Infineon TDM3885 User manual

User Manual Please read the Important Notice and Warnings at the end of this document V 1.0
www.infineon.com/optimos-ipol page 1 of 18 2022-04-28
UM_2111_PL12_2111_035514
User manual for TDM3885 evaluation board
4 A synchronous buck voltage regulator with integrated inductor
About this document
Scope and purpose
The TDM3885 4 A point-of-load (POL) module is an easy-to-use, fully integrated and highly efficient DC-DC
module. The module’s pulse width modulation (PWM) controller, MOSFETs and inductor make TDM3885 a
space-efficient solution, providing accurate power delivery. The TDM3885 employs an enhanced stability
engine that makes it stable with ceramic capacitors without compensation.
This user manual contains the schematic and bill of materials (BOM) for the EVAL_TDM3885_3.3Vout
engineering evaluation board. The guide describes operation and use of the evaluation board itself. Detailed
application information for TDM3885 is available in the TDM3885 datasheet.
Intended audience
This document is intended as a guide for design engineers evaluating the performance of TDM3885 with the
engineering EVAL_TDM3885_3.3Vout demo board.
Table of contents
About this document....................................................................................................................... 1
Scope and purpose ......................................................................................................................... 1
Intended audience.......................................................................................................................... 1
Table of contents............................................................................................................................ 1
1Board information.................................................................................................................. 2
1.1 Board picture and overview....................................................................................................................2
1.2 Board features.........................................................................................................................................2
1.3 Connections and operating instructions................................................................................................3
1.4 Power-on procedure ...............................................................................................................................4
1.5 PCB layout ...............................................................................................................................................5
1.6 Schematic................................................................................................................................................8
1.7 Bill of materials........................................................................................................................................9
2Typical operating waveforms .................................................................................................10
2.1 PVin = 5 V..................................................................................................................................................10
2.2 PVin = 12 V................................................................................................................................................11
Revision history.............................................................................................................................17

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User manual for TDM3885 evaluation board
4 A synchronous buck voltage regulator with integrated inductor
Board information
1Board information
1.1 Board picture and overview
VOUT [+]
GND
OCSET
SELECT
BODE PLOT
MEASUREMENT
VIN
SELECT
DEM/FCCM
SELECT
VIN [+]
GND
INPUT CAPACITORS
OUPUT CAPACITORS
TDM3885
Figure 1 TDM3885 evaluation board, dimensions (width x length x thickness) = 40 mm x 40 mm x
1.5 mm
1.2 Board features
•PVin = 12 V, Vout = 3.3 V, Iout = 0 A to 4 A
•PVin = 5 V, Vout = 3.3 V, Iout = 0 A to 3 A
•Fsw = 600 kHz
•Cin = 1 x 10 µF (25 V, MLCC, 0603) + 2 x 22 µF (25 V, MLCC, 0805) + 1 x 68 µF (25 V, POSCAP) + 1 x 2.2 µF
(16 V, MLCC, 0402)
•Cout = 3 x 47 µF (6.3 V, MLCC, 0805)
•TDM3885 IC size = 3.1 mm x 3.8 mm x 2.3 mm
•Board ID: TDM3885 EVB DB310 REV 5B

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User manual for TDM3885 evaluation board
4 A synchronous buck voltage regulator with integrated inductor
Board information
1.3 Connections and operating instructions
The TDM3885 demo board allows dual configuration +12 V or +5 V for the input power and can deliver up to 4 A
load current. The operation modes and overcurrent protection (OCP) limits can be selected through jumpers.
Table 1 Connections
Label
Description
Input
Vin
[J36] connect input power (+12 V or +5 V) to this pin
GND
[J37] return of input power
Vin SNS
[J46] sense pins for the PVin
Output
Vout
[J38] connect a load (4 A max.) to this pin
GND
[J39] return of Vout
Vout SNS
[J45] sense pins for the Vout
Bode
A
Use [J43] for bode plot measurement
B
Use [J43] for bode plot measurement
OCSET select
OC SET
Use [J29] jumper to select one of three OCP limits: 4 A; 5 A (w/o
jumper); 6 A
PVin select
Vin
Use [J30] jumper to select PVIN: +12 V or +5V
Pgood
Pgood
[TP7] test point, connect a scope probe to this pin to monitor
power good signal
EN
Enable node
[TP8] test point, connect a scope probe to this pin to monitor EN
signal
DEM/FCCM select
DEM/FCCM
Use [J31] jumper to select DEM or FCCM: DEM, FCCM (w/o) jumper

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4 A synchronous buck voltage regulator with integrated inductor
Board information
1.4 Power-on procedure
Table 2 Power-on steps
Jumper
Description
J29
Configure jumper to set OCP threshold
J30
Configure jumper to select PVin
J31
Configure jumper to select between FCCM and DEM
Load
Connect load to Vout [+], Vout [-]
Power supply
Connect power supply to Vin [+], Vin [-]
Apply PVin
PVin ≤ 14 V
Apply load current
Iout ≤ 4 A
Note: Make sure the input supply is turned off before reconfiguring any jumper placement.

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4 A synchronous buck voltage regulator with integrated inductor
Board information
1.5 PCB layout
The PCB is a six-layer board (1.5 in. x 1.5 in.) using FR4 material. Top and bottom layers use 0.5 oz. base copper
plus 1.5 oz. plating. Inner layers use 2 oz. copper. The PCB thickness is 0.062 in. Layer stack-up is top –GND1 –
GND2 –signal –GND3 –bottom.
The TDM3885 and other major power components are mounted on the top side of the board.
Figure 2 Layer stack-up –top and bottom

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4 A synchronous buck voltage regulator with integrated inductor
Board information
Figure 3 Layer stack-up –signal (top) and GND 1 (bottom)

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4 A synchronous buck voltage regulator with integrated inductor
Board information
Figure 4 GND 2 (top) and GND 3 (bottom)

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4 A synchronous buck voltage regulator with integrated inductor
Board information
1.6 Schematic
Figure 5 Schematic of the TDM3885 evaluation board

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4 A synchronous buck voltage regulator with integrated inductor
Board information
1.7 Bill of materials
Table 3 Bill of materials
Qty.
Part
reference
Value
Manufacturer
Part number
Description
1
C1
10 µF
Murata
GRM188R61E106MA73J
Ceramic capacitor, 10 µF, 0603, 25 V,
X5R, 20%
1
C2
0.1 µF
TDK
C1005X7R1C104K
Ceramic capacitor, 0.1 µF, 0402, 16 V,
X7R, 10%
1
C3
68 µF
Panasonic
25TQC68MYF
POSCAP, D2L, 25 V, 20%
3
C10, C11, C12
47 µF
TDK
C2012X5R0J476M
Ceramic capacitor, 47 µF, 0805, 6.3 V,
X5R, 20%
1
C16
2.2 µF
Murata
GRT155R61E225KE13D
2.2 µF, 0402, 25 V, X5R, 10%
1
C17
2.2 µF
TDK
C1005X6S1C225K050BC
Ceramic capacitor, 2.2 µF, 0402, 16 V,
X6S, 10%
1
C18
100 pF
JDI
500R07N101JV4T
100 pF, 0402, 50 V, C0G, 5%
2
C21, C22
22 µF
Murata
GRM21BR61E226ME44L
Ceramic capacitor, 22 µF, 0805, 25 V,
X5R, 20%
1
R5
0
Panasonic
ERJ-3GEY0R00V
Resistor, 0 Ω, 1/10 W, 5%, 0603
1
R7
39.2K
Panasonic
ERJ-2RKF3922x
Resistor, 39.2 kΩ, 1/10 W, 1%, 0402
2
R8, R12
49.9K
Panasonic
ERJ-2RKF4992X
Resistor, 49.9 kΩ, 1/10 W, 1%, 0402
1
R11
60.4K
Yageo
RC0402FR-0760K4L
Resistor, 60.4 kΩ, 1/10 W, 1%, 0402
1
R13
16.9K
Panasonic
ERJ-2RKF1692X
Resistor, 16.9 kΩ, 1/16 W, 1%, 0402
1
R14
24.9K
Panasonic
ERJ-2RKF2492X
Resistor, 24.9 kΩ, 1%, 1/10 W, 0402
1
R15
6.98K
Vishay
541-6.98KLCT-ND
Resistor, 6.98 kΩ, 1/16 W, 1%, 0402
1
U1
TDM3885
Infineon
TDM3885
4 A iPOL synchronous buck voltage
regulator with integrated inductor

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
2Typical operating waveforms
2.1 PVin = 5 V
Figure 6 Start-up, PVin = 5 V, Vout = 3.3 V, Iout = 0 A, FCCM. Ch1 = Vout, Ch2 = PVin,Ch3 = Pgood, Ch4 = VCC,
Ch5 = enable, Ch6 = Vfeedback
Figure 7 Start-up, PVin = 5 V, Vout = 3.3 V, Iout = 3 A, FCCM. Ch1 = Vout, Ch2 = PVin,Ch3 = Pgood, Ch4 = VCC,
Ch5 = enable, Ch6 = Vfeedback

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
2.2 PVin = 12 V
Figure 8 Start-up, PVin = 12 V, Vout = 3.3 V, Iout = 0 A, FCCM. Ch1 = Vout, Ch2 = PVin,Ch3 = Pgood, Ch4 = VCC,
Ch5 = enable, Ch6 = Vfeedback
Figure 9 Start-up, PVin = 12 V, Vout = 3.3 V, Iout = 4 A, FCCM. Ch1 = Vout, Ch2 = PVin,Ch3 = Pgood, Ch4 = VCC,
Ch5 = enable, Ch6 = Vfeedback

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
Figure 10 Start-up pre-bias (1 V), PVin = 12 V, Vout = 3.3 V, Iout = 0 A, FCCM. Ch1 = Vout, Ch2 = PVin,
Ch3 = Pgood, Ch4 = VCC, Ch5 = enable, Ch6 = Vfeedback
Figure 11 Short-circuit, PVin = 12 V, Vout = 3.3 V, Iout = 4 A, FCCM. Ch1 = Vout, Ch2 = PVin,Ch3 = Pgood,
Ch4 = VCC, Ch5 = enable, Ch6 = Vfeedback

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
Figure 12 Recover from a shorted Vout, PVin = 12 V, Vout = 3.3 V, Iout = 4 A, FCCM. Ch1 = Vout, Ch2 = PVin,
Ch3 = Pgood, Ch4 = VCC, Ch5 = enable, Ch6 = Vfeedback
Figure 13 Vout ripple, PVin = 12 V, Vout = 3.3 V, Iout = 4 A, FCCM. Ch1 = Vout

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
Figure 14 Transient response, PVin = 12 V, Vout = 3.3 V, Iout = 0 A to 3 A, FCCM. Ch1 = Vout, Ch2 = Iout.
Slew rate = 5 A/µS

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
Figure 15 Load regulation, PVin = 12 V, Vout = 3.3 V
Figure 16 Efficiency, PVin = 12 V, Vout = 3.3 V

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4 A synchronous buck voltage regulator with integrated inductor
Typical operating waveforms
Room temperature, no airflow.
Board data:
TDM3885 EVB DB310 REV 5B
Dimensions (width x length x thickness) = 40 mm x 40 mm x 1.5 mm
Figure 17 Thermal image of the board at 4 A load, PVin = 12 V, Vout = 3.3 V, Ta= 25°C

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User manual for TDM3885 evaluation board
4 A synchronous buck voltage regulator with integrated inductor
Revision history
Revision history
Document version
Date of release
Description of changes
V 1.0
2022-04-28
Initial release

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81726 Munich, Germany
© 2022 Infineon Technologies AG.
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product only and shall in no event be regarded as a
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product information given in this document with
respect to such application.
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(www.infineon.com).
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Edition 2022-04-28
UM_2111_PL12_2111_035514
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