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For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
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MAX16974 Evaluation Kit
Evaluates: MAX16974
General Description
The MAX16974 evaluation kit (EV kit) provides a proven
design to evaluate the MAX16974 high-voltage, 2.2MHz,
2A automotive step-down controller with low operating
current. It is designed to operate with 3.5V to 28V input
voltages, while using only 35µA quiescent current at no
load. The switching frequency is adjustable from 220kHz
to 2.2MHz and the output voltage is pin selectable at 5V
fixed or 1V to 10V adjustable. This EV kit is initially set up
to operate at 2.2MHz with a 5V output.
The EV kit PCB comes with a MAX16974AUE/V+ installed.
Features
S Wide 3.5V to 28V DC Supply Range
S 42V Input Transient Tolerance
S Proven PCB Layout
S Fully Assembled and Tested
Ordering Information
Component List
+Denotes lead(Pb)-free and RoHS compliant.
19-5661; Rev 0; 12/10
*EP = Exposed pad.
/V denotes an automotive qualified part.
PART TYPE
MAX16974EVKIT+ EV Kit
DESIGNATION QTY DESCRIPTION
CBST 1
0.1µF Q10%, 6.3V X5R ceramic
capacitor (0402)
TDK C1005X5R0J104K
CCOMP1 1
5600pF Q10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H562K
CCOMP2 0
Not installed, 120pF Q5%, 50V
C0G ceramic capacitor (0603)
Murata GRM1885C1H121J
CCRES 1
100pF Q5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H101J
CFB1 0 Not installed, ceramic capacitor
(0603)
CIN1 1
47µF Q20%, 50V electrolytic
capacitor (D8)
Panasonic EEE-FK1H470XP
CIN2, CIN3 2
0.1µF Q10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
CIN4, CIN5 2
4.7µF Q10%, 50V X7R ceramic
capacitors (1210)
Murata GRM32ER71H475K
COUT, COUT2 2
22µF Q20%, 10V X7R ceramic
capacitors (1210)
Murata GRM32ER71A226K
CSNUB 0
Not installed, 1000pF Q10%, 50V
X7R ceramic capacitor (0603)
Murata GRM188R71H102K
DESIGNATION QTY DESCRIPTION
CVL 1
2.2µF Q10%, 10V X7R ceramic
capacitor (0603)
Murata GRM188R71A225K
D1 1 3A, 60V Schottky diode
Diodes Inc. B360B
JU1 1 3-pin header
JU2, JU7 0 Not installed, 0I jumpers (0603)
JU3, JU6,
RTEST 30I Q5% resistors (0603)
L1 1
4.7µH Q20%, 2.8A, 20mI
inductor (7.0mm x 7.5mm)
Panasonic ETQP5M4R7YFM
LX 0 Not installed, multipurpose test
point
RCOMP 1 20kI Q1% resistor (0603)
RFB1, RFB2,
RFB3 0 Not installed, resistors (0603)
RFOSC 1 12.1kI Q1% resistor (0603)
RFSYNC 1 20kI Q5% resistor (0603)
RRESB 1 10kI Q5% resistor (0603)
RSNUB 0 Not installed, 3I Q5% resistor
(0603)
U1 1
High-voltage automotive step-
down converter (16 TSSOP-EP*)
Maxim MAX16974AUE/V+
— 1 Shunts
— 1 PCB: MAX16974 EVALUATION
KIT+
MAX16974 Evaluation Kit
Evaluates: MAX16974
2 ______________________________________________________________________________________
Note: Indicate that you are using the MAX16974 when contacting these component suppliers.
Component Suppliers
Quick Start
Recommended Equipment
• MAX16974EVkit
• 12Vat2ADCpowersupply
• Digitalvoltmeter(DVM)
• 2ADCload(2.5I, 10W)
Procedure
The EV kit is fully assembled and tested. Follow the steps
below to verify board operation:
1) Verify that all jumpers (JU1, JU2, JU3, JU6, and JU7)
are in their default positions, as shown in Table 1.
2) Connect the DVM between the VOUT and GND pads.
3) Connect the load between the VOUT and GND pads.
4) Connect the power supply between the EXT_VBAT
and GND pads.
5) Enable the 12V power supply.
6) Verify that VOUT = 5V.
7) Verify that RESB is high.
Detailed Description of Hardware
The MAX16974 EV kit provides a proven layout for the
MAX16974 IC. The EV kit is designed to fully demon-
strate the functionality of the IC as follows:
• Verifyoutput-voltageregulation
• Verify power-good behavior and reset-threshold
selection
• Easy programmability of different output voltages
between 1V and 10V
• Startupandshutdownperformance
• Current-limitperformance
The following detailed descriptions enable the user to
program the EV kit per application requirements.
External Clock Input (FSYNC)
The IC synchronizes to an external clock signal applied
at FSYNC. The signal at FSYNC must have a 10% higher
frequency than the internal clock period for proper
synchronization.
Output-Voltage/RESET Threshold
Resistive-Divider Network
The output voltage of the IC can be programmed
between 1V and 10V. Although the IC’s output voltage
and reset threshold can be set individually, the EV kit
supports the use of a combined resistive-divider network
to set the desired output voltage and the reset threshold
using three resistors (RFB1, RFB2, and RFB3). Use the
following formula to determine the RFB3 of the resistive-
divider network:
( )
REF OUT
RFB3 = RFB1+RFB2 +RFB3 V /V×
where VREF = 1V and VOUT is the desired output voltage.
( )
( )
REF_RES RES
RFB2 = RFB1+RFB2 +RFB3 V /V RFB3× −
where VREF_RES is 1.2V (refer to the Electrical
Characteristics section in the MAX16974 IC data sheet)
and VRES is the desired reset threshold in volts.
The precision of the reset-threshold function is depen-
dent on the tolerance of the resistors used for the divider.
Refer to the MAX16974 IC data sheet for details.
Some applications require the addition of a compensa-
tion capacitor at CFB1. Contact the factory for applica-
tions assistance.
The 0I resistors at JU3 and JU6 must be moved to
locations JU2 and JU7 to enable the combined resistive-
divider network. As shipped from the factory, the 0I
resistors are installed at JU3 and JU6, so that FB is tied
to VL and RESETI is tied to ground, selecting the factory
settings.
SUPPLIER PHONE WEBSITE
Diodes Incorporated 805-446-4800 www.diodes.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Panasonic Corp. 800-344-2112 www.panasonic.com
TDK Corp. 847-803-6100 www.component.tdk.com
MAX16974 Evaluation Kit
Evaluates: MAX16974
_______________________________________________________________________________________ 3
*Default position.
Table 1. Jumper Descriptions (JU1, JU2, JU3, JU6, JU7)
The RES signal is asserted when RESETI is below 1.2V.
The RFB1, RFB2, and RFB3 values should be chosen to
set RESETI = 1.2V when the OUT voltage is too low. The
recommended resistor-divider bias current is 50FA.
Reset-Timeout Selection
The CRES pin of the IC is for programming the power-
good delay for the IC. The internal threshold of the CRES
comparator is 1.25V. The CRES pin sources approxi-
mately 10µA current. Placing a capacitor (CCRES) from
CRES to GND programs the delay time of the power-
good indicator.
Output-Voltage Selection
Contact the factory for assistance in selecting compo-
nents for other output voltages.
JUMPER SIGNAL SHUNT POSITION DESCRIPTION
JU1 EN 1-2* EN is tied to VSUP (battery input); normal operation.
2-3 EN is tied to GND; shutdown.
JU2 FB 0I jumper installed Output voltage is determined by RFB1, RFB2, and RFB3. OUT regulates
FB to 1.00V at the RFB2/RFB3 junction. JU3 must be open.
Open* JU3 should be installed. See the JU3 description.
JU3 FB 0I jumper installed* FB is tied to BIAS; the output voltage is preset to 5V. JU2 must be open.
Open JU2 should be installed. See the JU2 description.
JU6 RESETI 0I jumper installed* RESETI is tied to GND; the reset threshold is preset to 90% of VOUT.
JU7 must be open.
Open JU7 should be installed. See the JU7 description.
JU7 RESETI 0I jumper installed Reset threshold is determined by RFB1, RFB2, and RFB3. Reset occurs
when RESETI drops down to 1.2V. JU6 must be open.
Open* JU6 should be installed. See the JU6 description.
MAX16974 Evaluation Kit
Evaluates: MAX16974
4 ______________________________________________________________________________________
Figure 1. MAX16974 EV Kit Schematic
MAX16974 Evaluation Kit
Evaluates: MAX16974
_______________________________________________________________________________________ 5
Figure 2. MAX16974 EV Kit Component Placement Guide—
Component Side
Figure 4. MAX16974 EV Kit PCB Layout—Ground Layer 2
Figure 3. MAX16974 EV Kit PCB Layout—Component Side
1.0”
1.0”
1.0”
MAX16974 Evaluation Kit
Evaluates: MAX16974
6 ______________________________________________________________________________________
Figure 5. MAX16974 EV Kit PCB Layout—Layer 3
Figure 7. MAX16974 EV Kit Component Placement Guide—
Solder Side
Figure 6. MAX16974 EV Kit PCB Layout—Solder Side
1.0”
1.0”
1.0”
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 7
© 2010 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX16974 Evaluation Kit
Evaluates: MAX16974
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 12/10 Initial release —
