MAX8989EVKIT [MAXIM]
Simple Logic On/Off Control;
| 型号： | MAX8989EVKIT |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Simple Logic On/Off Control |
| 文件： | 总6页 (文件大小：812K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MAX8989 Evaluation Kit
Evaluates: MAX8989
General Description
Features
The MAX8989 evaluation kit (EV kit) is a fully assembled
and tested circuit for evaluating the MAX8989 step-down
converter with linear bypass regulator. The EV kit oper-
ates from a 2.7V to 5.5V power supply or battery. The
output regulates to twice the voltage at REFIN (0.2V to
1.7V) and provides up to 2.5A drive capability.
S PA Step-Down Converter
25µs (typ) Settling Time for 0.4V to 3.2V Output-
Voltage Change
Dynamic Output-Voltage Setting from 0.4V to
V
IN
85mI PFET and 100% Duty Cycle for Low
Dropout
2MHz Switching Frequency
Low Output-Voltage Ripple
Component List
2% Output-Voltage Accuracy Over Load, Line,
and Temperature
DESIGNATION
QTY
DESCRIPTION
4.7FF 20%, 6.3V X5R ceramic
capacitors (0603)
TDK C1608X5R0J475M
Tiny External Components
S 2.5A Output-Current Capability
S Simple Logic On/Off Control
S Low 0.1µA Shutdown Current
S 2.7V to 5.5V Supply Voltage Range
S Thermal-Overload Protection
S Proven PCB Layout
C1, C2, C4, C5,
C6
5
1000pF Q5%, 50V C0G ceramic
capacitor (0402)
Murata GRM1555C1H102J
C3
C7
1
0
Not installed, ceramic capacitor
(0603)
JU1
JU2
1
1
2-pin header, 0.1in
3-pin header, 0.1in
S Fully Assembled and Tested
4.7FH Q20%, 252mI,
850mA inductor, 1.2mm (max)
height (2520)
TOKO 1239AS-H-4R7N=P2
(DFE252012C)
L1
1
Ordering Information
PART
TYPE
MAX8989EVKIT+
EV Kit
PWM step-down converter
(9 WLP, 0.5mm pitch)
Maxim MAX8989EWL+
U1
1
+Denotes lead(Pb)-free and RoHS compliant.
—
—
2
1
Shunts, 2-position
PCB: MAX8989 EVALUATION
KIT+
Component Suppliers
SUPPLIER
PHONE
WEBSITE
www.murata-northamerica.com
www.component.tdk.com
www.tokoam.com
Murata Electronics North America, Inc.
TDK Corp.
770-436-1300
847-803-6100
847-297-0070
TOKO America, Inc.
Note: Indicate that you are using the MAX8989 when contacting these component suppliers.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-5745; Rev 0; 1/11
MAX8989 Evaluation Kit
Evaluates: MAX8989
10) Turn on the power supply and voltage reference.
11) Install the shunt on jumper JU1.
Quick Start
Recommended Equipment
12) With the voltmeter, verify that the voltage from OUT to
PGND2 is approximately twice the reference voltage.
•ꢀ MAX8989 EV kit
•ꢀ 2.7V to 5.5V power supply or battery capable of
delivering 2.5A
Detailed Description of Hardware
•ꢀ Voltage reference or power supply capable of
providing 0.2V to 1.7V (must be able to sink and
source up to 1mA)
The MAX8989 output regulates to twice the voltage at
REFIN and provides up to 2.5A drive capability. REFIN
must connect to an external reference supply between
0.2V and 1.7V. Connect the ground of the reference
supply to the AGND PCB pad. Do not use AGND as a
power-ground connection.
•ꢀ Voltmeter
•ꢀ Load (resistor or electronic load)
Procedure
The EV kit is fully assembled and tested. Follow the steps
below to verify board operation:
Enable
Enable/shutdown control is provided by jumper JU1. For
normal operation, place a shunt on the pins of JU1. For
low-power shutdown mode, remove the shunt from JU1.
In shutdown mode, the step-down regulator and LDO are
off, reducing the supply current to 0.1µA (typ).
1) Preset the power supply to 3.7V.
2) Preset the voltage reference between 0.2V and 1.7V.
3) Turn off the power supply and reference. Do not turn
on the power supply until all connections are com-
pleted.
To drive the enable input from an external logic source,
remove the shunt on JU1. Connect the logic signal to pin
2 of JU1. Connect the signal ground to AGND. Refer to
the Electrical Characteristics section in the MAX8989 IC
data sheet for the required logic levels.
4) Remove the shunt from jumper JU1.
5) Connect the positive power-supply terminal to the
EV kit PCB pad labeled IN.
Skip Mode
The device has an optional skip mode. To enable skip
mode, connect pins 2-3 of jumper JU2. Skip mode pro-
vides the highest possible efficiency during light-load
conditions, reducing the no-load supply current to 115µA
(typ). Skip mode is only active when the output voltage is
less than 1V.
6) Connect the negative power-supply terminal to the
EV kit PCB pad labeled GND1.
7) Connect the positive voltage-reference terminal to
the EV kit PCB pad labeled REFIN.
8) Connect the negative voltage-reference terminal to
the EV kit PCB pad labeled AGND.
9) Connect the load from OUT to GND2.
To prevent the device from entering skip mode, connect
pins 1-2 of JU2.
Table 1. Jumper Settings (JU1, JU2)
SHUNT POSITION
JUMPER
OPEN
Shutdown mode
—
1-2
2-3
JU1
JU2
Output enabled
—
Forced-PWM operation
Skip mode enabled for light loads with V
< 1V
OUT
2
Maxim Integrated
MAX8989 Evaluation Kit
Evaluates: MAX8989
Figure 1. MAX8989 EV Kit Schematic
Maxim Integrated
3
MAX8989 Evaluation Kit
Evaluates: MAX8989
1.0”
1.0”
Figure 2. MAX8989 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX8989 EV Kit PCB Layout—Component Side
(Layer 1)
1.0”
Figure 4. MAX8989 EV Kit PCB Layout—Inner Layer 2
4
Maxim Integrated
MAX8989 Evaluation Kit
Evaluates: MAX8989
1.0”
1.0”
Figure 5. MAX8989 EV Kit PCB Layout—Inner Layer 3
Figure 6. MAX8989 EV Kit PCB Layout—Solder Side (Layer 4)
Maxim Integrated
5
MAX8989 Evaluation Kit
Evaluates: MAX8989
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
DESCRIPTION
0
1/11
Initial release
—
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent
licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max
limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
6
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
©
2011 Maxim Integrated Products, Inc.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
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