MAX1875EVKIT [MAXIM]
Evaluation Kit for the MAX1875/MAX1876/MAX1858 ; 评估板MAX1875 / MAX1876 / MAX1858\n
| 型号： | MAX1875EVKIT |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Evaluation Kit for the MAX1875/MAX1876/MAX1858
|
| 文件： | 总4页 (文件大小：154K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-2611; Rev 0; 10/02
MAX1875 Evaluation Kit
General Description
Features
ꢀ 8V to 18V Input Voltage Range
The MAX1875 evaluation kit (EV kit) demonstrates a low-
cost application circuit. This dual-PWM synchronous DC-
to-DC converter operates from unregulated AC adapters
and generates precision, low-voltage rails for broad-
band gateways, digital TVs, cable modems, and set-
top boxes.
ꢀ 1.8V and 3.3V Adjustable Output Voltages
ꢀ 3.5A Output Current (1.8V Output)
ꢀ 3.5A Output Current (3.3V Output)
ꢀ Lossless Foldback Current Limit
ꢀ 100kHz Switching Frequency
The MAX1875 EV kit provides dual 1.8V and 3.3V output
voltages from an 8V to 18V input voltage range. It delivers
up to 3.5A output current for the 1.8V output and the 3.3V
output, with greater than 90% efficiency. Both converters
operate 180 degrees out-of-phase to reduce input ripple
current. The EV kit operates at 100kHz switching frequency.
ꢀ RST Output with 140ms Delay
(MAX1876/MAX1858 only)
ꢀ 180 Degree Out-of-Phase Operation
ꢀ 24-Pin QSOP Package
This EV kit is a fully assembled and tested circuit
board. It also allows evaluation of other output voltages
in the 0.75V to 15V range.
ꢀ Low-Cost Components
ꢀ Fully Assembled and Tested
The MAX1875 EV kit can also be used to evaluate the
MAX1876 and MAX1858.
Ordering Information
PART
TEMP RANGE
IC PACKAGE
MAX1875EVKIT
0°C to +70°C
24 QSOP
Component List
DESIGNATION QTY
DESCRIPTION
DESIGNATION QTY
DESCRIPTION
27µH 5A power inductor
L2
1
390µF, 25V aluminum electrolytic
capacitors Sanyo 25MV390AX
C1, C4
2
N1A, N1B,
N2A, N2B
Dual N-channel MOSFETs 8-pin SO
Fairchild FDS6990A
2
C5, C6, C12
3
1
1
0.1µF ceramic capacitors (0805)
0.39µF ceramic capacitor (0805)
0.33µF ceramic capacitor (0805)
C7
C8
D2–D5
R1
0
1
2
1
1
1
1
1
1
1
1
2
1
1
2
1
2
1
Not installed (open)
8.06k
10k
1% resistor (0805)
1% resistors (0805)
1% resistor (0805)
1% resistor (0805)
5% resistor (0805)
5% resistor (0805)
1% resistor (0805)
1% resistor (0805)
5% resistor (0805)
5% resistor (0805)
5% resistors (0805)
1% resistor (0805)
1% resistor (0805)
R2, R4
R3
C9, C10, C11,
C13, C14
5
470µF, 10V aluminum electrolytic
capacitors Sanyo 10MV470AX
23.2k
60.4k
2.7k
2k
R5
C17
C18
1
1
2200pF ceramic capacitor (0805)
1500pF ceramic capacitor (0805)
R6
R7
0.22µF, 16V X5R ceramic capacitor
(0805) Taiyo Yuden EMK212BJ224KG
C19
C20
1
1
R8
49.9k
69.8k
100k
20
R9
4.7µF, 10V X5R ceramic capacitor
(1206) Taiyo Yuden LMK316BJ475ML
R10
R11
0.22µF, 50V X7R ceramic capacitor
(0805) Taiyo Yuden UMK212BJ224MG
or TDK C2012X7R1H224M
R12, R13
R14
3.9
C21
1
154k
84.5k
R15
C22, C23
2
0
0.01µF ceramic capacitors (0805)
Not installed (open)
JU1, JU2
U1
3-pin headers
C2, C3, C15
MAX1875EEG 24-pin QSOP
Shunts
100mA, 30V dual Schottky diode 23-pin
SOT Central Semiconductor CMPSH-3A
D1
L1
1
1
None
None
MAX1875 PC board
15µH 5A power inductor
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX1875 Evaluation Kit
Component Suppliers
SUPPLIER
Central Semiconductor
Fairchild
PHONE
FAX
WEBSITE
www.centralsemi.com
www.fairchildsemi.com
www.niec.co.jp
516-435-1110
408-721-2181
847-843-7500
619-661-6835
408-573-4150
847-390-4373
888-978-2638
516-435-1824
408-721-1635
847-843-2798
619-661-1055
408-573-4159
847-390-4428
605-886-8995
Nihon
Sanyo
www.sanyovideo.com
www.t-yuden.com
Taiyo Yuden
TDK
www.component.tdk.com
www.trans-power.com
Tyco Electronics (Transpower)
Note: Please indicate that you are using the MAX1875 when contacting these component suppliers.
Jumper Settings
Quick Start
Before beginning, the following equipment is required:
Table 1. Jumper JU1 Functions
(EN Mode Selection)
• 8V to 18V power supply
• Electronic loads capable of sinking 3.5A each
• Digital multimeters (DMMs)
JU1
EN PIN
MAX1875 OUTPUT
Connected to MAX1875 enabled, V
= 1.8V,
OUT1
1 and 2
• 100MHz dual-trace oscilloscope
VL
V
= 3.3V
OUT2
Follow these steps to verify board operation. Do not
turn on the power supply until all connections are
completed:
Connected to Shutdown mode, V
= 0V,
OUT1
2 and 3
GND
Connected to MAX1875 must be enabled by
EN pad an external signal
V
= 0V
OUT2
Not
Installed
1) Ensure that the circuit is connected correctly to the
supply and electronic loads before applying any
power. Set electronic loads in resistive mode.
2) Verify that the shunts are across JU1 pins 1 and 2
as well as JU2 pins 2 and 3.
Table 2. Jumper JU2 Functions
(SYNC Mode Selection)
3) Turn on power supply.
4) Verify that the output voltages are 1.8V and 3.3V.
JU2
SYNC PIN
EFFECT
Evaluating Other Output Voltages
The EV kit outputs are programmed for 1.8V and 3.3V.
However, the output voltages can also be adjusted
between 1V and 15V by selecting R1/R2 and R3/R4
values. Select the feedback resistors R2 and R4. R1
and R3 are then given by:
Used to sync up an additional
MAX1875. CKO is 2x DH1 and
phase shifted by 90 degrees.
Connected to
VL
1 and 2
Used to sync up an additional
single buck. CKO is the same
frequency and phase as DH1.
Connected to
GND
2 and 3
R1 (or R3) = R2 (or R4) x [(V
/ V ) - 1]
FB
OUT
Not
Installed
Connected to External clock is applied to
SYNC pad SYNC input (200kHz typ)
where V = 1V. Refer to the MAX1875 data sheet for
FB
selection of output capacitors, inductors, and compen-
sation networks.
Evaluating the MAX1876 and MAX1858
Replace U1 with the MAX1876/MAX1858.
2
_______________________________________________________________________________________
MAX1875 Evaluation Kit
Figure 1. MAX1875 EV Kit Schematic
_______________________________________________________________________________________
3
MAX1875 Evaluation Kit
Figure 2. MAX1875 EV Kit Component Placement Guide—
Top Silkscreen
Figure 3. MAX1875 EV Kit PC Board Layout—Component Side
Figure 4. MAX1875 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
相关型号：
MAX1876AEEG-T
Dual Switching Controller, Voltage-mode, 660kHz Switching Freq-Max, BICMOS, PDSO24, 0.150 INCH, 0.25 INCH PITCH, MO-137AE, QSOP-24
MAXIM
MAX1878
Micropower.Single-Supply.UCSP/SOT23 Comparator + Precision Reference ICs[MAX9039/MAX9040/MAX9041/MAX9042/MAX9043/MAX9050/MAX9051/MAX9052/MAX9053/MAX9039BEBT-T/MAX9040AEUK-T/MAX9040BEUK-T/MAX9041AESA/MAX9041AESA-T/MAX9041AEUT-T/MAX9041BESA/MAX9041BESA-T/MAX9041BEUT-T/MAX9050BEUK-T/MAX9051AESA/MAX9051AESA-T/MAX9051AEUT-T ]
MAXIM
©2020 ICPDF网 联系我们和版权申明