MaxLinear MxL7225 User manual

MaxLinear Confidential
TBD/18 006UMR02 i
• www.maxlinear.com • 006UMR02
MxL7225
25A Dual Phase
EVB User Manual

MxL7225 25A Dual Phase EVB User Manual Revision History
10/5/20 006UMR02 ii
Revision History
Document No. Release Date Change Description
006UMR02 10/5/20 Initial release.

MxL7225 25A Dual Phase EVB User Manual Table of Contents
10/5/20 006UMR02 iii
Table of Contents
Introduction......................................................................................................................................................... 1
Quick EVB Set Up and Start Up....................................................................................................................................1
Factory Settings ...................................................................................................................................................1
Quick Start Up ......................................................................................................................................................1
Reference Documentation ................................................................................................................................. 4
Ordering Information.......................................................................................................................................... 4
Evaluation Board Overview ............................................................................................................................... 5
Configuration and I/O Interfaces ....................................................................................................................... 6
MODE............................................................................................................................................................................6
RUN1, RUN2.................................................................................................................................................................6
TRACK1 SEL, TRACK2 SEL ........................................................................................................................................6
PHASMD .......................................................................................................................................................................6
EXTVCC........................................................................................................................................................................6
TEMP ............................................................................................................................................................................6
PGOOD1, PGOOD2......................................................................................................................................................6
SW1, SW2.....................................................................................................................................................................6
Set-Up Options.................................................................................................................................................... 7
Jumper J44 MODE........................................................................................................................................................7
Jumpers J30 RUN1 and J29 RUN2...............................................................................................................................7
Jumper J26 TRACK1 SEL.............................................................................................................................................7
Jumper J25 TRACK2 SEL.............................................................................................................................................8
Jumper J45 PHASMD ...................................................................................................................................................8
Test Interfaces..................................................................................................................................................... 9
Load Transient Circuit ...................................................................................................................................................9
MxL7225 EVB Mode Selection....................................................................................................................................10
Performance...................................................................................................................................................... 12
Efficiency .....................................................................................................................................................................12
Load Transient Response ...........................................................................................................................................13
Output Ripple ..............................................................................................................................................................14
Thermal .......................................................................................................................................................................15
MxL7225EVB Schematic .................................................................................................................................. 16
MxL7225EVB PCB Layers ................................................................................................................................ 19
MxL7225EVB Bill of Materials.......................................................................................................................... 21

MxL7225 25A Dual Phase EVB User Manual List of Figures
10/5/20 006UMR02 iv
List of Figures
Figure 1: Monitoring VIN and VOUT.........................................................................................................................................2
Figure 2: Top View of MxL7225 25A Dual Phase BGA EVB..................................................................................................3
Figure 3: Block Diagram MxL7225 Two Channel EVB...........................................................................................................5
Figure 4: Load Transient Circuit .............................................................................................................................................9
Figure 5: Mode 1 Block Diagram ..........................................................................................................................................11
Figure 6: Mode 2 Block Diagram ..........................................................................................................................................11
Figure 7: Mode 3 Block Diagram ..........................................................................................................................................11
Figure 8: Mode 4 Block Diagram ..........................................................................................................................................11
Figure 9: Mode 5 Block Diagram ..........................................................................................................................................11
Figure 10: Mode 6 Block Diagram ........................................................................................................................................11
Figure 11: Channel 1 Measured Efficiency (VOUT = 1.5V, fSW = 500kHz, Ch 2 Disabled)...................................................12
Figure 12: Channel 2 Measured Efficiency (VOUT = 1.0V, fSW = 500kHz, Ch 1 Disabled)...................................................12
Figure 13: Load Transient Response (VOUT = 1.5V, VIN = 12V) ..........................................................................................13
Figure 14: Load Transient Response (VOUT = 1.0V, VIN = 12V) ..........................................................................................13
Figure 15: Channel 1 Output Voltage Ripple (VIN = 12V, VOUT = 1.5V, Load = 25A) ..........................................................14
Figure 16: Channel 2 Output Voltage Ripple (VIN = 12V, VOUT = 1.0V, Load = 25A) ..........................................................14
Figure 17: Thermal Capture (VIN = 12V, VOUT = 1.5V, Load = 25A, 500kHz, Airflow = 200LFM) .......................................15
Figure 18: EVB Schematic ...................................................................................................................................................16
Figure 19: EVB Schematic, Continued .................................................................................................................................17
Figure 20: EVB Schematic, Continued .................................................................................................................................18
Figure 21: EVB PCB BGA Silkscreen Top ...........................................................................................................................19
Figure 22: EVB PCB BGA Layer 1 .......................................................................................................................................19
Figure 23: EVB PCB BGA Layer 2 .......................................................................................................................................19
Figure 24: EVB PCB BGA Layer 3 .......................................................................................................................................19
Figure 25: EVB PCB BGA Layer 4 .......................................................................................................................................20
Figure 26: EVB PCB BGA Layer 5 .......................................................................................................................................20
Figure 27: EVB PCB BGA Layer 6 .......................................................................................................................................20
Figure 28: EVB PCB BGA Silkscreen Bottom ......................................................................................................................20

MxL7225 25A Dual Phase EVB User Manual List of Tables
10/5/20 006UMR02 v
List of Tables
Table 1: Evaluation Board Ordering Part Number..................................................................................................................4
Table 2: Factory Settings........................................................................................................................................................7
Table 3: J44 Options ..............................................................................................................................................................7
Table 4: J30, J29 Options.......................................................................................................................................................7
Table 5: J26 Options ..............................................................................................................................................................7
Table 6: J25 Options ..............................................................................................................................................................8
Table 7: JP45 Options ............................................................................................................................................................8
Table 8: Board Stuffing for Operation Mode Selection .........................................................................................................10
Table 9: EVB BGA Bill of Materials ......................................................................................................................................21

MxL7225 25A Dual Phase EVB User Manual Introduction
10/5/20 006UMR02 1
Introduction
The MxL7225 evaluation board provides a platform to evaluate the features and performance of the MxL7225. The
MxL7225 is a dual 25A Power Module optimized for powering Telecom, Networking and Industrial equipment. There are
multiple EVBs for the MxL7225. This manual covers the 25A Dual Phase BGA Evaluation Boards.
Quick EVB Set Up and Start Up
Factory Settings
In addition to utilizing the 4.5V to 15V input voltage range and dual 25A maximum load current rating capabilities of the
MxL7225 Power Module, the Evaluation Board has been set up with the factory default configurations shown below for
quick set up and operation. Do not exceed the EVB maximum load current rating.
The factory default configuration (Table 2) for the MxL7225 Evaluation Board is:
■VOUT1 = 1.5V ±1.5%
■VOUT2 = 1.0V ±1.5%
■500kHz Switching Frequency
■CCM mode. For other modes, see Jumper J44 MODE.
■Run is enabled for both channels. See Jumpers J30
RUN1 and J29 RUN2.
■Soft-start is selected for both channels. See Jumper
J26 TRACK1 SEL and Jumper J25 TRACK2 SEL.
■CLKOUT phase is 90 degrees, see Jumper J45
PHASMD.
Quick Start Up
To quickly see the regulator in operation:
1. Use the factory settings and default configuration. If
other settings or components are desired, apply them
before the next steps and see Set-Up Options for more.
2. Connect a turned-off power supply that is within a VIN
specification of 4.5V to 15V, (12V typical) to VIN and
GND with short, thick leads. Use test pins VIN+ and
VIN- to monitor VIN and GND respectively. See
locations in Figure 1.
3. For the channel 1 output, connect an electronic load
initially set to 0A, that will be no more than the above
maximum IOUT (25A ), to VOUT1 and GND with short /
thick leads. Use test pins VOUT1 (J52) and
VOUT1_GND (J60) to monitor VOUT1 and GND
respectively. See locations in Figure 1.
4. For the channel 2 output, connect an electronic load
initially set to 0A, that will be no more than the above
maximum IOUT (25A ), to VOUT2 and GND with short,
thick leads. Use test pins VOUT2 (J53) and
VOUT2_GND (J61) to monitor VOUT2 and GND
respectively. See locations in Figure 1.
5. Turn on the power supply and check VOUT of both
channels. The EVB will power up and (factory default)
regulate the channel 1 output at 1.5V ±1.5% (1.4775V
to 1.5225V) and channel 2 output at 1.0V ±1.5%
(0.985V to 1.015V). Output ripple should be measured
across the output capacitors for each channel: C8 for
VOUT1 and C22 for VOUT2. Test points J52 and J53
can be used to monitor VOUT1 and VOUT2,
respectively.
6. Set or vary the load (do not exceed the maximum IOUT)
and check VOUT and other desired performance levels
such as regulation and efficiency.
See Configuration and I/O Interfaces and Load Transient
Circuit for more on testing and monitoring. For Single Rail
Dual Phase 50A Operation and to vary VOUT see MxL7225
EVB Mode Selection.

MxL7225 25A Dual Phase EVB User Manual Quick EVB Set Up and Start Up
10/5/20 006UMR02 2
Figure 1: Monitoring VIN and VOUT
A
-+VIN
+
-+-
VV
Load Load
AA
+
-+-
V
+-

MxL7225 25A Dual Phase EVB User Manual Quick EVB Set Up and Start Up
10/5/20 006UMR02 3
Figure 2: Top View of MxL7225 25A Dual Phase BGA EVB

MxL7225 25A Dual Phase EVB User Manual Reference Documentation
10/5/20 006UMR02 4
Reference Documentation
Please refer to the MxL7225 Data Sheet for additional information about the MxL7225, including efficiency curves for this
configuration with VIN = 12V. The datasheet also includes a full list of IC features, pinout, pin descriptions, typical
performance characteristics and external component calculations. This manual is meant to be used in conjunction with the
datasheet.
This manual provides EVB schematics, PCB layout and bill of materials that can be utilized to assist in your board design.
The schematics are also available on the MxL7225 product page.
Ordering Information
1. Refer to www.maxlinear.com/MxL7225 for most up-to-date Ordering Information.
Table 1: Evaluation Board Ordering Part Number
Power Module Evaluation Board Description
MxL7225-ABA-T MxL7225-EVK-1 MxL7225 Evaluation Board, Single Device, Dual Output

MxL7225 25A Dual Phase EVB User Manual Evaluation Board Overview
10/5/20 006UMR02 5
Evaluation Board Overview
The block diagram shown in Figure 3 illustrates the connection points for the VIN, VOUT1, VOUT2, TRACK, MODE_PLL
and RUN pins.
Figure 3: Block Diagram MxL7225 Two Channel EVB
VOUT1
VOUT2
PHASEMD
RUN2
TRACK2
MODE
RUN1
TRACK1
VIN
TRACK1
SELECT
JUMPER
(J26)
RUN1
SELECT
JUMPER
(J30)
MODE
SELECT
JUMPER
(J44)
TRACK2
SELECT
JUMPER
(J25)
RUN2
SELECT
JUMPER
(J29)
PHASEMD
SELECT
JUMPER
(J22)
OUTPUT
CONFIG
OPTION
DIFF
SENSE
OPTION
J6
VOUT1
CONNECTOR
J16
VOUT2
CONNECTOR
J58
IOSTEP
CONNECTOR
J16
VOUT2
CONNECTOR
J6
VOUT1
CONNECTOR
VIN
CONNECTOR
J9
MxL7225
VOUT1 VOUT2
TRANSIENT LOAD
CIRCUIT

MxL7225 25A Dual Phase EVB User Manual Configuration and I/O Interfaces
10/5/20 006UMR02 6
Configuration and I/O Interfaces
MODE
The MODE (J44) jumper is provided for overall device configuration:
Force Continuous Mode, Pulse-Skipping Mode and External Synchronization are selectable.
RUN1, RUN2
A RUN jumper is provided for both channels (J30 for RUN1 and J29 for RUN2).
TRACK1 SEL, TRACK2 SEL
A TRACK jumper is provided for both channels.
VOUT, EXT and SOFTSTART are selectable.
Test points are allocated for probing of TRACK1 (J26) and TRACK2 (J25).
PHASMD
A CLKOUT (J45) jumper is provided for clock phase selection.
60, 90 or 120 degrees of phase offset is configurable.
EXTVCC
An EXTVCC test point (J2) is provided to monitor or inject EXTVCC.
TEMP
A TEMP test point (J3) is provided to monitor temperature.
PGOOD1, PGOOD2
A PGOOD test point is provided for both channels (J24 for PGOOD1 and J23 for PGOOD2).
Both PGOOD signals are tied to INTVCC through 10kΩ resistors.
Note: The silkscreen on the evaluation board is reversed for PGOOD1 and PGOOD2.
SW1, SW2
A SW test point is provided for both switching signals (TP1 for SW1 and TP2 for SW2).

MxL7225 25A Dual Phase EVB User Manual Set-Up Options
10/5/20 006UMR02 7
Set-Up Options
Jumpers are factory installed per Table 2 to configure the EVB for operation. Jumper and testing options are described in
the next sections. Refer to the product datasheet for additional information.
Jumper J44 MODE
Jumpers J30 RUN1 and J29 RUN2
Jumper J26 TRACK1 SEL
Table 5: J26 Options
Table 2: Factory Settings
Jumper Label Factory Setting Description
J44 MODE Jumper 3-4 FCM
J30 RUN1 Jumper 1-2 On
J29 RUN2 Jumper 1-2 On
J26 TRACK1 Jumper 5-6 Soft-Start
J25 TRACK2 Jumper 5-6 Soft-Start
J45 PHASEMD No Jumper 90°
Table 3: J44 Options
Jumper Options Description
Jumper 1-2 PSM - Pulse Skipping Mode.
Jumper 3-4 FCM - Force Continuous Mode.
Pin 6 Apply an external clock to pin 6 to put both channels into continuous mode, synchronized to the applied clock.
Table 4: J30, J29 Options
Jumper Options Description
Jumper 1-2 On. RUN1/2 connected to VIN.
Jumper 2-3 Off. RUN1/2 connected to GND.
Jumper Options Description
Jumper 1-2 VOUT2 master track mode.
Jumper 3-4 External master track mode.
Jumper 5-6 Soft start. Track1 connected to cap to GND.

MxL7225 25A Dual Phase EVB User Manual Jumper J25 TRACK2 SEL
10/5/20 006UMR02 8
Jumper J25 TRACK2 SEL
Jumper J45 PHASMD
Table 6: J25 Options
Jumper Options Description
Jumper 1-2 VOUT1 master track mode.
Jumper 3-4 External master track mode.
Jumper 5-6 Soft start. Track1 connected to cap to GND.
Table 7: JP45 Options
Jumper Options Description
Jumper 1-2 120°
No Jumper 90°
Jumper 2-3 60°

MxL7225 25A Dual Phase EVB User Manual Test Interfaces
10/5/20 006UMR02 9
Test Interfaces
Load Transient Circuit
A load transient circuit is provided to allow optional testing of load transients. The IOSTEP clock input is used to drive the
transient signal. The load step generated by the FET (Q1) is very fast; the step slew rate is >40A/µs for a 12.5A transient
load test case.
To measure load transient response for either channel, use the circuit shown in Figure 4. To test CH1, populate R56 and
depopulate R57 and apply a small duty cycle pule signal to IOSTEP CLK input (~ 1%). Adjust the amplitude of the IOSTEP CLK
pulse to set the load current. Start at a pulse amplitude of 2V and increase while monitoring the IOSTEP (J59) voltage. The
load current at IOSTEP (J59) is 10mV/A. For an example, a 12.5mA load will occur when a 125mV pulse is observed at J59.
To test load transient response on CH2, depopulate R56 and populate R57 and repeat procedure.
Figure 4: Load Transient Circuit
VOUT1
(1,2) VOUT2 (1,2)
R56
DNP
J60
1
0603
R60
10 Kohm
0603
C39
1uF
R57
DNP
2512
R58
0.01 ohm
0603
C41
1uF
J61
1
0603
C40
1uF
Q1
SUD50N04
3
1
2
J58
1
2
J59
1
2
0603
C38
1uF
2512
R59
DNP
IOSTEP
IOSTEP_CLK

MxL7225 25A Dual Phase EVB User Manual MxL7225 EVB Mode Selection
10/5/20 006UMR02 10
MxL7225 EVB Mode Selection
The MxL7225 EVB can be configured for 6 different modes of operation:
■Mode 1: Dual 25A with no remote sense amplifier
■Mode 2: Dual 25A with remote sense amplifier on VOUT1
■Mode 3: Dual 25A with remote sense amplifier on VOUT2
■Mode 4: Single 50A with no remote sense amplifier
■Mode 5: Single 50A with remote sense amplifier on VOUT1
■Mode 6: Single 50A with remote sense amplifier on VOUT2
The stuffing options to configure the EVB into each of the 6 modes are shown below with the block diagram for each mode
on the next page.
Table 8: Board Stuffing for Operation Mode Selection
Pin
Function Component
Mode 1
Dual Rail
Single Phase
Diff Amp
NC
Mode 2
Dual Rail
Single Phase
Diff Amp
VOUT1
Mode 3
Dual Rail
Single Phase
Diff Amp
VOUT2
Mode 4
Single Rail
Dual Phase
Diff Amp
NC
Mode 5
Single Rail
Dual Phase
Diff Amp
VOUT1
Mode 6
Single Rail
Dual Phase
Diff Amp
VOUT2
2-Phase
(VOUT1)
R5 DNP DNP DNP 0Ω 0Ω 0Ω
2-Phase
(VOUT2)
R6 DNP DNP DNP 0Ω 0Ω 0Ω
VOUTS1 R4 0Ω DNP 0Ω 0Ω DNP DNP
VOUTS2 R7 0Ω 0Ω DNP DNP DNP DNP
DIFFP
(VOUT1+)
R34 DNP 0Ω DNP DNP 0Ω DNP
DIFFP
(VOUT2+)
R40 DNP DNP 0Ω DNP DNP 0Ω
DIFFN
(VOUT1-)
R54 DNP 0Ω DNP DNP 0Ω DNP
DIFFN
(VOUT2-)
R55 DNP DNP 0Ω DNP DNP 0Ω
DIFFOUT
(VOUTS1+)
R41 DNP 0Ω DNP DNP 0Ω DNP
DIFFOUT
(VOUTS2+)
R42 DNP DNP 0Ω DNP DNP 0Ω
TRACK R45 DNP DNP DNP 0Ω 0Ω 0Ω
TRACK1 J15 (5-6) On On On On On On
TRACK2 J32 (5-6) On On On Off Off Off
RUN R43 DNP DNP DNP 0Ω 0Ω 0Ω
COMP R44 DNP DNP DNP 0Ω 0Ω 0Ω
PGOOD R47 DNP DNP DNP 0Ω 0Ω 0Ω
VFB R46 DNP DNP DNP 0Ω 0Ω 0Ω

MxL7225 25A Dual Phase EVB User Manual MxL7225 EVB Mode Selection
10/5/20 006UMR02 11
Figure 5: Mode 1 Block Diagram Figure 6: Mode 2 Block Diagram
MODE1
Dual Rail Single Phase
Diff Amp -> NC
R3
R2
R4
R9
R8
VOUT1+
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUT2
VOUTS2
R7R7
MODE2
Dual Rail Single Phase
Diff Amp -> VOUT1
R2
R41
R9
R8
VOUT1+
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUTS2
VOUT2
R54
R34
R7
R3
Figure 7: Mode 3 Block Diagram Figure 8: Mode 4 Block Diagram
MODE3
Dual Rail Single Phase
Diff Amp -> VOUT2
R2
R3
VOUT1+
R42
R8
R9
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUT2
VOUTS2
R55
R40
R4
MODE4
Single Rail Dual Phase
Diff Amp -> NC
R3
R2
R4
R9
R8
VOUT1+
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUT2
VOUTS2
VOUT_50A
R5
R6
Figure 9: Mode 5 Block Diagram Figure 10: Mode 6 Block Diagram
MODE5
Single Rail Dual Phase
Diff Amp -> VOUT1
R41
R9
R8
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUT2
VOUTS2
VOUT_50A
R5
R6
R54
R34
R2
VOUT1+
R3
MODE6
Single Rail Dual
Diff Amp -> VOUT
R2
R3
VOUT1+
R42
R8
R9
VOUT2+
VOUT1-
VOUT2-
VOUT1
VOUTS1
DIFFP
DIFFN
DIFFOUT
VOUT2
VOUTS2
VOUT_50A
R5
R6
R55
R40

MxL7225 25A Dual Phase EVB User Manual Performance
10/5/20 006UMR02 12
Performance
Efficiency
Figure 11: Channel 1 Measured Efficiency (VOUT = 1.5V, fSW = 500kHz, Ch 2 Disabled)
Figure 12: Channel 2 Measured Efficiency (VOUT = 1.0V, fSW = 500kHz, Ch 1 Disabled)
65
70
75
80
85
90
95
0 5 10 15 20 25
Efficiency (%)
Load Current (A)
5V
IN
, 1.5V
OUT
12V
IN
, 1.5V
OUT
65
70
75
80
85
90
95
0 5 10 15 20 25
Efficiency (%)
Load Current (A)
5V
IN
, 1.0V
OUT
12V
IN
, 1.0V
OUT

MxL7225 25A Dual Phase EVB User Manual Load Transient Response
10/5/20 006UMR02 13
Load Transient Response
Figure 13: Load Transient Response (VOUT = 1.5V, VIN = 12V)
Figure 14: Load Transient Response (VOUT = 1.0V, VIN = 12V)

MxL7225 25A Dual Phase EVB User Manual Output Ripple
10/5/20 006UMR02 14
Output Ripple
2. Ripple waveform shown, measured at VOUT1 (J54). The ripple waveform characteristics ideally should be observed at the output capacitor closest to
the MxL7225, C8.
Figure 15: Channel 1 Output Voltage Ripple (VIN = 12V, VOUT = 1.5V, Load = 25A)
3. Ripple waveform shown, measured at VOUT2 (J55). The ripple waveform characteristics ideally should be observed at the output capacitor closest to
the MxL7225, C22.
Figure 16: Channel 2 Output Voltage Ripple (VIN = 12V, VOUT = 1.0V, Load = 25A)

MxL7225 25A Dual Phase EVB User Manual Thermal
10/5/20 006UMR02 15
Thermal
Figure 17: Thermal Capture (VIN = 12V, VOUT = 1.5V, Load = 25A, 500kHz, Airflow = 200LFM)