19-1749; Rev 0; 10/96
MAX849 Evaluation Kit
_______________General Description
The MAX849 evaluation kit (EV kit) is an assembled and
tested PC board that implements a complete, one-cell
to three-cell, high-power, low-noise, step-up DC-DC
power converter that鈥檚 ideal for portable phones and
other battery-operated equipment. With a 3.3V output
voltage, use one or two cells to get a 250mA to 700mA
output current. With a 5V output voltage, use three cells
or one lithium-ion (Li-Ion) battery to get an 850mA out-
put current.
The board includes clips for a standard AA-size bat-
tery, and provides a 10-pin header for user interfacing.
To evaluate the MAX848, order a free sample of the
MAX848ESE along with the MAX849 EV kit.
____________________________Features
o
250mA to 850mA Output Current!
V
IN
(V)
1.2
2.4
2.4
3.6
V
OUT
(V)
3.3
3.3
5.0
5.0
I
OUT
(mA)
250
700
500
850
Evaluates: MAX848/MAX849
o
90% Efficiency
o
Proven PC Board Layout
o
Fully Assembled and Tested
o
2-Channel Analog-to-Digital Converter (ADC) with
Serial Output for Voltage Monitoring
____________________Component List
DESIGNATION QTY
BAT1
C1
C2, C3
C4, C5
CF1, CF2
CF3
CI1
CI2
D1
J1
JU1
JU2
L1
R1
R2
R3
R4, R11
R5
R6, R7, R9,
R10
R8
U1
2
1
2
2
2
0
1
0
1
1
1
1
1
1
1
0
2
2
1
4
1
1
DESCRIPTION
Battery clips
Keystone 92
0.22碌F ceramic capacitor
0.1碌F ceramic capacitors
4.7nF ceramic capacitors
100碌F, 6V, 0.1ESR capacitors
AVX TPSD107M010R0100
Open
22碌F, 6V, low-ESR capacitor
AVX TPSD226M025R0200
Open
0.5A, 20V Schottky diode
Motorola MBR0520L
10-pin header
2-pin header
3-pin header
10碌H, 1.65A, 4.5mm inductor
Sumida CDR74B-100
10鈩? 5% resistor
61.9k鈩? 1% resistor
Open
Battery clips Keystone 92
1k鈩? 5% resistors
6.81k鈩? 1% resistor
1M鈩? 5% resistors
100k鈩? 5% resistor
Maxim MAX849ESE
______________Ordering Information
PART
MAX849EVKIT-SO
TEMP. RANGE
0擄C to +70擄C
BOARD TYPE
Surface Mount
_____________________________________
Quick
Start
This section describes how to operate the MAX849 EV
kit, and how to evaluate its performance.
Do not turn
on the power supply until all connections are com-
pleted.
1) Configure the jumper and resistor settings as
desired. For a standard 3.3V output and 90%
power-OK threshold, close jumper JU1 (Table 1).
2) Insert an AA-size battery cell into the battery clips.
Or, connect a 1V to 3V DC power supply to the VIN
and GND input pads. Turn on the power supply.
Quiescent supply current for the board with no load
should be less than 1mA.
3) The EV kit board turns on automatically, and VOUT
goes to 3.3V.
4) To operate in high-power PWM mode at a particular
frequency between 200kHz and 400kHz, leave JU2
open and drive the CLK/SEL pin with pulses at the
desired frequency. Or, let the MAX849 determine its
own PWM frequency by connecting JU2 1-2. To
operate in low-power PFM mode, connect JU2 2-3.
________________________________________________________________
Maxim Integrated Products
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For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
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