Datasheet

4) Verify that there is a shunt on pins 1-2 of jumper
JU4.
5) Connect the positive lead of the power supply to the
IN pad and connect the negative lead of the power
supply to the GND pad on the EV kit.
6) Connect the positive lead of the DMM to the OUT
pad and connect the negative lead of the DMM to
the GND pad on the EV kit.
7) Turn on the power supply.
8) Verify that the voltage at OUT is 1.8V.
9) Connect the load between OUT and GND.
10) Verify that the voltage at OUT is 1.8V.
Detailed Description
Evaluating Other Output Voltages
The MAX8643 EV kit comes preset to a 1.8V output
voltage. As shown in Table 1, the output voltage is pin-
programmable by the logic states of CTL1 and CTL2,
jumpers JU3 and JU4, respectively. CTL1 and CTL2
are three-level inputs: V
DD
, unconnected, and GND.
The logic states of CTL1 and CTL2 should be pro-
grammed only before power-up. To avoid damage to
the IC, CTL1 and CTL2 should not be changed once
soft-start is complete. If the output voltage needs to be
reprogrammed, cycle power or EN and reprogram dur-
ing or before soft-start.
When the output voltage of the MAX8643 is pro-
grammed to a preset voltage, Ri is internal to the IC
and R9 is not installed (Figure 1b).
Evaluates: MAX8643
MAX8643 Evaluation Kit
2 _______________________________________________________________________________________
Component List (continued)
DESIGNATION QTY DESCRIPTION
JU1, JU2 2 2-pin headers
JU3, JU4 2 3-pin headers
L1 1
0.47µH, 7.6mΩ, 9.6A inductor
(7.7mm x 7mm x 2mm)
TOKO FDV0620-R47
R1 1 10Ω ±5%, resistor (0603) lead free
R2 1 10kΩ ±5% resistor (0603) lead free
R3 1 1kΩ ±5%, resistor (0603) lead free
R4 1
2.67kΩ ±1%, resistor (0603) lead
free
R5 1 20kΩ ±5% resistor (0603) lead free
R6 1 158Ω ±1% resistor (0603) lead free
R7 1
49.9kΩ ±1% resistor (0603) lead
free
R8 0
Not installed, resistor (0603). Must
be 8.06kΩ ±1% resistor (0603)
when populated for adjustable
output voltage programming.
R9 0
Not installed, resistor (0603) for
adjustable output voltage
programming
R10 1 2.2Ω ±5% resistor (0603) lead free
U1 1
MAX8643ETG+
(24-pin, 4mm x 4mm TQFN)
— 5 Shunts
— 1 MAX8643 EV kit PCB
Component Suppliers
SUPPLIER PHONE WEBSITE
TDK 847-803-6100 www.component.tdk.com
TOKO 800-745-8656 www.toko.com
Vishay 402-563-6866 www.vishay.com
Table 1. CTL1 and CTL2 Output Voltage
Selection
CTL1/JU3 CTL2/JU4 V
OUT
(V)
2-3 2-3
0.6 or external
divider
1-2 1-2 0.7
2-3 Unconnected 0.8
2-3 1-2 1.0
Unconnected 2-3 1.2
Unconnected Unconnected 1.5
Unconnected 1-2 1.8
1-2 2-3 2.0
1-2 Unconnected 2.5
Note: Indicate that you are using the MAX8643 when contacting
these component suppliers.