19-1403; Rev 1; 8/99
MAX1677 Evaluation Kit
General Description
The MAX1677 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains
two separate switching-regulator circuits. The first cir-
cuit is configured for a +3.3V main output and +20V
LCD bias voltage. It accepts inputs from +0.7V to
+3.3V. The main +3.3V output supplies up to 350mA
from a 2-cell input, or 140mA from a 1-cell input, while
the LCD bias output supplies up to 12mA at +20V.
The second circuit converts a +0.7V to +3.3V battery
voltage to a +3.3V main output and a -20V LCD bias
voltage. The main +3.3V output supplies up to 350mA
from a 2-cell input, or 140mA from a 1-cell input, while
the LCD bias output supplies 10mA at -20V.
The MAX1677 features internal N-channel MOSFET
switches, a synchronous rectifier, low-battery compara-
tor, and selectable PFM/PWM mode. The MAX1677 EV
kit provides low quiescent current and high efficiency鈥?/div>
up to 95% for maximum battery life. Operation at
300kHz allows the use of tiny surface-mount inductors.
Features
o
+0.7V to MAIN
OUT
Battery Input Voltage
o
Dual Output Voltages
+3.3V Main Output and +20V LCD Bias Output
+3.3V Main Output and -20V LCD Bias Output
o
All Outputs Also Adjustable with External
Resistors
o
Up to 350mA from 2-Cell Input (Main Output )
o
Up to 140mA from 1-Cell Input (Main Output)
o
Up to 12mA Output Current (LCD Bias Output)
o
Internal N-Channel Switches and Synchronous
Rectifier
o
1碌A(chǔ) IC Shutdown Current
o
300kHz Switching Frequency
o
Surface-Mount Components
o
Fully Assembled and Tested
Evaluates: MAX1677
Ordering Information
PART
MAX1677EVKIT
TEMP. RANGE
0擄C to +70擄C
IC PACKAGE
16 QSOP
Component List
DESIGNATION QTY
C1, C2, C10,
C11
C3, C5, C13,
C14
C4, C12
4
DESCRIPTION
100碌F, 10V low-ESR tantalum caps
AVX TPSD107M010R0100 or
Sprague 593D107X0010D2T
0.1碌F ceramic capacitors
4.7碌F, 35V tantalum capacitors
AVX TPSC475M035R0600 or
Sprague 595D475X0035C2T
2.2碌F, 25V ceramic capacitor
United Chemi-Con/Marcon
THCR30E1E225Z
1碌F, 16V ceramic capacitors
Taiyo Yuden EMK316BJ105KL
TDK C3216X7R1C105M
Not installed
20V, 0.5A Schottky diodes
Motorola MBR0520LT3
40V, 0.5A Schottky diodes
Motorola MBR0540T3
DESIGNATION QTY
L1, L3
2
DESCRIPTION
10碌H inductors
Sumida CR54-100
10碌H inductors
Murata LQH4N100K04
TDK NLC32522T-100K
1.5M鈩?鹵5% resistor
100k鈩?鹵5% resistors
10鈩?鹵5% resistors
1.6M鈩?鹵5% resistor
Not installed
MAX1677EEE
3-pin headers
Shunts
MAX1677 PC board
MAX1677 data sheet
4
L2, L4
R3
R4, R12
R5, R13
R11
R1, R2,
R6鈥揜10,
R14鈥揜16
U1, U2
JU1鈥揓U6
2
1
2
2
1
0
2
6
6
1
1
2
C8
1
C16, C17
C6, C7, C9,
C15, D6
D1, D3
D2, D4, D5
2
0
2
3
None
None
None
________________________________________________________________
Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim鈥檚 website at www.maxim-ic.com.
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