19-1426; Rev 0; 2/99
MAX1688 Evaluation Kit
General Description
The MAX1688 evaluation kit (EV kit) is a boost switching
regulator for one Li-Ion cell or three NiCd/NiMH cells in
battery-powered systems. The EV kit accepts a positive
input between 2.7V and 6V and converts it to a 5V out-
put. It can easily deliver the current burst required for
cell-phone power amplifier systems. The MAX1688
reduces battery surge current by slowly charging a
reservoir capacitor, which supplies the necessary peak
energy for the current burst. As a result, the peak battery
input current is limited, thereby minimizing the battery
voltage sag and transient dips. The EV kit operates at
600kHz, allowing the use of small external components.
The MAX1688 EV kit provides low quiescent current
and high efficiency for maximum battery life. An internal
synchronous rectifier is used to provide over 90% con-
version efficiency. This EV kit is a fully assembled and
tested surface-mount circuit board. The MAX1688 EV
kit can also be used to evaluate the MAX1687.
o
2.7V to 6V Input Voltage Range
o
5V Output Voltage
o
Less than 500mV Output Voltage Droop with
1.42A Burst Current
o
90% Efficiency
o
Output Disconnected from Input during Shutdown
o
600kHz Switching Frequency
o
Internal MOSFET and Synchronous Rectifier
o
3碌A IC Shutdown Current
o
Surface-Mount Components (TSSOP Package)
o
Fully Assembled and Tested
Features
Evaluates: MAX1687
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/MAX1688
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Component List
DESIGNATION QTY
C1
C2
C3, C4
C5
L1
R1
R2, R3
R4
R5
U1
None
None
1
1
2
0
1
1
2
1
0
1
1
1
DESCRIPTION
47碌F, 16V tantalum capacitor
AVX TPSC476M016R0350 or
Sprague 595D476X0016C2T
0.1碌F ceramic capacitor
1000碌F, 6.3V electrolytic capacitors*
Sanyo 6CV1000AX
Not installed
10碌H inductor
Sumida CLS62B-100 or
Coiltronics TP2-100
60.4k鈩?1% resistor
20.0k鈩?1% resistors
1M鈩?5% resistor
Not installed (for MAX1687 only)
MAX1688EUE
MAX1688 PC board
MAX1688 data sheet
PART
Ordering Information
TEMP. RANGE
IC PACKAGE
MAX1688EVKIT
0擄C to +70擄C
16 TSSOP
Note:
To evaluate the MAX1687, order a MAX1687EUE sample
with the MAX1688 EV kit.
Quick Start
The MAX1688 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.
1) Connect a 3V supply voltage to the VIN pad.
Connect the supply ground to the GND pad.
2) Connect a voltmeter and load, if any, to the VOUT
pad.
3) Turn on the power supply.
4) Synchronize the GSM pulse load to the ON signal by
applying the logic signal that controls the power
amplifier to the ON/OFF pad. ON is low when GSM
load is applied.
5) Verify the output voltage is 5V. For other output volt-
ages, refer to the
Adjusting the Output Voltage
sec-
tion in the MAX1687/MAX1688 data sheet for instruc-
tions on selecting the feedback resistors.
*For
low-profile applications, use Sprague tantalum
595108X06R3R2.
Component Suppliers
SUPPLIER
AVX
Coiltronics
Dale-Vishay
Sanyo
Sprague
Sumida
PHONE
803-946-0690
561-241-7876
402-564-3131
619-661-6835
603-224-1961
708-956-0666
FAX
803-626-3123
561-241-9339
402-563-6418
619-661-1055
603-224-1430
708-956-0702
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Patent pending
________________________________________________________________
Maxim Integrated Products
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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.
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