COUT1
VIN
COUT8
10uF
50V
1210
VBUS
COUT5
150uF
16V
7343
CIN1
33uF
63V
J2
J1
J6
E2
E1
COUT2
OPT
E6
E5
GND
VBUS
GND
**
VIN-
GND
VIN
VIN+
GND
GND
VBUS
E4
VOUT1
VOUT1
7
IC NO.
*
Tuesday, September 08, 2015
8
SHEET 1
LTC7812EUH
DEMO CIRCUIT 2422A
OF 2
REV.
2
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
+
+
J5
C36
OPT
1206
J4
J3
E3
SHT 2
OV2
DL
APPROVED
WIDE VIN, STEP UP/DOWN POWER SUPPLY
TITLE: SCHEMATIC
SIZE
+
4~36VIN
VBUSFOLLOWSVINWHEN
VIN>VBUSSETVOLTAGE
[email protected]<8V
CIN3
10uF
50V
1210
COUT6
10uF
50V
1210
COUT4
4.7uF
16V
1206
VOUT1
VBUS_
BG2
TG2
BG1
S2-
VL2-
TG1
S2+
S1-
VSW2
VL1-
E13
9/08/15
DATE
8
S1+
SHT 2
PRODUCTION
SHT 2
REVISION HISTORY
DESCRIPTION
VSW1
C78
TBD
0805
CIN2
10uF
50V
1210
C5
4.7uF
50V
0805
0.003
C6
OPT
1210
APP ENG.
2
-
C79
TBD
0805
REV
ECO
RS1
C59
10uF
50V
1210
APPROVALS
RS3
0.004
RS2
0.004
C3
OPT
1210
4.7uH
VL1-
C51
4.7uF
50V
0805
L1
VL2-
C2
OPT
1210
VSW1
1.0uH
R82
OPT
L2
CUSTOMER NOTICE
VSW2
Q2
BSC093N04LS
C1
OPT
1210
*
2010
R101
VBUS
6
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.
4
4
Q21
BSC027N04LS
INTVCC
Q22
BSC027N04LS
CMDSH-4E
D2
R40
0
D1
4
Q1
BSC093N04LS
C21
0.1uF CMDSH-4E
R92
100K
INTVCC
5
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
12
1
2
3
1
D
C
B
A
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
SCHEMATIC DIAGRAM
dc2422af
VIN
E15
C39
OPT
0805
SGND
EXTVCC
E14
C40
OPT
0805
R55
OPT
EXTVCC
C73
TBD
0805
VBUS
C61
1uF
OPT
R93
C74
TBD
0805
VOUT1
SHT 1
SHT 1
S1-
VSW1
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.
VSW1
BG1
SHT 1
SHT 1
BG1
VSW1
TG1
4
4
Q19
OPT
OPT
R62
VIN VBUS
S1-
R53
OPT
VL1-
S1+
Q18
OPT
VIN
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
L3
SCALE = NONE
DL
LT
APPROVALS
BG2
VSW2
TG2
TBD
DATE:
N/A
SIZE
4
Q9
OPT
OPT
R91
TECHNOLOGY
4
C67
TBD
0805
S2+
R90
OPT
C68
TBD
1210
VL2-
S2-
D3
OPT
GND
VIN_EMI
IC NO.
Tuesday, September 08, 2015
SHEET 2
LTC7812EUH
DEMO CIRCUIT 2422A
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
Q11
OPT
VBUS
J10
J9
VL2- SHT 1
S2- SHT 1
WIDE VIN, STEP UP/DOWN POWER SUPPLY
TITLE: SCHEMATIC
BG2
VSW2
SHT 1
TBD
0805
TG2
SHT 1
OPT
R89
TBD
C65
R100
VSW2
SHT 1
C66
TBD
0805
SHT 1 S2+
SHT 1 VSW2
C80
10uF
50V
1210
VL1- SHT 1
S1+ SHT 1
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
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
CUSTOMER NOTICE
TG1
SHT 1
SHT 1
2.2
OPT
R86
R85
VBUS_
OPT
R51
VBIAS
VSW1
WHEN DCR SENSING IS IMPLEMENTED,SHORT RS1 & RS2.
REMOVE R30, R29, R80 & R81.STUFF R62 AND R91 WITH 0 OHMS.
CALCULATE R51, R53 & C15 AND R89, R90 & C56 PER THE DATA SHEET.
ALSO REFER TO QSG FOR EXAMPLE.
NOTE:
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
1
2
OPTIONAL DCR SENSING
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
SCHEMATIC DIAGRAM
dc2422af
13
DEMO MANUAL DC2422A-A,
DC2422A-B, DC2422A-C
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
dc2422af
14 Linear Technology Corporation
LT 1115 • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2015
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