DEMO MANUAL DC1802A
LTC3245EMSE
Wide V
IN
Range, Low Noise
250mA Buck-Boost Charge Pump
Description
Demonstration circuit DC1802A is a wide V
IN
range, low
noise, 250mA buck-boost charge pump featuring the
LTC
®
3245EMSE.
Design files for this circuit board are available at
http://www.linear.com/demo
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.
performance summary
SYMBOL
V
IN
V
OUT1
V
OUT2
V
FB
I
VOUT
PARAMETER
Input Voltage Range
Output Voltage
Output Voltage
Feedback Voltage
Output Current
Specifications are at T
A
= 25°C
CONDITIONS
SEL2 = HIGH, SEL1 = LOW
SEL2 = HIGH, SEL1 = HIGH
SEL2 = LOW SEL1 = HIGH
V
IN
> 5V, V
OUT
±4%, Burst Mode
®
Operation
V
IN
> 5V, V
OUT
±4%, Low Noise Mode
MIN
2.7
4.80
3.168
1.176
1.200
TYP
MAX
38
5.20
3.432
1.224
250
200
UNITS
V
V
V
V
mA
mA
assembly test proceDure
Refer to Figure 1 for the proper measurement equipment
setup and jumper settings 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 VBUS
or VOUT(x) and GND terminals. See Figure 2 for proper
scope probe technique.
1. Set PS1 = 13V, LD1 = 0A, SEL2 = HIGH, and SEL1 =
HIGH. Observe VOUT (VM2).
2. Set LD1 = 250mA. Observe VOUT (VM2).
3. Set SEL1 = LOW, LD1 = 0A. Observe VOUT (VM2).
4. Set LD1 to 250mA. Observe VOUT (VM2).
5. The value of V
OUT
can be programmed to any desired
value by populating R1 and R2.
dc1802af
1
DEMO MANUAL DC1802A
assembly test proceDure
+
PS1
AM1
A
–
+
+
V
AM2
A
VM2
–
+
–
LD1
1A
0V TO 5V
+
VM1
V
2.7V TO 38V
SUPPLY
1A
–
+
–
–
Figure 1. Proper Measurement Equipment Setup for DC1802A
Note: All connections from equipment should be Kelvin
connected directly to the board pins which they are con-
nected on this diagram and any input or output leads
should be twisted pair.
VIN
GND
Figure 2. Measuring Input or Output Ripple
dc1802af
2
DEMO MANUAL DC1802A
assembly test proceDure
Figures 3 and 4 are CISP25 radiated and conducted emis-
sions respectively. The data were collected in a GTEM cham-
ber and using a CISPR25 LISN for conducted emissions.
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.
GTEM Radiated Emissions, LTC3245
80
70
Detector=Peak Hold
RBW=120kHz
VBW=300kHz
Sweep Time=680ms, ≥ 10 Sweeps
# of Points=501
60
50
dBμV/m
40
30
20
10
Orientation X
0
Orientation Y
Orientation Z
CISPR 25 Class 5 Limit
‐10
0
100
200
300
400
500
Frequency (MHz)
600
700
800
900
1,000
Figure 3. CISPR25 Radiated Emissions
110
100
90
AMPLITUDE (dBµV)
80
70
60
50
40
30
20
10
0
100000
DETECTOR = PEAK
RBW = 9kHz, VBW = 30kHz
SWEEP TIME = 3.7 SEC
NUMBER OF POINTS = 501
1000000
10000000
100000000
DC1820A F04
FREQUENCY (?)
V
IN
= 13V, V
OUT
= 5V, LOAD = 240
WITH 33µF ELECTROLYTIC AND 3.3µF
CERAMIC INPUT CAPACITOR
DUT UNPOWERED
CISPR 25 CLASS 3 BROADBAND LIMIT
Figure 4. CISPR25 Conducted Emissions
dc1802af
3
DEMO MANUAL DC1802A
parts list
ITEM
1
2
3
4
4
5
6
QTY
0
1
1
1
0
1
1
REFERENCE
C1-OPT
C2
C3
C4
C5-OPT
R1
U1
PART DESCRIPTION
CAP, ELECTROLYTIC, 33µF, ±20%, 63V, 10mmX10.5mm
CAP, CHIP, X7R, 3.3µF, ±10%, 50V, 1210
CAP, CHIP, X5R, 1µF, ±10%, 10V, 0402
CAP, CHIP, X5R, 47µF, ±20%, 6.3V, 0805
CAP, CHIP, X5R, 100µF, ±20%, 6.3V, 1206
RES, CHIP, 0Ω JUMPER, 1/16W, 0402
IC, SMT, WIDE VIN RANGE, LOW NOISE 250mA
BUCK-BOOST CHARGE PUMP
RES, CHIP, ±1%, 1/16W, 0402
RES, CHIP, 470k, ±5%, 1/16W, 0402
TURRET, 0.09 DIA
TURRET, 0.061 DIA
3-Pin JUMPER, 2mm
SHUNT, 2mm
STAND-OFF, NYLON, 0.375"
MANUFACTURE / PART #
SUNCON, 63HVH33M
TDK, C3225X7R1H335K
TDK, C1005X5R1A105K
SAMSUNG, CL21A476MQYNNNB
MURATA, GRM31CR60J107ME39L
VISHAY, CRCW04020000Z0ED
LINEAR TECH., LTC3245EMSE
Required Circuit Components
Additional Demo Board Circuit Components
1
2
1
2
3
4
5
0
1
4
1
3
3
4
R2-OPT
R3
E1-E2, E4-E5
E3
JP1 JP3
XJP1-XJP3
USER SUPPLIED
VISHAY, CRCW0402470KJNED
MILL-MAX, 2501-2-00-80-00-00-07-0
MILL-MAX, 2308-2-00-80-00-00-07-0
SAMTEC, TMM-103-02-L-S
SAMTEC, 2SN-KB-G
KEYSTONE, 8832
Hardware For Demo Board Only
dc1802af
4
DEMO MANUAL DC1802A
schematic Diagram
dc1802af
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.
5
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
