MAXIM MAX1846EVKIT

19-2352; Rev 0; 2/02
MAX1846 Evaluation Kit
Features
♦ 3V to 16.5V Input Range
♦ MAX1846 Circuit Configured for +12V Into -5V at 2A
♦ MAX1847 Circuit Configured for +3.3V Into -12V at
400mA
♦ Evaluates Both the MAX1846 and MAX1847
Independently
♦ Fully Assembled and Tested
Ordering Information
PART
MAX1846EVKIT
TEMP RANGE
IC PACKAGE
-40°C to +85°C
10 µMAX
16 QSOP
Component List
DESIGNATION
C1, C11
C2, C3, C4
C5
C6, C16
C7, C8
C9, C19
C10
C12, C13,
C14
C15
QTY
DESCRIPTION
2
0.47µF ±10%, 25V, X7R ceramic
capacitors (0805)
Murata GRM40X7R474K025AL
DESIGNATION
QTY
DESCRIPTION
C17, C18
2
100µF ±20%, 10V POSCAPs
Sanyo 10TPB100M
C20
1
3
22µF ±20%, 10V, X5R ceramic
capacitors (1812)
Taiyo Yuden LMK432BJ226MM
390pF ±10%, 50V COG ceramic
capacitor (0805)
Murata GRM40COG391K050AL
C21, C22
2
1
0.22µF ±10%, 25V, X7R ceramic
capacitor (0805)
Murata GRM40X7R224K025AL
1000pF ±10%, 50V COG ceramic
capacitors (0805)
Murata GRM40COG102K050AL
D1, D2
2
2
220pF ±10%, 50V COG ceramic
capacitors (0805)
Murata GRM40COG221K050AL
5A, 40V Schottky diodes (SMC)
Central Semiconductor CMSH5-40
2
47µF ±20%, 16V POSCAPs
Sanyo 16TPB47M
2
0.1µF ±10%, 50V, X7R ceramic
capacitors (0805)
Taiyo Yuden UMK212BJ104KG
1
1200pF ±10%, 50V COG ceramic
capacitor (0805)
Murata GRM40COG122K050AL
3
1
10µF ±20%, 25V, X5R ceramic
capacitors (1812)
Taiyo Yuden TMK432BJ106MM
0.047µF ±10%, 25V, X7R ceramic
capacitor (0805)
Murata GRM40X7R473K025AL
JU1, JU2
2
Jumpers, SIP3, 3-pin headers
JU1, JU2
2
Shunts
L1, L2
2
10µH, 10A power inductors
Coilcraft DO5022P-103 or
Coiltronics UP4B-100
P1
1
-8.0A, -20V P-channel MOSFET
Fairchild FDS6375 (SO-8)
P2
1
-8.8A, -30V P-channel MOSFET
Fairchild FDS6685 (SO-8)
R1
1
0Ω ±5% resistor (0805)
R2, R9
2
22kΩ ±5% resistors (0805)
R3
1
10kΩ ±5% resistor (0805)
R4, R11
2
150kΩ ±5% resistors (0805)
________________________________________________________________ Maxim Integrated Products
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.
1
Evaluates: MAX1846/MAX1847
General Description
The MAX1846 evaluation kit (EV kit) contains both the
MAX1846 and MAX1847. Both devices are inverting,
current-mode, constant-frequency PWM controllers.
The MAX1846 circuit is configured for a +12V input and
a -5V output at 2A. The MAX1847 circuit is configured
for a +3.3V input and a -12V output at 400mA. Each circuit is powered separately so there is no interaction
between the two circuits. The MAX1846 is available in a
10-pin µMAX package and the MAX1847 is available in
a 16-pin QSOP package.
The MAX1846 EV kit is a fully assembled and tested
surface-mount circuit board. With minimal modification,
it can also be used to evaluate other output voltages.
Evaluates: MAX1846/MAX1847
MAX1846 Evaluation Kit
Component List (continued)
DESIGNATION
QTY
DESCRIPTION
R5, R12
2
20mΩ 1W ±1% sense resistors
(2512)
Dale WSL-2512-R020-F
R6
1
95.3kΩ ±1% resistor (0805)
R7, R14
2
10kΩ ±1% resistors (0805)
R8
1
Not installed (0805)
R10
1
8.2kΩ ±5% resistor (0805)
R13
1
40.2kΩ ±1% resistor (0805)
R15, R16
2
100Ω ±5% resistors (0805)
U1
1
MAX1847 (16-pin QSOP)
U2
1
MAX1846 (10-pin µMAX)
None
1
MAX1846 data sheet
None
1
MAX1846 EV kit data sheet
Quick Start
The MAX1846 EV kit is fully assembled and tested.
Follow these steps to verify board operation.
Do not turn on the power supply until all connections are completed.
MAX1847 Output (-12V)
1) Verify that a shunt is across pins 1 and 2 of jumper
JU1 (SHDN).
2) Verify that a shunt is across pins 2 and 3 of jumper
JU2 (SYNC).
3) Connect a voltmeter to the VOUT pad.
4) Preset a 3V to 5.5V DC power supply to 3V. Turn off
power supply. This power supply should be able to
supply 3A continuous current.
5) Connect the power supply to the VIN pad. Connect
the supply ground to the GND pad.
6) Connect a load up to 400mA between VOUT and GND.
7) Turn on the power supply and gradually increase
the input voltage through the 3V to 5.5V range.
8) Verify that VOUT is -12V throughout the +3V to
+5.5V input voltage range.
Component Suppliers
SUPPLIER
AVX
PHONE
WEBSITE
Capacitors
803-946-0690
www.avxcorp.com
Diodes
516-435-1110
www.centralsemi.com
Coilcraft
Inductors
847-639-6400
www.coilcraft.com
Coiltronics (Cooper)
Inductors
561-752-5000
www.cooperet.com
Dale
Resistors
402-564-3131
www.vishay.com/brands/dale/main.html
Fairchild
MOSFETs
408-721-2181
www.fairchildsemi.com
International Rectifier
MOSFETs
310-322-3331
www.irf.com
IRC
Resistors
512-992-7900
www.irctt.com
Capacitors
864-963-6300
www.kemet.com
Murata
Capacitors
770-436-1300
www.murata.com
Panasonic
Capacitors
Resistors
201-348-7522
www.panasonic.com
Sanyo
Capacitors
619-661-6835
www.secc.co.jp
Sprague
Capacitors
603-224-1961
www.vishay.com/brands/sprague/main.html
Sumida
Inductors
847-956-0666
www.remtechcorp.com
Capacitors
800-368-2496
www.t-yuden.com
Resistors
203-268-6261
www.vishay.com/brands/vitramon/main/html
Central Semiconductor
Kemet
Taiyo Yuden
Vitramon
2
COMPONENT
_______________________________________________________________________________________
MAX1846 Evaluation Kit
2) Connect a “turned off” 12.0V DC power supply to
the VIN1 pad. This power supply should be able to
supply 2A continuous current.
3) Connect the supply ground to the GND pad.
4) Connect a load up to 2A between VOUT1 and GND.
5) Turn on the power supply and verify that VOUT1 is
-5V.
Detailed Description
The MAX1846 EV kit contains two high-efficiency, PWM
inverting controllers. The MAX1846 is configured to
convert a +12V input to a -5V output and is capable of
delivering up to 2A of current. The MAX1847 is configured to convert a +3V to +5.5V input to -12V and will
deliver in excess of 400mA depending on the input
voltage. Both devices are inverting, current-mode, constant-frequency PWM controllers capable of operating
at frequencies from 100kHz to 500kHz with a simple
resistor change (R4 and R11). The EV board is configured to operate at 300kHz. Note that for optimum efficiency and stability, other components may need to be
optimized, depending on the operating frequency
selected. Refer to the MAX1846/MAX1847 data sheet
for more information. The MAX1847 can be synchronized to an external clock signal in the same frequency
range and also has a shutdown feature. The MAX1846
is in an ultra-compact 10-pin µMAX package and the
MAX1847 is in a 16-pin QSOP package.
Jumper Selection
Shutdown Mode
The MAX1847 features a shutdown mode that reduces
quiescent current. The 3-pin jumper (JU1) selects the
shutdown mode for the MAX1847. To enable the
MAX1847 shutdown mode, connect pins 2 and 3 on
JU1 with the supplied shunt. For normal operation, connect pins 1 and 2.
Synchronized Mode
The MAX1847 features a synchronized mode that
enables the operating frequency to be controlled by an
external clock. To utilize the synchronized mode,
remove the shunt on jumper JU2 connecting pins 2 and
3 and place it on pins 1 and 2. Connect an external frequency source to the SYNC pad. The external frequency source must be a TTL level and have a 20% to 80%
duty cycle.
Note: The value of R4 must program an internal oscillator frequency lower than the frequency of the external
clock. Refer to the MAX1846/MAX1847 data sheet for
more information.
_______________________________________________________________________________________
3
Evaluates: MAX1846/MAX1847
MAX1846 Output (-5V)
1) Connect a voltmeter to the VOUT1 pad.
Evaluates: MAX1846/MAX1847
MAX1846 Evaluation Kit
12V
VIN1
GND
C13
10µF
25V
C12
10µF
25V
R8
OPEN
1
VL
C11
0.47µF
C14
10µF
25V
R9
22kΩ
10
IN
EXT
4
9
23
1
P2
5 678
R10
8.2kΩ
C15
0.047µF
-5V AT 2A
VOUT1
3
COMP
U2
C16
220pF
MAX1846
CS
8
C22
1000pF
2
4
R11
150kΩ
D2
C19
0.1µF
PGND
FREQ
FB
REF
GND
6
R16
100Ω
C17
100µF
10V
L2
10µH
C18
100µF
10V
GND
R12
0.02Ω
1W
1%
R13
40.2kΩ
1%
7
5
C20
390pF
R14
10kΩ
1%
Figure 1. MAX1846 EV Kit Schematic
4
_______________________________________________________________________________________
MAX1846 Evaluation Kit
Evaluates: MAX1846/MAX1847
3V TO 5.5V
VIN
C3
22µF
10V
C2
22µF
10V
GND
C4
22µF
10V
R1
0Ω
R2
22kΩ
C1
0.47µF
2
VL
15
IN
1
2
3
8
JU1
SHDN
EXT
4
14
1
23
P1
SYNC
1
2
3
16
JU2
56 78
SYNC
U1
R3
10kΩ
C5
0.22µF
4
MAX1847
COMP
C6
220pF
CS
N.C.
N.C.
3
5
R4
150kΩ
FREQ
PGND
R15
100Ω
13
9
7
C21
1000pF
D1
-12V AT 400mA
VOUT
C7
47µF
16V
L1
10µH
R5
0.02Ω
1W
1%
C8
47µF
16V
GND
R6
95.3kΩ
1%
12
REF
C9
0.1µF
FB
POL
1
GND GND
10
11
6
C10
1200pF
R7
10kΩ
1%
Figure 2. MAX1847 EV Kit Schematic
_______________________________________________________________________________________
5
Evaluates: MAX1846/MAX1847
MAX1846 Evaluation Kit
Figure 3. MAX1846 EV Kit Component Placement Guide—
Component Side
Figure 4. MAX1846 EV Kit PC Board Layout—Component Side
Figure 5. MAX1846 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.
6 _____________________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.