DC2235A - Demo Manual

DEMO MANUAL DC2235A
LTC3265EDHC
Low Noise Dual Supply with Boost
and Inverting Charge Pumps
DESCRIPTION
Demonstration Circuit 2235A has boost and inverting
charge pumps each with a low noise LDO post regulator
featuring the LTC®3265EDHC. The LTC3265 operates with
an input voltage from 4.5V to 16V for the boost charge
pump and from 4.5V to 32V for the inverting charge pump.
The demo board provides selectable LDO± output set magnitudes of 5V, 15V, and 24V for each polarity. The demo
board also provides the means to select between low power
Burst Mode® operation or low noise constant-frequency
PERFORMANCE SUMMARY
SYMBOL
PARAMETER
mode operation, plus select an operating frequency of
500kHz, 200kHz, or 50kHz.
The LTC3265 data sheet gives a complete description of
the device, operation and application information. The data
sheet must be read in conjunction with this demo manual.
Design files for this circuit board are available at
http://www.linear.com/demo/DC2235A
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
TYP
MAX
UNITS
VIN_P
VIN_P Input Voltage Range
4.5
16
V
VIN_N
VIN_N Input Voltage Range
4.5
32
V
VLDO+
LDO+ Output Voltage
1.2
32
V
VLDO
–
LDO– Output Voltage
VIN_N
VOUT+
VOUT+ Output Voltage Range
MODE = 0V (Const. Freq.)
MODE ≥ 2V (Burst)
VIN_P • 2
0.94 • VIN_P • 2
V
V
VOUT–
VOUT– Output Voltage Range
MODE = 0V (Const. Freq.)
MODE ≥ 2V (Burst)
–VIN_N
–0.94 • VIN_N
V
V
VIN_P • 2 ≥ LDO+ Set Point + 0.8V
≤ LDO– Set Point – 0.5V
–32
–1.2
V
BOARD PHOTO
dc2235af
1
DEMO MANUAL DC2235A
TYPICAL APPLICATIONS
LDO Rejection of VOUT ± Ripple
Low Noise ±15V Outputs from a Single 12V Input
1µF
CBST+ CBST –
VOUT+
VIN_N
12V
1µF
+15V
10µF
LTC3265
EN+
EN–
ADJ+
BYP+
MODE
GND
CINV+
BYP–
CINV –
ADJ–
VOUT–
LDO–
VLDO+
10mV/DIV
AC-COUPLED
VLDO–
10mV/DIV
AC-COUPLED
10µF
LDO+
VIN_P
10µF
VOUT+
10mV/DIV
AC-COUPLED
100nF
604K
VOUT–
10mV/DIV
AC-COUPLED
52.3k
1µs/DIV
100nF
VIN_P = 12V, VIN_N = VOUT
VLDO+ = 15V
VLDO– = –15V
fOSC = 500kHz
ILDO+ = 20mA
ILDO– = –20mA
52.3k
604K
10µF
RT
DC2235A TA01b
+
–15V
10µF
DC2235A TA01a
QUICK START PROCEDURE
Refer to Figure 1 for the proper measurement equipment
setup and jumper settings and follow the procedure below.
5. Slowly increase the load on LDO+ to 50mA and observe
the output ripple and the output voltage on LDO+.
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. See Figure 2 for proper scope
probe technique.
6. Set the LDO+ load and the LDO– load to 0mA and turn
off PS1.
1. Make sure the jumper settings are as follows:
JP1: EN+ is on the ON position
JP2: EN– is on the ON position
JP3: MODE is in the Burst position
JP4: FREQ is on the 500kHz position
JP5: LDO+ is set to 15V setting
JP6: LDO– is set to –15V setting
2. Set SW1 to the VOUT+ position.
3. Set PS1 to 12V.
4. Slowly increase load on LDO– to –50mA and observe
how output ripple on VOUT– changes and how burst
frequency increases. When the load is large enough,
the charge pump will run constant-frequency.
2
7. Set SW1 to the VIN_P position.
8. Set JP5 LDO+ jumper to 5V position and JP6 LDO– to
the –5V position.
Note: It is recommended to remove power or disable
the respective regulators prior to changing the positions of the LDO± output jumpers (JP5, JP6).
9. Repeat steps 3 through 6.
10.Set JP5 LDO+ jumper to 24V position and JP6 LDO– to
the –24V position.
11.Set SW1 to the VOUT+ position
12.Turn on and set PS1 to 15V.
13.Repeat steps 4 through 6.
14.Return JP5 LDO+ jumper to 15V position and JP5
LDO– to the –15V position.
15.Turn on and set PS1 to 12V.
dc2235af
DEMO MANUAL DC2235A
QUICK START PROCEDURE
16.Slowly increase the load on VOUT+ to 100mA and observe the output ripple and output voltage on VOUT+.
17.Set the load on VOUT
+ to 0mA.
18.Slowly increase the load on VOUT– to –100mA and
observe the output ripple and output voltage on VOUT–.
19.Set the load on VOUT
– to 0mA.
20.Change JP3 MODE jumper from Burst Mode operation to
the constant-frequency mode and repeat steps 16 to 19.
21.Change JP4 FREQ jumper from 500kHz to 200kHz then
slowly increase the load on VOUT+ from 0mA to 50mA and
observe the output ripple and output voltage on VOUT+.
22.Set the load on VOUT+ to 0mA.
23.Slowly increase the load on VOUT– to –50mA and observe the output ripple and output voltage on VOUT–.
24.Set the load on VOUT– to 0mA.
25.Change JP4 FREQ jumper from 200kHz to 50kHz. Slowly
increase the load on VOUT+ from 0mA to 10mA and observe
the output ripple and output voltage on VOUT+.
26.Set the load on VOUT+ to 0mA.
27.Slowly increase the load on VOUT– to -10mA and observe the output ripple and output voltage on VOUT–.
28.Set the load on VOUT– to 0mA.
29.Turn off the loads and supply when done.
Figure 1. Proper Measurement Equipment Setup for DC2235A
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3
DEMO MANUAL DC2235A
QUICK START PROCEDURE
Figure 2. Measuring Input or Output Ripple
APPLICATIONS INFORMATION
Figure 3 illustrates the voltage loss from the ideal boost
charge pump output voltage of 2 • VIN_P to the measured
VOUT+ voltage. Figure 4 illustrates the voltage loss from
3.0
RT = 200kΩ
VIN_P = 10V
2.5
2.0
RT = 1.2MΩ
1.5
1.0
0.5
RT = GND
0
0.1
1
10
LOAD CURRENT (mA)
100
DC2235A F03
Figure 3. VOUT+ Voltage Loss vs Output Current
(Constant-Frequency Mode)
4
VIN_P = VIN_N = 10V
RT = 200kΩ
2.5
(VIN_N–|VOUT–|) VOLTAGE (V)
(2 • VIN_P– VOUT+) VOLTAGE (V)
3.0
the ideal inverting charge pump output voltage of –VIN_N
to the measured VOUT– voltage.
2.0
1.5
RT = GND
1.0
0.5
0
0.1
RT = 1.2MΩ
1
10
LOAD CURRENT (mA)
100
DC2235A F04
Figure 4. VOUT– Voltage Loss vs Output Current
(Constant-Frequency Mode)
dc2235af
DEMO MANUAL DC2235A
APPLICATIONS INFORMATION
Figures 5 and 6 are CISPR radiated and conducted
emissions respectively. The data were collected in a
GTEM chamber and using a CISPR25 LISN for conducted
emissions. The EMI tests were conducted using a 12V
input on VIN_P, VOUT+ connected to VIN_N via SW1 of the
demo board, and a 600Ω resistor load between LDO+ and
LDO– in constant-frequency mode with a 500kHz oscillator
frequency. Linear Technology has made every effort to
provide useful and accurate EMI data, but it remains the
responsibility of the customer to ensure product compliance with applicable rules and regulations.
110
50
100
40
AMPLITUDE (dBμV)
90
dBμV/m
30
20
10
80
70
60
50
40
30
20
0
10
–10
0 100 200 300 400 500 600 700 800 900 1000
FREQUENCY (MHz)
dc2235 F05
VIN = 12V, VOUT = ±15V, 600Ω LOAD RESISTOR
WITHOUT C1 INSTALLED
VIN = 12V, VOUT = ±15V, 600Ω LOAD RESISTOR
WITH C1 = 10μF
CISPR22 LIMIT LINE
Figure 5. CISPR22 Radiated Emissions
0
100k
1M
10M
FREQUENCY (Hz)
100M
dc2235a F06
VIN = 12V, VOUT = ±15V, LOAD = 600Ω
WITHOUT C1 INSTALLED
VIN = 12V, VOUT = ±15V, LOAD = 600Ω
WITH C1 = 10μF
CISPR25 LIMITS FOR BROADBAND
CONDUCTED DISTURBANCES ON POWER
INPUT TERMINALS PEAK LIMIT (CLASS 3)
Figure 6. CISPR25 Conducted Emissions
dc2235af
5
DEMO MANUAL DC2235A
PARTS LIST
ITEM
QTY
REFERENCE
PART DESCRIPTION
MANUFACTURER/PART NUMBER
Required Circuit Components
1
1
C2
CAP, CHIP, X7R,10µF, ±10%, 25V, 1206
WURTH ELEKTRONIK, 885012208069
2
5
C3, C6, C10, C12, C14
CAP, CHIP, X7S, 10µF, ±10%, 50V, 1210
TDK, C3225X7S1H106K250AB
3
1
C4
CAP, CHIP, X7R, 1µF, ±10%, 25V, 0805
TDK, C2012X7R1E105K125AB
4
1
C13
CAP, CHIP, X7R, 1µF, ±10%, 50V, 1206
TDK, C3216X7R1H105K160AB
5
2
R3, R9
RES 604kΩ 1/16W 1% 0402 SMD
VISHAY, CRCW0402604KFKED
6
2
R11, R12
RES 52.3kΩ 1/16W 1% 0402 SMD
VISHAY, CRCW040252K3FKED
7
1
U1
LOW NOISE DUAL SUPPLY WITH BOOST AND
INVERTING CHARGE PUMPS
LINEAR TECH., LTC3265EDHC#PBF
C1
CAP, CHIP, X7R,10µF, ±10%, 25V, 1206
WURTH, 885012208069
Additional Demo Board Circuit Components
8
1
9
0
C5, C7, C9 (OPT)
CAP, CHIP, 25V, 0603
10
2
C8, C11
CAP, CHIP, X7R, .1µF, ±10%, 16V, 0402
MURATA, GRM155R71C104KA88D
11
2
C15, C16
CAP, CHIP, NPO, 10pF, ±5%, 50V, 0402
AVX, 04025A100JAT2A
12
3
R1, R6, R13
RES 1.0MΩ 1/16W 5% 0402 SMD
VISHAY, CRCW04021M00JNED
13
2
R2, R8
RES 1.0MΩ 1/16W 1% 0402 SMD
VISHAY, CRCW04021M00FKED
14
2
R4, R10
RES 165kΩ 1/16W 1% 0402 SMD
VISHAY, CRCW0402165KFKED
15
3
R5, R7, R14
RES 4.7kΩ 1/16W 5% 0402 SMD
VISHAY, CRCW04024K70JNED
16
1
R15
RES 909kΩ 1/16W 1% 0402 SMD
VISHAY, CRCW0402909KFKED
17
1
R16
RES 200kΩ 1/16W 1% 0402 SMD
VISHAY, CRCW0402200KFKED
3
JP1, JP2, JP3
HEADER, 3-PIN 1 ROW 0.079CC
SULLIN, NRPN031PAEN-RC
Hardware
18
6
19
1
JP4
HEADER, 4-PIN 1 ROW 0.079CC
SULLIN, NRPN041PAEN-RC
20
2
JP5, JP6
HEADER, 2 × 3 PINS, 2mm
SULLIN, NRPN032PAEN-RC
21
6
JP1-JP6
SHUNT, 2mm
SAMTEC, 2SN-BK-G
22
10
E1, E2, E7-E14
TP, TURRET, 0.094", PBF
MILL-MAX, 2501-2-00-80-00-00-07-0
23
4
E3-E6
TURRET, 0.061" DIA
MILL-MAX, 2308-2-00-80-00-00-07-0
24
4
MH1-MH4
STAND-OFF, NYLON 0.375" TALL
KEYSTONE, 8832 (SNAP ON)
25
1
SW1
10mm × 2.5mm, SLIDE SWITCH, THT
WURTH ELEKTRONIK, 450301014042
dc2235af
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.
E6
E5
E4
E3
E2
JP1
4.7k
5%
R14
4.7k
5%
R7
4.7k
5%
R5
OFF
ON
EN+
C1
10uF
25V
1206
(1210)
1
2
3
JP2
EN -
C5
OPT
25V
0603
OFF
ON
R1
1.0M
5%
VIN_P
1
2
3
2. INSTALL SHUNTS AS SHOWN.
1. ALL RESISTORS ARE 0402, 1%, 1/16W
ALL CAPACITORS ARE 0402, 10%
SW1
CONST
FREQ JP3
MODE
C7
OPT
25V
0603
BURST
R6
1.0M
5%
1
2
3
WURTH
450301014042
VIN_P
VOUT+
VIN_P
NOTE: UNLESS OTHERWISE SPECIFIED
GND
MODE
EN -
EN+
GND
4.5V - 16V
VIN_P
C9
OPT
25V
0603
2
3
4
C12
10uF
50V
1210
500kHz
200kHz
JP4
FREQ
1
50kHz
R13
1.0M
5%
VIN_P
VIN_N
C2
10uF
25V
1206
(1210)
R16
200k
R15
909k
12
14
4
13
9
11
1
2
C13
1uF
50V
1206 10
C4
1uF
25V
0805
3
RT
MODE
EN-
EN+
CINV+
CINV-
VIN_N
CBST-
CBST+
VIN_P
U1
LTC3265
19
GND
C14
10uF
50V
1210
C11
0.1uF
16V
R9
604k
JP6
** LDO-
R8
1.0M
R3
604k
JP5
** LDO+
R2
1.0M
C8
0.1uF
16V
C3
10uF
50V
1210
R10
165k
R4
165k
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
CUSTOMER NOTICE
8
7
5
6
16
15
17
18
APPROVALS
C16
10pF
50V
R12
52.3k
R11
52.3k
C15
10pF
50V
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.
NC
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
APP ENG. MARTY M.
CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
VOUT-
LDO -
BYP-
ADJ-
ADJ+
BYP+
LDO +
VOUT+
24V
15V
5V
-24V
-15V
-5V
E1
DATE:
N/A
SIZE
APPROVED
DATE
VOUT+
GND
LDO 50mA
GND
LDO +
50mA
GND
( 2 · VIN_P ) *
E14
GND
VOUT( - VIN_N ) *
E13
E12
E11
E10
E9
E8
E7
M. MERCHANT 05 - 28 - 15
LTC3265EDHC
DEMO CIRCUIT 2235A
05 - 28 - 15
IC NO.
SHEET
1
OF
LOW NOISE DUAL SUPPLY WITH
BOOST AND INVERTING CHARGE PUMPS
TECHNOLOGY
1
3
REV.
1630 McCarthy Blvd.
Milpitas, CA 95035
Phone: (408)432-1900 www.linear.com
Fax: (408)434-0507
LTC Confidential-For Customer Use Only
WHILE CONVERTER IS ENABLED, THE LDO OUPUT WILL
INCREASE TO THE RESPECTIVE VOUT INPUT.
** WARNING: IF LDO± OUTPUT JUMPER (JP5, JP6) IS REMOVED
* SEE DEMO MANUAL FOR VOUT ± CURRENT CAPABILITY
DESCRIPTION
PRODUCTION FAB
3
REVISION HISTORY
REV
TITLE: SCHEMATIC
C10
10uF
50V
1210
C6
10uF
50V
1210
ECO
DEMO MANUAL DC2235A
SCHEMATIC DIAGRAM
dc2235af
7
DEMO MANUAL DC2235A
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
8
dc2235af
Linear Technology Corporation
LT 0915 • 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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