19-1871; Rev 0; 12/00
MAX1747 Evaluation Kit
General Description
The MAX1747 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains
three charge-pump regulators. The first one is a high-
current step-up DC-DC converter and is configured for
a +5V output that provides up to 200mA of current. The
other two charge pumps are low-current charge pumps
that generate positive and negative voltages. A +3.0VDC
to +3.6VDC source can be utilized to power the EV kit
input.
The low-current negative charge-pump circuit is config-
ured for a -7V output; the low-current positive charge-
pump circuit is configured for a +12V output. Both cir-
cuits provide up to 20mA of current. The high-current
step-up DC-DC converter or the EV kit’s input source
can be used to power either or both charge pumps.
The MAX1747 EV kit demonstrates an inductorless and
low profile (1.1mm max) solution. Operation up to
1.23MHz allows the use of tiny surface-mount compo-
nents and provides fast transient response.
o
Three Charge-Pump Regulators
+5V Output at 200mA
+12V Output at 20mA
-7V Output at 20mA
o
High-Current Output Regulated to ±1%
o
Adjustable Outputs
o
Integrated Power MOSFETs
o
1µA Shutdown Current
o
Switching Frequency Up to 1.23MHz
o
Fast Transient Response
o
Surface-Mount Components
o
Fully Assembled and Tested
Features
o
Low-Profile Solution, 1.1mm max Height
Evaluates: MAX1747
Ordering Information
PART
MAX1747EVKIT
TEMP.RANGE
0°C to +70°C
IC PACKAGE
20 TSSOP
Component List
DESIGNATION
C1, C2, C3,
C17
QTY
4
DESCRIPTION
4.7µF, 6.3V X7R ceramic
capacitors (1210)
Taiyo Yuden LMK325BJ475MD
1µF, 16V X5R ceramic
capacitors (1206)
Murata GRM42-6X5R105K016
0.47µF, 25V X7R ceramic
capacitors (1206)
Murata GRM42-6X7R474K025
0.1µF, 16V X7R ceramic
capacitors (0603)
Taiyo Yuden EMK107BJ104KA
1500pF, 50V X7R ceramic
capacitor (0603)
Taiyo Yuden UMK107BJ152KZ
0.22µF, 10V X7R ceramic
capacitor (0603)
Taiyo Yuden LMK107BJ224KA
Not installed (1210)
DESIGNATION
D1–D4
R1
R2, R4, R6
R3
R5
R7
R8
R10
U1
JU1
JU2, JU3
None
None
None
None
QTY
4
1
3
1
1
0
1
1
1
1
2
3
1
1
1
DESCRIPTION
200mA, 25V Schottky diodes
(SOT23)
Fairchild BAT54S
150kΩ ±1% resistor (0805)
49.9kΩ ±1% resistors (0805)
432kΩ ±1% resistor (0805)
280kΩ ±1% resistor (0805)
Not installed (0805)
107kΩ ±1% resistor (0805)
1MΩ ±5% resistor (0805)
MAX1747EUP (20 TSSOP)
2-pin header
3-pin headers
Shunts (JU1, JU2, JU3)
MAX1747 PC board
MAX1747 data sheet
MAX1747 EV kit data sheet
C5, C7, C20,
C21, C22
5
C6, C8, C14
3
C9, C11, C12,
C15, C16, C19
6
C10
1
C13
C4, C18
1
0
________________________________________________________________
Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX1747 Evaluation Kit
Evaluates: MAX1747
Component Suppliers
SUPPLIER
Fairchild
Murata
Nihon
Taiyo Yuden
PHONE
408-822-2000
814-237-1431
661-867-2555
408-573-4150
FAX
408-822-2102
814-238-0490
661-867-2698
408-573-4159
The low-current negative charge pump provides -7V
output; other negative output voltages can be evaluat-
ed by replacing two voltage feedback resistors. The
output can be adjusted to -8V.
The low-current positive charge pump provides a +12V
output (VP); other output voltages can be evaluated by
replacing two voltage feedback resistors. The output
can be adjusted up to +13V.
Jumper options allow either charge-pump circuit to be
fed power from the EV kit’s input (VIN) or the high-cur-
rent step-up DC-DC converter output (VOUT).
The MAX1747 switching frequency is determined by
resistor R8 and the voltage supplied to the EV kit input
pad (VIN). Applying a voltage in the range of +3.0V to
+3.6V to the VIN pad causes the switching frequency
to operate in the 980kHz to 1.23MHz range, respective-
ly.
An off-board CMOS or bipolar transistor can control the
EV kit’s shutdown feature.
Note:
Please indicate that you are using the MAX1747 when
contacting these component suppliers.
Quick Start
The MAX1747 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.
Output
1) Connect a voltmeter to the VOUT pad.
2) Verify that shunts are present across pins 1 and 2
of jumpers JU2 (SUPN) and JU3 (SUPP). Verify that
jumper JU1 (SHDN) does not have a shunt
installed.
3) Connect a +3.0VDC to +3.6VDC power supply to
the VIN pad.
4) Connect the supply ground to the GND pad.
5) Turn on the power supply and verify that the high-
current step-up DC-DC converter output (VOUT) is
+5V.
6) Verify that the low-current negative charge pump
output (VN) is -7V.
7) Verify that the low-current positive charge pump
output (VP) is +12V.
For instructions on selecting the feedback resistors for
other output voltages, see the
Evaluating Other Output
Voltages
section. The input voltage range is +3.0V to
+3.6V when selecting the output voltage.
Jumper Selection
Shutdown Mode
The MAX1747 EV kit features a shutdown mode that
reduces the EV kit’s quiescent current to less than
60µA (typ). The two-pin jumper, JU1, selects the shut-
down modes for the MAX1747. Table 1 lists the selec-
table jumper options.
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
None
Installed
SHDN
PIN
Connected to VIN
via R8
Connected to GND
OUTPUT
MAX1747 enabled,
operation up to 1.23MHz
Shutdown mode,
VOUT = 0
Detailed Description
The MAX1747 EV kit contains a high-current step-up
DC-DC converter and two low-current charge-pump
circuits. The EV kit’s voltage input range is from +3.0V
to +3.6V as configured, and can be extended to oper-
ate in the +2.7V to +5.5V range. The high-current step-
up DC-DC converter output voltage can be adjusted
from +VIN to +5.5V with resistors.
A CMOS open-drain or bipolar open-collector transistor
can be connected to the EV kit
SHDN
pad and ground
to control the shutdown mode. The shunt for jumper
JU1 must be removed for this feature to function.
Low-Current Negative Voltage Source
The MAX1747 EV kit features an option to choose
which voltage source feeds the low-current negative
charge-pump circuit. Jumper JU2 selects the input volt-
age source for pin SUPN on the MAX1747. Table 2 lists
the options.
2
_______________________________________________________________________________________
MAX1747 Evaluation Kit
Table 2. Jumper JU2 Functions
SHUNT
LOCATION
1, 2
SUPN PIN
Connected to
VOUT
Connected to
VIN
OPERATING
MODE
VOUT voltage source
feeds low-current
negative input
Input voltage source,
VIN feeds low-current
negative input
Low-Current Positive Charge-Pump
Output Voltages (VP)
The MAX1747 EV kit’s low-current positive charge-
pump output is set to +12V by feedback resistors (R3,
R4). To generate output voltages other than +12V,
select different external voltage-divider resistors (R3,
R4). Refer to
Output Voltage Selection
in the MAX1747
data sheet for instructions on selecting the resistors.
Jumper JU4 is provided to improve the efficiency of the
low-current positive charge pump for output voltages
under 10V. See Table 3 for the jumper selection of out-
put voltage ranges.
Evaluates: MAX1747
2, 3
Low-Current Positive Voltage Efficiency
The MAX1747 EV kit features an option to improve the
low-current positive charge pump efficiency for low out-
put voltages at VP. Jumper JU3 selects the voltage
source for the maximum pump voltage, and thus, maxi-
mum efficiency. Table 3 lists the options.
Table 3. Jumper JU3 Functions
SHUNT
LOCATION
1, 2
2, 3
DIODE D1
Connected to VOUT
Connected to VIN
OPERATING
MODE
VP > 10V; VOUT feeds D1
VP < 10V; VIN feeds D1
Evaluating Other
Output Voltages
High-Current Step-Up DC-DC Converter
Output Voltages (VOUT)
The MAX1747 EV kit’s high-current step-up DC-DC
converter output is set to +5V by feedback resistors
(R1, R2). To generate output voltages other than +5V,
select different external voltage-divider resistors (R1,
R2). Refer to
Output Voltage Selection
in the MAX1747
data sheet for instructions on selecting the resistors.
Low-Current Negative Charge-Pump
Output Voltages (VN)
The MAX1747 EV kit’s low-current negative charge-
pump output is set to -7V by feedback resistors (R5,
R6). To generate output voltages other than -7V, select
different external voltage-divider resistors (R5, R6).
Refer to
Output Voltage Selection
in the MAX1747 data
sheet for instructions on selecting the resistors. See
Table 2 for the jumper selection of input voltage
ranges.
_______________________________________________________________________________________
3
Evaluates: MAX1747
MAX1747 Evaluation Kit
Figure 1. MAX1747 EV Kit Schematic
4
C1
4.7µF
6.3V
C17
4.7µF
6.3V
R7
SHORT
18
6
IN
OUT
FB
3
RDY
15
C19
0.1µF
D1
1
L
3
R
1
2
JU3
VIN
12
DRVN
DRVP
C16
0.1µF
3
14
3
C11
0.1µF
1
2
VOUT
VOUT
JU2
D4
R
3
1 L
2
R
D3
3
C12
0.1µF
D2
1 L
10
FBN
R 2
C5
1µF
R3
432k
1%
GND
C15
0.1µF
VIN
3
C20
1µF
1
2
13
SUPN
SUPP
R2
49.9k
1%
C22
1µF
C4
OPEN
R1
150k
1%
C3
4.7µF
6.3V
4
C2
4.7µF
6.3V
GND
SUPM
20
+5V
VOUT
R10
1M
RDY
C9
0.1µF
C21
1µF
C18
OPEN
2
+3.0V TO +3.6V
VIN
GND
C8
0.47µF
U1
MAX1747
L
C6
0.47µF
+12V
VP
-7V
R5
280k
1%
R6
49.9k
1%
8
REF
CXP
11
SHDN
JU1
SHDN
5
INTG
C10
1500pF
GND
7
PGND
16
TGND
TGND
C13
0.22µF
FBP
9
19
C14
0.47µF
CXN
17
1
2
VN
C7
1µF
GND
R8
107k
1%
VIN
_______________________________________________________________________________________
R4
49.9k
1%
MAX1747 Evaluation Kit
Evaluates: MAX1747
1.0"
Figure 2. MAX1747 EV Kit Component Placement Guide—
Component Side
1.0"
Figure 3. MAX1747 EV Kit PC Board Layout—Component Side
1.0"
Figure 4. MAX1747 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.
5
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2000 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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