MAX1945 Datasheet, PDF (1/6 Pages) Maxim Integrated Products – Evaluation Kit

19-2615; Rev 1; 1/03
MAX1945 Evaluation Kit
General Description
The MAX1945 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that contains a
high-efficiency step-down switching-regulator circuit for
applications requiring on-board postregulation. The cir-
cuit utilizes a MAX1945R regulator featuring ±4% voltage
margining and is configured for a 1.8V output voltage.
The circuit provides up to 6A of current. A 2.6V to 5.5V
DC source can be utilized to power the circuit’s input.
The MAX1945R IC features an internal power MOSFET
switch and an internal synchronous rectifier. The
MAX1945 EV kit provides connections for the SYNC
input. It also provides an output to synchronize another
MAX1945 EV kit clock 180 degrees out-of-phase. Pulse-
width modulated (PWM) operation at 500kHz allows the
use of tiny surface-mount components.
Component List
DESIGNATION QTY
DESCRIPTION
C1
1
100µF ±20%, 8V polymer capacitor
(7.3 x 4.3)
Panasonic EEFUE0K101R
180µF ±20%, 4V polymer capacitor
C2
1 (7.3 x 4.3)
Panasonic EEFUE0G181R
C3, C6, C7
0.1µF ±10%, 10V X7R ceramic
3 capacitors (0603)
AVX 0603ZC104KAT
0.22µF ±10%, 6.3V X7R ceramic
C4
1 capacitor (0603)
AVX 06036C224KAT
100pF ±5%, 50V COG ceramic
C5
1 capacitor (0603)
TDK C1608COG1H101JT
1µF ±10%, 16V X7R ceramic
C8
1 capacitor (1206)
TDK C3216X7R1C105KT
D1
J1
JU1, JU2, JU3
1
100mA, 30V Schottky diode (SOD-523)
Central Semiconductor CMOSH-3
0
Scope probe connector (not installed)
FCI 33JR135-1
3 2-pin headers
Features
♦ 0.970in x 0.840in Circuit Footprint
♦ 2.6V to 5.5V Input Range
♦ Output Voltage
1.8V/2.5V Preset
0.8V to 0.85x VIN Adjustable
♦ Provides Up to 6A Output Current
♦ ±4% Voltage Margining
♦ Internal Power Switch and Synchronous Rectifier
♦ 500kHz/1MHz PWM Selectable Switching
Frequency
♦ SYNC Input: Synchronizes from 400kHz to 1.2MHz
TTL/CMOS Clock
♦ SYNC Output: Drives 2nd MAX1945 Switching 180
Degrees Out-of-Phase
♦ All Surface-Mount Components
♦ Fully Assembled and Tested
PART
MAX1945EVKIT
*EP = Exposed pad.
Ordering Information
TEMP RANGE
0°C to +70°C
IC PACKAGE
28 TSSOP-EP*
Quick Start
Required Equipment
The following equipment is required before beginning:
• One 2.6V to 5.5V power supply capable of providing 5A
• One voltmeter
The MAX1945 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:
1.8V Output Voltage (Nominal)
1) Verify that jumpers JU1 (CTL1) and JU2 (CTL2) do
not have shunts across their respective pins.
2) Verify that a shunt is across the pins of jumper JU3
(SYNC).
3) Verify that jumper JU4 (FBSEL, 1.8V) has a shunt
installed across pins 2 and 3.
4) Connect the voltmeter to the VOUT and PGND
pads.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.