Maxim MAX1556 Max1556 evaluation kit Datasheet

19-3415; Rev 0; 9/04
MAX1556 Evaluation Kit
The MAX1556 evaluation kit (EV kit) is a fully assembled
and tested circuit board that evaluates the MAX1556
and MAX1557 PWM step-down DC-DC converters. The
circuit operates from 2.6V to 5.5V. The MAX1556 delivers up to 1.2A and has pin-selectable 1.8V, 2.5V, 3.3V,
and adjustable output. The MAX1557 delivers up to
600mA and has pin-selectable 1V, 1.3V, 1.5V, and
adjustable output. Each circuit features an on-board
shutdown control.
Component List
DESIGNATION
QTY
DESCRIPTION
Features
♦ Up to 97% Efficiency
♦ 95% Efficiency at 1mA Load Current
♦ 1MHz PWM Switching Frequency
♦ Tiny Inductors
♦ Pin-Selectable Output Voltages
MAX1556: 3.3V, 2.5V, 1.8V, and Adjustable
MAX1557: 1.5V, 1.3V, 1.0V, and Adjustable
♦ 1.2A Guaranteed Output Current (MAX1556)
♦ Voltage Positioning Optimizes Load-Transient
Response
♦ Low 16µA Quiescent Current
2
10µF ±10%, 6.3V X5R ceramic
capacitors (0805)
Murata GRM21BR60J106K or
equivalent
♦ Analog Soft-Start with Zero Overshoot Current
C2, C7
2
22µF ±10%, 6.3V X5R ceramic
capacitors (1206)
Murata GRM31CR60J226K or
equivalent
C3, C8
0
Not installed, capacitors (0805)
2
0.001µF ±10%, 50V X7R ceramic
capacitors (0402)
Murata GRP155R71H102K or
equivalent
C1, C6
C4, C9
C5, C10
0
Not installed, capacitors (0603)
C11
1
0.47µF ±10%, 6.3V X5R ceramic
capacitor (0402)
Murata GRM155R60J474K or
equivalent
JU1–JU6
6
3-pin headers
L1
1
3.3µH inductor, 0.036Ω, 1.3A,
5.0mm x 5.0mm x 2.0mm
Taiyo Yuden LMNP04SB3R3N
L2
1
4.7µH inductor, 0.05Ω, 1.2A, 5.0mm
x 5.0mm x 2.0mm
Taiyo Yuden LMNP04SB4R7N
R1, R3
0
Shorted on PC board, resistors
(0603)
R2, R4
0
Not installed, resistors (0603)
R5
1
100Ω ±1% resistor (0402)
U1
1
MAX1556ETB
U2
1
MAX1557ETB
None
6
Shunts, position 2
None
1
MAX1556 EV kit PC board
♦ Low 27µA Quiescent Current in Dropout
♦ Low 0.1µA Shutdown Current
♦ Small, 10-Pin, 3mm x 3mm TDFN Package
♦ Fully Assembled and Tested
Ordering Information
PART
MAX1556EVKIT
TEMP RANGE
IC PACKAGE
0°C to +70°C
10 TDFN-EP*
*EP = Exposed paddle.
Component Suppliers
SUPPLIER
PHONE
WEBSITE
Murata
814-237-1431
www.murata.com
Taiyo Yuden
408-573-4150
www.t-yuden.com
Vishay
402-563-6866
www.vishay.com
Note: Indicate that you are using the MAX1556 when contacting
these component suppliers.
Quick Start
Recommended Equipment
•
One variable DC power supply capable of supplying up to 5.5V at 1.2A
•
One voltmeter (DMM)
________________________________________________________________ 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: MAX1556/MAX1557
General Description
Evaluates: MAX1556/MAX1557
MAX1556 Evaluation Kit
Procedure (MAX1556ETB)
The MAX1556 EV kit is fully assembled and tested.
Follow the steps below to verify board operation:
1) Select the desired output voltage with JU1, JU2,
and JU3 (see Table 1). The EV kit is preset to a
1.8V output.
2) Connect the positive terminal of the voltmeter to the
pad labeled OUT. Connect the ground terminal of
the voltmeter to the pad labeled GND nearest the
OUT pad. Connect a load from OUT to the GND
pad closest to OUT.
3) Preset the power supply to between 2.6V and 5.5V,
and turn the power supply off. Do not turn on the
power supply until all connections are completed.
4) Connect the positive power-supply terminal to the
pad labeled IN. Connect the power-supply ground
to the pad labeled GND nearest the IN pad.
5) Turn on the power supply and verify the output voltage is the desired voltage from setting JU1, JU2,
and JU3 (default is 1.8V).
5) Turn on the power supply and verify the output voltage is the desired voltage from setting JU4, JU5,
and JU6 (default is 1.0V).
Detailed Description
The MAX1556 EV kit contains two separate PWM stepdown DC-DC converter circuits. Either circuit can be
powered from a DC power supply with a 2.6V to 5.5V
input range. The top and bottom circuit are separate from
each other and do not share a common ground plane.
The top circuit (MAX1556) provides pin-selectable output voltages of 3.3V, 2.5V, 1.8V, and adjustable at 1.2A.
The bottom circuit (MAX1557) provides pin-selectable
output voltages of 1.5V, 1.3V, 1.0V, and adjustable at
600mA.
Pin-Selectable Output Voltages
The MAX1556 output voltage is selected with JU1 and
JU2, as shown in Table 1.
The MAX1557 output voltage is selected with JU4 and
JU5, as shown in Table 2.
Procedure (MAX1557ETB)
Evaluating Other Output Voltages
The MAX1556 EV kit is fully assembled and tested.
Follow the steps below to verify board operation:
1) Select the desired output voltage with JU4, JU5,
and JU6 (see Table 2). The EV kit is preset to a
1.0V output.
The MAX1556 EV kit comes with the MAX1556 preset to
a 1.8V output and the MAX1557 preset to a 1V output.
To evaluate other voltages besides the preset values,
set the MAX1556 (or MAX1557) to adjustable mode.
The footprints for the feedback resistors are available
on the backside of the evaluation kit. Refer to the
Adjusting the Output Voltage section in the MAX1556
data sheet for a detailed description on calculating
these feedback resistor values for the desired output
voltage. Resistor R1 for the MAX1556 circuit (R3 on
MAX1557) is shorted on the evaluation kit. This short
must be cut prior to the placement of a resistor on the
footprint. Resistor R2 for the MAX1556 circuit (R4 for
MAX1557) is open and requires no modification before
placing a resistor on the footprint.
2) Connect the positive terminal of the voltmeter to the
pad labeled OUT2. Connect the ground terminal of
the voltmeter to the pad labeled GND2 nearest the
OUT2 pad. Connect a load from OUT2 to the GND2
pad closest to OUT2.
3) Preset the power supply to between 2.6V and 5.5V,
and turn the power supply off. Do not turn on the
power supply until all connections are completed.
4) Connect the positive power-supply terminal to the
pad labeled IN2. Connect the power-supply ground
to the pad labeled GND2 nearest the IN2 pad.
Table 1. Output Voltage Selection (MAX1556ETB)
JU1
JU2
JU3
MAX1556 VOUT
1 and 2
1 and 2
1 and 2
1.8V
1 and 2
2 and 3
1 and 2
2.5V
2 and 3
1 and 2
1 and 2
3.3V
2 and 3
2 and 3
1 and 2
ADJ
—
—
2 and 3
Shutdown
Note: Default configuration is JU1, JU2, and JU3 (1 and 2).
2
_______________________________________________________________________________________
MAX1556 Evaluation Kit
JU4
JU5
JU6
MAX1557 VOUT
1 and 2
1 and 2
1 and 2
1.0V
1 and 2
2 and 3
1 and 2
1.3V
2 and 3
1 and 2
1 and 2
1.5V
2 and 3
2 and 3
1 and 2
ADJ
—
—
2 and 3
Shutdown
Note: Default configuration is JU4, JU5, and JU6 (1 and 2).
External Shutdown Control
The MAX1556 EV kit comes preset with SHDN and
SHDN2 pulled high so that the MAX1556 and MAX1557
are enabled when the input voltage is applied. To operate
the shutdown control from an external signal, remove the
IN
9
IN_P
shunt on JU3 for the MAX1556 (JU6 for the MAX1557).
Apply a logic high to SHDN to enable the MAX1556, or
apply a logic low to shut down the MAX1556. Apply a
logic high to SHDN2 to enable the MAX1557, or apply a
logic low to shut down the MAX1557.
LX
8
C1
10µF
R5
100Ω
L1
3.3µH
C2
22µF
U1
1
IN
MAX1556
PGND
C11
0.47µF
OUT
1
JU1 2
3
SHDN
10
1
3
5
2
JU3
1
2
3
JU2
6
OUT
C3
OPEN
C5
OPEN
7
R1
SHORT
GND
4
GND
R2
OPEN
D1
SHDN
SS
3
C4
0.001µF
D2
GND
2
EXPOSED PAD
CONNECTED TO GND
Figure 1a. MAX1556 EV Kit Schematic (MAX1556)
_______________________________________________________________________________________
3
Evaluates: MAX1556/MAX1557
Table 2. Output Voltage Selection (MAX1557ETB)
Evaluates: MAX1556/MAX1557
MAX1556 Evaluation Kit
IN2
9
IN_P
LX
8
C6
10µF
L2
4.7µH
C7
22µF
U2
1
IN
MAX1557
PGND
OUT
1
JU4 2
3
SHDN2
10
1
3
5
2
JU6
1
2
3
JU5
6
OUT2
C8
OPEN
C10
OPEN
7
R3
SHORT
GND2
4
GND2
R4
OPEN
D1
SHDN
SS
3
C9
0.001µF
D2
GND
2
EXPOSED PAD
CONNECTED TO GND
Figure 1b. MAX1556 EV Kit Schematic (MAX1557)
4
_______________________________________________________________________________________
MAX1556 Evaluation Kit
Evaluates: MAX1556/MAX1557
Figure 2. MAX1556 EV Kit Component Placement Guide—Component Side
Figure 3. MAX1556 EV Kit Component Placement Guide—Solder Side
_______________________________________________________________________________________
5
Evaluates: MAX1556/MAX1557
MAX1556 Evaluation Kit
Figure 4. MAX1556 EV Kit PC Board Layout—Component Side
Figure 5. MAX1556 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
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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