19-2168; Rev 0; 9/01
MAX1864 Evaluation Kit
General Description
The MAX1864 evaluation kit (EV kit) demonstrates the
MAX1864鈥檚 standard application circuit. This EV kit
operates from 8V to 24V, generating three positive out-
put voltages.
The MAX1864 EV kit includes a current-mode synchro-
nous step-down controller and two positive regulator
gain blocks. The main synchronous step-down con-
troller provides a 3.3V output voltage with 1A output
current from an 8V to 24V input voltage range. The pos-
itive regulator gain blocks use an external PNP pass
transistor to generate 2.5V with 300mA output current
from the main 3.3V output, and 5V with 100mA output
current using coupled windings from the step-down
converter. The EV kit operates at 200kHz switching fre-
quency, allowing the use of low-cost aluminum elec-
trolytic capacitors and a low-cost power transformer.
This EV kit is a fully assembled and tested circuit
board. It also allows the evaluation of other main output
voltages in the 1.236V to 5.5V range by installing feed-
back resistors R8 and R9.
o
8V to 24V Input Voltage Range
o
Preset 3.3V Main Output Voltage
o
1A Main Output Current
o
200kHz Switching Frequency
o
No Current-Sense Resistor
o
Linear Regulator Output Voltages
2.5V at 300mA
5.0V at 100mA
o
Adjustable Output Voltages
o
Power-Good Output
o
16-Pin QSOP Package
o
Low-Cost Components
o
Fully Assembled and Tested
Features
Evaluates: MAX1864
Ordering Information
PART
MAX1864EVKIT
TEMP. RANGE
0擄C to +70擄C
IC PACKAGE
16 QSOP
Component List
DESIGNATION
C1
QTY
1
DESCRIPTION
100碌F, 35V aluminum electrolytic
capacitor
Sanyo 35MV100AX
470碌F, 10V aluminum electrolytic
capacitors
Sanyo 10MV470AX
0.1碌F ceramic capacitor (0805)
1碌F, 10V X5R ceramic capacitor
(0805)
Taiyo Yuden LMK212BJ105MG
8200pF ceramic capacitor (0805)
10碌F, 6.3V X5R ceramic
capacitors (1210)
Taiyo Yuden JMK325BJ106MN
or TDK C3216X5R0J106M
4700pF ceramic capacitor (0805)
2200pF ceramic capacitor (0805)
1碌F, 25V X7R ceramic capacitor
(1206)
Taiyo Yuden TMK316BJ105ML
or TDK C3216X7R1E105M
DESIGNATION
R1
R2, R5
R3, R4, R12
R6
R7
R8, R10, R11
R9
R13, R14
D1
QTY
1
2
3
1
1
0
0
2
1
DESCRIPTION
47k鈩?鹵5% resistor (0805)
220鈩?鹵5% resistors (0805)
10k鈩?鹵1% resistors (0805)
30.1k鈩?鹵1% resistor (0805)
100k鈩?鹵5% resistor (0805)
Not installed (0805)
Not installed (short PC trace)
10鈩?鹵5% resistors (0805)
Schottky diode
Central Semiconductor CMPSH-3
0.5A Schottky diode
Nihon EP05Q03L or
ON Semiconductor (Motorola)
MBR0540
Dual N-channel MOSFET
International Rectifier IRF7303 or
Fairchild NDS9956A
PNP transistor (DPAK)
Fairchild KSH30
C2, C9
C3
C4
C5
C6, C7, C8,
C12
C10
C11
C13
2
1
1
1
4
1
1
1
D2
1
N1A, N1B
1
Q1
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim鈥檚 website at www.maxim-ic.com.
1
2
3
4
