MAXIM MAX1701EVKIT

19-4759; Rev 1; 1/99
MAX1701 Evaluation Kit
____________________________Features
The MAX1701 evaluation kit provides a regulated 3.3V
output while operating on input voltages as low as 0.7V.
The input may be a DC source or a 1 to 2–cell battery.
Efficiency is up to 95% with output loads up to 200mA.
The kit, which uses surface-mount components, is fully
assembled and tested for quick evaluation. Jumpers
are provided to select the output voltage, switching
mode, and shutdown control. This EV kit can also be
used to evaluate the MAX1700. Simply order a free
sample of the MAX1700EEE and replace the
MAX1701EEE that comes installed on the board.
♦ 3.3V Output
____________________Component List
DESIGNATION QTY
♦ 0.7V to 3.5V Input
♦ Up to 95% Efficiency
♦ 3µA Shutdown Current
♦ 300kHz PWM Operation
♦ Optional Low-Power PFM Mode
♦ Small Surface-Mount Components
_______________Ordering Information
DESCRIPTION
C1
1
22µF, 25V, low-ESR tantalum capacitor
AVX TPSD226M025R0200
Sprague 593D226X0025D
C2, C3
2
0.22µF, 25V ceramic capacitors
C4
1
0.10µF, 25V ceramic capacitor
1
100µF, 10V low-ESR tantalum capacitor AVX TPSD107M010R0100 or
Sprague 593D107X0010D7
C5
♦ 200mA Output
PART
TEMP. RANGE
PIN-PACKAGE
0°C to +70°C
16-pin QSOP
MAX1701EVKIT
______________Component Suppliers
SUPPLIER
PHONE
FAX
AVX
(803) 946-0690
(803) 626-3123
Coilcraft
(847) 639-6400
(847) 639-1469
(561) 241-7876
(561) 241-9339
C6, C7
0
Not installed. Space for optional user
capacitor.
Coiltronics
Sprague
(603) 224-1961
(603) 224-1430
D1
1
0.5A, 20V Schottky diode
Motorola MBR0520L
Sumida
(847) 956-0666
(847) 956-0702
Motorola
(303) 675-2140
(303) 675-2150
J1, J2, J3
3
3-pin jumpers
J4, J5
2
2-pin jumpers
L1
1
10µH, 1.6A power inductor
CoilCraft DO3316-103,
Coiltronics UP1B-100,
Sumida CDR74B-100
R1, R4, R6
3
100kΩ, 1% resistors
R2, R3, R5
3
Not installed
R7, R8, R9
3
100kΩ, 5% resistors
R10, R11, R12
3
1MΩ, 5% resistors
R13
1
10Ω, 5% resistor
U1
1
MAX1701EEE
None
5
Shunts
None
1
3.4” x 2.4” printed circuit board
None
1
MAX1700/MAX1701 data sheet
_________________________Quick Start
The MAX1701 EV kit is shipped fully assembled and
tested. Follow these steps to verify board operation. Do
not turn on the power supply until all connections
are completed.
1) Verify that the shunts are connected as listed in
Table 2 for a 3.3V output.
2) Connect a +1.1V to +3.3V supply to the pad marked
VIN. The ground connects to the GND pad. Note:
the input voltage may drop as low as 0.7V after startup.
3) Connect a voltmeter to the VOUT pad.
4) Turn on the power and verify that the output voltage
is 3.3V.
5) Connect a load (if any).
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Evaluates: MAX1700/MAX1701
________________General Description
Evaluates: MAX1700/MAX1701
MAX1701 Evaluation Kit
_______________Detailed Description
Jumper Selection
Five jumpers on the printed circuit board allow user
selection of several configurations. Table 1 lists the
jumpers and their functions. Table 2 lists the jumper
positions when the board is set for normal 3.3V output
operation.
Component Selection
The final circuit performance is determined by the quality of the components surrounding the MAX1701. The
power inductor must not saturate at the 1.6A maximum
peak current produced by MAX1701. Inductors in the
Component List all have high current ratings and low
coil resistance.
Table 1. Jumper Functions
JUMPER
J1
SHUNT
LOCATION
ONA connected to GND
MAX1701 is disabled if ONB is VOUT.
2 and 3
ONA connected to VOUT
MAX1701 is enabled.
ONA is not controlled by the board
ONA must be driven by a signal connected
to the ONA pad.
1 and 2
ONB connected to GND
MAX1701 is enabled.
2 and 3
ONB connected to VOUT
MAX1701 is disabled if ONA = GND.
ONB is not controlled by the board
ONB must be driven by a signal connected
to the ONB pad.
1 and 2
CLK/SEL connected to GND
Low-power mode, MAX1701 operates in
the PFM mode.
2 and 3
CLK/SEL connected to VOUT
High-power mode, MAX1701 operates in
the PWM mode.
CLK/SEL connected to CLK/SEL pad
CLK/SEL pin can be driven by an external
source to select power mode, or a 200kHz
to 400kHz signal to control switching frequency.
FB connected to GND
VOUT is preset to 3.3V.
FB connected to the resistor divider
Resistors must be installed in R3 and R4 for
proper circuit operation.
Shorted for normal operation
VOUT connected to pull-up resistors.
Pull-ups disconnected
R7–R9 are disconnected so that MAX1701
shutdown current may be verified.
Open
J3
Open
Shorted
J4
Open
Shorted
J5
MAX1701 OPERATION
1 and 2
Open
J2
PIN
CONNECTION
Open
Table 2. Jumper Position for Normal 3.3V Operation
2
JUMPER
SHUNT
LOCATION
PIN
CONNECTION
J1
2 and 3
ONA connected to VOUT
MAX1701 is enabled.
J2
1 and 2
ONB connected to GND
MAX1701 is enabled.
J3
2 and 3
CLK/SEL connected to VOUT
High-power mode, MAX1701 operates in
the PWM mode.
J4
Shorted
FB connected to GND
VOUT is preset to 3.3V. This jumper must
be shorted or resistors installed in R3 and
R4 for proper circuit operation.
J5
Shorted
VOUT connected to pull-up resistors
MAX1701 OPERATION
_______________________________________________________________________________________
MAX1701 Evaluation Kit
nected between LX and P OUT as close to the IC as
possible. A Schottky diode is specified for the lower forward voltage drop as well as the fast switching characteristic. Most Schottky diodes with a sufficient current
rating will work. The diode for the evaluation board was
selected for its small size.
A separate low-noise ground plane connects pin 5 to
the reference and signal grounds. This low-noise
ground plane is then connected to the power-ground
plane at the PGND pin (Figure 4).
A low-ESR input capacitor must be located physically
close to the inductor. The Schottky diode must be con-
VIN 0.7V TO 3.5V
C1
22µF
25V
GND
R2
OPEN
L1
10µH
1
R1
100k
1%
2
3
LX
LBN
POUT
OUT
FB
C7
OPEN
8
2
AO
3
J2
7
2
R3
OPEN
J4
R4
100k
1%
R7
100k
R8
100k
R9
100k
AO
ONA
1
ONB
J5
C4
0.1µF
11
R11
1M
3
C6
OPEN
R13
10
14
C3
0.22µF
MAX1701
J1
15
U1
VOUT
ONA
C5
100µF
10V
REF
C2
0.22µF
VOUT
D1
13
LBP
LBO
9
LO BATT
16
ONB
1
POK
PWR 0K
6
3
CLK/SEL
J3
4
2
1
R10
1M
R12
1M
CLK/SEL
AIN
GND
PGND
5
12
AIN
10
R6
100k
1%
R5
OPEN
Figure 1. MAX1701 EV Kit Schematic
_______________________________________________________________________________________
3
Evaluates: MAX1700/MAX1701
The input and output capacitors must have low equivalent series resistance (ESR) to handle the high peak
currents found in switching regulators. Low ESR is
especially critical in low-voltage circuits to reduce the
AC voltage across the capacitors. A higher ESR on the
output capacitor will increase the output ripple.
Consider using parallel capacitors to reduce the total
ESR if the application requires lower output ripple. An
additional output capacitor (C6) may be required for
output current greater than 200mA or output voltages
less than 3.3V.
Evaluates: MAX1700/MAX1701
MAX1701 Evaluation Kit
1.0"
1.0"
Figure 2. MAX1701 EV Kit Component Placement Guide
Figure 3. MAX1701 EV Kit PC Board Layout—Component Side
1.0"
Figure 4. MAX1701 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
© 1999 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.