MAXIM MAX1747EVKIT

19-1871; Rev 0; 12/00
MAX1747 Evaluation Kit
Features
♦ Low-Profile Solution, 1.1mm max Height
The low-current negative charge-pump circuit is configured for a -7V output; the low-current positive chargepump circuit is configured for a +12V output. Both circuits 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 components and provides fast transient response.
♦ Integrated Power MOSFETs
♦ Three Charge-Pump Regulators
+5V Output at 200mA
+12V Output at 20mA
-7V Output at 20mA
♦ High-Current Output Regulated to ±1%
♦ Adjustable Outputs
♦ 1µA Shutdown Current
♦ Switching Frequency Up to 1.23MHz
♦ Fast Transient Response
♦ Surface-Mount Components
♦ Fully Assembled and Tested
Ordering Information
PART
MAX1747EVKIT
TEMP.RANGE
IC PACKAGE
0°C to +70°C
20 TSSOP
Component List
DESIGNATION
QTY
C1, C2, C3,
C17
4
5
C5, C7, C20,
C21, C22
C6, C8, C14
C9, C11, C12,
C15, C16, C19
C10
3
6
1
DESIGNATION
QTY
4.7µF, 6.3V X7R ceramic
capacitors (1210)
Taiyo Yuden LMK325BJ475MD
D1–D4
4
200mA, 25V Schottky diodes
(SOT23)
Fairchild BAT54S
1µF, 16V X5R ceramic
capacitors (1206)
Murata GRM42-6X5R105K016
R1
1
150kΩ ±1% resistor (0805)
R2, R4, R6
3
49.9kΩ ±1% resistors (0805)
R3
1
432kΩ ±1% resistor (0805)
0.47µF, 25V X7R ceramic
capacitors (1206)
Murata GRM42-6X7R474K025
R5
1
280kΩ ±1% resistor (0805)
R7
0
Not installed (0805)
R8
1
107kΩ ±1% resistor (0805)
0.1µF, 16V X7R ceramic
capacitors (0603)
Taiyo Yuden EMK107BJ104KA
R10
1
1MΩ ±5% resistor (0805)
U1
1
MAX1747EUP (20 TSSOP)
JU1
1
2-pin header
1500pF, 50V X7R ceramic
capacitor (0603)
Taiyo Yuden UMK107BJ152KZ
JU2, JU3
2
3-pin headers
None
3
Shunts (JU1, JU2, JU3)
None
1
MAX1747 PC board
None
1
MAX1747 data sheet
None
1
MAX1747 EV kit data sheet
DESCRIPTION
C13
1
0.22µF, 10V X7R ceramic
capacitor (0603)
Taiyo Yuden LMK107BJ224KA
C4, C18
0
Not installed (1210)
DESCRIPTION
________________________________________________________________ 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.
Evaluates: MAX1747
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 highcurrent 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.
Evaluates: MAX1747
MAX1747 Evaluation Kit
Component Suppliers
SUPPLIER
PHONE
FAX
Fairchild
408-822-2000
408-822-2102
Murata
814-237-1431
814-238-0490
Nihon
661-867-2555
661-867-2698
Taiyo Yuden
408-573-4150
408-573-4159
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 highcurrent step-up DC-DC converter output (VOUT) is
+5V.
The low-current negative charge pump provides -7V
output; other negative output voltages can be evaluated 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-current 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, respectively.
An off-board CMOS or bipolar transistor can control the
EV kit’s shutdown feature.
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 shutdown modes for the MAX1747. Table 1 lists the selectable jumper options.
Table 1. Jumper JU1 Functions
6) Verify that the low-current negative charge pump
output (VN) is -7V.
SHUNT
LOCATION
SHDN PIN
OUTPUT
7) Verify that the low-current positive charge pump
output (VP) is +12V.
None
Connected to VIN
via R8
MAX1747 enabled,
operation up to 1.23MHz
Installed
Connected to GND
Shutdown mode,
VOUT = 0
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.
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 operate in the +2.7V to +5.5V range. The high-current stepup DC-DC converter output voltage can be adjusted
from +VIN to +5.5V with resistors.
2
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 voltage source for pin SUPN on the MAX1747. Table 2 lists
the options.
_______________________________________________________________________________________
MAX1747 Evaluation Kit
SHUNT
LOCATION
SUPN PIN
OPERATING
MODE
1, 2
Connected to
VOUT
VOUT voltage source
feeds low-current
negative input
2, 3
Connected to
VIN
Input voltage source,
VIN feeds low-current
negative input
Low-Current Positive Voltage Efficiency
The MAX1747 EV kit features an option to improve the
low-current positive charge pump efficiency for low output voltages at VP. Jumper JU3 selects the voltage
source for the maximum pump voltage, and thus, maximum efficiency. Table 3 lists the options.
Low-Current Positive Charge-Pump
Output Voltages (VP)
The MAX1747 EV kit’s low-current positive chargepump 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 output voltage ranges.
Table 3. Jumper JU3 Functions
SHUNT
LOCATION
DIODE D1
OPERATING
MODE
1, 2
Connected to VOUT
VP > 10V; VOUT feeds D1
2, 3
Connected to VIN
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 chargepump 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
Table 2. Jumper JU2 Functions
4
GND
VN
-7V
GND
C7
1µF
C8
0.47µF
+3.0V TO +3.6V
VIN
SHDN
VIN
RDY
R
R
1 L
D3
2
1 L
2
C1
4.7µF
6.3V
D4
R8
107k
1%
3
3
R5
280k
1%
C16
0.1µF
3
1
2
C18
OPEN
JU2
R10
1M
C15
0.1µF
VIN
VOUT
C17
4.7µF
6.3V
JU1
C10
1500pF
C13
0.22µF
R6
49.9k
1%
C20
1µF
C9
0.1µF
R7
SHORT
5
11
8
10
12
13
3
6
C21
1µF
INTG
SHDN
REF
FBN
DRVN
SUPN
RDY
IN
U1
PGND
16
MAX1747
GND
7
18
SUPM
TGND
TGND
CXN
CXP
FBP
DRVP
SUPP
FB
OUT
2
1
17
19
9
14
15
4
20
3
3
C14
0.47µF
C12
0.1µF
C11
0.1µF
C19
0.1µF
R2
49.9k
1%
D2
D1
R1
150k
1%
1
2
R 2
L
R
L
1
R4
49.9k
1%
C6
0.47µF
JU3
R3
432k
1%
3
1
2
C22
1µF
C5
1µF
VIN
VOUT
+12V
C4
OPEN
GND
VP
C3
4.7µF
6.3V
C2
4.7µF
6.3V
+5V
GND
VOUT
Evaluates: MAX1747
MAX1747 Evaluation Kit
Figure 1. MAX1747 EV Kit Schematic
_______________________________________________________________________________________
MAX1747 Evaluation Kit
Evaluates: MAX1747
1.0"
1.0"
Figure 2. MAX1747 EV Kit Component Placement Guide—
Component Side
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.
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Printed USA
is a registered trademark of Maxim Integrated Products.