19-2585; Rev 0; 9/02
MAX6470 Evaluation Kit
General Description
The MAX6470 evaluation kit (EV kit) circuit features the
MAX6470 low-dropout linear regulator with an integrat-
ed microprocessor reset output signal. The circuit pro-
vides a preset 3.3V output from a 3.6V to 5.5V input
range and delivers 300mA of load current. The
MAX6470 EV kit is a fully assembled and tested sur-
face-mount circuit board that accommodates the
MAX6470 IC in both the 6-pin SOT23 and 8-pin QFN
packages. The EV kit board can also be used to evalu-
ate the MAX6469–MAX6476 linear regulators. For out-
put voltages less than 3.3V, the input voltage range can
go down to 2.5V.
o
Preset 3.3V Output
o
Adjustable Output Voltage (1.2V to 5V)
o
300mA Output Current
o
57mV (typ) Dropout Voltage at 150mA Output
Current
o
Microprocessor
RESET
Output Signal with
Timeout Period
o
Supports 6-Pin SOT23 and 8-Pin QFN Packages
o
Fully Assembled and Tested
Features
Evaluates: MAX6469–MAX6476
Component List
DESIGNATION QTY
DESCRIPTION
1µF
±10%,
6.3V X5R ceramic
capacitor (0603)
Taiyo Yuden JMK107BJ105KA or
TDK C1608X5R1A105K
3.3µF
±10%,
6.3V X5R ceramic
capacitor (0805)
Taiyo Yuden JMK212BJ335KG or
TDK C2012X5R1A335K
Not installed, capacitor (0603)
Not installed, capacitor (0805)
Not installed, resistors (0603)
100kΩ
±5%
resistor (0603)
MAX6470UT33BD3 (6-pin SOT23),
top mark ABFG
Not installed (8-pin QFN)
3-pin headers
Shunts (JU1, JU2)
MAX6470 PC board
MAX6470 data sheet
MAX6470 EV kit data sheet
PART
MAX6470EVKIT
Ordering Information
TEMP RANGE
0°C to +70°C
IC PACKAGE
6 SOT23
C1
1
Quick Start
The MAX6470 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) Verify that shunts are installed across pins 1 and 2
of jumpers JU1 (SHDN) and JU2 (RESET).
2) Connect voltmeters to the VOUT and
RESET
PC
board pads.
3) Connect a 3.6V to 5.5V DC power supply to the VIN
pad. Connect the supply ground to the GND pad.
4) Turn on the power supply.
5) Verify that VOUT and
RESET
each measure 3.3V.
6) Decrease the power supply to 2.8V.
7) Verify that
RESET
measures approximately 0V.
C2
C3
C4
R1, R2, R4, R5
R3
U1
U2
JU1, JU2
None
None
None
None
1
0
0
0
1
1
0
2
2
1
1
1
Component Suppliers
SUPPLIER
Taiyo Yuden
TDK
PHONE
800-348-2496
847-803-6100
FAX
847-925-0899
847-390-4405
WEBSITE
www.t-yuden.com
www.component.tdk.com
Note:
Please indicate that you are using the MAX6470 when contacting these component suppliers.
________________________________________________________________
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.
MAX6470 Evaluation Kit
Evaluates: MAX6469–MAX6476
Detailed Description
The MAX6470 EV kit is a fully assembled surface-mount
circuit board that contains the MAX6470 low-dropout
linear voltage regulator. The circuit operates with a 3.6V
to 5.5V supply range and is preset for an output voltage
of 3.3V. The EV kit can supply up to 300mA of load cur-
rent. At an output of 3.3V and 300mA load current, the
maximum dropout voltage is 114mV. The preset output
voltage can be adjusted by reconfiguring the feedback
circuitry on the board.
The MAX6470 EV kit board can evaluate the
MAX6469–MAX6476 low-dropout linear regulators in
SOT23 or QFN packages with the preset output volt-
ages ranging from 1.5V to 3.3V in 100mV increments.
These devices consume only 82µA (typ) of supply cur-
rent while providing up to 300mA of output current.
Reset Output
The microprocessor supervisory reset circuitry is fully
integrated into the MAX6470UT_ _BD3 ICs. The open-
drain
RESET
output asserts a logic low when V
OUT
is
12.5% below the nominal voltage output. The circuit
also asserts the
RESET
output during power-up, power-
down, and brownout conditions. Jumper JU2 is provid-
ed to pull the
RESET
signal up to V
OUT
or to an external
voltage connected to the VREF pad. See Table 2 for
jumper JU2 configuration.
Table 2. Jumper JU2
SHUNT LOCATION
1 and 2
2 and 3
EV KIT OPERATION
RESET
logic high = V
OUT
RESET
logic high = external V
REF
Adjusting the Output Voltage
V
OUT
can be adjusted by cutting open the trace across
resistor R2 and installing feedback resistors R1 and R2.
The equation to adjust the output voltage is the following:
V
OUT
= V
SET
(1 + (R1/R2))
where V
SET
= 1.23V
Resistor R2 must be 50kΩ or less to maintain stability,
accuracy, and high-frequency power-supply rejection.
V
OUT
can be adjusted from 1.23V (V
SET
) to 5V.
PC Board Dual Circuitry
The MAX6470 PC board accommodates the
MAX6469–MAX6476 ICs in both a 6-pin SOT23 pack-
age and an 8-pin QFN package. The MAX6470 board
layout features the dual circuitry in parallel. The SOT23
circuit is populated and fully functional. The QFN circuit
is left unpopulated of all components. The two PC
board circuits share all the input and output connec-
tions except for the resistor feedback networks.
To evaluate the IC in the QFN package, remove the lin-
ear regulator U1 and install the QFN package on the U2
PC board pad. The preset output can now be evaluated.
If the output voltage needs to be adjusted, cut the trace
on R5 and install resistors R4 and R5 to configure the
desired output voltage at VOUT. It is recommended that
capacitors C1 and C2 be removed and capacitors C3
and C4 be installed to reduce trace impedance from the
input and output connections. Output capacitors C3 and
C4 must be low-ESR components. It is also recom-
mended for capacitor C4 to be a minimum of 3.3µF.
Additional Features
The MAX6469–MAX6476 ICs are similar but do differ in
their pinout configurations. For specific pinout informa-
tion, refer to the MAX6469–MAX6476 data sheet.
Shutdown Input
The EV kit features a logic
SHDN
input that allows the
regulator to shut down, thus reducing the total input
current consumption of the device. In shutdown mode,
the pass transistor, control circuit, reference, and all
biases are turned off, reducing the supply current to
below 1µA. Jumper JU1 can be used to shutdown or
enable the linear regulator. See Table 1 for jumper JU1
configurations.
Table 1. Jumper JU1
SHUNT
LOCATION
1 and 2
2 and 3
None
SHDN
PIN
Connected to VIN
Connected to GND
Connected to
external controller
EV KIT
OPERATION
U1 enabled
Shutdown mode
External controller
sets mode
2
_______________________________________________________________________________________
MAX6470 Evaluation Kit
Evaluates: MAX6469–MAX6476
VIN
VIN
C1
1µF
GND
VIN
SHDN
1
2
3
SHDN
R3
100kΩ
VOUT
1
2
3
JU1
2
1
IN
OUT
6
C2
3.3µF
5
RESET
2
SHDN
RESET
4
RESET
VOUT
VOUT
U1
MAX6470
R1
OPEN
GND
SET
R2
SHORT
GND
JU2
VREF
VIN
1
IN
OUT
8
C4
OPEN
VOUT
U2
2
C3
OPEN
3
GND
SET
6
IN
MAX6470
7
OUT
QFN
R4
OPEN
R5
SHORT
SHDN
4
SHDN
RESET
5
RESET
Figure 1. MAX6470 EV Kit Schematic
_______________________________________________________________________________________
3
MAX6470 Evaluation Kit
Evaluates: MAX6469–MAX6476
Figure 2. MAX6470 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX6470 EV Kit PC Board Layout—Component Side
Figure 4. MAX6470 EV Kit PC Board Layout—Solder Side
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
4
_____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2002 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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