MAX20734 Evaluation Kit
Evaluates: MAX20734
General Description
The MAX20734 Evaluation Kit (EV kit) serves as a
reference platform for evaluating the MAX20734 volt-
age regulator IC. This single-chip, integrated switching
regulator provides an extremely compact, low cost, highly
efficient, fast, accurate and reliable power delivery
solution for emerging low-output voltage applications up
to 40A. Refer to the MAX20734 IC data sheet for more
information.
The EV kit comprises a fully-assembled and tested PCB
implementation of the MAX20734. Jumper pins, test
points, and input/output connectors are included for flex-
ibility and ease-of-use in a wide range of applications.
The evaluation board is configured with an edge strip to
allow high di/dt loading when evaluating the system. The
+V
OUT
connection is on the top side, while the return (or
-V
OUT
) is on the bottom side, directly mirroring the top-
side strip.
Either solder directly to the output strip or use the J8
terminal block to interface to a load.
Quick Start
Required Equipment
●
MAX20734 EV kit
●
0A to 40A load
● Oscilloscope, probes, voltmeter
●
4.5V to 16V power supply
Optional Equipment
● MAXPOWERTOOL002# USB-to-PMBus interface
dongle
● Maxim PowerTool software
Procedure
1)
The EV kit is fully assembled and tested. Verfiy board
operation using these steps:
Connect a powered-off 4.5V to 16V input supply
to J1.
• Optionally, connect supply sense leads to V
DD1
and GND1 for best accuracy.
Connect the load to J3 or J8.
If Maxim PowerTool software is used, connect the
MAXPOWERTOOL002# USB-to-PMBus interface
dongle to J704 and to the USB port on the PC.
Connect the V
OUT
scope probe/voltmeter to J4 or
J11, as desired.
• J4 and J11 are connected to the sense point for
best accuracy.
Position the SW1 toggle switch, pointing away from
J1 to enable the IC (if desired).
Turn on the input supply and observe that
V
OUT
= 1V.
For efficiency measurements, J6 has the appropriate
Kelvin sense points.
Features
2)
3)
4)
● High Efficiency and Power Density
●
Low Component Count
●
Small Solution Size
• 509mm
2
Including Inductor and Output Capacitors
● Optimized Performance
● Reduced Design-In Time
● Interfaces to Maxim PMBus™ Dongle and
PowerTool™ GUI
● Proven PCB Layout
● Fully Assembled and Tested
5)
6)
7)
Ordering Information
appears at end of data sheet.
PMBus is a trademark of SMIF, Inc.
PowerTool is a trademark of Maxim Integrated Products, Inc.
19-8621; Rev 0; 8/16
MAX20734 Evaluation Kit
Evaluates: MAX20734
Operation
Status Monitoring
Whenever the part is actively regulating, and the output
voltage is within the power-good window, the STAT pin
is high. In all other conditions, including enabled but in
a fault state, the STAT pin is pulled low. Refer to the
MAX20734 IC data sheet for more details.
The MAX20734 IC is a monolithic, high-frequency step-
down switching regulator optimized for applications
requiring small size, high efficiency, and low output volt-
ages. Detailed product and application information is
provided in the MAX20734 IC data sheet.
Output Enable (OE)
OE is used to enable/disable the output voltage. The
output
voltage is enabled/disabled by SW1. Pointing SW1
in the direction of the silkscreened arrow enables the
regulator.
Input-Voltage Monitoring
The V
DD1
and GND1 sense points monitor the input
supply.
Switching-Voltage Monitoring
The switching waveform can be monitored on VX1.
Output-Voltage Selection
The MAX20734
EV kit is set up to initially boot up to an
output voltage
of 1V. This has been accomplished by
setting the reference to come up to a V
BOOT
of 0.6484V
and placing a voltage-divider in the feedback path with
a divide ratio of 0.6484. The reference voltage can be
changed through PMBus, in which case the output volt-
age follows the reference voltage divided by the 0.6484
divide ratio. To achieve higher output voltages, a higher
divide ratio can be used. Note that the PMBus command-
ed and reported V
OUT
is actually the voltage at the sense
pins, so with the feedback-divider in place, the divide ratio
must be taken into account.
R
GAIN
and C
OUT
can also be changed to affect
performance. Refer to the MAX20734 IC data sheet for
more details.
Output-Voltage Monitoring
J4-1 and J4-2 monitor the output voltage of V
OUT
and
GND, respectively. These test points should not be used
for loading. Alternatively, scopejack J11 can be used to
monitor the output voltage.
Efficiency Testing
J6 provides convenient access to the appropriate V
IN
and
V
OUT
sense points.
● VIN_EFF± are on J6 pins 1 and 2.
● VOUT_EFF± are on J6 pins 3 and 4.
● Input and output currents should be measured with
0.1% lab shunts.
● For increased accuracy, shunt mismatch can be
measured and calibrated out by doing a test running
the same current through both shunts.
Soft-Start and Switching Frequency
These are programmable parameters. For the EV kit,
soft-start is set to 3ms and switching frequency is set to
400kHz.
Ordering Information
DEVICE TYPE
MAX20734EVKIT#
#Denotes RoHS compliant.
TYPE
EV Kit
www.maximintegrated.com
Maxim Integrated
│
2
MAX20734 Evaluation Kit
Evaluates: MAX20734
MAX20734 Bill of Materials
Part Reference
C1, C74, C75
C24
C3
C32
C5, C6, C10, C11
C50
C60, C61
C62, C63, C66, C67, C69, C70, C71, C76, C77
C7
C8
C9, C36, C51
GND1, GND2, GND3, LOOP, VDD1, VX1
J1, J8
J11
J3
J4
J6
J7
J704
L1
R1
R10, R20, R21, R22, R23
R11, R14
R2
R4
R5, R8
R6
R9
SW1
U1
Quantity
3
1
1
1
4
1
2
9
1
1
3
6
2
1
1
1
1
1
1
1
1
5
2
1
1
2
1
1
1
1
1
Description
100uF, 25V, 20%, TANTALUM
0.01uF, 25V, 10%, X7R
0.1uF, 25V, 10%, X7R
1000pF, 50V, 10%, X7R
47uF, 25V, 20%, X5R
22uF, 6.3V, 20%, X6S
1.0uF, 25V, 20%, X5R
100uf, 6.3V, 20%, X5R
1uF, 25V, 10%, X7R
0.22uF, 16V, 10%, X7R
10uF, 6.3V, 20%, X5R
1_PIN-1X1 Straight
2_PIN-2 Pin, Terminal Block w/Screws, Blue
Shielded Scope Probe Jack, Vertical
2_Pin-Edge Fingers
VOUT-DIF-1X2 Straight
8_PIN-2X4 Straight
6_PIN-2X3 Straight
16_PIN-BoxHeader 2x8
170nH, 10%, Isat= 66A
1.78KΩ, 1%, 1/16W
1KΩ, 5%, 1/16W
0Ω, 5%, 1/16W
162KΩ, 1%, 1/16W
10Ω, 1%, 1/16W
20KΩ, 5%, 1/16W
1.87KΩ, 1%, 1/16W
3.48KΩ, 1%, 1/16W
DPDT-DPDT, 6pins, 1switch
MAX20734
PCB# 35-900335-01-00
www.maximintegrated.com
Maxim Integrated
│
3
VDDH
VDD1
VDDH
J1
+
C1
100uF
GND1
1
+
C2
+
C72
+
C73
+
C74
Do Not Stuff
Do Not Stuff
Do Not Stuff
100uF
+
C75
100uF
1
2
1
2
1
1
VCC
VDDH
10
5
1
1
2
VCC
VDDH
AGND
GND
PGMA
R14
0
0402
R9
3.48K
0402
C38
Do Not Stuff
0402
R13
Do Not Stuff
0402
PGMB
SMALERT
11
6
www.maximintegrated.com
Input Supply Sense+
Input Supply
C3
0.1uF
X7R
0402
C7
1uF
X7R
0603
C5
47uF
X5R
1206
C6
47uF
X5R
1206
C10
47uF
X5R
1206
C11
47uF
X5R
1206
GND_POWER
2,3
3.3V
2,3
PGMA
2
PGMB
2,3
SMALERT
2,3
MAX20734 Schematics
STAT
2
OE
2
Input Supply Sense-
DATA
3
MAX20734 Evaluation Kit
CLK
3
VOUT
2
VX1
GND2
VOUT
C22
C17
C13
Do Not Stuff Do Not Stuff Do Not Stuff
0805
0805
0805
C62
100uf
1206
C63
100uf
1206
C64
Do Not Stuff
1206
C9
10uF
X5R
0402
LOOP
U1
R10
1K
0402
C26
C18
C14
Do Not Stuff Do Not Stuff Do Not Stuff
0805
0805
0805
J4
VOUT-DIF
C51
10uF
X5R
0402
C36
10uF
X5R
0402
VCC
R5
0402
BST
VX
170nH
R12
Do Not Stuff
0402
SENSE_VOUT
10
VSENSE+
VSENSE-
C39
R6
Do Not Stuff
1.87K
0402
0402
0
0402
Diff Pair
2
VSENSE-
1
VSENSE+
R11
R4
0402
C24
0.01uF
0402
C37
Do Not Stuff
0402
MAX20734
7
VX
8
BST
L1
20K
STAT
4
PGMA
SMALERT
PGMB
STAT
OE
DATA
CLK
3
15
13
9
14
12
C8
0.22uF
X7R
0402
C65
Do Not Stuff
1206
C66
100uf
1206
C67
100uf
1206
R8
0402
20K
OE
PGMA
SMALERT
C27
C19
C15
Do Not Stuff Do Not Stuff Do Not Stuff
0805
0805
0805
C68
Do Not Stuff
1206
C69
100uf
1206
C70
100uf
1206
C32
1000pF
0402
PGMB
STAT
OE
C33
C40
C34
Do Not Stuff Do Not Stuff Do Not Stuff
0805
0805
0805
C71
100uf
1206
C76
100uf
1206
SNS
C77
100uf
1206
DATA
3.3V
CLK
R15 0402
Do Not Stuff
VOUT
Diff Pair
C52
C47
C44
C12
C53
C16
C46
Do Not Stuff Do Not Stuff Do Not Stuff Do Not Stuff Do Not Stuff Do Not Stuff Do Not Stuff
0805
0805
0805
0805
0805
0805
0805
R1
1.78K
0402
C4
R2
Do Not Stuff
162K
0402
0402
C23
R3
Do Not Stuff Do Not Stuff
0402
0402
C31
Do Not Stuff
0402
PMBus Addr = 0
Tss = 3ms
Vboot = 0.65V
Rgain = 1.6m-ohm
Valley OCP = 35A
Fsw = 400kHz
C45
C48
Do Not Stuff Do Not Stuff
0805
0805
C20
Do Not Stuff
0805
C30
C49
Do Not Stuff Do Not Stuff
0805
0805
+
C29
Do Not Stuff
+
C28
Do Not Stuff
C42
Do Not Stuff
0805
L2
VOUT
C50
22uF
0805
C41
Do Not Stuff
0805
C43
Do Not Stuff
0805
VX
Combo footprint to fit L1 or L2
MTG1
HS1
TIM1
Do Not Stuff
Do Not Stuff
Do Not Stuff
Do Not Stuff
MTG2
Evaluates: MAX20734
38-900335-01-00-06
Maxim Integrated
│
4
VDDH
1
DATA
6
5
OE
Do Not Stuff
1,3
2
4
6
8
1
OE
STAT
4
2
3
PGMA
PGMB
SMALERT
1
Vin
C35
Do Not Stuff
X7R
0603
GND
4
BYPASS
6
2
3.3V
Vout
5
1
C57
Do Not Stuff
X5R
0402
J11
1
2
2
2
J9
1
2
+
C56
Do Not Stuff
Do Not Stuff
To Load
R20
VDDH
1K
C60
1.0uF
0402
25V
X5R
R23
VOUT_EFF-
1K
VIN_EFF-
1K
C61
1.0uF
0402
25V
X5R
1K
VIN_EFF+
VOUT
VOUT_EFF+
R22
R21
Evaluates: MAX20734
38-900335-01-00-06
GND
C58
Do Not Stuff
X7R
0402
2
3
J8
1
1
2_Pin
+VOUT
www.maximintegrated.com
Efficiency Test
J6
VIN_EFF-
VOUT_EFF-
1
3
5
7
2
4
6
1
3
5
3
2
PGMB
1
4
VIN_EFF+
VOUT_EFF+
J7
GND3
1
R26
Do Not Stuff
1,3
SW4
SW1
Enable
Vboot Restore
3
ON/OFF
5
VOUT
4
12VB
LP2992AIM5-3.3/NOPB
U3
1
3
2
VDDH
SW3
SCOPE_PROBE_JACK
J3
GND_POWER
1,3
3.3V
1,3
PGMA
1
PGMB
1,3
SMALERT
1,3
STAT
1
OE
1
CLK
1,3
MAX20734 Evaluation Kit
MAX20734 Schematics (continued)
VOUT
1
Maxim Integrated
│
5
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