Texas Instruments TPS65251 User manual

User’s Guide
TPS65251 Buck Converter Evaluation Module User's
Guide
Table of Contents
1 Introduction.............................................................................................................................................................................2
2 Background.............................................................................................................................................................................3
3 Schematic................................................................................................................................................................................4
4 Placement (Top Layer)............................................................................................................................................................6
5 Bench Test Setup Conditions................................................................................................................................................ 7
5.1 Headers Description and Jumper Placement.....................................................................................................................7
5.2 Jumpers..............................................................................................................................................................................8
5.3 Test Points and Placement.................................................................................................................................................8
6 Power-Up Procedure.............................................................................................................................................................. 9
7 Bill of Materials..................................................................................................................................................................... 10
8 Revision History....................................................................................................................................................................11
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www.ti.com Table of Contents
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1 Introduction
This document presents the information required to power the TPS65251 PMIC as well as the support
documentation including schematic and bill of materials.
Introduction www.ti.com
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2 Background
The TPS65251 PMIC is designed to provide 3-A and 2-A continuous outputs with an operational range of 4.5 V
to 18 V and an externally set switching frequency ranging from 300 kHz to 2.2 MHz. When the PMIC is not fully
loaded, Buck1 can be loaded to 3.5 A and Buck2 and Buck3 to 2.5 A.
As there are many possible options to set the converters, Table 2-1 presents the performance specification
summary for the EVM.
Table 2-1. Input Voltage and Output Current Summary
EVM TEST CONDITIONS OUTPUT CURRENT RANGE
TPS65251EVM VIN = 4.5 V to 13 V
fsw = 500 kHz
Buck1, 1.2 V, 3 A
Buck2, 1.8 V, 2 A
Buck3, 3.3 V, 2 A
(25°C ambient)
This evaluation module is designed to provide access to the features of the TPS65251. Some modifications
can be made to this module to test performance at different input and output voltages, current and frequency
operation. Please contact TI Field Applications Group for advice on these matters.
www.ti.com Background
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3 Schematic
See next page.
The resistor and capacitor values have been chosen according to the guidelines presented on the TPS65251
spec available at http://focus.ti.com/docs/prod/folders/print/tps65251.html.
Note that for the purpose of gains-phase measurements R10, R19 and R21 (0 Ω on the EVM) need to be
replaced by suitable low value resistors as per the network analyzer setup required. Test points are provided on
either end of the resistors to allow for easy measurement.
Schematic www.ti.com
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10uF
C26
100K
R18
40.2K
R9
4.7nF
C13
GND
47nF C7
GND
VIN
ENB1
80.6K
R12
10uFC9
22uF
C12
GND
GND
GND
4.7nF
C4
GND
4.7nF
C2
20K
R5
GND
383K
R7
GND
100K
R1
47nFC24
47nFC8
GND
VIN
10uFC10
GND
VIN
10uFC17
ENB3
GND
22uF
C16
GND
22uF
C11
4.7uH
L3
TDK-SLF7055
GND
3.3uF
C27
GND
PGOOD
VIN
FB1
40.2K R11
4.7nF
C18
GND
32.4K
R15
FB2
40.2K
R20
4.7nF
C15
GND
12.7K
R13
FB3
FB2
FB3
FB1
4.7nF
C1
20K
R3
GND
120K
R4
4.7nF
C3
GND
4.7nF
C25
120K
R16
4.7nF
C28
20K
R17
GND
1.8V@2A
3.31V@2A
1.2V@3A
V7V
V3V
4.7nF
C5
GND
4.7nF
C6
GND
GND
4.7nF
C29
GND
1.2V@3A
10uF
C30
GND
JP5 JP6
GND
GND
JP4
GND
JP2
V3V
GND
JP3
V3V
0
R10
0
R19
0
R21
TP14
GND
TP15
GND
GND
TP1
GND
TP2
GND
TP12
VOUT2
TP5
VOUT1
TP10
FB1A
TP16
FB2A
TP8
FB3A
TP4
VOUT3
TP33
V3V
JP1
GND
GND
GND
TP28
TP29
TP27
1 2 3
J1
VOUT1
GND
GND
4.7uH
L2
TDK-SLF7055
4.7uH
L1
TDK-SLF7055
VOUT1
VOUT2
VOUT3
PGOOD
1 2
J3
VIN
AGND
GND
GND
DNI
C20
DNI
C14
DNI
C19
1 2
J2
VOUT2
1 2
J6
VOUT3
RLIM3 1
SS3 2
COMP3 3
FB3 4
SYNC 5
ROSC 6
FB1 7
CMP1 8
SS1 9
RLIM1 10
EN1
11
BST1
12
VIN1
13
LX1
14
LX1
15
LX2
16
LX2
17
VIN2
18
BST2
19
EN2
20
RLIM2
21
SS2
22
COMP2
23
FB2
24
LOW_P (SDA)
25
GND (SCLK)
26
PGOOD
27
V7V
28
V3V
29
AGND
30
GND 31
VIN 32 VIN 33 VIN 34
GND 35
LX3 36 LX3 37
VIN3 38
BST3 39
EN3 40
PwrPad
41
U1
TPS65251
Pin 25 SDA
and Pin 26
SCLK access
Figure 3-1. TPS65251 Schematic
www.ti.com Schematic
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4 Placement (Top Layer)
Figure 4-1. Placement (Top Layer)
Placement (Top Layer) www.ti.com
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5 Bench Test Setup Conditions
5.1 Headers Description and Jumper Placement
Vin
4.5V – 18V
Vout_1
Vout 2
Vout 3
EN 1
Vout 1
EN 2
Vout 2
EN 3
Vout 3
SCLKLOW PSYNC
+
+
+
Figure 5-1. Headers Description and Jumper Placement
Test points:
Black – GND
White – Each output, feed-back, power good and VIN. All marking on PCB.
www.ti.com Bench Test Setup Conditions
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5.2 Jumpers
Table 5-1. Jumpers
JUMPER
NO. FUNCTION PLACEMENT COMMENT
JP1 SYNC input For buck internal clock fit jumper.
For external SYNC connect as per drawing.
Jumper must be fitted if no external SYNC
is used
JP2 Buck1 enable (EN1)
For automatic start-up fit jumper to V3V.
For sequencing do not fit jumper.
To disable converter fit jumper to GND.
Fit according to test requirement
JP3 Buck3 enable (EN3)
For automatic start-up fit jumper to V3V.
For sequencing do not fit jumper.
To disable converter fit jumper to GND.
Fit according to test requirement
JP4 Buck2 enable (EN2)
For automatic start-up fit jumper to V3V.
For sequencing do not fit jumper.
To disable converter fit jumper to GND.
Fit according to test requirement
JP5 LOW_P
Low power: Power save mode ON/OFF. If need
low power mode test, should connect V3V internal
regulator test point (TP29).
Fit according to test requirement. During
normal operation jumper must be fitted.
JP6 GND For normal operation fit jumper (GND) Fit according to test requirement. During
normal operation jumper must be fitted.
5.3 Test Points and Placement
Buck converter outputs are red and have a label for easy location. Close to any of these test points there are
black ground test points to allow for DVM measurement or to use a metal exposed scope probe to reduce
common mode noise measurements. All test points are described in Table 5-2.
Table 5-2. Test Points and Placement
TEST
POINT NAME SIGNAL COLOR COMMENT
TP1 GND Ground Black
TP2 GND Ground Black
TP3 AGND Ground Not fitted. Only Via.
TP4 VOUT3 Buck3 output White
TP5 VOUT1 Buck1 output White
TP8 FB3A Input for gain-phase measurement Buck3 White Normally not used
TP10 FB1A Input for gain-phase measurement Buck1 White Normally not used
TP12 VOUT2 Buck2 output White Normally not used
TP14 GND Ground Black
TP15 GND Ground Black
TP16 FB2A Input for gain-phase measurement Buck2 White Normally not used
TP27 PGOOD Power Good (open drain connected to Buck1 output) White
TP28 V7V V7V pin (internal rail) White
TP29 V3V V3V pin (internal rail) White
TP33 VIN Input supply White
Bench Test Setup Conditions www.ti.com
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6 Power-Up Procedure
1. Define which converters are to be enabled or disabled by connecting the correct jumpers accordingly
(enable to V3V, disable to GND for all cases).
2. Apply a DC voltage to jumper J3. Polarity is clearly marked on the silk-screen.
3. Verify that the relevant converters are powered up by the output voltages. The whole start-up process will
take around 100 ms. PGOOD will be asserted after 1 s.
4. Apply loads to the output connectors.
5. For low power and SYNC operation remove the jumpers and connect control supplies as indicated in the
bench test setup section.
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7 Bill of Materials
Table 7-1. Bill of Materials
ITEM QUANTITY DESIGNATOR VALUE FOOTPRINT MANUFACTURER MANUFACTURER
PART NO. DESCRIPTION COMMENT
1 9
C1, C2, C3,
C4, C5, C6,
C25, C28, C29
4.7 nF 603 Panasonic -ECG ECJ-1VB1H472K 4700PF 50V
X7R 0603 Ceramic capacitor
2 3 C7, C8, C24 47 nF 603 Panasonic -ECG ECJ-1VF1H473Z 47000PF 50V
Y5V 0603 Ceramic capacitor
3 3 C9, C10, C17 10 µF 1206 Panasonic -ECG ECJ-3YB1E106M 10UF 25V X5R
1206 Ceramic capacitor
4 3 C11, C12, C16 22 µF 1210 Panasonic -ECG ECJ-4YB1E226M 22UF 25V X5R
1210 Ceramic capacitor
5 3 C13, C15, C18 470 pF 603 Panasonic -ECG ECJ-1VB2A471K 470PF 100V
X7R 0603 Ceramic capacitor
6 3 C14, C19, C20 DNI 603 Capacitor
7 1 C26 10 µF 805 Panasonic -ECG ECJ-2FB1A106K 10UF 10V X5R
0805 Ceramic capacitor
8 1 C27 3.3 µF 603 TDK C1608X5R1A335K 3.3UF 10V X5R
0603 Ceramic capacitor
9 1 C30 10 µF 1206 Panasonic -ECG ECJ-3YB1E106M 10UF 25V, X5R
1206 Ceramic capacitor
10 1 J1 TB_3X3.5MM OnShoreTechnology Inc ED555/3DS
Terminal,
3 pin, 6 A,
3.5 mm
VOUT1
11 1 J2, J3, J6 TB_2X3.5MM OnShoreTechnology Inc ED555/2DS
Terminal,
2 pin, 6 A,
3.5 mm
TBLK_6A_2X3.5MM
12 3 JP1, JP5, JP6 JMP0.2 Mil-Max 800-10-064-10-0010
00
SIP HEADER
STRAIGHT
PCB
JUMPER 2 PIN
13 3 JP2, JP3, JP4 JMP0.3 Mil-Max 800-10-064-10-0010
00
SIP HEADER
STRAIGHT
PCB
JUMPER 2 PIN
14 3 L1, L2, L3 4.7 µH IND_SLF7055 TDK Corporation SLF7055T-4R7N3R
1-3PF
Magnetic-Core
Inductor TDK-SLF7055
15 2 R1, R18 100 kΩ 603 Panasonic -ECG ERA-3AEB104V
RES 100 kΩ
1/10 W .1%
0603 SMD
Resistor
16 3 R3, R5, R17 20 kΩ 603 Panasonic -ECG ERA-3YEB203V
RES 20 kΩ
1/10 W .1%
0603 SMD
Resistor
17 2 R4, R16 150 kΩ 603 Panasonic -ECG ERJ-3EKF1503V
RES 150 kΩ
1/10 W 1%
0603 SMD
Resistor
18 1 R7 383 kΩ 603 Panasonic -ECG ERJ-3EKF3833V
RES 383 kΩ
1/10 W 1%
0603 SMD
Resistor
19 1 R8 DNI 603 Panasonic -ECG ERJ-3GEY0R00V
RES ZERO Ω
1/10 W 5%
0603 SMD
Resistor
20 3 R9, R11, R20 360 kΩ 603 Panasonic -ECG ERJ-3EKF3603V
RES 360 kΩ
1/10 W 1%
0603 SMD
Res1
21 3 R10, R19, R21 49.9 Ω 603 Susumu Co Ltd RR0816Q-49R9-
D-68R
RES 49.9 Ω
1/16 W .5%
0603 SMD
Res1
22 1 R12 715 kΩ 603 Panasonic -ECG ERJ-3EKF7153V
RES 715 kΩ
1/10 W 1%
0603 SMD
Resistor
23 1 R13 115 kΩ 603 Panasonic -ECG ERJ-3EKF1153V
RES 115 kΩ
1/10 W 1%
0603 SMD
Resistor
24 1 R15 287 kΩ 603 Panasonic -ECG ERJ-3EKF2873V
RES 287 kΩ
1/10 W 1%
0603 SMD
Resistor
Bill of Materials www.ti.com
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